bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of NeuN immunoreactivity in primary brain tumours: conclusions for rational use in diagnostic histopathology
Authors: Preusser M , Laggner U , Haberler C , Heinzl H , Budka H , Hainfellner J A
Published: February 2006

Aims : NeuN is considered to be a marker of neuronal differentiation in brain tumours. Our aim was to perform, for the first time, a systematic and comparative analysis of NeuN expression in all major brain tumour subtypes to provide guidance for the rational use of NeuN immunohistochemistry in diagnostic histopathology.

Methods and results : Anti‐NeuN immunohistochemistry was performed on paraffin‐embedded biopsy specimens of 106 diffuse astrocytomas, 100 pilocytic astrocytomas, 107 ependymomas, 59 1p‐aberrant oligodendroglial neoplasms, 115 glioblastomas, 115 medulloblastomas, 14 gangliogliomas/gangliocytomas and 10 central neurocytomas. We found no NeuN expression in pilocytic astrocytoma, whereas all other investigated tumour subtypes showed focal or widespread expression in varying proportions of cases. Comparing NeuN expression in clear cell tumours, widespread NeuN expression had a positive predictive value of 76.9% (95% confidence interval 46.2, 95.0) for central neurocytoma. Lack of NeuN expression had a positive predictive value of 87.3% (76.5, 94.4) for oligodendroglioma.

Conclusions : Immunohistochemistry can detect NeuN expression in all major brain tumour subtypes except pilocytic astrocytoma. In the individual case, assessment of NeuN expression may be helpful in the differential diagnosis of clear cell primary brain tumours but does not seem to be useful for the differential diagnosis of other brain tumour subtypes.
Haemosiderotic fibrolipomatous tumour (so‐called haemosiderotic fibrohistiocytic lipomatous tumour): analysis of 13 new cases in support of a distinct entity
Authors: Browne T‐J , Fletcher C D M
Published: February 2006

Aims : To describe 13 new cases of a rare soft tissue neoplasm currently known as haemosiderotic fibrohistiocytic lipomatous tumour (HFHLL) and to further its characterization.

Methods and results : Patients were eight females and five males, aged 8 months to 74 years. Lesions ranged in size from 10 to 130 mm (median 45). Twelve of 13 lesions were located in the ankle/foot region; one involved the hand. Grossly the lesions were fatty/gelatinous or lipoma‐like. They were characterized by varying proportions of mature adipocytes and fibroblastic spindle cells, associated with haemosiderin pigment present predominantly in macrophages within the spindle cell component. Dissecting between adipocytic lobules were septa containing short spindle cells with streaming, swirling or honeycomb growth patterns. Most tumours contained scattered osteoclast‐like giant cells. Mitoses were rare and only one case showed mild atypia. Immunohistochemistry in 10 cases showed 7/9 CD34+; all were negative for smooth muscle actin, CD68, S100 and desmin. Follow‐up in nine cases ranging from 1 to 130 months (median 12) showed local recurrence in three but no metastasis.

Conclusions : So‐called HFHLL, better termed haemosiderotic fibrolipomatous tumour, is a distinct lesion characterized by an admixture of fibroblastic spindle cells, mature adipocytes and haemosiderin pigmentation, shows a predilection for the distal extremities and quite often recurs locally.
Enhancement of antitumour immunity by a novel chemotactic antigen DNA vaccine encoding chemokines and multiepitopes of prostate‐tumour‐associated antigens
Authors: Qin Hanjun , Zhou Chunxia , Wang Dongmei , Ma Wenbo , Liang Xiao , Lin Chen , Zhang Youhui , Zhang Shuren
Published: February 2006

DNA vaccines provide an attractive technology against cancer because of their safety record in humans and ease of construction, testing and manufacture. In this study, several DNA fragments encoding multiple cytotoxic T lymphocyte (CTL) and T helper cell epitopes were selected from human prostate‐specific membrane antigen (hPSM), mouse prostatic acid phosphatase (mPAP), and human prostate‐specific antigen (hPSA). These DNA fragments were ligated together to form a novel fusion gene, termed the 3P gene. The secondary lymphoid tissue chemokine (SLC), 3P and human immunoglobulin G Fc genes were inserted into pcDNA3.1 to construct a DNA vaccine, designated pSLC‐3P‐Fc. After vaccination, the DNA is taken up by cells that produce and secrete the SLC‐3P‐Fc fusion proteins, termed chemotactic antigen (chemo‐antigen). The secreted chemo‐antigens, in addition to promoting the co‐localization of naive, non‐polarized memory T cells and dendritic cells, are efficiently captured and processed by dendritic cells via receptor‐mediated endocytosis and then cross‐presented to both major histocompatibility complex class I and class II in a cognate manner. The results of this study demonstrate that vaccination with pSLC‐3P‐Fc by gene gun inoculation induced a strong antitumour response in a mouse tumour model, which significantly inhibited tumour growth and prolonged the survival time of the tumour‐bearing mice. In vitro, the secreted SLC‐3P‐Fc fusion protein can attract lymphocytes from human peripheral blood mononuclear cells (PBMC); when human lymphocytes were stimulated by pSLC‐3P‐Fc‐transfected autologous PBMC, CTLs were induced which could specifically kill hPSM‐, hPAP‐, or hPSA‐expressing tumour cells. These observations provide a new vaccine strategy for cancer therapy through promoting the co‐localization of lymphocytes and the concomitant enhancement of antigen‐specific CD4+ helper and CD8+ cytotoxic T‐cell responses against tumour.
Monocyte CD64 or CD89 targeting by surfactant protein D/anti‐Fc receptor mediates bacterial uptake
Authors: Tacken Paul J. , Batenburg Joseph J.
Published: February 2006

We recently showed that a chimeric protein, consisting of a recombinant fragment of human surfactant protein D (rfSP‐D) coupled to a Fab′ fragment directed against the human Fcα receptor (CD89), effectively targets pathogens recognized by SP‐D to human neutrophils. The present study evaluates the effectiveness of chimeric rfSP‐D/anti‐Fc receptor proteins targeting Escherichia coli to CD89 or to the Fcγ receptor I (CD64) on monocytes. Both chimeric rfSP‐D/anti‐Fc receptor proteins increased internalization of E. coli by the human promonocytic cell line U937, but only after induction of monocytic differentiation, despite the fact that the expression levels of CD64 and CD89 on undifferentiated cells were at least as high as on differentiated cells. The two chimeric rfSP‐D/anti‐Fc receptor proteins did not enhance each other's effect on E. coli uptake. Targeting to differentiated U937 cells was inhibited by blocking the interaction either between the rfSP‐D part of the chimeric molecule and E. coli, or between the anti‐Fc receptor Fab′ fragment and the Fc receptor on the U937 cell. In conclusion, both CD64 and CD89 on U937 cells prove to be suitable for targeting by rfSP‐D/anti‐Fc receptor proteins. However, in addition to mere Fc receptor expression, effective targeting requires monocytic differentiation.
Enhancement of DNA vaccine potency through linkage of antigen to filamentous bacteriophage coat protein III domain I
Authors: Cuesta Ángel M. , Suárez Eduardo , Larsen Martin , Jensen Kim Bak , Sanz Laura , Compte Marta , Kristensen Peter , Álvarez‐Vallina Luis
Published: February 2006

Although DNA‐based cancer vaccines have been successfully tested in mouse models, a major drawback of cancer vaccination still remains, namely that tumour antigens are weak and fail to generate a vigorous immune response in tumour‐bearing patients. Genetic technology offers strategies for promoting immune pathways by adding immune‐activating genes to the tumour antigen sequence. In this work, we converted a model non‐immunogenic antigen into a vaccine by fusing it to domain I of the filamentous bacteriophage coat protein III gene. Vaccination with a DNA construct encoding the domain I fusion generated antigen‐specific T helper 1‐type cellular immune responses. These results demonstrate that the incorporation of protein III into a DNA vaccine formulation can modulate the gene‐mediated immune response and may thus provide a strategy for improving its therapeutic effect.
Inactivation of Escherichia coli O157:H7 and Listeria monocytogenes inoculated on raw salmon fillets by pulsed UV‐light treatment
Authors: Ozer Nil P. , Demirci Ali
Published: February 2006

The efficacy of pulsed UV‐light to inactivate of Escherichia coli O157:H7 and Listeria monocytogenes Scott A on salmon fillets was investigated in this study by evaluating the effects of treatment times and distance from the UV strobe. The sterilization system generated 5.6 J cm−2 per pulse at the lamp surface for an input voltage of 3800 V and three pulses per second. Skin or muscle side inoculated salmon fillet (8 cm × 1.5 cm) in a Petri dish was placed on shelf at three different distances from the UV strobe; 3, 5, and 8 cm. At each distance, the pulsed UV‐light treatment was performed for 15, 30, 45, and 60 s. For E. coli O157:H7, maximum log10 reduction was 1.09 log10 CFU g−1 on muscle side at 8 cm for 60‐s treatment, whereas 0.86 log10 CFU g−1 reduction on skin at 5 cm for 30‐s treatment. For L. monocytogenes Scott A, maximum reduction was 1.02 log10 CFU g−1 at 8 cm for 60‐s treatment on skin side, whereas 0.74 log10 CFU g−1 reduction on muscle at 8 cm for 60‐s treatment. The fillet's surface temperature increased up to 100degrC within 60‐s treatment time. Therefore, some fish samples were overheated after 30 and 45 s at 3‐ and 5‐cm distances from light source, respectively, which resulted in visual colour and quality changes. Overall, this study demonstrated that about one log reduction (c. 90%) of E. coli O157:H7 or L. monocytogenes could be achieved at 60‐s treatment at 8 cm distance without affecting the quality.
Compositional and physical properties of yogurts manufactured from milk and whey cheese concentrated by ultrafiltration
Authors: Magenis Renata B. , Prudêncio Elane S. , Amboni Renata D. M. C. , Cerqueira Júnior Noel G. , Oliveira Ricardo V. B. , Soldi Valdir , Benedet Honório D.
Published: February 2006

Yogurts made with 80% milk retentate (MR) [Volume Reduction Factor (VRF) = 1.5] and 20% cheese whey retentate (WR; VRF = 8.0) (yogurt 1) and yogurts made with 100% MR through ultrafiltration have been evaluated as to flow, texture profile analysis (TPA) and syneresis index. As with MR and WR, their physico‐chemical composition was also determined. The yogurt to which WR had been added showed; less apparent viscosity and greater tixotrophya; less firmness and adhesiveness and greater cohesiveness; higher syneresis index, less protein and mineral content, and greater lipid content in comparison with the yogurt made only with MR.
Properties of soluble protein powders from Alaska pollock (Theragra chalcogramma)
Authors: Sathivel Subramaniam , Bechtel Peter J.
Published: February 2006

Soluble protein powders were produced from pollock by‐products and evaluated for their functional, nutritional and rheological properties. Soluble protein powders were made from pollock viscera (PVSP), viscera without liver (PVWLSP), heads (PHSP), frames (PFSP), trimmings (PTSP), and liver (PLSP) and had protein contents ranging from 65.0% to 78.9%. Yield of PVWLSP was higher than that of other pollock proteins powder and PTSP had the highest nitrogen solubility value (85.7%). Emulsion capacity and emulsion stability of the pollock protein powders ranged from 29% to 34.5% (mL of oil per 200 mg of protein) and 65.3% to 77.6%, respectively. Highest and lowest fat adsorption values were observed for PFSP (10.6 mL of oil per gram of protein) and PVSP (4.1 mL of oil per gram of protein), respectively. Fish protein powder samples were good sources in K, P, and Mg and amino acids. Emulsions made with pollock soluble protein powders exhibited viscoelastic characteristics.
Rheological and physical evaluation of jet‐cooked oat bran in low calorie cookies†
Authors: Lee Suyong , Inglett George E.
Published: February 2006

Different levels of shortening in cookies (10%, 20% and 30% by weight) were replaced with 20% jet‐cooked oat bran, also called Nutrim oat bran (OB), to prepare cookies with fewer calories. The cookies containing Nutrim OB were investigated in terms of rheological and physical properties and compared with a control. As more shortening was replaced with Nutrim OB, a decrease in the diameter and an increase in the height of cookies were observed. The increased moisture content from Nutrim OB caused a decrease in the dynamic viscoelastic properties of cookie dough. Squeezing flow method showed shear thinning behaviours in all cookie doughs. Also, the elongational viscosity of cookie dough decreased significantly with more replacement of shortening with Nutrim OB. The rheological properties of cookie dough during baking indicated that all of the samples had similar types of viscoelastic characteristics during baking. However, the cookies containing more Nutrim OB exhibited more elastic properties which resulted in a decreased cookie diameter. There was no significant difference in cookie hardness among samples with up to 20% shortening replacement but the cookies became lighter in colour as the Nutrim OB content was increased.
Cognitive, language and social‐cognitive skills of individuals with fragile X syndrome with and without autism
Authors: Lewis P. , Abbeduto L. , Murphy M. , Richmond E. , Giles N. , Bruno L. , Schroeder S.
Published: February 2006

Background  It is not known whether those with co‐morbid fragile X syndrome (FXS) and autism represent a distinct subtype of FXS; whether the especially severe cognitive delays seen in studies of young children with co‐morbid FXS and autism compared with those with only FXS continue into adolescence and young adulthood; and whether autism in those with FXS is ‘true autism’, i.e. reflects the same underlying problems as idiopathic autism.

Method  We compared the non‐verbal IQ of adolescents and young adults with co‐morbid FXS and autism (n = 10) with those with only FXS (n = 44). We then created a subsample of those with FXS only, matched on non‐verbal IQ, mental age and gender (n = 21) to the subsample of those with co‐morbid FXS and autism. We compared the two groups on measures of expressive language, receptive language (lexical, grammatical morphology and syntactic patterns), and a theory of mind task.

Results  Those with co‐morbid FXS and autism had lower non‐verbal IQs than those with only FXS. The participants with co‐morbid FXS and autism did not perform as well as the cognitive ability‐ and gender‐matched participants with only FXS on the three measures of receptive language or the theory of mind task; there were no differences on the expressive language measure.

Conclusions  Our findings support the notion that those with co‐morbid FXS and autism represent a distinct subtype of FXS, with more impairment in receptive language and theory of mind even when controlling for their lower non‐verbal IQ relative to those with only FXS. The greater cognitive impairments observed in those with co‐morbid FXS and autism continues into adolescence and young adulthood; and the autism seen in those with FXS appears to be the same as idiopathic autism.
Pivot appliances – is there a distractive effect on the temporomandibular joint?
Authors: SEEDORF H. , SCHOLZ A. , KIRSCH I. , FENSKE C. , JÜDE H. D.
Published: February 2006

summary  The purpose of this study was to investigate the distractive effect of posterior occlusal pivots on the temporomandibular joint. The study comprised 23 healthy subjects. None of them had a third molar and none of them had a missing tooth or showed tooth mobility. All subjects clenched (i) on 1 mm tin foil positioned between the teeth 17/47 and 27/37; (ii) on a stiff bite registration material of 1 mm thickness that prevented protrusion because of its bold occlusal relief. During clenching on the tin foil and on the protrusion preventing bite registration material, respectively, the vertical and horizontal condylar position was measured using a 6 d.f. ultrasonic motion analyser. Clenching with maximal force on the tin foil lead to a noticeable anterior downward directed movement of the condyle. Clenching on the protrusion preventing pivot, however, caused a statistically significant upward condylar movement of about 0·3 mm. These results indicate that occlusal pivots have no distractive effect on the temporomandibular joint but can lead to unwanted joint compression, if they are designed in a way that is preventing protrusion.
Is condylar position a predictor for functional signs of TMJ hypermobility?
Authors: KALAYKOVA S. , NAEIJE M. , HUDDLESTON SLATER J. J. R. , LOBBEZOO F.
Published: February 2006

summary  Temporomandibular joint (TMJ) hypermobility is noted only when it interferes with smooth mandibular movements. These interferences (viz. clicking sounds and jerky mandibular movements) result from condylar dislocation in front of the eminence at wide mouth opening, or alternatively in front of the articular disc (posterior disc displacement). The aim of this study was to test the hypothesis that condyles of hypermobile persons are positioned more anterosuperiorly to the crest of the eminence during maximum mouth opening than those of persons without TMJ hypermobility. Possible posterior disc displacement was also evaluated. Nine persons with symptomatic hypermobility and nine control persons free of internal derangements were included, their diagnoses being based upon opto‐electronic movement recordings. Condylar positions during maximum mouth opening were analysed on magnetic resonance images with two slightly different methods, showing the degree to which the condyles are displaced around the eminence. No posterior disc displacements were found in any of the magnetic resonance images. After excluding an outlier and using both measurement methods, a small difference in condylar position was found between the two groups of subjects. The condyles of all hypermobile persons travelled beyond the eminence; however, so were the condyles of nearly half of the non‐hypermobiles. The large overlap between both groups suggests that condylar position alone is not a good predictor for symptomatic TMJ hypermobility. It is probably the combination of condylar location in front of the eminence with a particular line of action of the masticatory muscles, which gives rise to functional signs of hypermobility.
Risk factors associated with symptoms of temporomandibular disorders in a population of 50‐ and 60‐year‐old subjects
Authors: JOHANSSON A. , UNELL L. , CARLSSON G. E. , SÖDERFELDT B. , HALLING A.
Published: February 2006

summary  The aims of this study were first to investigate, by means of a mail questionnaire, variables from three domains: (i) socio‐economic attributes; (ii) general and oral health; and (iii) dental attitudes and behaviours in a large sample of 50‐ and 60‐year‐old subjects, and second to compare subjects with or without reported temporomandibular joint (TMJ) pain with respect to these variables. In 2002, a questionnaire was mailed to all 50‐ and 60‐year‐old subjects in two Swedish counties, Örebro and Östergötland (n = 17 138; n50 = 8878; n60 = 8260). Individuals not responding within 2 weeks were given a reminder. If still not answering, a new questionnaire was sent. The final response rate was 72·8% (n = 12 468). The reported responses to questions regarding ‘pain in the TMJ region’ and ‘difficulty to open the mouth wide’ were dichotomized into two groups: (i) no temporomandibular disorders (TMD) symptoms; and (ii) some, rather great or severe TMD symptoms. Striking differences in demographic, occupational, general and oral health conditions were found between the groups with and without TMD symptoms. The strongest risk indicator for both pain and dysfunction was reported bruxism. Women, younger subjects (50 years old) and blue‐collar workers were significantly more prevalent in the TMD symptom groups. Variables related to impaired general and oral health were more common in the groups with reported TMD problems, whereas satisfaction with received dental care and with teeth was lower. Individuals with reported TMD symptoms differed significantly from those without TMD symptoms in socio‐economic attributes, general and oral health symptoms, dental conditions and satisfaction with their teeth.
Recovery of peroxides in saliva during home bleaching – influence of smoking
Authors: HANNIG C. , WILLENBÜCHER S. , BECKER K. , MAHONY C. , ATTIN T.
Published: February 2006

summary  The study aimed at determining hydrogen peroxide recovery in saliva during use of different home bleaching products by smokers and non‐smokers. Peroxide recovery was evaluated with respect to the safe level reported in the literature. Determination of peroxide levels in saliva was performed with peroxidase, phenol and 4‐aminoantipyrin in a photometric method. Four different bleaching regimens were used by 10 smokers and 10 non‐smokers: Whitestrips, Vivastyle (tray‐based) and two paint‐on products (Crest Night Effects, Colgate Simply White). Whole saliva was collected and total amount of peroxide (mg) released during the 60 min bleaching period was determined: Colgate Simply White: 2·67 ±0·88 (non‐smokers); 2·66 ± 1·17 (smokers); Crest Night Effects: 0·23 ± 0·13 (non‐smokers); 0·25 ±0·16 (smokers); Vivastyle: 2·47 ± 0·82 (non‐smokers), 2·44 ± 1·31 (smokers); Whitestrips: 1·39 ± 0·62 (non‐smokers), 2·02 ± 1·86 (smokers). In terms of amount of peroxide kg−1 body weight the bleaching systems led to a single exposure of 0·004–0·046 mg kg−1, which is distinctly less than safe daily dose of 0·26 mg kg−1 day−1, if calculated for a small person (58 kg). The criterion smoker versus non‐smokers had no influence on peroxide levels in the oral cavity. Conclusion: Smoking did not appear to impact the anti‐oxidant defence capacity of the oral cavity with respect to degrading peroxides released from bleaching products. Significantly lower amounts of peroxides were detected in saliva during application of the paint‐on product Crest Nights Effects compared with the other bleaching systems.
Extensive intraspecific polymorphism detected by SSCP at the nuclear C‐mos gene in the endemic Iberian lizard Lacerta schreiberi
Authors: GODINHO RAQUEL , DOMINGUES VERA , CRESPO EDUARDO G. , FERRAND NUNO
Published: February 2006

C‐mos is a highly conserved intronless gene that has proved useful in the analysis of ancient phylogenetic relationships within vertebrates. We selected the Iberian endemic Schreiber's green lizard (Lacerta schreiberi) that persisted in allopatric refugia since the late Pliocene to investigate the utility of the C‐mos nuclear gene for intraspecific phylogeographic studies. Our combination of DNA sequencing with the high resolving power of single‐strand conformational polymorphism (SSCP) effectively discriminated four common alleles showing strong population structuring (FST = 0.46). In addition, reconstruction of allele phylogenetic relationships further improved our understanding of C‐mos spatial patterns of variation and allowed a comparison with previously described mitochondrial DNA data. Finally, limited sequencing of an extended C‐mos fragment in six additional Lacerta species showed extensive polymorphism, to our knowledge representing a rare example of variation in a highly conserved nuclear gene.
Biogeographic patterns and phylogeography of dwarf chameleons (Bradypodion) in an African biodiversity hotspot
Authors: TOLLEY KRYSTAL A. , BURGER MARIUS , TURNER ANDREW A. , MATTHEE CONRAD A.
Published: February 2006

The southern African landscape appears to have experienced frequent shifts in vegetation associated with climatic change through the mid‐Miocene and Plio–Pleistocene. One group whose historical biogeography may have been affected by these fluctuations are the dwarf chameleons (Bradypodion), due to their associations with distinct vegetation types. Thus, this group provides an opportunity to investigate historical biogeography in light of climatic fluctuations. A total of 138 dwarf chameleons from the Cape Floristic Region of South Africa were sequenced for two mitochondrial genes (ND2 and 16S), and resulting phylogenetic analyses showed two well‐supported clades that are distributed allopatrically. Within clades, diversity among some lineages was low, and haplotype networks showed patterns of reticulate evolution and incomplete lineage sorting, suggesting relatively recent origins for some of these lineages. A dispersal‐vicariance analysis and a relaxed Bayesian clock suggest that vicariance between the two main clades occurred in the mid‐Miocene, and that both dispersal and vicariance have played a role in shaping present‐day distributions. These analyses also suggest that the most recent series of lineage diversification events probably occurred within the last 3–6 million years. This suggests that the origins of many present‐day lineages were founded in the Plio–Pleistocene, a time period that corresponds to the reduction of forests in the region and the establishment of the fynbos biome.
Biogeographic history of an Australian freshwater shrimp, Paratya australiensis (Atyidae): the role life history transition in phylogeographic diversification
Authors: COOK B. D. , BAKER A. M. , PAGE T. J. , GRANT S. C. , FAWCETT J. H. , HURWOOD D. A. , HUGHES J. M.
Published: February 2006

The widespread distribution of the freshwater shrimp Paratya australiensis in eastern Australia suggests that populations of this species have been connected in the past. Amphidromy is ancestral in these shrimps, although many extant populations are known to be restricted to freshwater habitats. In this study, we used a fragment of the cytochrome c oxidase I mitochondrial DNA (mtDNA) gene to examine diversity within P. australiensis and to assess the relative importance of amphidromy in its evolutionary history. We hypothesized that if transitions from an amphidromous to a freshwater life history were important, then we would find a number of divergent lineages restricted to single or groups of nearby drainages. Alternatively, if amphidromy was maintained within the species historically, we expected to find lineages distributed over many drainages. We assumed that the only way for divergence to occur within amphidromous lineages was if dispersal was limited to between nearby estuaries, which, during arid periods in the earth's history, became isolated from one another. We found nine highly divergent mtDNA lineages, estimated to have diverged from one another in the late Miocene/early Pliocene, when the climate was more arid than at present. Despite this, the geographic distribution of lineages and haplotypes within lineages did not support the notion of a stepping‐stone model of dispersal between estuaries. We conclude that the extensive divergence has most likely arisen through a number of independent amphidromy–freshwater life history transitions, rather than via historical isolation of amphidromy populations. We also found evidence for extensive movement between coastal and inland drainages, supporting the notion that secondary contact between lineages may have occurred as a result of drainage rearrangements. Finally, our data indicate that P. australiensis is likely a complex of cryptic species, some of which are widely distributed, and others geographically restricted.
Seasonal changes in pollinator activity influence pollen dispersal and seed production of the alpine shrub Rhododendron aureum (Ericaceae)
Authors: HIRAO A. S. , KAMEYAMA Y. , OHARA M. , ISAGI Y. , KUDO G.
Published: February 2006

In alpine ecosystems, microscale variation in snowmelt timing often causes different flowering phenology of the same plant species and seasonal changes in pollinator activity. We compared the variations in insect visitation, pollen dispersal, mating patterns, and sexual reproduction of Rhododendron aureum early and late in the flowering season using five microsatellites. Insects visiting the flowers were rare early in the flowering season (mid‐June), when major pollinators were bumblebee queens and flies. In contrast, frequent visitations by bumblebee workers were observed late in the season (late July). Two‐generation analysis of pollen pool structure demonstrated that quality of pollen‐mediated gene flow was more diverse late in the season in parallel with the high pollinator activity. The effective number of pollen donors per fruit (Nep) increased late in the season (Nep = 2.2–2.7 early, 3.4–4.4 late). However, both the outcrossing rate (tm) and seed‐set ratio per fruit were smaller late in the season (tm = 0.89 and 0.71, seed‐set ratio = 0.52 and 0.18, early and late in the season, respectively). In addition, biparental inbreeding occurred only late in the season. We conclude that R. aureum shows contrasting patterns of pollen movement and seed production between early and late season: in early season, seed production can be high but genetically less diverse and, during late season, be reduced, possibly due to higher inbreeding and inbreeding depression, but have greater genetic diversity. Thus, more pollinator activity does not always mean more pollen movement.
Genetic structure of sibling butterfly species affected byWolbachiainfection sweep: evolutionary and biogeographical implications
Authors: NARITA SATOKO , NOMURA MASASHI , KATO YOSHIOMI , FUKATSU TAKEMA
Published: February 2006

It was recently recognized that in Japan, the common yellow butterfly,Eurema hecabe, consists of two sibling species, which have been unnamed yet and tentatively called yellow (Y) type and brown (B) type. We investigated the diversity of nuclear and mitochondrial genes in Japanese populations of Y type and B type ofE. hecabe. The phylogeny based on nuclear genes agreed with the distinction between Y type and B type, which had been also supported by a wide array of biological data. However, the phylogeny based on mitochondrial genes did not reflect the distinction. PCR survey ofWolbachiarevealed that B‐type populations were all infected while Y‐type populations contained both infected and uninfected individuals. A single genotype ofWolbachia, which was inferred to be a CI‐inducing strain from theirwspgene sequence, was prevalent in these populations. Notably, the mitochondrial phylogeny was in perfect agreement with the pattern ofWolbachiainfection, suggesting that theWolbachiainfection had affected the mitochondrial genetic structure of the host insects. Probably, theWolbachiastrain and the associated mitochondrial genomes have been occasionally introduced from B‐type populations to Y‐type populations through migration and subsequent interspecific hybridization, and CI‐driven population sweep has been spreading theWolbachiastrain and the particular mitochondrial haplotypes, which originated from B‐type populations, into Y‐type populations. On the basis of these results together with the geological and biogeographical knowledge of the Japanese Archipelago, we proposed an evolutionary hypothesis on the invasion and spread ofWolbachiainfection in B‐type and Y‐type ofE. hecabe.
Late Quaternary climate change and spatial genetic structure in the shrubBanksia hookeriana
Authors: KRAUSS SIEGFRIED L. , HE TIANHUA , LAMONT BYRON B. , MILLER BEN P. , ENRIGHT NEAL J.
Published: February 2006

Spatial genetic variation within species is influenced by both contemporary and historical factors. We attempted to assess the impact of increased aridity and lower temperatures associated with the last glacial maximum on possible refugia and the structuring of genetic variation inBanksia hookeriana, a shrub species restricted to deep sands on the Eneabba sandplain and adjacent Gingin Scarp/Dandaragan Plateau, centred 300 km north of Perth, Western Australia. We used optically stimulated luminescence (OSL) dating to estimate the last time these sands were mobile, as well as amplified fragment length polymorphisms (AFLP) to infer spatial patterns and the phylogeographical history of genetic variation among 15 populations ofB. hookeriana. While genetic variation at the species level was high, with 96.6% of 238 AFLP markers polymorphic, average within population gene diversity was low (Hpop = 0.16). Of the total genetic variation, an analysis of molecular variance (amova) partitioned 70% within populations, 24% among populations within substrate and 6% between substrates. There was an isolation‐by‐distance effect among populations within the same substrate, but not across substrates, and ordination highlighted genetic differentiation between the sandplain and scarp/plateau populations. A neighbour‐joining tree identified the sandplain populations as a distinct clade, with the exception of the most northern sandplain population, which clustered with two northern and eastern plateau populations. The most southern plateau populations formed a clade sister to the sandplain clade. OSL dating of sand at six extant populations suggested that dunes were last mobile 15 000–35 000 years ago, with no clear difference in the ages of sandplain and plateau dunes. These data are consistent with a historical scenario of (re)colonization from isolated refugia of smaller populations either within the patchily vegetated sandplain and/or refugia at the northern, eastern and southern sandplain/scarp margins following postglacial climate amelioration and dune stabilization. Historic interpretations were confounded by the possible effects of long‐distance dispersal, natural selection by substrate, and weak and/or ancient introgression with the sister species,Banksia prionotes.
Genetic structure is influenced by landscape features: empirical evidence from a roe deer population
Authors: COULON A. , GUILLOT G. , COSSON J.‐F. , ANGIBAULT J. M. A. , AULAGNIER S. , CARGNELUTTI B. , GALAN M. , HEWISON A. J. M.
Published: February 2006

The delimitation of population units is of primary importance in population management and conservation biology. Moreover, when coupled with landscape data, the description of population genetic structure can provide valuable knowledge about the permeability of landscape features, which is often difficult to assess by direct methods (e.g. telemetry). In this study, we investigated the genetic structuring of a roe deer population which recently recolonized a fragmented landscape. We sampled 1148 individuals from a 40 × 55‐km area containing several putative barriers to deer movements, and hence to gene flow, namely a highway, rivers and several canals. In order to assess the effect of these landscape features on genetic structure, we implemented a spatial statistical model known as geneland which analyses genetic structure, explicitly taking into account the spatial nature of the problem. Two genetic units were inferred, exhibiting a very low level of differentiation (FST = 0.008). The location of their boundaries suggested that there are no absolute barriers in this study area, but that the combination of several landscape features with low permeability can lead to population differentiation. Our analysis hence suggests that the landscape has a significant influence on the structuring of the population under study. It also illustrates the use of geneland as a powerful method to infer population structure, even in situations of young populations exhibiting low genetic differentiation.
Age‐independent telomere length predicts fitness in two bird Species
Authors: PAULINY ANGELA , WAGNER RICHARD H. , AUGUSTIN JAKOB , SZÉP TIBOR , BLOMQVIST DONALD
Published: February 2006

Telomeres are dynamic DNA‐protein structures that form protective caps at the ends of eukaryotic chromosomes. Although initial telomere length is partly genetically determined, subsequent accelerated telomere shortening has been linked to elevated levels of oxidative stress. Recent studies show that short telomere length alone is insufficient to induce cellular senescence; advanced attrition of these repetitive DNA sequences does, however, reflect ageing processes. Furthermore, telomeres vary widely in length between individuals of the same age, suggesting that individuals differ in their exposure or response to telomere‐shortening stress factors. Here, we show that residual telomere length predicts fitness components in two phylogenetically distant bird species: longevity in sand martins, Riparia riparia, and lifetime reproductive success in dunlins, Calidris alpina. Our results therefore imply that individuals with longer than expected telomeres for their age are of higher quality.
Evidence for a large‐scale population structure among accessions of Arabidopsis thaliana: possible causes and consequences for the distribution of linkage disequilibrium
Authors: OSTROWSKI MARIE‐FRANCE , DAVID JACQUES , SANTONI SYLVAIN , MCKHANN HEATHER , REBOUD XAVIER , LE CORRE VALERIE , CAMILLERI CHRISTINE , BRUNEL DOMINIQUE , BOUCHEZ DAVID , FAURE BENOIT , BATAILLON THOMAS
Published: February 2006

The existence of a large‐scale population structure was investigated in Arabidopsis thaliana by studying patterns of polymorphism in a set of 71 European accessions. We used sequence polymorphism surveyed in 10 fragments of ∼600 nucleotides and a set of nine microsatellite markers. Population structure was investigated using a model‐based inference framework. Among the accessions studied, the presence of four groups was inferred using genetic data, without using prior information on the geographical origin of the accessions. Significant genetic isolation by geographical distance was detected at the group level, together with a geographical gradient in allelic richness across groups. These results are discussed with respect to the previously proposed scenario of postglacial colonization of Europe from putative glacial refugia. Finally, the contribution of the inferred structure to linkage disequilibrium among 171 pairs of essentially unlinked markers was also investigated. Linkage disequilibrium analysis revealed that significant associations detected in the whole sample were mainly due to genetic differentiation among the inferred groups. We discuss the implication of this finding for future association studies in A. thaliana.
Phylogeographic structure and past history of the circum‐Mediterranean species Tomicus destruens Woll. (Coleoptera: Scolytinae)
Authors: HORN A. , ROUX‐MORABITO G. , LIEUTIER F. , KERDELHUE C.
Published: February 2006

Phylogeographic studies are often focused on temperate European species with relict footholds in the Mediterranean region. Past climatic oscillations usually induced range contractions and expansions from refugial areas located in southern Europe, and spatial distribution of genetic diversity show that northward expansions were usually pioneer‐like. Actually, few studies have focused on circum‐Mediterranean species, which probably were not influenced in the same way by climatic oscillations. We present the phylogeography of the bark beetle Tomicus destruens, which is restricted to the whole Mediterranean basin and the Atlantic coasts of North Africa and Portugal. We systematically sequenced 617 bp of the mitochondrial genes COI and COII for 42 populations (N = 219). Analysis revealed 53 haplotypes geographically structured in two clades, namely eastern and western clades, that diverged during the Pleistocene. A contact zone was identified along the Adriatic coast of Italy. Interestingly, we found contrasting levels of genetic structure within each clade. The eastern group was characterized by a significant phylogeographic pattern and low levels of gene flow, whereas the western group barely showed a spatial structure in haplotype distribution. Moreover, the main pine hosts were different between groups, with the Aleppo‐brutia complex in the east and the maritime pine in the west. Potential roles of host species, climatic parameters and geographical barriers are discussed and the phylogeographic patterns are compared to classical models of postglacial recolonization in Europe.
Multifunctional analysis of Chlamydia‐specific genes in a yeast expression system
Authors: Sisko Jennifer L. , Spaeth Kris , Kumar Yadunanda , Valdivia Raphael H.
Published: February 2006

Our understanding of how obligate intracellular pathogens co‐opt eukaryotic cellular functions has been limited by their intractability to genetic manipulation and by the abundance of pathogen‐specific genes with no known functional homologues. In this report we describe a gene expression system to characterize proteins of unknown function from the obligate intracellular bacterial pathogen Chlamydia trachomatis. We have devised a homologous recombination‐based cloning strategy to construct an ordered array of Saccharomyces cerevisiae strains expressing all Chlamydia‐specific genes. These strains were screened to identify chlamydial proteins that impaired various yeast cellular functions or that displayed tropism towards eukaryotic organelles. In addition, to identify bacterial factors that are secreted into the host cell, recombinant chlamydial proteins were screened for reactivity towards antisera raised against vacuolar membranes purified from infected mammalian cells. We report the identification of 34 C. trachomatis proteins that impact yeast cellular functions or are tropic for a range of eukaryotic organelles including mitochondria, nucleus and cytoplasmic lipid droplets, and a new family of Chlamydia‐specific proteins that are exported from the parasitopherous vacuole. The versatility of molecular manipulations and protein expression in yeast allows for the rapid construction of comprehensive protein expression arrays to explore the function of pathogen‐specific gene products from microorganisms that are difficult to genetically manipulate, grow in culture or too dangerous for routine analysis in the laboratory.
A gene involved in modifying transfer RNA is required for fungal pathogenicity and stress tolerance of Colletotrichum lagenarium
Authors: Takano Yoshitaka , Takayanagi Naoyuki , Hori Hiroyuki , Ikeuchi Yoshiho , Suzuki Tsutomu , Kimura Akiko , Okuno Tetsuro
Published: February 2006

7‐Methylguanosine (m7G) modification of tRNA occurs widely in prokaryotes and eukaryotes, although information about its biological roles is limited. Here, we report that a gene involved in m7G modification of tRNA is required for infection by the phytopathogenic fungus Colletotrichum lagenarium. Analysis of the infection‐deficient mutant of C. lagenarium, produced by plasmid insertional mutagenesis, identified a tagged gene that is designated APH1. The aph1 mutants, generated by targeted gene disruption, exhibit significant reduction in pathogenicity on the host plants. We conclude that APH1 is required for fungal infection in C. lagenarium. Aph1 showed a strong similarity to Saccharomyces cerevisiae Trm8 involved in m7G modification of tRNA. The m7G content of tRNA from the aph1 deletion mutant was severely reduced compared with that from the wild type, indicating that APH1 is required for m7G methyltransferase activity. Appressoria formed by the aph1 mutants developed penetration hyphae into cellophane, suggesting that appressoria of the mutants retain basic function for penetration. However, the aph1 mutants failed to develop intracellular penetration hyphae into epidermis of the host plants, suggesting a specific requirement of APH1 for appressorium‐mediated host invasion. The mutants also had increased sensitivity to salinity and H2O2 stresses. Interestingly, a heat shock treatment on the host plants enabled the aph1 mutant to penetrate them. These data suggest that the APH1 is required for the plant invasion, probably to overcome environmental stresses derived from basal preinvasion (penetration) defence of the host plants.
An unusual pattern of protein expression and localization of yeast alanyl‐tRNA synthetase isoforms
Authors: Huang Hsiao‐Yun , Tang Huei‐Lin , Chao Hen‐Yi , Yeh Lu‐Shu , Wang Chien‐Chia
Published: February 2006

Previous studies have shown that in Saccharomyces cerevisiae the mitochondrial and cytoplasmic forms of alanyl‐tRNA synthetase are encoded by a single nuclear gene, ALA1, through alternative use of in‐frame successive ACG triplets and a downstream AUG triplet. Here we show that despite the obvious participation of the non‐AUG‐initiated leader peptide in mitochondrial localization, the leader peptide per se cannot target a cytoplasmic passenger protein into mitochondria under normal conditions. Functional mapping further shows that an efficient targeting signal is composed of the leader peptide and an 18‐residue sequence downstream of Met1. Consistent to this observation, overexpression of the cytoplasmic form enables it to overcome the compartmental barrier and function in the mitochondria as well, but deletion of as few as eight amino acid residues from its amino‐terminus eliminates such a potential. Thus, the sequence upstream of the first in‐frame AUG initiator not only carries an unusual initiation site, but also contributes to a novel pattern of protein expression and localization.
Inhibition of Lon‐dependent degradation of the Escherichia coli transcription activator SoxS by interaction with ‘soxbox’ DNA or RNA polymerase
Authors: Shah Ishita M. , Wolf Richard E.
Published: February 2006

Escherichia coli SoxS, the direct transcription activator of the SoxRS (superoxide) regulon, is intrinsically unstable with an in vivo half‐life of ∼2 min. Overexpression of SoxS is lethal, but mutations interfering with DNA binding relieve the toxicity. Here, we determined the effects on the half‐life of SoxS of alanine substitutions that confer defects in positive control, i.e. transcription activation, or in specific DNA binding. We found that both types of mutations render SoxS more unstable than the wild‐type protein, as if ‘soxbox’ DNA and RNA polymerase serve as stabilizing ligands in vivo that protect SoxS from degradation by Lon, the protease shown previously to be primarily responsible for its turnover. Indeed, we found that the addition of soxbox DNA or RNA polymerase to an in vitro degradation system decreases the rate of SoxS proteolysis by Lon protease. To the best of our knowledge, these are the first examples of target DNA and RNA polymerase serving as ligands that inhibit the turnover of an unstable transcription activator.
Physician knowledge of Rome symptom criteria for irritable bowel syndrome is poor among non‐gastroenterologists
Authors: Charapata C. , Mertz H.
Published: February 2006

Abstract  Rome I criteria are highly specific for irritable bowel syndrome (IBS) when red flag signs and symptoms are absent. Physician knowledge of Rome criteria may reduce diagnostic testing. We assessed: (i) physician knowledge of Rome criteria among internists, gastroenterologists and surgeons; (ii) laboratory and endoscopical testing suggested by physicians for sample IBS patients. Physicians of all training levels in internal medicine, gastroenterology, and surgery completed an anonymous questionnaire at a University Medical Center. Subjects were asked to identify Rome criteria among distracters. Sample IBS patients were presented, and physicians were asked to suggest a diagnostic workup based on the choices provided on the questionnaire. Rome knowledge was highest among gastroenterologists and lowest among surgeons. Physicians suggested endoscopical procedures in 67% of IBS patients with diarrhoea and in 46% with constipation. There was no difference among specialties in amount of laboratory or endoscopical testing suggested. Knowledge and use of the Rome criteria or their positive predictive value (PPV) for IBS did not correlate with reduced diagnostic testing. Education regarding the Rome criteria should be extended to surgical specialists who are likely to evaluate and operate on IBS patients. Endoscopical evaluation of IBS patients may be excessive.