bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the protective effect of oestradiol against toxicity induced by 6‐hydroxydopamine and 1‐methyl‐4‐phenylpyridinium ion (MPP+) towards dopaminergic mesencephalic neurones in primary culture
Authors: Callier Sophie , Le Saux Maryvonne , Lhiaubet Anne‐Marie , Paolo Thérèse Di , Rostène William , Pelaprat Didier
Published: March 2003

Recent findings suggest that gonadal steroid hormones are neuroprotective and may provide clinical benefits in delaying the development of Parkinson's disease. In this report we investigated the ability of oestradiol to protect mesencephalic dopaminergic neurones cultured in serum‐free or serum‐supplemented medium from toxicity induced by 6‐hydroxydopamine or 1‐methyl‐4‐phenylpyridinium ion (MPP+). The efficiency of both toxins and oestradiol was evaluated by tyrosine hydroxylase (TH) immunocytochemistry, [3H]dopamine ([3H]DA) uptake, length of dopaminergic processes and␣lactate dehydrogenase (LDH) release measurement. In␣cultures grown in serum‐supplemented medium, a 2‐h pre‐treatment with high concentrations (10–100 µm) of 17β‐oestradiol or 17α‐oestradiol, the stereoisomer with weak oestrogenic activity, protected both dopaminergic and non‐dopaminergic neurones from toxicity induced by 6‐hydroxydopamine (6‐OHDA; 40 or 100 µm) and by the high MPP+concentrations (50 µm) necessary to obtain significant neuronal death under those culture conditions. At these concentrations, MPP+was no longer selective for dopaminergic neurones but affected all cells present in the culture. In contrast, the hormonal treatments did not protect against selective degeneration of dopaminergic neurones induced by lower MPP+concentrations (below 10 µm), related to inhibition of complex I of respiratory chain. In cultures grown in serum‐free medium, oestradiol concentrations higher than 1 µminduced neuronal degeneration and no protection against 6‐OHDA or MPP+toxicity was observed at lower concentrations of the steroid. The neuroprotective effects of 17α‐ or 17β‐oestradiol evidenced in this model might be due to the antioxidant properties of these compounds. However, other non‐genomic effects of the steroids cannot be excluded.
Bidirectional changes in synapsin I phosphorylation at MAP kinase‐dependent sites by acute neuronal excitation in vivo
Authors: Yamagata Yoko , Jovanovic Jasmina N. , Czernik Andrew J. , Greengard Paul , Obata Kunihiko
Published: March 2003

Synapsin I is a synaptic vesicle‐associated protein which is phosphorylated at multiple sites by various kinases. It has been proposed to play a role in the regulation of neurotransmitter release and the organization of cytoskeletal architecture in the presynaptic terminal. To better understand the physiological regulation of its phosphorylation in vivo, we induced acute, reversible neuronal excitation by electroconvulsive treatment (ECT) in rats, and studied its effects on synapsin I phosphorylation at sites 3, 4/5 and 6 by immunoblot analyses of homogenates from hippocampus and parietal cortex using phospho‐site‐specific antibodies. A decrease in phosphorylation at all sites was observed soon after the electrical stimulation, followed by a large increase in phosphorylation at site 4/5 peaking at 5 min and a moderate increase in phosphorylation at site 6 peaking at 20 min. Systemic injection of SL327, a mitogen‐activated protein kinase (MAPK) kinase inhibitor, prior to ECT, suppressed the increase in phospho‐site 4/5 level, as well as that in MAPK activity, but not that in phospho‐site 6 level. Thus, phosphorylation at site 4/5 of synapsin I has been shown to be regulated by MAPK in vivo.
FKHRL1 and its homologs are new targets of nerve growth factor Trk receptor signaling
Authors: Zheng Wen‐Hua , Kar Satyabrata , Quirion Rémi
Published: March 2003

We report that the Forkhead family of transcription factors, FKHRL1, FKHR and AFX are novel components of neurotrophin receptor signaling. NGF rapidly induced the phosphorylation of FKHRL1 in PC12 cells. This effect is mediated by high‐affinity TrkA receptor as nerve growth factor (NGF) induced the phosphorylation of FKHRL1 only in TrkA expressing cells and not p75‐expressing cells. Additional experiments with various kinase inhibitors, the transient expression of constitutively active and dominant‐negative Akt, and in vitro kinase assay revealed that phosphatidylinositol‐3 (PtdIns3)/Akt kinase mediated the actions of NGF. Similar data were obtained for brain‐derived neurotrophic factor (BDNF), neurotrophin‐3 (NT‐3) and neurotrophin‐4 (NT‐4) in primary cortical cultured neurons. These findings demonstrate for the first time that the phosphorylation of the Forkhead family of transcription factors can be modulated by neurotrophins via Trk receptors and PtdIns3K/Akt kinase (but not MAP or S6p70 kinases) in neuronal and non‐neuronal cells. Moreover, survival assays with the PtdIns3 kinase inhibitor LY294002, active and dominant‐negative forms of Akt indicate that the phosphorylation of FKHRL1 plays a role in neurotrophins‐mediated cell survival.
Influence of solar UV‐B radiation on peatland microbial communities of southern Argentinia
Authors: Searles Peter S. , Kropp Bradley R. , Flint Stephan D. , Caldwell Martyn M.
Published: March 2003

Stratospheric ozone depletion occurs over Tierra del Fuego, Argentina, in the austral spring and summer due to the Antarctic ‘ozone hole’ and the general erosion of the ozone layer. Thus, we investigated the responses of microbial communities to manipulations of solar UV‐B radiation.

Results reported here are for field plots receiving either near‐ambient or reduced solar UV‐B using plastic filters in a Sphagnum peatland and a Carex fen during the second and third years of UV‐B manipulations.

The total number of testate amoebae (Protozoa, Rhizopoda) inhabiting the upper centimeter of Sphagnum magellanicum was greater under near‐ambient solar UV‐B than under reduced UV‐B. No response to UV‐B manipulation was apparent for rotifers, nematodes, bacteria, microfungi, and a common microalga (Euglena mutabilis) inhabiting the S. magellanicum. On leaves of small Nothofagus antarctica trees, the ratio of upper: lower leaf‐surface fungal populations for the genus Aureobasidium and for total fungi indicated lower populations on the upper, relative to the lower, surface under near‐ambient solar UV‐B.

When responses to modifications of the solar UV‐B flux were detected, these involved both direct UV‐B inhibition and indirect consequences of UV‐B manipulation.
Noise‐free Determination of Isochromatic Fringe Order by Load Stepping
Authors: Tamrakar D. K. , Ramesh K.
Published: March 2003

The traditional ambiguity in the sign of fractional retardation in certain zones of the model by phase shifting technique has been overcome with the development of load stepping in digital photoelasticity. However, the existing methodology of load stepping introduces several points in the model domain that are subjected to excessive noise. A new methodology has been proposed that combines the merits of load stepping and phase shifting to obtain fractional retardation free of noise and ambiguity over the model domain.
Evaluation of the HemoCue plasma haemoglobin analyser for assessing haemolysis in red cell concentrates during storage
Authors: Cardigan R. , Smith K.
Published: March 2003

Background and Objectives To evaluate the HemoCue plasma haemoglobin (Hb) analyser for determining supernatant Hb in red cell concentrates (RCC) during storage and compare this to a spectrophotometric method.

Materials and Methods Samples from RCC (n = 20) at days 0, 7, 21, 35 and 42 of storage were tested by both methods for supernatant Hb.

Results Results are given as median with range. There was a significant correlation (r = 0·97, P < 0·0001), but statistically significant difference between the two methods (0·72 (0·36–2·77) spectrophotometric vs. 0·70 (0·3–2·6) g/l HemoCue). However, the mean bias was negligible at 0·06 g/l. The HemoCue method gave a interassay coefficient of variation of 5·6% at 1·2 g/l and was linear to at least 20 g/l.

Conclusion The HemoCue plasma haemoglobin analyser is a simple, rapid, reliable and accurate method for the determination of supernatant Hb in RCC at the end of storage and compares well to established methods for supernatant Hb measurement.
A petrogenetic grid for aluminous granulite facies metapelites in the KFMASH system
Authors: McDade P. , Harley S. L.
Published: March 2003

Due to the retrograde cation exchange problems experienced by conventional geothermobarometers above their closure temperatures, petrogenetic grids are a potentially powerful alternative to unravelling the P–T evolution of ultrahigh‐T granulite terranes. A new qualitative KFMASH (K2O–FeO–MgO–Al2O3–SiO2–H2O) petrogenetic grid for Mg–Al rich metapelites containing K‐feldspar, sillimanite and quartzofeldspathic melt that successfully accounts for the majority of assemblages composed of variations of sapphirine, spinel, garnet, orthopyroxene, cordierite, biotite and quartz is developed. Univariant reactions are predicted utilizing a newly derived ‘melt projection’ and these reactions are entirely consistent with algebraically calculated reaction coefficients obtained using a set of standard phase compositions. Based upon observations of commonly associated mineral assemblages in natural lithologies the [Spr, Spl], [Qtz, Spl], [Bt, Spl], [Opx, Spr], [Opx, Qtz] and [Bt, Opx] invariant points are assumed to be stable, whilst the [Grt, Spr], [Grt, Qtz], [Spr, Qtz] and [Crd, Qtz] are assumed to be metastable. Biotite‐bearing assemblages are confined to the lowest temperatures, and sapphirine + quartz to the highest temperatures. Orthopyroxene + sillimanite ± quartz assemblages are confined to the highest pressures, whilst spinel‐bearing assemblages are stabilized by lower pressures. The alternative choice of invariant point stability leads to significant differences between this grid and previously proposed topologies. Spinel cannot be stable along with the orthopyroxene and sillimanite assemblage as previously proposed. Further, more subtle differences in topology result from the treatment of H2O in the chemographic projection used to deduce univariant reactions, and projecting from a water‐bearing quartzofeldspathic melt does not yield the same reaction coefficients as projection from H2O. The new grid allows reinterpretation of previously proposed evolutionary P–T paths for Mg–Al rich granulites from the Napier Complex and Rauer Group, East Antarctica, and In Ouzzal, Algeria.
The role of ICT as a promoter of students' cooperation
Authors: Schulz‐Zander R. , Büchter A. , Dalmer R.
Published: March 2003

Abstract The Second Information Technology in Education Study — Module 2 (SITES‐M2) in Germany investigated 12 cases of innovative pedagogical practice using technology (IPPUT) in primary, lower and upper secondary schools. One theme that emerged from the analysis of these cases was students' cooperation. It seems that the co‐occurrence of ICT‐use and students' cooperation and collaboration is not accidental. The focus of this paper is an analysis and classification of the students' cooperation identified in the IPPUTs.
The effects of graphical overviews on knowledge acquisition in hypertext
Authors: De Jong T. , Van Der Hulst A.
Published: March 2003

Abstract A central aspect of designing hypertext for learning concerns the structure of the information in the hypertext and the view the learner is offered of this structure. In this study, a hypertext environment was enhanced with a graphical overview that represented the basic, inherent, structure of the domain and the layout was designed in such a way that learners were unobtrusively encouraged to follow a sequence of exploration that followed the domain structure. This so‐called ‘visual’ lay‐out was compared with two lay‐outs that presented randomly positioned nodes. One of these two lay‐outs contained hints (using ‘highlighting’) to stimulate learners to follow a domain related exploration similar to the one incorporated in the visual lay‐out. The other (‘control’) lay‐out did not provide such hints. Results showed that participants from both the ‘visual’ and the ‘hints’ conditions demonstrated a more domain‐related exploration pattern than participants from the ‘control’ condition. Participants in the ‘visual’ lay‐out did not show a better recall of the content of the nodes as such, but showed a significantly better acquisition of knowledge of structure than participants from the other two conditions. These data indicate that a visual display conveys knowledge in its own right and that knowledge gained does not depend on the exploration route followed in the hypertext material.
Models of pedagogical implementation of ICT in Israeli schools
Authors: Mioduser D. , Nachmias R. , Tubin D. , Forkosh‐Baruch A.
Published: March 2003

Abstract  The paper analyses the data collected in 10 schools in Israel which have incorporated ICT in unique ways and have succeeded in devising innovative classroom pedagogies and changes in teachers and students roles and outcomes. The major research questions addressed are: What levels of innovation were observed in the participant schools, and in which domains? How did the level of innovation in the various domains vary among and within schools? What correlation patterns among levels of innovation in the various domains can be identified? The data were analysed by mean of the innovation analysis schema developed for characterising ICT‐based educational innovations. The findings indicate that most schools were in a transition stage towards fully innovative pedagogical implementation; school activities were effected differentially by ICT, thus creating ‘islands of innovation’; these islands however, have the potential to pull forward other areas of activity and people in the school; the domains most affected by ICT were the school's digital space, the didactic solutions implemented and the students' roles and outcomes.
Structural organization of the estα31 gene in a Colombian strain of Culex quinquefasciatus differs from that in Cuba
Authors: De Silva D. , Hemingway J.
Published: March 2003

Abstract In Culex mosquitoes (Diptera: Culicidae), the most common mechanism for resistance to organophosphorus (OP) insecticides involves amplification of one or more esterases. Two esterase loci are often involved, with different allelic forms co‐amplified. Estα31 is co‐amplified with estβ1 in a Colombian (COL) strain of Culex quinquefasciatus Say. These two alleles co‐migrate on acrylamide gels, often leading to misscoring of the phenotype as elevation of a single estβ enzyme. By sequencing COL genomic DNA, we determined the estα31 gene length is 1623 nucleotides. The open reading frame of estα31 encodes a 540 amino acid protein, as for estα21 in strain Pel RR from Sri Lanka. The intron/exon boundaries of estα31 are identical to those of estα21, suggesting that they are alleles of the same locus. The COL estα31 gene differs from estα32 in strain MRES from Cuba, although they have equivalent electrophoretic mobility, showing that these two strains contain distinct resistance‐associated amplicons. Twenty nucleotide differences were scored between the MRES partial 495 bp sequence and that in the COL strain, with two amino acid changes, demonstrating distinct estα enzymes. Our sequencing data show 95% identity between the three estα genes (each has six introns and seven exons) in OP‐resistant Cx. quinquefasciatus. Amplified estα31 and estβ1 are at least 10 kb apart in temephos‐selected COL and 2.7 kb apart in Pel RR, whereas these non‐amplified genes are only 1.7 kb apart in the non‐selected parental COL stock, as in Pel SS (susceptible Sri Lankan strain), demonstrating that this region of the genome is susceptible to expansion and contraction.
Combined molecular and morphological evidence on the phylogeny of the earliest lepidopteran lineages
Authors: Wiegmann Brian M. , Regier Jerome C. , Mitter Charles
Published: March 2003

Agreement among recent morphological and molecular phylogenetic analyses has strengthened estimates of the relationships among the earliest lineages of the holometabolan order Lepidoptera. For a few major groups, evidence for monophyly and basal relationships remains relatively weak or contradictory — chiefly within the clades of basal Glossata and Heteroneura. Here we assess the support for these controversial areas of lepidopteran classification through molecular systematic investigation of 18S rDNA sequence variation. Parsimony and maximum likelihood analyses are presented for 1379 alignable sites of 18S. These data are then combined with 61 morphological features scored for major lineages of basal Glossata and Heteroneura. Our 18S rDNA data support recent hypotheses for the placement of Micropterigidae and Agathiphagidae as the basal‐most lineages of Lepidoptera, and support the monophyly of the groups Neolepidoptera and Exoporia. 18S data alone are shown to be insufficient for resolving the monophyly and relationships of the Glossata, and for specifying relationships above the Neolepidoptera. Combination of the 18S data with published morphological ground‐plan scorings improves overall support for the morphology‐based hypothesis for basal glossatans, but phylogenetic resolution among published alternatives for the basal Heteroneura remains a major question for lepidopteran systematics.
Expression of CTLA‐4 by Human Monocytes
Authors: Wang X.‐B. , Giscombe R. , Yan Z. , Heiden T. , Xu D. , Lefvert A. K.
Published: March 2003

Cytotoxic T lymphocyte‐associated molecule‐4 (CTLA‐4) is a receptor present on T cells that plays a critical role in the downregulation of antigen‐activated immune responses. CTLA‐4 interacts with the ligands CD80 and CD86 on antigen‐presenting cells (APC), and also directs the assembly of inhibitory signalling complexes that lead to quiescence or anergy. In this study, we show that human monocytes constitutively express CTLA‐4. About 3% of monocytes expressed CTLA‐4 on the cell surface, whereas the intracellular expression was higher and present in about 20% of the monocytes. The sequences of the cDNAs from human monocytes were identical to the sequences of CTLA‐4 from T cells. Expression of CTLA‐4 was also confirmed in the activated myelomonocytic cell lines U937 and THP‐1. Monocytes, but not T cells, activated by interferon (IFN)‐γ also secreted soluble CTLA‐4 in vitro. The CTLA‐4 expression was upregulated upon treatment with phorbol 12‐myristate 13‐acetate (PMA) and IFN‐γ. This increased expression could be partially abolished by staurosporine, an inhibitor of protein kinase C (PKC). Ligation of CTLA‐4 in the monocyte‐like cell‐line U937 with antibodies against CTLA‐4 partially inhibited the proliferation of cells and the upregulation of cell‐surface markers CD86, CD54, HLA‐DR and HLA‐DQ induced by IFN‐γ and Staphylococcus aureus, Cowan I strain (SAC). Ligation of CTLA‐4 suppressed the PMA‐stimulated activation of transcription activator protein 1 (AP‐1) and nuclear factor (NF)‐κB in the U937 cell line, indicating the involvement of an inhibitory signal transduction. These data provide the first evidence that CTLA‐4 is constitutively expressed by monocytes and thus might be important for the regulation of immune mechanisms associated with monocytes.
Association of Antigen Specificity and Migratory Capacity of Memory T Cells in Rheumatoid Arthritis
Authors: Shadidi K. R. , Thompson K. M. , Henriksen J. E. , Natvig J. B. , Aarvak T.
Published: March 2003

Among the T cell pool of multiple specificities in the rheumatoid synovial tissues (ST) we have previously shown a lack of proliferative response of T cells to Acanthamoeba polyphaga[1]. In contrast, peripheral blood (PB) derived T cells proliferate to the antigen. The aim of the present study was to establish whether there is a preferential migration of some T cell specificities to the joint in rheumatoid arthritis (RA) patients dependent on the chemokine system, and to identify which chemokine receptors are involved in the migratory process. For this purpose, PB‐derived T cell lines and clones from RA patients specific for A. polyphaga, herpes simplex virus (HSV) and Campylobacter jejuni were developed. Their migratory capacities towards ST‐derived chemokine supernatants were analysed. Expression of CCR1, CCR2, CCR5, CCR6, CCR7, CXCR3 and CXCR4 were analysed by FACS, and attracting chemokines were identified by blocking studies. We found that the migratory capacities of T cells specific for C. jejuni and HSV were markedly higher against synovial chemokines than T cells specific for A. polyphaga. CCR5 and CXCR3 were expressed by all high‐migrating T cell lines and clones. CCR2 was expressed at higher levels on the high‐migrating T cell lines compared with the low‐migrating A. polyphaga lines. Neutralization of RANTES (regulated upon activation normal T cell expressed and secreted) in the ST cell‐derived supernatant reduced T cell migration of all T cell lines and clones by 60–90%, while neutralization of MCP‐1 reduced the migratory capacity of CCR2‐expressing T cells by 45–80%. In conclusion, the ability of T cells to migrate towards chemokines produced by ST cells is associated with the T cell specificity. Blocking of single chemokines substantially reduced the migratory capacity of memory T cells to ST cell‐derived supernatant indicating unique roles for each chemokine receptor in the process of T cell migration.
A potent, morph‐specific parturition stimulant in the overwintering host plant of the black bean aphid, Aphis fabae
Authors: Powell Glen , Hardie Jim
Published: March 2003

Abstract. The black bean aphid, Aphis fabae Scopoli, has a host‐alternating life cycle. Winged female autumn migrants (gynoparae) develop on numerous summer host plants but as adults will only colonize the winter host (spindle, Euonymus europaeus L.). When stylet activities of gynoparae were electrically recorded during access to a spindle leaf, the insects spent the majority (75%) of the 6‐h experimental period penetrating the plant surface and a large proportion of it (44%) ingesting from either phloem or xylem vessels. Most (95%) gynoparae initiated reproduction on spindle, producing 4.15 ± 0.59 offspring per adult by the end of the experiment (mean ± SEM). By contrast, gynoparae placed on a seedling of their natal, summer host (broad bean, Vicia faba L.) penetrated the plant for only 39% of the available time, rarely ingested plant sap and never reproduced. The number of nymphs deposited on spindle leaves was not correlated with the occurrence or duration of ingestion from vascular tissues, suggesting that parturition stimulants are detected before feeding, probably during penetration of nonvascular cells. Presentation of an aqueous spindle extract to the aphids in artificial feeding chambers showed that water‐soluble spindle factors evoke stimulation of parturition by gynoparae in 72‐h bioassays. The stimulant was extremely potent, remaining active until the total extracted material was diluted to less than 10 p.p.m. Stylet activities and reproductive responses were also evaluated for summer winged females (alate virginoparae), which have a broad host range, and will colonize both bean and spindle under laboratory conditions. On both of these plant species, virginoparae often ingested plant sap and deposited nymphs during the 6‐h electrical recording experiment (producing 4.60 ± 0.48 offspring on bean; 2.70 ± 0.35 on spindle: mean ± SEM), but no significant correlations were found between reproduction and the occurrence or duration of particular stylet activities. Aqueous host‐plant extracts had no effect on the numbers of offspring deposited by virginoparae in artificial feeding chambers, showing that this form of the aphid is not responsive to the spindle‐derived parturition stimulant. The results highlight the need for more information on the factors determining host acceptance and parturition by polyphagous aphid phenotypes.
Resistance of the honey bee, Apis mellifera to the acarian parasite Varroa destructor: behavioural and electroantennographic data
Authors: Martin Caroline , Provost Erick , Roux Maurice , Bruchou Claude , Crauser Didier , Clement Jean‐Luc , Le Conte Yves
Published: March 2003

Abstract. One way in which Apis mellifera honey bees resist Varroa destructor is by detection and elimination of nestmates. This study uses behavioural tests and electroanntennography to assess the role of chemostimuli in recognition by honey bees of this acarian ectoparasite. Behavioural tests using living or dead parasites involved observation of honey bee grooming activity (antennation) under controlled conditions in Petri dishes, and removal behaviour (uncapping and elimination of parasitized and unparasitized control brood cells) under natural conditions. Some bees from colonies with both small and large parasite populations showed aggressive behaviour (biting). No difference was observed according to whether the mite was dead or alive. Under natural conditions, bees uncapped more parasitized cells than control cells. Electroantennographic tests were performed to measure sensitivity to various Varroa extracts at three concentrations (10, 20 and 30 Varroa Equivalents). Only 30 Varroa Equivalent methanol extracts made from Varroa collected from brood cells elicited significantly greater antennal response than controls (pure solvent). All three methanol extracts elicited significantly greater antennal response than controls. No response was observed using Varroa extracts made with acetone or hexane. These findings suggest that polar products may act as chemostimuli for recognition of V. destructor by honey bees. Further study will be necessary to determine which polar products are involved in this recognition and assess grooming and removal behaviour using these products.
Phylogenetic relationships in the louse genus Penenirmus based on nuclear (EF‐1α) and mitochondrial (COI) DNA sequences
Authors: Johnson Kevin P. , Moyle Robert G. , Witt Christopher C. , Faucett Robert C. , Weckstein Jason D.
Published: March 2003

Abstract. Ischnoceran lice in genus Penenirmus are parasites of birds in orders Piciformes and Passeriformes. No comprehensive revision of this genus has been published, but a few host‐based revisions have been done. Here we present a phylogenetic analysis of Penenirmus based on nuclear (elongation factor‐1 alpha) and mitochondrial (cytochrome oxidase I) gene sequences. Sequences from portions of both these genes provide a well resolved tree that is relatively stable across methods of analysis and to bootstrap resampling. Some aspects of the Penenirmus phylogeny reflect the phylogeny of their avian hosts. We identified monophyly of a group of Penenirmus species occurring on Passeriformes as well as monophyly of a group containing species sometimes placed in a genus Picophilopterus. Species of Penenirmus occurring on Old World barbets fall in several positions at the base of the tree, suggesting that other lineages of Penenirmus may be derived from those occurring on Old World barbets.
Bacterial otitis media: Current vaccine development strategies
Authors: Cripps Allan W , Kyd Jennelle
Published: March 2003

Otitis media is the most common reason for children less than 5 years of age to visit a medical practitioner. Whilst the disease rarely results in death, there is significant associated morbidity. The most common complication is loss of hearing at a critical stage of the development of speech, language and cognitive abilities in children.
Antigenic properties of the GroEL‐like protein of Campylobacter rectus
Authors: Hinode D. , Yokoyama M. , Tanabe S. , Yoshioka M. , Nakamura R.
Published: March 2003

The purpose of this study was to clarify the antigenic properties of the GroEL‐like protein of Campylobacter rectus using a specific polyclonal antibody directed to the purified 64‐kDa GroEL‐like protein (pAb‐CrGroEL), a polyclonal antibody directed to the Actinobacillus actinomycetemcomitans GroEL‐like protein (pAb‐AaGroEL) and a monoclonal antibody against the recombinant human HSP60 (mAb‐HuHSP60). In SDS‐PAGE/Western immunoblotting analysis, mAb‐HuHSP60, pAb‐CrGroEL and pAb‐AaGroEL were found to react with the GroEL‐like protein (64‐kDa) present in all C. rectus strains. A 150‐kDa protein in C. rectus ATCC 33238 also reacted strongly with pAb‐CrGroEL. This 150‐kDa protein was found to be present on the surface‐associated material of bacterial cells, as determined by transmission electron microscopy and immunogold labelling of cells with pAb‐CrGroEL. Analysis of the first 20 N‐terminal amino acids of the sequence of the 150‐kDa protein revealed a strong homology (80%) with the C. rectus surface layer (S‐layer) protein. Investigation of the biochemical nature of antigenic determinants using periodic acid and proteolytic enzymes showed that the C. rectus GroEL‐like protein possessed immunodominant epitopes in both peptide and carbohydrate chains, and that the immunoreactive determinants of the 150‐kDa protein belonged to carbohydrate. These results suggest that the GroEL‐like protein and the S‐layer protein of C. rectus may share the same carbohydrate epitopes.
The oat mitochondrial permeability transition and its implication in victorin binding and induced cell death
Authors: Curtis Marc J. , Wolpert Thomas J.
Published: March 2003

The mitochondrion has emerged as a key regulator of apoptosis, a form of animal programmed cell death (PCD). The mitochondrial permeability transition (MPT), facilitated by a pore‐mediated, rapid permeability increase in the inner membrane, has been implicated as an early and critical step of apoptosis. Victorin, the host‐selective toxin produced by Cochliobolus victoriae, the causal agent of victoria blight of oats, has been demonstrated to bind to the mitochondrial P‐protein and also induces a form of PCD. Previous results suggest that a MPT may facilitate victorin's access to the mitochondrial matrix and binding to the P‐protein: (i) victorin‐induced cell death displays features similar to apoptosis; (ii) in vivo, victorin binds to the mitochondrial P‐protein only in toxin‐sensitive genotypes whereas victorin binds equally well to P‐protein isolated from toxin‐sensitive and insensitive oats; (iii) isolated, untreated mitochondria are impermeable to victorin. The data implicate an in vivo change in mitochondrial permeability in response to victorin. This study focused on whether oat mitochondria can undergo a MPT. Isolated oat mitochondria demonstrated high‐amplitude swelling when treated with spermine or Ca2+ in the presence of the Ca2+‐ionophore A23187, and when treated with mastoparan, an inducer of the MPT in rat liver mitochondria. In all cases, swelling demonstrated size exclusion in the range 0.9–1.7 kDa, similar to that found in animal mitochondria. Further, MPT‐inducing conditions permitted victorin access to the mitochondrial matrix and binding to the P‐protein. In vivo, victorin treatment induced the collapse of mitochondrial transmembrane potential within 2 h, indicating a MPT. Also, the victorin‐induced collapse of membrane potential was clearly distinct from that induced by uncoupling respiration, as the latter event prevented the victorin‐induced PCD response and binding to P‐protein. These results demonstrate that a MPT can occur in oat mitochondria in vitro, and are consistent with the hypothesis that an MPT, which allows victorin access to the mitochondrial matrix and binding to the P‐protein, occurs in vivo during victorin‐induced PCD.
Arabidopsis RPP4 is a member of the RPP5 multigene family of TIR‐NB‐LRR genes and confers downy mildew resistance through multiple signalling components
Authors: Van Der Biezen Erik A. , Freddie Cecilie T. , Kahn Katherine , Parker Jane E. , Jones Jonathan D. G.
Published: March 2003

In Arabidopsis, RPP4 confers resistance to Peronospora parasitica (P.p.) races Emoy2 and Emwa1 (downy mildew). We identified RPP4 in Col‐0 as a member of the clustered RPP5 multigene family encoding nucleotide‐binding leucine‐rich repeat proteins with Toll/interleukin‐1 receptor domains. RPP4 is the orthologue of RPP5 which, in addition to recognizing P.p. race Noco2, also mediates resistance to Emoy2 and Emwa1. Most differences between RPP4 and RPP5 occur in residues that constitute the TIR domain and in LRR residues that are predicted to confer recognition specificity. RPP4 requires the action of at least 12 defence components, including DTH9, EDS1, PAD4, PAL, PBS2, PBS3, SID1, SID2 and salicylic acid. The ndr1, npr1 and rps5‐1 mutations partially compromise RPP4 function in cotyledons but not in true leaves. The identification of RPP4 as a TIR‐NB‐LRR protein, coupled with its dependence on certain signalling components in true leaves, is consistent with the hypothesis that distinct NB‐LRR protein classes differentially signal through EDS1 and NDR1. Our results suggest that RPP4‐mediated resistance is developmentally regulated and that in cotyledons there is cross‐talk between EDS1 and NDR1 signalling and processes regulating systemic acquired resistance.
Prenatal diagnosis of isolated unilateral pulmonary agenesis in the second trimester
Authors: Viora E. , Sciarrone A. , Bastonero S. , Errante G. , Campogrande M.
Published: March 2003

Unilateral pulmonary agenesis is a very rare developmental malformation that is often associated with other anomalies including non‐immune hydrops. We describe a case of isolated unilateral pulmonary agenesis diagnosed in the second trimester by gray‐scale and color Doppler ultrasound. Copyright © 2002 ISUOG
Uterine artery Doppler at 11–14 weeks of gestation in chromosomally abnormal fetuses
Authors: Bindra R. , Curcio P. , Cicero S. , Martin A. , Nicolaides K. H.
Published: March 2003

Objective

To determine whether the major chromosomal abnormalities are associated with impaired placentation in the first trimester of pregnancy.

Methods

This was a prospective study of 692 singleton pregnancies undergoing fetal karyotyping at 11–14 weeks of gestation. Uterine artery Doppler was carried out and the mean pulsatility index was calculated just before chorionic villus sampling.

Results

The fetal karyotype was normal in 613 pregnancies and abnormal in 79, including 39 cases of trisomy 21, 11 of trisomy 18, 11 of trisomy 13, eight of Turner syndrome and 10 with other defects. There were no significant differences in the median value of uterine artery mean PI between any of the individual groups. Although in the combined group of trisomy 18, trisomy 13 and Turner syndrome fetuses, the median pulsatility index (1.60) was significantly higher than in the chromosomally normal group (median pulsatility index, 1.51; P = 0.021), in the majority of abnormal fetuses (24 of 30) mean pulsatility index was below the 95th centile of the normal group (mean pulsatility index, 2.34). There was no significant association between uterine artery mean pulsatility index and fetal nuchal translucency thickness or fetal growth deficit.

Conclusions

The high intrauterine lethality and fetal growth restriction associated with the major chromosomal abnormalities are unlikely to be the consequence of impaired placentation in the first trimester of pregnancy.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Monitoring of fetuses with intrauterine growth restriction: a longitudinal study
Authors: Hecher K. , Bilardo C. M. , Stigter R. H. , Ville Y. , Hackelöer B. J. , Kok H. J. , Senat M. V. , Visser G. H. A.
Published: March 2003

Objective

To describe the time sequence of changes in fetal monitoring variables in intrauterine growth restriction and to correlate these findings with fetal outcome at delivery.

Methods

This was a prospective longitudinal observational multicenter study on 110 singleton pregnancies with growth‐restricted fetuses after 24 weeks of gestation. Short‐term variation of fetal heart rate, pulsatility indices of fetal arterial and venous Doppler waveforms and amniotic fluid index were assessed at each monitoring session. The study population was divided into two groups: Group 1 comprised pregnancies with severely premature fetuses, which were delivered ≤ 32 weeks and Group 2 included pregnancies delivered after 32 completed weeks. Logistic regression was used for modeling the probability for abnormality of a variable in relation to the time interval before delivery. Trends over time were analyzed for all variables by multilevel analysis.

Results

Ninety‐three (60 in Group 1 and 33 in Group 2) fetuses had at least three data sets (median, 4; range, 3–27) and had the last measurements taken within 24 h of delivery or intrauterine death. The percentage of abnormal test results and the degree of abnormality were higher in Group 1 compared to Group 2. Amniotic fluid index and umbilical artery pulsatility index were the first variables to become abnormal, followed by the middle cerebral artery, aorta, short‐term variation, ductus venosus and inferior vena cava. In Group 1, short‐term variation and ductus venosus pulsatility index showed mirror images of each other in their trend over time. Perinatal mortality was significantly higher if both variables were abnormal compared to only one or neither being abnormal (13/33 (39%) vs. 4/60 (7%); P = 0.0002; Fisher's exact test).

Conclusion

Ductus venosus pulsatility index and short‐term variation of fetal heart rate are important indicators for the optimal timing of delivery before 32 weeks of gestation. Delivery should be considered if one of these parameters becomes persistently abnormal.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Controlled fetal blood‐letting of the recipient twin as a new method for the treatment of severe twin–twin transfusion syndrome: preliminary results
Authors: Bellotti M. , Rognoni G. , de Gasperi C. , Panteghini M. , Berlanda N. , Ferrazzi E. , Buscaglia M.
Published: March 2003

Objective

To investigate the feasibility of withdrawal of blood from the recipient twin as a new method for the treatment of severe twin–twin transfusion syndrome.

Methods

Seven consecutive monozygotic monochorionic twin pregnancies affected by severe twin–twin transfusion syndrome were treated. Fetal blood was withdrawn from the recipient twin using cordocentesis. The volume of blood to be removed was determined using the formula for intrauterine blood transfusion of anemic fetuses. Fetal outcome was evaluated in relation to changes in the amniotic fluid and in growth curves (comparing the differences between the centiles of the estimated fetal weight before the procedure and the centiles of weight at birth), fetal mortality, gestational age at delivery, neonatal weight and neurological damage.

Results

Overall, seven of the 14 (50%) fetuses survived; at least one fetus survived in five (71%) pregnancies, both fetuses survived in two (29%) pregnancies, while in two (29%) pregnancies there were no survivors. No maternal complications were observed. At follow‐up, one (14%) baby had minor neurological damage.

Conclusions

Withdrawal of blood from the recipient twin in the treatment of severe twin–twin transfusion syndrome was associated with survival similar to that of the alternative techniques of serial amniodrainage and fetoscopic laser surgery, with some possible advantages such as reduced neurological damage compared with serial amniodrainage. It is also less invasive compared with fetoscopic laser surgery.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Fetal aortic isthmus growth and morphology in late gestation
Authors: Nomiyama M. , Ueda Y. , Toyota Y. , Kawano H.
Published: March 2003

Objective

To establish normal values for fetal aortic isthmus diameter in late gestation and to identify any changes in aortic isthmus dimensions and morphology in pathological conditions.

Methods

In this prospective study, the fetal aortic isthmus was evaluated in 110 low‐risk pregnant women at between 30 and 40 weeks of gestation and 42 pregnant women who were at high risk for congenital heart defects. From coronal echocardiographic images of the connection between the aorta and ductus arteriosus, the internal diameter of the aorta was measured at the middle of the isthmus, at the point of the isthmus just proximal to the entry of the ductus arteriosus and at the descending aorta below the entry of the ductus arteriosus.

Results

Correlation coefficients for the diameter of each aortic segment when related to gestational age varied from r = 0.60 to r = 0.80 (P < 0.001 for each), and growth curves were derived from the third and 97th percentiles about each linear regression analysis. The mean and the third percentile for the ratio of the isthmus just proximal to the entry of the ductus arteriosus to the middle of the isthmus were 1 and 0.81. In one fetus of the high‐risk patients, a contraductal shelf and the accompanying area of tubular isthmic hypoplasia were suspected and a diagnosis of coarctation of the aorta was subsequently confirmed after birth. In two fetuses with growth restriction and one fetus with intestinal atresia, the isthmus diameters were below the third percentile but the ratios of the isthmus end to the middle of the aortic isthmus were all normal and no cardiac anomalies were detected after birth.

Conclusions

We could establish normal values for aortic isthmus diameters in late gestation from a coronal view and identify even minimal changes in aortic isthmus dimensions and morphology in pathological conditions. Copyright © 2002 ISUOG
Prenatal detection of mesoblastic nephroma by sonography and magnetic resonance imaging
Authors: Won H. S. , Jung E. , Lee P. R. , Lee I. S. , Kim A. , Kim J. K. , Cho K. S. , Nam J. H.
Published: March 2003

Congenital mesoblastic nephroma is the most common neonatal kidney tumor and surgical excision is almost always curative. We report the prenatal detection of congenital mesoblastic nephroma by sonography and magnetic resonance imaging. After birth, a right nephrectomy was performed and the baby recovered well. Copyright © 2002 ISUOG
Organization and developmental expression of the mosquito vitellogenin receptor gene
Authors: Cho K.‐H. , Raikhel A. S.
Published: March 2003

Vitellogenin is a precursor of the major yolk protein, vitellin. It is internalized by developing oocytes via receptor‐mediated endocytosis. Previously, we characterized the vitellogenin receptor (VgR) from oocytes of the mosquito Aedes aegypti[Sappington, T.W., Kokoza, V.A., Cho, W.L. and Raikhel, A.S. (1996) Molecular characterization of the mosquito vitellogenin receptor reveals unexpected high homology to the Drosophila yolk protein receptor. Proc Natl Acad Sci USA 93: 8934–8939]. The VgR receptor has a unique structure with two putative ligand‐binding domains. In order to understand the regulation of this important molecule, we characterized the VgR gene structure and its expression during vitellogenesis in the mosquito A. aegypti. We report here that the VgR gene was separated by five introns that have an average length of 60 bp, except for the second intron which was more than 20 kb long. Most introns were located within the coding regions of the first protein domain. We isolated two allelic variations of the VgR gene, VgR1 and VgR2, the nucleotide sequences of which differing only in their 5′‐flanking regions. Considering their frequency in the mosquito genome, VgR2 appeared to be a major allele. The expression of VgR mRNA was studied by the Northern blot analysis and in situ hybridization. The level of the VgR transcript started to rise in the ovary one day post‐eclosion. It continued its dramatic rise during the vitellogenic period, reaching its peak at 24 h PBM. The VgR transcript was present exclusively in ovaries where it was seen in oocytes and nurse cells of primary follicles and germ‐line cells of the germarium.
Repression of Manduca sexta ferritin synthesis by IRP1/IRE interaction
Authors: Zhang D. , Albert D. W. , Kohlhepp P. , D.‐Pham D. Q. , Winzerling J. J.
Published: March 2003

Mammalian ferritin subunit synthesis is controlled at the translational level by the iron regulatory protein 1 (IRP1)/iron responsive element (IRE) interaction. Insect haemolymph ferritin subunit messages have an IRE in the 5′‐untranslated region (UTR). We have shown that recombinant M. sexta IRP1 represses the in vitro translation of both the heavy and light chain ferritin subunits from this species without altering transcription. Deletion of either the 5′‐UTR or the IRE from the mRNA abolishes IRP1 repression. Our studies indicated that the translational control of ferritin synthesis by IRP/IRE interaction could occur in insects in a manner similar to that of mammals. To our knowledge, this is the first report of the control of insect ferritin synthesis by IRP1/IRE interaction. Furthermore, this is the first indication that the synthesis of a secreted ferritin subunit can also be controlled in this manner.
Germ‐line transformation of the Australian sheep blowfly Lucilia cuprina
Authors: Heinrich J. C. , Li X. , Henry R. A. , Haack N. , Stringfellow L. , Heath A. C. G. , Scott M. J.
Published: March 2003

The Australian sheep blowfly, Lucilia cuprina, is the most important economic insect pest for the sheep industries in Australia and New Zealand. piggyBac‐mediated germ‐line transformation of L. cuprina was achieved with a helper plasmid that had the Drosophila melanogaster hsp70 promoter controlling expression of the transposase and a piggyBac vector with an EGFP marker gene. Two transformant lines were obtained, at a frequency of approximately 1–2% per fertile G0. One of these lines has a single copy of the transgene, the other most likely has four copies. This is the first report of germ‐line transformation of L. cuprina and is an important step towards the generation of engineered strains that would be suitable for male‐only release eradication/suppression programmes.
Population‐scale laboratory studies of the effect of transgenic plants on nontarget insects
Authors: Schuler T. H. , Denholm I. , Jouanin L. , Clark S. J. , Clark A. J. , Poppy G. M.
Published: March 2003

Studies of the effects of insect‐resistant transgenic plants on beneficial insects have, to date, concentrated mainly on either small‐scale ‘worst case scenario’ laboratory experiments or on field trials. We present a laboratory method using large population cages that represent an intermediate experimental scale, allowing the study of ecological and behavioural interactions between transgenic plants, pests and their natural enemies under more controlled conditions than is possible in the field. Previous studies have also concentrated on natural enemies of lepidopteran and coleopteran target pests. However, natural enemies of other pests, which are not controlled by the transgenic plants, are also potentially exposed to the transgene product when feeding on hosts. The reduction in the use of insecticides on transgenic crops could lead to increasing problems with such nontarget pests, normally controlled by sprays, especially if there are any negative effects of the transgenic plant on their natural enemies. This study tested two lines of insect‐resistant transgenic oilseed rape (Brassica napus) for side‐effects on the hymenopteran parasitoid Diaeretiella rapae and its aphid host, Myzus persicae. One transgenic line expressed the δ‐endotoxin Cry1Ac from Bacillus thuringiensis (Bt) and a second expressed the proteinase inhibitor oryzacystatin I (OC‐I) from rice. These transgenic plant lines were developed to provide resistance to lepidopteran and coleopteran pests, respectively. No detrimental effects of the transgenic oilseed rape lines on the ability of the parasitoid to control aphid populations were observed. Adult parasitoid emergence and sex ratio were also not consistently altered on the transgenic oilseed rape lines compared with the wild‐type lines.