bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clonal analysis reveals high rate of structural mutations in fimbrial adhesins of extraintestinal pathogenic Escherichia coli
Authors: Weissman Scott J. , Chattopadhyay Sujay , Aprikian Pavel , Obata‐Yasuoka Mana , Yarova‐Yarovaya Yuliya , Stapleton Ann , Ba‐Thein William , Dykhuizen Daniel , Johnson James R. , Sokurenko Evgeni V. 
Published: November 2005

SummaryType 1 fimbriae of Escherichia coli mediate mannose‐specific adhesion to host epithelial surfaces and consist of a major, antigenically variable pilin subunit, FimA, and a minor, structurally conserved adhesive subunit, FimH, located on the fimbrial tip. We have analysed the variability of fimA and fimH in strains of vaginal and other origin that belong to one of the most prominent clonal groups of extraintestinal pathogenic E. coli, comprised of O1:K1‐, O2:K1‐ and O18:K1‐based serotypes. Multiple locus sequence typing (MLST) of this group revealed that the strains have identical (at all but one nucleotide position) eight housekeeping loci around the genome and belong to the ST95 complex defined by the publicly available E. coli MLST database. Multiple highly diverse fimA alleles have been introduced into the ST95 clonal complex via horizontal transfer, at a frequency comparable to that of genes defining the major O‐ and H‐antigens. However, no further significant FimA diversification has occurred via point mutation after the transfers. In contrast, while fimH alleles also move horizontally (along with the fimA loci), they acquire point amino acid replacements at a higher rate than either housekeeping genes or fimA. These FimH mutations enhance binding to monomannose receptors and bacterial tropism for human vaginal epithelium. A similar pattern of rapid within‐clonal structural evolution of the adhesive, but not pilin, subunit is also seen, respectively, in papG and papA alleles of the di‐galactose‐specific P‐fimbriae. Thus, while structurally diverse pilin subunits of E. coli fimbriae are under selective pressure for frequent horizontal transfer between clones, the adhesive subunits of extraintestinal E. coli are under strong positive selection (Dn/Ds > 1 for fimH and papG) for functionally adaptive amino acid replacements.
Phosphorylation and functional analysis of the sporulation initiation factor Spo0A from Clostridium botulinum
Authors: Wörner Kristina , Szurmant Hendrik , Chiang Christina , Hoch James A. 
Published: November 2005

SummaryThe initiation of sporulation in aerobic Bacillus species is regulated by the phosphorelay consisting of several sensor histidine kinases, the Spo0F response regulator, the Spo0B phosphotransferase and the Spo0A transcription factor that upon phosphorylation represses genes for growth and activates the developmental process. Clostridium species lack both Spo0F and Spo0B and the identities of the sensor histidine kinases are unknown. The amino acid sequence of Spo0A is highly conserved in Clostridium botulinum relative to Bacillus subtilis but the cloned C. botulinum Spo0A was unable to complement a spo0A mutant of B. subtilis for sporulation. However, it was able to repress the abrB gene of B. subtilis. Active site mutations in Spo0A still repressed, indicating this activity was independent of phosphorylation. An orphan sensor histidine kinase of C. botulinum appeared to normally phosphorylate C. botulinum Spo0A and expression of this kinase in combination with C. botulinum Spo0A in B. subtilis was lethal, suggesting phosphorylation of C. botulinum Spo0A repressed essential growth genes as a prerequisite to sporulation but could not compensate for this effect by inducing sporulation. A chimera Spo0A consisting of a B. subtilis Spo0A response regulator domain fused to a C. botulinum DNA‐binding domain was capable of restoring sporulation to a spo0A mutant of B. subtilis albeit at less than wild‐type levels. The data suggest that induction of sporulation requires interactions of both domains of Spo0A with other conserved proteins and despite the high conservation of the amino acid sequence of C. botulinum Spo0A, some of these interactions have been lost.
Metabolic regulation of type III secretion gene expression in Pseudomonas aeruginosa
Authors: Rietsch Arne , Mekalanos John J. 
Published: November 2005

SummaryType III secretion‐mediated cytotoxicity is one of the key virulence mechanisms of the opportunistic pathogen Pseudomonas aeruginosa. Prior data from several laboratories have established that metabolism is a key factor in the regulation of type III secretion gene expression in P. aeruginosa. Here we use a fluorescence‐activated cell sorter (FACS)‐based approach to investigate expression of type III secretion genes at a single‐cell level. The data demonstrate that the metabolic state regulates the percentage of cells that are able to induce type III secretion gene expression under inducing conditions. We also present evidence that this regulation is the result of an effect of the growth conditions on the ability of P. aeruginosa to assemble a functional type III secretion apparatus. Preliminary data suggest that the metabolite that controls type III secretion gene expression is derived from acetyl‐CoA and that this regulation may, in part, be mediated by changes in the intracellular concentration of cyclic‐AMP.
Synthesis of α‐glucans in fission yeast spores is carried out by three α‐glucan synthase paralogues, Mok12p, Mok13p and Mok14p
Authors: García Ignacio , Tajadura Virginia , Martín Victoria , Toda Takashi , Sánchez Yolanda 
Published: November 2005

SummaryFission yeast possesses a family of (1,3)‐α‐glucan synthase‐related genes; one of them, mok1+/ags1+, plays an essential function in morphogenesis during vegetative growth. Here we show that three mok1+ paralogues –mok12+, mok13+ and mok14+– are required for sporulation to succeed, acting at different stages of the spore wall maturation process. Mutation of mok12+ affected the efficiency of spore formation and spore viability. Deletion of mok13+ does not affect spore viability but the spores showed reduced resistance to stress conditions. mok14Δ mutant spores failed to accumulate the amylose‐like spore wall‐specific polymer. mok12+, mok13+ and mok14+ expression was restricted to sporulating cells and the proteins localized to the spore envelope but with different timing. mok11+ was also induced during the sporulation process although its deletion did not show apparently a sporulation defect. In vegetative cells, β‐glucans are more abundant than α‐glucans (55% versus 28%). In spores, the situation was the opposite, α‐glucans accounted for 46% while β‐glucans were approximately 38% of the total polysaccharides. We found at least two types of α‐glucan polymers, Mok12p and Mok13p, were involved in the synthesis of the greater part of α‐glucan in the spores envelope, a polymer that is mainly digested with α‐1,3 glucanase, while Mok14p, homologous to starch synthases, was required for the synthesis of the iodine‐reactive polymer that is made of α‐1,4 glucose residues.
Linkage of dermatomyositis in the Shetland Sheepdog to chromosome 35
Authors: CLARK LEIGH ANNE , CREDILLE KELLY M. , MURPHY KEITH E. , REES CHRISTINE A. 
Published: November 2005

Abstract  Dermatomyositis is an inflammatory disease of the skin and muscle and is most commonly found in the Shetland sheepdog. Both the clinical presentation and the age of onset of dermatomyositis vary widely, and the inability to diagnose dermatomyositis before clinical symptoms ensue has made control of the disease difficult. Identification of a genetic marker that cosegregates with dermatomyositis would facilitate the development of a DNA‐based test for the early detection of affected dogs. We report the use of linkage disequilibrium (LD) mapping to identify linkage to phenotypic dermatomyositis in the Shetland sheepdog. One marker, microsatellite marker FH3570 on canine chromosome 35, had evidence of LD (P = 0.00002). Further studies are necessary to narrow the region harbouring the dermatomyositis locus, identify candidate genes and determine mode of inheritance.
Clinical, immunological and histopathological findings in a subpopulation of dogs with pododermatitis
Authors: BREATHNACH RORY M. , BAKER KENNETH P. , QUINN PATRICK J , MCGEADY THOMAS A. , AHERNE CAROL M. , JONES BOYD R. 
Published: November 2005

Abstract  Clinical, immunological and histopathological findings in 20 adult dogs of varying breeds with chronic (≥ 6 months) inflammation confined to the pedal skin were compared over a 2‐year period with those of a group of age‐matched controls (n = 20). All affected dogs were pruritic but systemically well. Lesions were present on all four feet in 18/20 cases. Affected feet were characteristically erythematous, swollen, painful and alopecic. Sinus tracts were evident in 4/20 dogs. Despite a methodical series of diagnostic tests, no underlying cause was identified. None of the dogs responded to antimicrobial therapy administered for 8 weeks, none had evidence of ectoparasitism and none satisfied the criteria for atopic dermatitis. There was no response to a dietary trial using a novel protein source. The condition was characterized histopathologically by epidermal hyperplasia, hyperkeratosis, spongiosis, dermal oedema and perivascular aggregates of lymphocytes and plasma cells. Clinical signs did not correlate with histopathological findings. Affected dogs had significantly elevated serum IgG and IgM concentrations. The results of lymphocyte proliferation assays and phenotypic studies to determine the relative percentage of CD3+, CD4+, CD8+ and CD21+ lymphocyte subsets, and the ratio of CD4+/CD8+ cells were not significantly different between groups. No age, sex or seasonal predilections were noted. All dogs subsequently responded to immunosuppressive doses of prednisolone or cyclosporin. The term immunomodulatory‐responsive lymphocytic–plasmacytic pododermatitis is proposed to denote what may be a previously unrecognized condition in some dogs with pododermatitis of undetermined aetiology.
Irrigation and Nutrient Effects on Growth and Water–Yield Relationship of Wheat (Triticum aestivum L.) in Central India
Authors: Mandal K. G. , Hati K. M. , Misra A. K. , Bandyopadhyay K. K. , Mohanty M. 
Published: November 2005

AbstractIncreasing production of wheat from a limited water supply can result from efficient irrigation and nutrient management. A 3‐year field experiment was conducted at the Indian Institute of Soil Science, Bhopal, to study the growth, yield, seasonal evapotranspiration (ET) and water use efficiency (WUE), and the water–yield relationship of wheat in a soybean–wheat cropping system on vertisols. Three levels of irrigation, viz. I0, no post‐sowing irrigation; I1, two irrigations [crown root initiation (CRI) and flowering stage]; and I2, three irrigations (CRI, maximum tillering and flowering stage) and three nutrient management treatments, viz. F0, control (without fertilizer/manure); F1, 100 % NPK (100–21.5–24.9 kg ha−1); and F2, 100 % NPK + farmyard manure (FYM‐10 t ha−1) were tested in a split‐plot design with three replication. It has been established (through anova) that the year effect was rather negligible and the interaction effects of irrigation and nutrient management on the growth parameters, ET, yield components, yield and WUE were significant. Plant height, progressive leaf area index, dry matter accumulation and crop growth rate were higher in I2F2, and I2F1 and I1F2 were statistically at par. The seasonal ET increased significantly with the increase in water supply in every nutrient treatment and it was highest in I2F2 and lowest in I0F0. The highest grain yield was obtained in I2F2; and a similar yield was recorded in I3F1 and I2F2. This shows a strong interaction effect between irrigation and nutrients. Yield components, viz. number of ears m−2, number of grains ear−1 and 1000‐grain weight were significant. The higher number of ears m−2 containing greater number of grains with relatively heavier weights appeared to have contributed to the higher yield in I1F2, I2F1 and I2F2. The highest WUE obtained in I0F2 did not correspond to the highest yield and maximum ET, but a WUE of 10.43 kg ha−1 mm−1 in the I2F2 combination corresponded with the highest yield and the seasonal ET requirement was 391.8, which was 137 % greater than the water use at maximum WUE. The ET–grain yield relationship was linear, with a lowest regression slope (i.e. marginal WUE) and elasticity of water production (Ewp) in F0 and a considerably higher slope and Ewp in F1 and F2. As the Ewp is positive and close to one in 100 % NPK treatment, the scope of improving WUE and yield with only inorganic fertilizer is very little, and relatively greater scope exists in the integrated management of organic manure and inorganic fertilizer. The results suggest that integrated nutrient management (100 % NPK + FYM) in conjunction with three irrigations maximized yield of wheat with concomitant improvement in ET and WUE under limited water availability.
Genotypic Variation in Root Systems of Chickpea (Cicer arietinum L.) across Environments
Authors: Yusuf Ali M. , Johansen C. , Krishnamurthy L. , Hamid A. 
Published: November 2005

AbstractRoot systems of various chickpea genotypes were studied over time and in diverse environments, – varying in soil bulk density, phosphorus (P) levels and moisture regimes. In a pot study comparing a range of chickpea genotypes, ICC 4958 and ICCV 94916‐4 produced higher root length density (RLD) and root dry weight (RDW), which were better expressed under P stress conditions. In two field experiments in soils of intermediate and high soil bulk densities, ICC 4958 also had greater RLD and RDW, particularly under soil moisture stress conditions. The expression of greater rooting ability of ICC 4958 under a wide range of environmental conditions confirms its suitability as a parent for genetically enhancing drought resistance and P acquisition ability. The superiority of ICC 4958 over other genotypes was for root proliferation expressed through RLD. Thus, the variation in RLD can be the most relevant root trait that reflects chickpea's potential for soil moisture or P acquisition.
Nitrogen Accumulation and Translocation for Winter Wheat under Different Irrigation Regimes
Authors: Xu Z. Z. , Yu Z. W. , Wang D. , Zhang Y. L. 
Published: November 2005

AbstractThe translocation of pre‐anthesis nitrogen to the grain is an important source for winter wheat. The relation between the nitrogen translocation and irrigation regime was studied in the field under a rain‐proof trough shelter. Nitrogen (N) translocation amount, N translocation efficiency decreased with a decline in irrigation amount or by excessive irrigation. Compared with different organs, the leaf and stem had higher N translocation amounts, and contributions to grain for both cultivars – Jinan 17 and Lumai 21, indicating that stem also is a major N source for grain development. The contribution of pre‐anthesis total above ground N to grain N ranged from 57 to 76 %, indicating the importance of pre‐anthesis storage of N for achieving high grain N concentrations. Grain nitrogen and yield (kg ha−1) were positively and significantly correlated with the N translocation amounts and contributions, respectively, suggesting that the sink strength may be involved in the translocation of N from a vegetative organ to the grain. N harvest index (NHI) was significantly correlated with N translocation efficiency, suggesting that the latter is a prerequisite for increasing grain N and improving grain quality. The experiment showed that N translocation status is enhanced by better irrigation practices, but limited by severely deficient or excessive irrigation.
Maize Yields as Affected by Short‐ and Long‐Term Improved Fallows: A Comparative Analysis in the Asian Humid Tropics
Authors: Schelbert R. , Sangakkara U. R. , Stamp P. 
Published: November 2005

AbstractImproved short‐ or long‐term fallows are considered suitable low external input technologies for maintaining productivity and sustainability of tropical smallholder upland cropping units, although comparisons on the benefits of this technology are not widely reported. A field study evaluated the impact of improved short (6 months) and long‐term fallow (18 months) using Crotalaria juncea and Tithonia diversifolia, in relation to a natural fallow of the same durations, on the productivity of maize (Zea mays), the most important upland cereal in tropical Asia, over a minor season. The use of improved fallows, especially Tithonia, increased maize yields over the Crotalaria or natural fallow. While the overall yields of maize after a long fallow were greater, the beneficial impact of the green manures was significantly higher in the short fallows. The causal factors for this trend, including biomass production of the improved fallows and possible impact on soils, along with the greater benefits of short‐term fallows for increasing maize yields in the tropics due to lower requirements of unproductive time are presented.
Effects of repeated low‐dose UVB irradiation on the hyphal growth of Candida albicans
Authors: Brasch J. , Kay C. 
Published: November 2005

SummaryUltraviolet B light (UVB) can have negative phototropic effects on fungi. Candida albicans is often found on human skin exposed to UVB. Therefore, it is of medical interest to know whether a negative phototropic response to UVB irradiation can support an invasive growth of this potentially dangerous agent. In our study we investigated how repeated irradiation with low doses of UVB can influence the hyphal growth of C. albicans. Six randomly chosen strains of C. albicans were tested. Formation of hyphae was induced and maintained within transparent agar plates. The fungi were exposed to UVB three times daily for 7 days from either the obverse or the reverse side during incubation. The wavelength spectrum was in the range of 310–315 nm, single doses were between 0.0018 and 0.432 J cm−2. After 7 days the morphology and growth direction of C. albicans cells were determined microscopically. All six strains showed a common and dose‐dependent response to UVB irradiation: the progression of hyphal growth was inhibited, no phototropic effects were seen and as a new finding an increased formation of blastospores was observed. We conclude that an irradiation of human skin colonized by C. albicans with doses of UVB that can occur under natural or artificial conditions is unlikely to trigger skin invasion by C. albicans.
Invasive fungal sinusitis of isolated sphenoid sinus in immunocompetent subjects
Authors: Chopra Hemant , Dua Kapil , Malhotra Vineeta , Gupta Rishi Pal , Puri Harpreet 
Published: November 2005

SummaryInvasive fungal sinusitis of the paranasal sinuses in a healthy immunocompetent person is uncommon. Isolated involvement of any paranasal sinus, particularly sphenoid sinus is rare. In this study, five immunocompetent patients who had no nasal complaints but obscure symptoms of headache and orbital symptoms such as diplopia, retro‐orbital pain and loss of vision were diagnosed to be having fulminant fungal sinusitis of the sphenoid sinus. Three patients had aspergillosis and two patients had mucormycosis. These patients initially presented to neurologists and ophthalmologists because they had no ENT complaints. The diagnosis was made on endoscopy, radiology and histopathology. They were treated aggressively according to the standard protocols. The purpose of this paper is to bring to light the changing clinical spectrum of invasive fungal sinusitis. It can occur in immunocompetent patients and in the form of isolated sphenoid sinus involvement.
Incubation of human chorioamniotic membranes with Candida albicans induces differential synthesis and secretion of interleukin‐1β, interleukin‐6, prostaglandin E2, and 92 kDa type IV collagenase
Authors: Zaga‐Clavellina Veronica , López Guadalupe García , Estrada‐Gutierrez Guadalupe , Martinez‐Flores Alfonso , Maida‐Claros Rolando , Beltran‐Montoya Jorge , Vadillo‐Ortega Felipe 
Published: November 2005

SummaryAscendant colonization of pathogenic microorganisms from the vagina to the uterus is strongly associated to preterm labour and premature rupture of membranes. This study evaluated the secretion of interleukin (IL)‐1β, tumour necrosis factor (TNF)α, IL‐6, prostaglandin E2 (PGE2), and metalloproteinases 9 and 2 by the human chorioamnion stimulated with Candida albicans. Chorioamniotic membranes were obtained after delivery by elective Cesarean section from women at 37–40 weeks of gestation without evidence of active labour. The membranes were mounted in Transwell devices that form two independent compartments, which allow testing the individual responses and contributions of the amnion and choriodecidua. One million CFU ml−1 of C. albicans was added to either the amniotic or choriodecidual surface and secretions of the markers were measured in both compartments using specific enzyme‐linked immunosorbent assay and zymography. Fetal membranes followed different secretion patterns of proinflammatory cytokines depending on the side to which the stimulus was applied. IL‐1β was produced in higher amounts in the presence of C. albicans when applied to the choriodecidual side; TNFα and IL‐6 secretion did not change in either the amnion or choriodecidual region. PGE2 synthesis depicted a different pattern, the amniotic tissue was more responsive than the choriodecidual tissue, and this response tended to be higher even when only the amniotic side was stimulated. Matrix metalloproteinases (MMP)‐9 increased after stimulation, being the choriodecidua its main source. Selective stimulation with C. albicans induced a differential secretion of IL‐1β, PGE2, and MMP‐9, resulting from a cooperative and bidirectional communication between the amnion and the choriodecidua.
Comparison of polar lipids from yeast and mycelial forms of Candida albicans and Candida dubliniensis
Authors: Zarei Mahmoudabadi A. , Drucker D. B. 
Published: November 2005

SummaryThe aim of the present study was to compare polar lipids of yeast and mycelial forms of both Candida albicans and Candida dubliniensis. Cultures were harvested from Lee's medium after incubation at 37 °C for 48 h. Yeast and mycelial forms were washed, separated from one another, dried and lipids extracted and prepared for fast atom bombardment mass spectrometry analysis in the negative‐ion mode. For fatty acids, differences between the yeast and mycelial forms were greater for C. dubliniensis than for C. albicans. For the phospholipid families, phosphatidic acid and phosphatidylethanolamine, differences between yeast and mycelial forms were greater for C. dubliniensis than for C. albicans. For both species, it is concluded that both fatty acid and phospholipid molecular species compositions differ according to whether the cells are in the yeast or mycelial form.