bluuebunny/crossref_metadata_2025 huggingface dataset:
Humor and Laughter may Influence Health. I. History and Background
Authors: Bennett Mary Payne , Lengacher Cecile A.
Published: January 2006

Articles in both the lay and professional literature have extolled the virtues of humor, many giving the impression that the health benefits of humor are well documented by the scientific and medical community. The concept that humor or laughter can be therapeutic goes back to biblical times and this belief has received varying levels of support from the scientific community at different points in its history. Current research indicates that using humor is well accepted by the public and is frequently used as a coping mechanism. However, the scientific evidence of the benefits of using humor on various health related outcomes still leaves many questions unanswered.
Unconventional translation of mammalian LINE-1 retrotransposons
Authors: Alisch Reid S. , Garcia-Perez Jose L. , Muotri Alysson R. , Gage Fred H. , Moran John V.
Published: January 2006

Long Interspersed Element-1 (LINE-1 or L1) retrotransposons encode proteins required for their mobility (ORF1p and ORF2p), yet little is known about how L1 mRNA is translated. Here, we show that ORF2 translation generally initiates from the first in-frame methionine codon of ORF2, and that both ORF1 and the inter-ORF spacer are dispensable for ORF2 translation. Remarkably, changing the ORF2 AUG codon to any other coding triplet is compatible with retrotransposition. However, introducing a premature termination codon in ORF1 or a thermostable hairpin in the inter-ORF spacer reduces ORF2p translation or L1 retrotransposition to ∼5% of wild-type levels. Similar data obtained from “natural” and codon optimized “synthetic” mouse L1s lead us to propose that ORF2 is translated by an unconventional termination/reinitiation mechanism.
Tissue-specific RNAi reveals that WT1 expression in nurse cells controls germ cell survival and spermatogenesis
Authors: Rao Manjeet K. , Pham John , Imam J. Saadi , MacLean James A. , Murali Deepa , Furuta Yasuhide , Sinha-Hikim Amiya P. , Wilkinson Miles F.
Published: January 2006

Using a novel tissue-specific RNA interference (RNAi) approach that mimics the principle by which naturally occurring microRNAs (miRNA) are made, we demonstrate that the Wilms' tumor 1 (WT1) transcription factor has an essential role in spermatogenesis. Mice depleted of WT1 in Sertoli nurse cells suffered from increased germ cell apoptosis, loss of adherens junctions, disregulation of adherence junction-associated genes, and impaired fertility. These effects were recapitulated in transgenic mice expressing a dominant-negative form of WT1 in Sertoli cells, demonstrating the validity of our RNAi approach. Our results indicate that the tumor suppressor WT1 promotes Sertoli cell-germ cell signaling events driving spermatogenesis.
A rapidly filled capillary mount for both dry powder and polycrystalline slurry samples
Authors: Von Dreele R. B.
Published: January 2006

A method of rapid capillary sample loading of either dry powder or polycrystalline slurry has been developed. By embedding a Millipore filter in a Kapton capillary tube, one can then draw either loose dry powder or polycrystalline slurry into the tube and pack the solid against the filter, creating a dense column of powder suitable for a Debye–Scherrer powder diffraction experiment.
Line profile analysis: pattern modellingversusprofile fitting
Authors: Scardi Paolo , Leoni Matteo
Published: January 2006

Powder diffraction data collected on a nanocrystalline ceria sample within a round robin conducted by the IUCr Commission on Powder Diffraction were analysed by two alternative approaches: (i) whole-powder-pattern modelling based upon a fundamental microstructural parameters approach, and (ii) a traditional whole-powder-pattern fitting followed by Williamson–Hall and Warren–Averbach analysis. While the former gives results in close agreement with those of transmission electron microscopy, the latter tends to overestimate the domain size effect, providing size values about 20% smaller. The origin of the discrepancy can be traced back to a substantial inadequacy of profile fitting with Voigt profiles, which leads to systematic errors in the following line profile analysis by traditional methods. However, independently of the model, those systematic errors seem to have little effect on the volume-weighted mean size.
Oriented sols for fiber diffraction from limited quantities or hazardous materials
Authors: Kendall Amy , Stubbs Gerald
Published: January 2006

A method for making oriented sols for fiber diffraction is described. Samples are made by centrifuging dilute solutions of filamentous assemblies in thin-walled glass X-ray capillaries for several days at low speeds. Orientation is improved by exposure to high magnetic fields. The method is demonstrated for tobacco mosaic virus and potato virus X, and shown to produce orientation comparable with that achieved by conventional methods of specimen preparation. The method requires much smaller quantities than conventional methods, and is better suited for use with hazardous materials and labile assemblies.
X-ray diffraction single-crystal structure characterization of iron ludwigite from room temperature to 15 K
Authors: Mir M. , Janczak Jan , Mascarenhas Y. P.
Published: January 2006

Iron ludwigite exhibits a superstructure between 283 and 144 K. Anomalies in its transport properties are due to a structural transition related to a charge-ordering phenomenon in the low-dimensional structure. This ordering produces a commensurate transversal charge density wave in the system. To understand these structural characteristics, an X-ray single-crystal diffraction study has been performed at 300 and 15 K. No changes were found in the crystalline structure, except for contraction of the cell volume. The bond-valence sum for each cation shows that at room temperature each Fe4—Fe2—Fe4 triad is composed of three Fe3+ions with one extra electron per triad, and at 15 K in each Fe4a—Fe2—Fe4btriad the extra electron is accommodated in the Fe4a—Fe2 pair of each triad.
Symmetrization of diffraction peak profiles measured with a high-resolution synchrotron X-ray powder diffractometer
Authors: Ida T. , Hibino H.
Published: January 2006

The asymmetry of diffraction peak profiles observed with a high-resolution synchrotron powder X-ray diffractometer has been successfully removed by a double deconvolution method. In the first step, the asymmetry caused by the axial divergence aberration of the diffractometer is removed by a whole-pattern deconvolution method based on ana prioritheoretical model for the aberration. In the second step, the residual asymmetry, the origin of which can be ascribed to the aberrations of the beamline optics, is also removed by a whole-pattern deconvolution method, based on an empirical model derived from the analysis of experimental diffraction peak profiles of a standard Si powder (NIST SRM640b). The beamline aberration has been modelled by the convolution of a pseudo-Voigt or Voigt function with an exponential distribution function. It has been found that the angular dependence of the asymmetry parameter in the exponential function is almost proportional to tanθ, which supports the idea that the residual asymmetry should be ascribed mainly to the intrinsic asymmetry in the spectroscopic distribution of the source X-ray supplied by the beamline optics of the synchrotron facility. Recently developed procedures of whole-pattern deconvolution have been improved to treat the singularity of the instrumental function in the measured angular range. Formulae for the whole-pattern deconvolution based on the Williamson–Hall-type dependence of the width parameter of the instrumental function have also been developed. The method was applied to the diffraction intensity data of a standard ZnO powder sample (NIST SRM674) measured with a high-resolution powder diffractometer on beamline BL4B2at the Photon Factory. The structure parameters of ZnO were refined from the integrated peak intensities, which were extracted by an individual profile fitting method applying symmetric profile models. The refined structure parameters coincide fairly well with those obtained from single-crystal data.
Automated diffraction image analysis and spot searching for high-throughput crystal screening
Authors: Zhang Zepu , Sauter Nicholas K. , van den Bedem Henry , Snell Gyorgy , Deacon Ashley M.
Published: January 2006

A new software package,DISTL(Diffraction Image Screening Tool and Library), for the rapid analysis of X-ray diffraction patterns collected from macromolecular crystals is presented. Within seconds, the program characterizes the strength and quality of the Bragg spots, determines the limiting resolution of the image, and identifies deleterious features such as ice-rings and intense salt reflections. The procedure also generates a reliable set of intense peaks for auto-indexing. The ability to classify a large number of crystals quickly will be especially useful at synchrotron and home-laboratory X-ray sources where automated crystal screening and data collection systems have been implemented.
Phase imaging using time-of-flight neutron diffraction
Authors: Gutmann M. J. , Kockelmann W. , Chapon L. C. , Radaelli P. G.
Published: January 2006

A technique that allows the spatial distribution of crystallographic phases in the interior of an object to be reconstructed from neutron time-of-flight (TOF) diffraction is described. To this end, the shift of the Bragg peaks due to the so-called `geometrical aberration' is exploited. A collimated incident white beam is used to perform a translational or rotational scan of the object whilst collecting a TOF data set for each sample position or orientation. Depending on the location of any scattering material along the line of the incident beam path through the object, the measuredd-spacings of the corresponding Bragg peaks are shifted with respect to their nominal values, which are attained only at the geometrical centre of the instrument. Using a formula that is usually employed to correct for sample offset, the phase distribution along the incident beamline can be directly reconstructed, without the need to perform a tomographic reconstruction. Results are shown from a demonstration experiment carried out on a cylindrical Al container enclosing an arrangement of Cu and Fe rods. On the basis of this formalism, an optimized experimental geometry is described and the potential and limits of this technique are explored, as are its applicability to X-ray and constant-wavelength neutron diffraction.
Increased laser Doppler flow in skin tumors corresponds to elevated vessel density and reactive hyperemia
Authors: Stücker Markus , Springer Christian , Paech Volker , Hermes Nico , Hoffmann Matthias , Altmeyer Peter
Published: January 2006

Background/purpose: Tumor angiogenesis plays a key role in tumor growth and formation of metastasis. Quantitative analysis of tumor blood flow is a prerequisite for developing novel treatment strategies such as antiangiogenic and antivascular treatment options. Laser Doppler flow in malignant melanomas has been shown to be increased compared with normal skin and melanocytic nevi. This study investigated whether this phenomenon is originated by elevated blood vessel density or by reactive hyperemia.

Methods: Laser Doppler flow was studied in 35 melanocytic nevi, 22 malignant melanomas and three basal cell carcinomas. After excision digital imaging analysis was performed in microtome sections (factor VIII‐associated antigen and CD 31 labelled). The ratio of vessel area in histological sections from tumor tissue and in non‐lesional skin was calculated and related to Doppler flow values.

Results: Malignant melanomas demonstrated an enlargement of vessel cross‐sectional area by factor 3.7±1.9 and of Doppler flow by factor 10.56±10.7, and melanocytic nevi accomplished increase of vessel cross‐sectional area by factor 1.7±0.9 and of Doppler flow by factor 2.7±3.5.

Conclusion: The laser Doppler flow is influenced by the number and the velocity of erythrocytes in the tissue. The greater increase of laser Doppler flow than of vessel density in histological sections demonstrates that the flow signal in skin tumors is caused by neovascularization as well as by functional hyperemia. Laser Doppler perfusion imaging is a useful method for non‐invasive, repeated and quantitative assessment of tumor vascular network and effects of antiangiogenic treatment directed vs. tumor vasculature in vivo, but it cannot distinguish between increased vessel density and reactive hyperemia.
Sensitive skin: correlation with skin surface microrelief appearance
Authors: Sparavigna Adele , Di Pietro Antonino , Setaro Michele
Published: January 2006

Background/purpose: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief.

Methods: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)).

Results: A significant correlation was found between intensity of symptoms in stingers and ISI (rs=−0.47; P<0.001).

Conclusion: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition.
The incidence and pathophysiology of hyponatraemia after subarachnoid haemorrhage
Authors: Sherlock Mark , O'Sullivan Eoin , Agha Amar , Behan Lucy Ann , Rawluk Danny , Brennan Paul , Tormey William , Thompson Christopher J.
Published: January 2006

Background  Hyponatraemia is common following subarachnoid haemorrhage (SAH) but the pathogenesis is unclear.

Objective  To establish the incidence, pathophysiology and consequences of hyponatraemia following SAH.

Methods  A retrospective case‐note analysis of all patients with SAH admitted to Beaumont Hospital between January 2002 and September 2003. Three hundred and sixteen cases of SAH were substantiated by computed tomography (CT) scan and angiogram findings. Hyponatraemia was defined as plasma sodium < 135 mmol/l.

Results  One hundred and seventy‐nine patients (56·6%) developed hyponatraemia and 62 (19·6%) developed significant hyponatraemia (plasma sodium < 130 mmol/l). The incidence of severe hyponatraemia following hypophysectomy was lower in the period of analysis (5/81, 6·2%, P < 0·01). Hyponatraemia was more common in patients with identified aneurysms (anterior circulation 102/168, 60·7%, posterior circulation 56/95, 60·8%) than in those with no radiological aneurysm (21/54, 38·8%, P < 0·001). Hyponatraemia was more common after aneurysmal clipping (68/103, 66%) or coiling (82/132, 62%) than after conservative treatment (29/81, 36%, P < 0·001). The aetiology of significant hyponatraemia was the syndrome of inappropriate antidiuretic hormone secretion (SIADH) 39/62 (69·2%), cerebral salt‐wasting syndrome (CSWS) 4/62 (6·5%), hypovolaemic hyponatraemia 13/62 (21%), hypervolaemic hyponatraemia 3/62 (4·8%) and mixed CSW/SIADH 3/62 (4·8%). Hyponatraemia was associated with longer hospital stay (24·0 ± 2·6 vs. 11·8 ± 0·8 days, P < 0·001) but did not affect mortality (P = 0·07). Hyponatraemia developed more than 7 days following SAH in 21·4% and more then 7 days following intervention in 31·8%.

Conclusions  Hyponatraemia is common following SAH and is associated with longer hospital stay. Clipping and coiling of aneurysms are associated with higher rates of hyponatraemia. SIADH is the commonest cause of hyponatraemia after SAH. Delayed hyponatraemia is common, and has implications for early discharge strategies.
Pond canopy cover: a resource gradient for anuran larvae
Authors: SCHIESARI LUIS
Published: January 2006

1. The gradient in pond canopy cover strongly influences freshwater species distributions. This study tested the effects of canopy cover on the performance of two species of larval anurans, a canopy cover generalist (Rana sylvatica, the wood frog) and an open‐canopy specialist (R. pipiens, the leopard frog), and tested which factors co‐varying with canopy cover mediate these effects.

2. A field transplant experiment demonstrated that canopy cover had negative performance effects on both species. However, leopard frogs, which grow faster than wood frogs in open‐canopy ponds, were more strongly affected by closed‐canopy pond conditions.

3. Closed‐canopy ponds had lower temperature, dissolved oxygen (DO), and food nutritional quality as indicated by carbon‐to‐nitrogen ratio (C : N) analysis of field‐sampled food types, and of gut contents of transplanted larvae.

4. Laboratory experiments demonstrated that higher temperature and food quality but not DO substantially increased larval growth. However, only food quality increased growth rates of leopard frogs more than wood frogs.

5. The strong correlation of growth rates to gut content C : N in the field, and the similarity of growth curves as a function of resource quality in the field and laboratory, strongly suggest that resources are of primary importance in mediating intraspecific, and especially interspecific differences in performance across the canopy cover gradient.
Changing habitat associations of a thermally constrained species, the silver‐spotted skipper butterfly, in response to climate warming
Authors: DAVIES ZOE G. , WILSON ROBERT J. , COLES SOPHIE , THOMAS CHRIS D.
Published: January 2006

The impact of climate change on the distribution, abundance, phenology and ecophysiology of species is already well documented, whereas the influence of climate change on habitat choice and utilization has received little attention. Here we report the changing habitat associations of a thermally constrained grassland butterfly, Hesperia comma, over 20 years.

Between 1982 and 2001–2, the optimum percentage of bare ground within habitat used for egg‐laying shifted from 41% to 21%.

Egg‐laying rates are temperature‐dependent and females actively adjust microhabitat usage in response to temperature variations; relatively warmer host plants are chosen or oviposition at low ambient temperatures, and cooler host plants at high ambient temperatures.

Climate warming has increased the availability of thermally suitable habitat for H. comma at the cool, northern edge of the species’ distribution, therefore increasing: (a) egg‐laying rate and potentially the realized rate of population increase; (b) effective area of habitat patches as more microhabitats within a given vegetation fragment are now suitable for egg‐laying; (c) buffering of populations against environmental variation as eggs are laid within a wider range of microhabitats; and (d) the number of habitat patches in the landscape that are currently available for colonization (including the use of more northerly facing aspects; Thomas et al., Nature, 2001, 411, 577–581).

Conservationists often assume the habitat requirements of a species to be constant, and manage habitats to maintain these conditions. For many species, these requirements are likely to change in response to climate warming, and care must be taken not to manage habitats based on outdated prescriptions.
The relationship between pollen and extant vegetation across an arid urban ecosystem and surrounding desert in Southwest USA
Authors: Stuart Glenn , Gries Corinna , Hope Diane
Published: January 2006

Aim  In this paper, we explore the relationship between pollen concentration in surface soil and extant perennial vegetation across a rapidly urbanizing arid ecosystem along with its surrounding agricultural and native Sonoran Desert land. We also investigate whether taxa behave as expected from known pollination characteristics (e.g. anemophilous vs. zoophilous) and whether the pollen–plant relationship differs between the undeveloped desert and agro‐urban regions.

Location  We used a probability‐based sampling scheme at 200, 900‐m2 sites across the Central Arizona–Phoenix region, a 6400‐km2 area of the south‐western USA.

Methods  Pollen–plant abundances were mapped across the study area using interpolation techniques, summary bar charts and scatterplots, then two statistical approaches were applied to examine the data quantitatively. Firstly, we used regression analysis of paired pollen concentration and plant cover data; secondly, pc‐ord was used on a cross‐matrix (contingency table) containing the presence/absence scores of both pollen and plants for each taxon at each site.

Results  Mapping and quantitative analysis revealed that pollen–plant relationships do vary both between anemophilous and zoophilous groupings and by individual taxon. They also revealed that distribution patterns of both pollen and plant abundance vary consistently across the three main landscape types (desert, urban, agricultural) and that pollen taxa groupings are consistent with pollination method and source plant distribution regardless of landscape type.

Main conclusions  These findings provide a broad range of comparative data to facilitate palynological reconstruction of past vegetation and aid in assessing types of prehistoric impacts on this vegetation. They also document that significant variation can occur in pollen rain across a city, even for taxa with widely distributed pollen, leading to the conclusion that forecasting pollen distribution patterns for allergy‐related pollen types using only one or a few pollen traps is likely to entail substantial error.
Chromosome healing by de novo telomere addition in Saccharomyces cerevisiae
Authors: Pennaneach Vincent , Putnam Christopher D. , Kolodner Richard D.
Published: January 2006

The repair of spontaneous or induced DNA damage by homologous recombination (HR) in Saccharomyces cerevisiae will suppress chromosome rearrangements. Alternative chromosome healing pathways can result in chromosomal instability. One of these pathways is de novo telomere addition where the end of a broken chromosome is stabilized by telomerase‐dependent addition of telomeres at non‐telomeric sites. De novo telomere addition requires the recruitment of telomerase to chromosomal targets. Subsequently, annealing of the telomerase reverse transcriptase RNA‐template (guide RNA) at short regions of homology is followed by extension of the nascent 3′‐end of the broken chromosome to copy a short region of the telomerase guide RNA; multiple cycles of this process yield the new telomere. Proteins including Pif1 helicase, the single‐stranded DNA‐binding protein Cdc13 and the Ku heterocomplex are known to participate in native telomere functions and also regulate the de novo telomere addition reaction. Studies of the sequences added at de novo telomeres have lead to a detailed description of the annealing–extension–dissociation cycles that copy the telomerase guide RNA, which can explain the heterogeneity of telomeric repeats at de novo and native telomeres in S. cerevisiae.
Hfq‐dependent alterations of the transcriptome profile and effects on quorum sensing in Pseudomonas aeruginosa
Authors: Sonnleitner Elisabeth , Schuster Martin , Sorger‐Domenigg Theresa , Greenberg Everett Peter , Bläsi Udo
Published: January 2006

The Pseudomonas aeruginosa quorum‐sensing (QS) systems, Las and Rhl, control the production of several virulence factors and other proteins, which are important to sustain adverse conditions. A comparative transcriptome analysis of a rpoS – and a rpoS–hfq – strain indicated that the Sm‐like RNA‐binding protein Hfq affects approximately 5% of the P. aeruginosa O1 transcripts. Among these transcripts 72 were identified to be QS regulated. Expression studies revealed that Hfq does not control the master regulators of the Las system, LasR and LasI. Upon entry into stationary phase, Hfq exerted a moderate stimulatory effect on translation of the rhlR gene and on the qscR gene, encoding a LasR/RhlR homologue. However, Hfq considerably stimulated translation of the rhlI gene, encoding the synthetase of the autoinducer N‐Butyryl‐homoserine lactone (C4‐HSL). Correspondingly, the C4‐HSL levels were reduced in a hfq– strain. To elucidate the stimulatory effect of Hfq on rhlI expression we asked whether Hfq affects the stability of the regulatory RNAs RsmY and RsmZ, which have been implicated in sequestration of the translational repressor RsmA, which in turn is known to negatively regulate RhlI synthesis. We demonstrate that Hfq binds to and stabilizes the regulatory RNA RsmY, which is further shown to bind to the regulatory protein RsmA. A model for the Hfq regulatory network is presented, wherein an alleviation of the negative effect of RsmA accounts for the observed stimulation of rhlI expression by Hfq. The model is corroborated by the observation that a rsmY– mutant mimics the hfq – phenotype with regard to rhlI expression.
The role of proton motive force in expression of the Staphylococcus aureus cid and lrg operons
Authors: Patton Toni G. , Yang Soo‐Jin , Bayles Kenneth W.
Published: January 2006

The Staphylococcus aureus cidABC and lrgAB operons have been shown to play a key role in the regulation of murein hydrolase activity and cell death in a manner thought to be analogous to bacteriophage‐encoded holins and anti‐holins respectively. Because of these functions, it has been proposed that the regulation of these operons is tightly controlled and responsive to key metabolic signals. The current study revealed the presence of two overlapping regulatory pathways controlling cidABC and lrgAB expression, one dependent on acetic acid and the other dependent on proton motive force (PMF). The latter pathway was analysed using agents that affect various aspects of the PMF. Gramicidin and carbonyl cyanide m‐chlorophenylhydrazone (CCCP), antimicrobial agents that dissipate the ΔpH and membrane potential (ΔΨ), both enhanced lrgAB expression. Restoration of the PMF by incubation of the bacteria in the presence of glucose restored lrgAB expression back to the uninduced state. In addition, valinomycin, which specifically collapses the ΔΨ, also induced lrgAB expression. In contrast, nigericin, which dissipates the ΔpH component of the PMF, was found to have a minimal effect on ΔΨ and lrgAB transcription. Finally, the ΔΨ‐inducible expression of lrgAB was shown to be dependent on the previously characterized LytSR two‐component regulatory system that is involved in the regulation of autolysis. The results of this study support a model in which the LytSR regulatory system responds to a collapse in ΔΨ by inducing the transcription of the lrgAB operon.
Identification of a megaplasmid centromere reveals genetic structural diversity within the repABC family of basic replicons
Authors: MacLellan Shawn R. , Zaheer Rahat , Sartor Andrea L. , MacLean Allyson M. , Finan Turlough M.
Published: January 2006

The basic replication unit of many plasmids and second chromosomes in the alpha‐proteobacteria consists of a repABC locus that encodes the trans‐ and cis‐acting components required for both semiautonomous replication and replicon maintenance in a cell population. In terms of physical genetic organization and at the nucleotide sequence level, repABC loci are well conserved across various genera. As with all repABC‐type replicons that have been genetically characterized, the 1.4 Mb pSymA and 1.7 Mb pSymB megaplasmids from the plant endosymbiont Sinorhizobium meliloti encode strong incompatibility (inc) determinants. We have identified a novel inc sequence upstream of the repA2 gene in pSymA that is not present on pSymB and not reported in other repABC plasmids that have been characterized. This region, in concert with the repA and repB genes, stabilizes a test plasmid indicating that it constitutes a partitioning (par) system for the megaplasmid. Purified RepB binds to this sequence and binding may be enhanced by RepA. We have isolated 19 point mutations that eliminate incompatibility, reduce RepB binding or the stabilization phenotype associated with this sequence and all of these map to a 16‐nucleotide palindromic sequence centred 330 bp upstream of the repA2 gene. An additional five near‐perfect repeats of this palindrome are located further upstream of the repA2 gene and we show that they share some conservation with known RepB binding sites in different locations on other repABC plasmids and to two sequences found on the tumour inducing plasmid of Agrobacterium tumefaciens. These additional palindromes also bind RepB but one of them does not display obvious incompatibility effects. A heterogenic distribution of par sequences demonstrates unexpected diversity in the structural genetic organization of repABC loci, despite their obvious levels of similarity.
Visceral sensation and colitis: inflammation and hypersensitivity do not always go hand in hand
Authors: Sharkey K. A.
Published: January 2006

Abstract  Visceral sensitivity and inflammation are discussed in relation to novel observations in the current issue of the Journal by Larsson and her colleagues. This paper shows that neither acute nor chronic intestinal inflammation initiated by dextran sodium sulfate is associated with an increase in visceral sensitivity to balloon distension in mice. These findings are discussed in the context of recent work highlighting the role of mast cells, the induction of endogenous antinociceptive pathways and the role of altered bacterial flora in visceral hypersensitivity.
Ghrelin does not stimulate gastrointestinal motility and gastric emptying: an experimental study of conscious dogs
Authors: Ohno T. , Kamiyama Y. , Aihara R. , Nakabayashi T. , Mochiki E. , Asao T. , Kuwano H.
Published: January 2006

Abstract  Ghrelin is a peptide that was discovered in endocrine cells of the stomach. However, its action in regulating the fasted and fed motor activity of the digestive tract is not fully understood. In the present study, we examined the effects of an intravenous (i.v.) injection of canine ghrelin on the physiological fasted and fed motor activities in the stomach, duodenum, jejunum and colon of freely moving conscious dogs. An i.v. injection of canine ghrelin released growth hormone in a dose‐dependent manner; however, it did not stimulate the motor activity of the digestive tract in either the fasted or the fed state. Moreover, an i.v. injection of high‐dose canine ghrelin significantly reduced the motility index in the gastric body in the fasted state. Ghrelin did not accelerate gastric emptying, either. These results differ from previous reports dealing with rodents. It is significant that such results were obtained in research with dogs, which are larger animals.
The Northern Ireland Phytophthora infestans population 1998–2002 characterized by genotypic and phenotypic markers
Authors: Cooke L. R. , Carlisle D. J. , Donaghy C. , Quinn M. , Perez F. M. , Deahl K. L.
Published: January 2006

A total of 204 isolates of Phytophthora infestans from Northern Ireland, almost all from commercial potato crops, were collected over 5 years (1998–2002). Phenotypic diversity was assessed using mating type and metalaxyl resistance; genotypic diversity was assessed using two allozyme loci (glucose‐6‐phosphate isomerase, Gpi, and peptidase, Pep), mitochondrial DNA haplotype and the multilocus RFLP probe RG57. All isolates were A1 mating type and Gpi 100/100. The majority were Pep 100/100, but four Pep 83/100 and six Pep 96/100 isolates were identified. Three mtDNA haplotypes were detected; haplotype IIa was the most common, but each year up to 2001 its frequency declined, with a concomitant increase in Ia isolates. Three isolates had the rare haplotype IIb, but this was only detected in 1998. Metalaxyl resistance and mtDNA haplotype were markedly associated: most haplotype Ia isolates were metalaxyl‐resistant, whereas haplotype IIa was more commonly associated with metalaxyl sensitivity. Analysis of a subsample of 91 isolates revealed nine RG57 genotypes, three associated exclusively with haplotype IIa and six exclusively with haplotype Ia. The most common RG57 genotype (51% of isolates) comprised both metalaxyl‐resistant and ‐sensitive haplotype IIa isolates. However, of haplotype Ia isolates, all metalaxyl‐resistant phenotypes belonged to one of four RG57 types, one of which was the second most frequent overall (29% of isolates), while all metalaxyl‐sensitive isolates belonged to one of two other types. The P. infestans population in Northern Ireland appears to consist of a limited number of clones related to, but differentiated from, the populations in mainland Britain and elsewhere in Europe.
Trichothecenes and aggressiveness of Fusarium graminearum causing seedling blight and root rot in cereals
Authors: Wang H. , Hwang S. F. , Eudes F. , Chang K. F. , Howard R. J. , Turnbull G. D.
Published: January 2006

Greenhouse trials conducted in 2003 and 2004 investigated the impact of trichothecenes on the severity of seedling blight and root rot in common wheat (Triticum aestivum), durum wheat (Triticum turgidum var. durum), barley (Hordeum vulgare) and triticale (×Triticosecale 6x) using two trichothecene‐producing and two trichothecene‐nonproducing Fusarium graminearum strains. In 2003 seedling emergence and survival following soil infestation of the trichothecene‐producing strain (Gz3639) were significantly reduced compared with the trichothecene‐nonproducing strain (GzT40), while root‐rot incidence and severity were increased significantly. In 2004, two trichothecene‐producing strains (Gz3639 and GzT106) reduced seedling emergence and survival (P ≤ 0·01) in eight of 10 crops/cultivars based on single‐degree‐of‐freedom contrasts. However, when results from all strains were combined no significant differences were observed between two trichothecene‐producing and two trichothecene‐nonproducing F. graminearum strains. Inoculation with GzT106, a trichothecene‐producing ‘add‐back’ strain, resulted in more severe root rot symptoms in eight of 10 cultivars (P ≤ 0·01–0·05) and lower seedling emergence and survival in seven of 10 cultivars (P ≤ 0·01–0·10), compared with the wild‐type parental strain Gz3639. The presence of trichothecenes may play an important role in the aggressiveness of F. graminearum.
Occurrence of yellowing viruses (Beet pseudo‐yellows virus, Cucurbit yellow stunting disorder virus and Cucurbit aphid‐borne yellows virus) affecting cucurbits in Greece
Authors: Boubourakas I. N. , Avgelis A. D. , Kyriakopoulou P. E. , Katis N. I.
Published: January 2006

A survey of the incidence of yellowing viruses in Greek glasshouse (and occasional field) cucumber and melon crops was carried out during 2000–03. In most cases disease incidence ranged from 50 to 80%. Simplex RT‐PCR was used for the detection of Beet pseudo‐yellows virus (BPYV) and Cucurbit yellow stunting disorder virus (CYSDV), and DAS‐ELISA for the detection of Cucurbit aphid‐borne yellows virus (CABYV). The results showed that BPYV was the predominant virus in cucumber and melon crops, whereas CYSDV, reported for first time in Greece, was isolated only in three regions of southern Greece: Rhodes, Crete and Arkadia. CABYV was detected only in three cucumber glasshouses in Pella (Macedonia). A simplified triplex RT‐PCR method using a simple sample‐preparation protocol was developed to allow rapid, sensitive and simultaneous detection of the three viruses. Sequence comparisons of the PCR products of BPYV and CYSDV revealed 98·7 and 100% amino acid identity, respectively, with previously reported sequences. The arable weed species Amaranthus retroflexus, Selosia cristata, Sonchus oleraceus and Sonchus sp. were identified as potential BPYV reservoirs.
Isolation and characterization of nonpathogenic Fusarium oxysporum isolates from the rhizosphere of healthy banana plants
Authors: Nel B. , Steinberg C. , Labuschagne N. , Viljoen A.
Published: January 2006

One of the most serious diseases of banana is fusarium wilt, caused by Fusarium oxysporum f.sp. cubense (Foc). The objectives of this study were to isolate and identify nonpathogenic F. oxysporum strains from soils suppressive to banana wilt, and to determine the diversity of these isolates. More than 100 Fusarium strains were isolated from the rhizosphere of banana plants and identified to species level. Pathogenicity testing was carried out to confirm that these isolates were nonpathogens of banana. A PCR‐based RFLP analysis of the intergenic spacer region of the ribosomal RNA operon was used to characterize the nonpathogens. The isolates were also compared with isolates of Foc from South Africa and the known biological control isolate of F. oxysporum, Fo47. The species‐specific primers FOF1 and FOR1, in addition to morphological features, were used to confirm the identity of F. oxysporum isolates included in the PCR‐RFLP analysis. Twelve different genotypes could be distinguished, identified by a six‐letter code allocated to each isolate following digestion with the restriction enzymes HaeIII, HhaI, HinfI, MspI, RsaI and ScrfI. Eleven of these included nonpathogenic F. oxysporum isolates, and these groups could all be distinguished from the genotype that included Foc. Fo47 was included in one of the genotype groups consisting of nonpathogenic F. oxysporum isolates from South Africa.
Predicting the risk of weed infestation in winter oilseed rape crops
Authors: PRIMOT S , VALANTIN‐MORISON M , MAKOWSKI D
Published: January 2006

Chemical weed control before crop and weed emergence is a systematic practice in winter oilseed rape crops in France. It would be profitable both for farmers and the environment to predict the level of weed infestation early on in the growing season and to control weeds only when necessary using post‐emergence weed control. The objective of this paper was to develop and evaluate simple models to predict weed biomass in oilseed rape crops. The model input variables were related to weed population characteristics and farmers’ practices. The models can be used to classify oilseed rape plots into two categories: plots with a level of weed infestation above a threshold or those with level of weed infestation below a threshold. A data set including 3 years of experiments, conducted across several regions in France, was used to estimate the parameters and to evaluate the models. High values of sensitivity and specificity were obtained when weed biomass was predicted as a function of sowing date, type of soil tillage, soil mineral nitrogen, crop density, weed density at emergence, and main characteristics of the most abundant weed species. Model performance strongly decreased when input variables related to the weed population were not taken into account. The best models correctly classified 90% of the plots with high weed infestation and 64% of the plots with low weed infestation.
Seroprevalence of HHV‐8 infection in the pediatric population of two university hospitals in Rio de Janeiro, Brazil
Authors: Avelleira João Carlos Regazzi , Lupi Omar , Caterino‐de‐Araujo Adele , Santos‐Fortuna Elizabeth de los
Published: January 2006

Background  The authors present a serologic survey of the prevalence of herpesvirus‐8 (HHV‐8) among 171 children from 0 to 12 years old in Rio de Janeiro, Brazil.

Materials and methods  Sera were tested for latent nuclear and lytic antigens using indirect immunofluorescence and Western blotting.

Results  Serology for HHV‐8 was positive in 16 of 171 patients (9.35%). Among 13 HIV‐positive patients, four (31%) were also positive for HHV‐8. The seropositivity among healthy children was 7.6%, and females were significantly (P < 0.002) more associated with HHV‐8 seropositivity (16%) than males (1.1%).

Conclusions  We detected a higher HHV‐8 seroprevalence among the pediatric population in Rio de Janeiro, Brazil, when compared with similar studies performed in other countries. Nonsexual routes of transmission are a possible explanation for this pattern. The unusual finding of a higher seroprevalence among female children could be explained by a specific route of exposition or even an epidemiological bias.
Polymorphic eruption of pregnancy
Authors: Petropoulou Haritini , Georgala Sofia , Katsambas Andreas D.
Published: January 2006

Polymorphic eruption of pregnancy (PEP) is a benign, self‐limiting, pruritic disorder of pregnancy, which usually affects the primigravida during the last trimester or immediately postpartum. Its pathogenesis is unclear and its clinical manifestations are variable, leading frequently to an incorrect diagnosis. In cases of PEP the histological findings are nonspecific and the laboratory results, including direct immunofluorescence (DIF) and indirect immunofluorescence (IIF), are negative. Polymorphic eruption of pregnancy is not associated with any fetal risk and symptomatic treatment is all that is usually required.

In this review we present the clinical presentation of PEP and a differential diagnosis which defines PEP as a separate entity. We will also review all current data of possible etiologic factors, histologic and immunologic findings, prognosis and therapy.
Treatment of diffuse cutaneous leishmaniasis with miltefosine: a case report
Authors: Zerpa Olga , Blanco Belkys , Kannee Carmen , Ulrich Marian , Sindermann Herbert , Engel Juergen , Convit Jacinto
Published: January 2006

Background  A 31‐year‐old man who has suffered since age 3 from diffuse cutaneous leishmaniasis (DCL), a disease with profound physical and psychosocial repercussions and no effective treatment at present, was treated with miltefosine.

Methods  The patient was treated for 120 days, 100 mg/day for 1 week, then 150 mg/day subsequently.

Results  Lesions were free of parasites at 43 days, and no signs of infiltration were present at day 76. No adverse side effects were observed.

Conclusions  The dramatic clinical effect of miltefosine in this patient appears to fully justify further evaluation of this experimental therapy in DCL.
Healing effect of Pilocarpine gel 4% on skin lesions of pemphigus vulgaris
Authors: Iraji Fariba , Yoosefi AliReza
Published: January 2006

Background  The high rate of morbidity and mortality resulting from long‐term use of corticosteroids in pemphigus vulgaris (PV) warrants discovery of a new treatment strategy. Based on a new theory on the pathophysiology of PV, cholinomimetics can block the process of blister formation.

Aims  This study was conducted to evaluate the clinical effectiveness of Pilocarpine gel in the treatment of skin lesions of PV.

Methods  In a double‐blind, placebo‐controlled study, three PV patients with a total of 64 skin lesions were treated by either Pilocarpine or placebo gel. After 15 days of treatment an epithelialization index of the two groups was compared.

Results  The mean of the epithelialization index in skin lesions that received Pilocarpine was significantly higher than that of the placebo group (40.3 ± 1.7 vs. 24.4 ± 3.3, P < 0.001).

Conclusions  Pilocarpine gel effectively treats PV.
Impaired synaptic plasticity in a rat model of tuberous sclerosis
Authors: Von Der Brelie Christian , Waltereit Robert , Zhang Lian , Beck Heinz , Kirschstein Timo
Published: January 2006

Tuberous sclerosis complex (TSC) is a common hereditary disorder caused by mutations in either the TSC1 or TSC2 genes, and characterized by severe epilepsy, cerebral hamartomas and mental retardation. We have used rats that are heterozygous for an autosomal‐dominant germline mutation in the TSC2 gene (TSC2+/– rats) to examine the consequences of TSC2 mutations for hippocampal synaptic plasticity. While basal synaptic transmission in the Schaffer collateral–CA1 synapse was not altered, paired‐pulse plasticity was significantly enhanced in TSC2+/– rats (interpulse intervals 20–200 ms). Moreover, TSC2+/– rats exhibited a marked reduction of different forms of synaptic plasticity. Long‐term potentiation (LTP) elicited following high‐frequency tetanization of Schaffer collaterals was significantly decreased from 1.45 ± 0.05‐fold potentiation to 1.15 ± 0.04 (measured after 60 min). This difference in LTP levels between TSC2+/– and wild‐type rats also persisted in the presence of the γ‐aminobutyric acid (GABA)A receptor antagonist bicuculline. In addition to changed LTP, the level of long‐term depression (LTD) elicited by different forms of low‐frequency stimulation was significantly less in TSC2+/– rats. These results suggest that TSC2 mutations may cause hippocampal synapses to lose much of their potential for activity‐dependent synaptic modification. An understanding of the underlying molecular pathways may suggest new therapeutic approaches aimed at inhibiting the development of the profound mental retardation in TSC.
The increased rate of prostate specific antigen testing has not affected prostate cancer presentation in an inner city population in the UK
Authors: MOKETE MOEKETSI , SHACKLEY DAVID C. , BETTS CHRISTOPHER D. , O'FLYNN KIERAN J. , CLARKE NOEL W.
Published: January 2006

OBJECTIVE

To assess whether the increased use of prostate‐specific antigen (PSA) testing over the last 15 years has changed the way prostate cancer presents in an inner city UK population, where PSA screening rates might be expected to be lower than in epidemiological studies based in North America, where there is a significant tendency to a localized stage and earlier age at diagnosis.

PATIENTS AND METHODS

The study comprised a 5‐year retrospective and 5‐year prospective analysis of data on 704 men diagnosed with prostate cancer over the 10‐year period since the introduction of PSA testing (1994–2003).

RESULTS

The median (range) age at presentation remained unchanged, at 72 (45–94) years; the PSA level at diagnosis was 20–46 µg/L, with a steady decline after 1997. There was no significant change in stage at diagnosis; overall, 38 (20–44)% presented with clinically localized disease, 37 (31–48)% with locally advanced and 25 (18–29)% with metastatic disease. The Gleason grade changed significantly, with more moderately differentiated tumours and a decline in well‐differentiated cancers. Closer examination showed this to have been due to a change in diagnostic practice rather than a true population trend. PSA testing increased over the 10 years of the study (2.35 times), with requests from general practitioners rising seven times, compared with urologists or other hospital doctors (1.25 and 2.3 times, respectively). Community PSA testing remained lower than in other reported UK series, which may be explained in part by the lower socio‐economic status of the population assessed.

CONCLUSION

There was no apparent change in patient age or tumour stage in men presenting with prostate cancer over a 10‐year period after the introduction of PSA testing. While there was an increase in PSA testing during the study period, the testing rate remains much lower than in other reported series from the UK.