bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tempo and mode of speciation in the Baja California disjunct fish species Anisotremus davidsonii
Authors: BERNARDI GIACOMO , LAPE JENNIFER 
Published: October 2005

AbstractThe Baja California region provides a natural setting for studying the early mechanisms of allopatric speciation in marine systems. Disjunct fish populations from several species that occur in the northern Gulf of California and northern Pacific coast of Baja California, but are absent from its southern shores, were previously shown to be genetically isolated, making them excellent candidates for studying allopatry. In addition, one of these species, the sargo Anisotremus davidsonii, has two pairs of congeneric Panamic trans‐isthmian geminate species that allow for internal molecular clock calibration. Phylogeographic and demographic approaches based on mitochondrial (cytochrome b) and nuclear (S7 ribosomal protein) sequences showed that A. davidsonii entered the gulf from the south, and later colonized the Pacific coast, approximately 0.6–0.16 million years ago. Pacific coast colonization may have used a route either around the southern cape of Baja California or across the peninsula through a natural seaway. However, while several seaways have been described from different geological times, none matches the dates of population disjunction, yet much geological work remains to be done in that area. At the present time, there is no evidence for dispersal around the southern tip of the Baja California Peninsula. Signatures of incipient allopatric speciation were observed, such as the reciprocal monophyly of disjunct populations for the mitochondrial marker. However, other characteristics were lacking, such as a strong difference in divergence and coalescence times. Taken together, these results suggest that disjunct populations of A. davidsonii may be consistent with the earliest stages of allopatric speciation.
Population genetic analysis identifies source–sink dynamics for two sympatric garter snake species (Thamnophis elegans and Thamnophis sirtalis)
Authors: MANIER MOLLIE K. , ARNOLD STEVAN J. 
Published: October 2005

AbstractPopulation genetic structure can be shaped by multiple ecological and evolutionary factors, but the genetic consequences of these factors for multiple species inhabiting the same environment remain unexplored. We used microsatellite markers to examine the population structures of two coexisting species of garter snake, Thamnophis elegans and Thamnophis sirtalis, to determine if shared landscape and biology imposed similar population genetic structures. These snakes inhabit a series of ponds, lakes and flooded meadows in northern California and tend to converge on prey type wherever they coexist. Both garter snakes had comparable effective population sizes and bidirectional migration rates (estimated using a maximum‐likelihood method based on the coalescent) with low but significant levels of genetic differentiation (FST = 0.024 for T. elegans and 0.035 for T. sirtalis). Asymmetrical gene flow revealed large source populations for both species as well as potential sinks, suggesting frequent extinction–recolonization and metapopulation dynamics. In addition, we found a significant correlation between their genetic structures based on both pairwise FSTs for shared populations (P = 0.009) and for bidirectional migration rates (P = 0.024). Possible ecological and evolutionary factors influencing similarities and differences in genetic structure for the two species are discussed. Genetic measures of effective population size and migration rates obtained in this study are also compared with estimates obtained from mark–recapture data.
The polysaccharide capsule of the pathogenic fungus Cryptococcus neoformans enlarges by distal growth and is rearranged during budding
Authors: Zaragoza Oscar , Telzak Andrew , Bryan Ruth A. , Dadachova Ekaterina , Casadevall Arturo 
Published: October 2005

SummaryThe capsule of Cryptococcus neoformans can undergo dramatic enlargement, a phenomenon associated with virulence. A prior study that used Ab to the capsule as a marker for older capsular material concluded that capsule growth involved the intermixing of new and old capsular material with displacement of older capsular polysaccharide towards the surface. Here we have revisited that question using complement (C), which binds to capsular polysaccharide covalently, and cannot redistribute by dissociation and binding at different sites. The experimental approach involved binding of C to cells with small capsules, inducing capsule growth, and following the location of C relative to the cell wall as the capsule enlarged. C remained close to the cell wall during capsule growth, indicating that capsule enlargement occurred by addition of new polysaccharide near the capsule edge. This conclusion was confirmed by an independent method that employed radioactive metabolic labelling of newly synthesized capsule with 3H‐mannose followed by gradual capsular stripping with γ‐radiation. Capsule growth proceeded to a certain size, which was a function of cell size, and was not degraded when the cells were transferred to a non‐inducing medium. During budding, an opening appeared in the capsule of the mother cell that permitted the nascent bud to separate. Scanning EM suggested that a physical separation formed between the capsules of the mother and daughter cells during budding, which may avoid mixture between both capsules. Our results indicate that C. neoformans capsular enlargement also occurs by apical growth and that budding results in capsular rearrangements.
P1 plasmid partition: in vivo evidence for the ParA‐ and ParB‐mediated formation of an anchored parS complex in the absence of a partner parS
Authors: Edgar Rotem , Biek Donald , Yarmolinsky Michael 
Published: October 2005

SummaryParA and ParB proteins and cis‐acting site, parS, are required to partition plasmid P1 faithfully to daughter cells. The process may initiate from plasmids paired by ParB at which recruited ParA then acts to effect the separation. We previously reported evidence for ParB‐mediated pairing of parS sites on plasmids in the absence of ParA. In DNA gyrase‐inhibited cells, the pairing prevented diffusion of transcription‐generated positive supercoils. This supercoil trapping was almost entirely in plasmid dimers, where the location of the parS sites in cis facilitated their pairing. Here we show that the addition of ParA blocked supercoil diffusion also in plasmid monomers. The possibility that this result is attributed to an enhancement by ParA of ParB‐mediated pairing in trans is consistent with our finding that ParA appeared to partially suppress the pairing defect of two mutant ParB proteins. However, enhanced pairing alone could not account for the diffusion barrier in plasmid monomers; it was manifest in monomers even when they were largely devoid of partners in the same cell. Apparently, ParA altered the ParB–parS complex such that it could no longer swivel, most likely by anchoring it, a reaction of probable relevance to partition.
Porphyromonas gingivalis‐induced platelet aggregation in plasma depends on Hgp44 adhesin but not Rgp proteinase
Authors: Naito Mariko , Sakai Eiko , Shi Yixin , Ideguchi Hiroshi , Shoji Mikio , Ohara Naoya , Yamamoto Kenji , Nakayama Koji 
Published: October 2005

SummaryEvidence from recent epidemiological studies suggests a link between periodontal infections and increased risk of atherosclerosis and related cardiovascular and cerebrovascular events in human subjects. One of the major pathogens of periodontitis, Porphyromonas gingivalis, has the ability to aggregate human platelets in platelet‐rich plasma (PRP). Mechanism of P. gingivalis‐induced platelet aggregation in PRP was investigated. Proteinase inhibitors toward Arg‐gingipain (Rgp) and Lys‐gingipain (Kgp) did not suppress P. gingivalis‐induced platelet aggregation in PRP, whereas the Rgp inhibitor markedly inhibited P. gingivalis‐induced platelet aggregation using  washed  platelets.  Mutant  analysis  revealed  that P. gingivalis‐induced platelet aggregation in PRP depended on Rgp‐, Kgp‐ and haemagglutinin A (HagA)‐encoding genes that intragenically coded for adhesins such as Hgp44. Hgp44 adhesin on the bacterial cell surface, which was processed by Rgp and Kgp proteinases, was essential for P. gingivalis‐induced platelet aggregation in PRP. P. gingivalis cell‐reactive IgG in plasma, and FcγRIIa receptor and to a lesser extent GPIbα receptor on platelets were found to be a prerequisite for P. gingivalis‐induced platelet aggregation in PRP. These results reveal a novel mechanism of platelet aggregation by P. gingivalis.
Cytopathic changes and pro‐inflammatory cytokines induced by Naegleria fowleri trophozoites in rat microglial cells and protective effects of an anti‐Nfa1 antibody
Authors: OH Y.‐H. , JEONG S.‐R. , KIM J.‐H. , SONG K.‐J. , KIM K. , PARK S. , SOHN S. , SHIN H.‐J. 
Published: October 2005

SUMMARYNaegleria fowleri, a free‐living amoeba, causes fatal primary amoebic meningoencephalitis in experimental animals and humans. The nfa1 gene (360 bp) was previously cloned from a cDNA library of pathogenic N. fowleri by immunoscreening, and produced a 13·1‐kDa recombinant protein that showed pseudopodia‐specific localization by immunocytochemistry. On the basis of an idea that the pseudopodia‐specific Nfa1 protein seems to be involved in the pathogenicity of N. fowleri, the cytopathic activity of N. fowleri trophozoites co‐cultured with rat microglial cells was observed, and the effects of an anti‐Nfa1 antibody in a co‐culture system were elucidated. Using light, scanning and transmission electron microscopy, it was seen that N. fowleri trophozoites in contact with microglial cells produced vigorous pseudopodia and a food‐cup structure. Microglial cells were destroyed by N. fowleri trophozoites as seen from necrotic cell death in a time‐dependent manner. In a51Cr release assay, N. fowleri showed 17·8%, 24·9%, 54·6% and 98% cytotoxicity against microglial cells at 3, 6, 12 and 24 h post‐incubation, respectively. However, when anti‐Nfa1 antibody was added in a coculture system, N. fowleri cytotoxicity was reduced to 15·5%, 20·3%, 46·7% and 66·9%, respectively. Moreover, microglial cells co‐cultured with N. fowleri trophozoites secreted the pro‐inflammatory cytokines, TNF‐α, IL‐1β and IL‐6. In the presence of anti‐Nfa1 antibody, the secretion of TNF‐α was slightly, but not significantly, decreased.
The stimulating effects of ethylene and auxin on petiole elongation and on hyponastic curvature are independent processes in submerged Rumex palustris
Authors: COX MARJOLEIN C. H. , PEETERS ANTON J. M. , VOESENEK LAURENTIUS A. C. J. 
Published: October 2005

ABSTRACTThe flooding‐tolerant plant species Rumex palustris (Sm.) responds to complete submergence with stimulation of petiole elongation mediated by the gaseous hormone ethylene. We examined the involvement of auxin in petiole elongation. The manipulation of petiolar auxin levels by removing the leaf blade, or by addition of synthetic auxins or auxin transport inhibitors, led to the finding that auxin plays an important role in submergence‐induced petiole elongation in R. palustris. A detailed kinetic analysis revealed a transient effect of removing the auxin source (leaf blade), explaining why earlier studies in which less frequent measurements were taken failed to identify any role for auxin in petiole elongation. We previously showed that the onset of stimulated petiole elongation depends on a more upright petiole angle being reached by means of hyponastic (upward) curvature, a differential growth process that is also regulated by ethylene and auxin. This raised the possibility that both ethylene and auxin stimulate elongation only indirectly by influencing hyponastic growth. We show here that the action of ethylene and auxin in promoting petiole elongation in submerged R. palustris is independent of the promoting effect that these hormones also exert on the hyponastic curvature of the same petiole.
NMR metabolite profiling analysis reveals changes in phospholipid metabolism associated with the re‐establishment of desiccation tolerance upon osmotic stress in germinated radicles of cucumber
Authors: AVELANGE‐MACHEREL M.‐H. , LY‐VU B. , DELAUNAY J. , RICHOMME P. , LEPRINCE O. 
Published: October 2005

ABSTRACTThe adaptation of metabolism is thought to play a role in the acquisition of desiccation tolerance (DT). However, the importance of such a role and whether specific regulatory pathways exist remain to be assessed. Using in vitro31P and 13C nuclear magnetic resonance (NMR) spectroscopy and biochemical assays, we analysed metabolite profiles of perchloric extracts from germinating radicles of cucumber to identify changes in carbon and phosphate metabolism associated with DT. Emerged radicles measuring 2 mm long can be rendered tolerant to desiccation by incubation in a polyethylene glycol (PEG) solution with a water potential of −1.5 MPa. However, in 4‐mm‐long emerged radicles, this treatment was ineffective. This manipulable system enabled the discrimination of changes in metabolites associated with DT from those associated with the response to osmotic stress. Independent of radicle length, the PEG treatment resulted in an increase in sucrose (Suc) content, whereas glucose (Glc), fructose (Fru) and the hexose phosphate pool, as well as phosphoenolpyruvate decreased three‐ to fourfold. In addition, three derivatives arising early during phospholipid catabolism (glycerylphosphorylcholine, glycerylphosphorylethanolamine and glycerylphosphorylinositol) appeared in the PEG‐treated radicles. Interestingly, phospholipid degradation was much more pronounced in osmotically challenged radicles that remain sensitive to drying. This was proved by the appearance of catabolites, such as phosphocholine and phosphoethanolamine, solely in 4 mm PEG‐treated radicles. Furthermore, glycerol‐3‐phosphate and its derivative 3‐phosphoglycerate increased significantly. Our data suggest that the metabolic response leading to the re‐establishment of DT is not entirely identical to that of an osmotic response. It is inferred that membrane remodelling and/or increased phospholipid catabolism is an adaptive response common to osmotic adjustment and DT but is controlled differently in tolerant and sensitive radicles.
Reduced levels of volatile emissions in jasmonate‐deficientspr2tomato mutants favour oviposition by insect herbivores
Authors: SÁNCHEZ‐HERNÁNDEZ CARLA , LÓPEZ MERCEDES G. , DÉLANO‐FRIER JOHN P. 
Published: October 2005

ABSTRACTTomato plants release volatile organic compounds (VOCs) following insect or mechanical damage. In this study, the constitutive and wound‐induced emission levels of VOCs in suppressor of prosystemin‐mediated responses2 (spr2) mutant plants, compromised in linolenic acid (LA) and jasmonic acid (JA) synthesis, and in 35S::prosystemin (35S::prosys) plants, having upregulated direct defence responses, were compared. Thespr2mutants produced constitutively lower levels of VOCs, which were nonetheless increased in response to (a)biotic damage, although at lower levels than wild‐type (Wt) and35S::prosysplants. No significant differences in VOC emissions were detected between the latter two genotypes, thereby suggesting that systemin does not regulate indirect defence responses, whereas differences in fatty acid composition inspr2plants led to the predominant emission of saturated C6 volatiles in response to wounding. The expression of 1‐deoxy‐d‐xylulose 5‐phosphate synthase (DXS2), a key gene involved in VOC synthesis in the chloroplast, was only upregulated inManduca sextaL.‐damaged Wt and35S::prosysplants. However, its expression was restored inspr2plants by exogenous LA or JA, suggesting that abated VOC emissions inspr2plants are correlated with loweredDXS2expression. Bioassays with two different insects showed that adult females significantly preferredspr2plants, indicating that lowered levels of VOCs in tomato influence plant selection by insects during oviposition.
Relationship of measles vaccination with anaemia and malaria in western Kenya
Authors: Desai Meghna R. , Holtz Timothy H. , Helfand Rita , Terlouw Dianne J. , Wannemuehler Kathleen A. , Kariuki Simon K. , Shi Ya Ping , Nahlen Bernard L. , Ter Kuile Feiko O. 
Published: October 2005

SummaryObjective  Mild viral illness, including that following immunization with live attenuated measles virus (LAMV), has been associated with transient decreases in haemoglobin (Hb) and cellular immune response that may persist for several weeks. In areas of intense malaria transmission, such as western Kenya, infants experience a progressive drop in Hb until age 9–10 months and one‐third may have Hb < 8 g/dl. These children may be at risk of developing severe anaemia with further haematological insult. The objective of this paper was to determine if immunization with LAMV was associated with increased risk of transient anaemia and malaria infection.Methods  Data from previous cross‐sectional surveys (n = 5970) and one cohort study (n = 546) conducted among pre‐school children were analyzed retrospectively.Results  Measles vaccination coverage between 12 and 23 months of age ranged from 44.8% to 62.7%. Hb concentrations in children aged 6–23 months with documented measles immunization within the previous 14 or 30 days (n = 103) were similar to those with no history of measles immunization in the previous 90 days (n = 996); mean differences [95% confidence interval (CI)] by 30 days were: in cross‐sectional surveys, −0.49 g/dl (−1.12, 0.14); in the cohort study, −0.032 g/dl (−0.52, 0.46). Similarly, the risk of malaria parasitemia or severe to moderate anaemia did not differ.Conclusion  These data do not suggest that the transient decrease in Hb and cellular immune response after immunization with LAMV results in clinically significant changes in the risk of subsequent severe to moderate anaemia or malaria in young children living in malaria‐endemic regions.
Bipolaris keratomycosis
Authors: Saha Rumpa , Das Shukla 
Published: October 2005

SummaryA case of mycotic keratitis caused by Bipolaris spicifera is reported. The corneal ulcer developed after 1 week of treatment with corticosteroids and antibiotics. Septate, branched, dematiaceous hyphal elements were detected in the corneal scrapings on two occasions and repeated cultures were positive for this fungus. The infection was resolved with natamycin and itraconazole although the corneal opacity remained and the patient is now waiting for a keratoplasty.
Superficial mycoses due to Trichophyton violaceum in Athens, Greece: a 15‐year retrospective study
Authors: Frangoulis E. , Papadogeorgakis H. , Athanasopoulou B. , Katsambas A. 
Published: October 2005

SummaryThis is a retrospective study on the superficial mycoses due to Trichophyton violaceum in the greater Athens area for the last 15 years – 1989–2003. During this period 104 patients were found to have an infection due to T. violaceum– an incidence rate of 0.75% of all dermatophytosis. Of the patients 59 were Greeks, 15 Greek Gypsies and 30 immigrants mostly from Albania (50%). Of them 58 were children, 46 adults (mainly women, 34 cases). Trichophyton violaceum infection was presented with a variety of manifestations (127 cases). The prevailing was tinea capitis present in 85 patients – 57 children, 24 women and four men (women : men 6 : 1). Tinea capitis together with other forms of the infection was found in 14 patients. Tinea facie, corporis, manuum, barbae and unguium were seen in nineteen patients. The isolation rate of T. violaceum infection in the Greek population remained at a low level for three decades after the mid‐1960s. However, a substantial increase in the isolation rate is observed in the mid‐1990s attributed mainly to the influx of economic immigrants from countries where the infection is endemic.
Preoperative diagnosis of gastric cancer using 2‐D magnetic resonance imaging with 3‐D reconstruction techniques
Authors: ZHONG Liang , LI Lei , SUN Jian Hua , XU Jian Rong 
Published: October 2005

OBJECTIVE:  To investigate the clinical value of 2‐D magnetic resonance imaging (MRI) with 3‐D reconstruction techniques for the preoperative diagnosis and TNM‐staging of gastric cancer.METHODS:  Using a Philips Gyroscan NT 1.0T superconductive unit, MRI using the water‐filling method was performed in 15 patients with suspected gastric cancers. The 2‐D MRI sequences included TSE‐T1WI, TSE‐T2WI and fat suppression (SPIR). The source images of magnetic resonance hydrography (heavily TSE‐T2WI sequence) were reconstructed using the Philips EasyVision viewing workstation. Four 3‐D postprocessing algorithms, including maximum intensity projection, surface shaded viewing, volume rendering and virtual endoscopy, were performed and compared with the results of a barium study and endoscopy. All 15 patients with 16 gastric cancers had their diagnosis confirmed by postoperative pathological findings.RESULTS:  2‐D MRI and 3‐D reconstruction images were successfully obtained for all 15 patients. The maximum intensity projection, surface shaded viewing, and volume rendering images corresponded to the upper gastrointestinal series findings, and the virtual endoscopy images corresponded to the gastroscopic views. In 16 gastric lesions, MRI correctly diagnosed 14 (87.5%) advanced gastric cancers, and the tumor location, size and classification were also accurately identified. The accuracy of MRI for determining the preoperative TNM stage was 64.3% (9/14), and there was significant correlation between these results and those from the histopathological studies (P < 0.01). Based on T, N and M factors, the staging accuracy of MRI was 71.4% (10/14), 57.1% (8/14) and 85.7% (12/14), respectively.CONCLUSIONS:  2‐D MRI with 3‐D reconstruction is an effective method for the preoperative diagnosis and TNM staging of gastric cancer. However, the detection of early cancers or benign lesions and N‐staging should be further studied.
Correlation between a gene polymorphism of tumor necrosis factor and inflammatory bowel disease
Authors: SONG Ying , WU Kai Chun , ZHANG Li , HAO Zhi Ming , LI Hong Tao , ZHANG Ling Xia , QIAO Tai Dong , LI Cai Ning , FAN Dai Ming 
Published: October 2005

OBJECTIVES:  To analyze polymorphism of the tumor necrosis factor (TNF) gene in inflammatory bowel disease (IBD) patients from the Han Chinese ethnic group, and to investigate the role of polymorphism in the pathogenesis of IBD.METHODS:  Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques were used to analyze gene polymorphisms in the TNF‐α and TNF‐β genes in 131 patients with IBD.RESULTS:  The genotype frequency and allelic frequency of TNF‐α−308 in patients with ulcerative colitis (UC) were 15.5% and 8.7%, respectively, significantly higher than the control population (4.1% and 2.0%, respectively; P < 0.001). There was no significant difference between patients with Crohn's disease (CD) and the normal population with regard to the genotype frequency and allelic frequency of TNF‐α−308, and neither were there any differences with regard to TNF‐β+252 in patients with IBD (UC and CD) and the normal population. The TNF‐α−308 polymorphism and the TNF‐β+252 loci did not correlate with age, gender, disease activity or lesion site for IBD patients.CONCLUSIONS:  The TNF‐α−308 allele may be related to susceptibility to UC. The TNF‐α−308 gene polymorphism is not involved in pathogenesis of CD. No correlation was found between the TNF‐β+252 polymorphism and IBD. Polymorphisms of the TNF‐α−308 and TNF‐β+252 loci do not correlate with age, gender, disease activity or lesion site.