bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patent foramen ovale, a possible cause of symptomatic migraine: a study of 74 patients with acute ischemic stroke.
Authors: Sztajzel R , Genoud D , Roth S , Mermillod B , Le Floch‐Rohr J 
Published: December 2004

Cerebrovasc Dis. 2002;13(2):102‐106Recent studies reported an increased prevalence of patent foramen ovale (PFO) in patients with migraine with aura (MA  +). To investigate the possible relationship between MA  + and paradoxical embolism, we studied the prevalence of both conditions. Investigation of PFO was undertaken in 74 consecutive patients presenting with an acute stroke of undetermined origin. The patients were questioned about MA  + or migraine without aura (MA  −) according to the criteria of the International Headache Society. Follow‐up was performed to investigate the evolution of MA  + and MA  − according to different treatments of stroke. PFO was found in 44 of 74 patients, 16 of whom had MA  + (36%), compared to 4 (13%) MA  + patients without PFO (p  =  0.03). Of 25 patients in whom the PFO was considered to play a causal role in the stroke, 13 (52%) had MA  +, whereas only 3 (16%) of 19 patients in whom PFO was considered unrelated had MA  + (p  =  0.014). Thirty‐nine of the patients with MA  + and MA  − were studied over a mean follow‐up of 13 months. Seven of 15 patients with MA  + and PFO, treated either with surgical closure or anticoagulants, noticed complete disappearance of MA  + attacks. The prevalence of MA  + is high among stroke patients with PFO. In patients with a high presumption of paradoxical embolism, the proportion of MA  + is increased, and this suggests a possible role of this association in the occurrence of the cerebrovascular event. Forty‐seven percent of patients with PFO and MA  + reported complete suppression of their aura attacks after surgical closure or anticoagulant treatment. This finding suggests that at least in some patients, MA  + attacks may be due to paradoxical embolism.Comment: Reach for the stethoscope/echocardiogram! This paper emphasizes the importance of physicians adopting a holistic approach to patients with migraine, not forgetting to check for clinical signs of a septal defect and, if in doubt, to refer for cardiological review to exclude a surgically treatable source of paradoxical emboli. DSM
What predicts evolution from episodic to chronic cluster headache?
Authors: Torelli P , Manzoni GC 
Published: December 2004

Curr Pain Headache. Rep 2002 Feb;6(1):65‐70Over the last few years, attention has increasingly been focused on the evolution of cluster headache over time. Predictive factors have been identified that are correlated with an increased risk of unfavorable evolution from the episodic form to the chronic form of cluster headache. Late onset, the presence of sporadic attacks, a high frequency of cluster periods, and short‐lived duration of remission periods when the headache is still in its episodic form all correlate with a possible worsening of the clinical picture over time. The reasons for evolution of episodic cluster headache to chronic are still unknown, but some factors, such as head trauma and other lifestyle factors—eg, cigarette smoking and alcohol intake—have been suggested as having a negative influence on the course of cluster headache over time.Comment: Further longitudinal epidemiological research is needed to assess the impact of smoking cessation in these patients and to confirm or refute the hypotheses suggested in this paper. DSM Lee Kudrow documented that smoking, like nitroglycerin, lowers oxygen tension, which in turn can precipitate cluster attacks. Another possibility is that smoking and nitroglycerine are nitric oxide (NO) delivery systems and that the NO both precipitates attacks and worsens long‐term cluster prognosis. SJT
Pristine New Zealand forest soil is a strong methane sink
Authors: Price Sally J. , Sherlock Robert R. , Kelliher Francis M. , McSeveny Tony M. , Tate Kevin R. , Condron Leo M. 
Published: December 2004

AbstractMethanotrophic bacteria oxidize methane (CH4) in forest soils that cover ∼30% of Earth's land surface. The first measurements for a pristine Southern Hemisphere forest are reported here. Soil CH4 oxidation rate averaged 10.5±0.6 kg CH4 ha−1 yr−1, with the greatest rates in dry warm soil (up to 17 kg CH4 ha−1 yr−1). Methanotrophic activity was concentrated beneath the organic horizon at 50–100 mm depth. Water content was the principal regulator of (r2=0.88) from the most common value of field capacity to less than half of this when the soil was driest. Multiple linear regression analysis showed that soil temperature was not very influential. However, inverse co‐variability confounded the separation of soil water and temperature effects in situ. Fick's law explained the role of water content in regulating gas diffusion and substrate supply to the methanotrophs and the importance of pore size distribution and tortuosity. This analysis also showed that the chambers used in the study did not affect the oxidation rate measurements. The soil was always a net sink for atmospheric CH4 and no net CH4 (or nitrous oxide, N2O) emissions were measured over the 17‐month long study. For New Zealand, national‐scale extrapolation of our data suggested the potential to offset 13% of CH4 emissions from ca. 90 M ruminant animals. Our average was about 6.5 times higher than rates reported for most Northern Hemisphere forest soils. This very high was attributed to the lack of anthropogenic disturbance for at least 3000–5000 years and the low rate of atmospheric nitrogen deposition. Our truly baseline data could represent a valid preagricultural, preindustrial estimate of the soil sink for temperate latitudes.
Possible Roles for Mannitol and Mannitol Dehydrogenase in the Biotrophic Plant PathogenUromyces fabae
Authors: Voegele Ralf T. , Hahn Matthias , Lohaus Gertrud , Link Tobias , Heiser Ingrid , Mendgen Kurt 
Published: December 2004

AbstractLevels of the C6-polyol mannitol were observed to rise dramatically in the biotrophic interaction of the rust fungus Uromyces fabae and its host plant Vicia faba. Mannitol was found in millimolar concentrations in extracts and apoplastic fluids of infected leaves and also in extracts of spores. We suggest that this polyol might have at least a dual function: first, as a carbohydrate storage compound, and second, as a scavenger of reactive oxygen species. Mannitol accumulation is accompanied by high expression of a mannitol dehydrogenase (MAD1) in haustoria. While MAD1 transcripts were detected in haustoria only, immunolocalization studies show that the gene product is also present in spores. Kinetic and thermodynamic analyses of the MAD1p catalyzed reactions indicate that the enzyme might be responsible for the production of mannitol in haustoria and for the utilization of mannitol in spores. Since V. faba is normally unable to synthesize or utilize polyols, the multipurpose usage of mannitol seems an ideal strategy for the fungal pathogen.
The Cytokinin Requirement for Cell Division in Cultured Nicotiana plumbaginifolia Cells Can Be Satisfied by Yeast Cdc25 Protein Tyrosine Phosphatase. Implications for Mechanisms of Cytokinin Response and Plant Development
Authors: Zhang Kerong , Diederich Ludger , John Peter C.L. 
Published: December 2004

Abstract
Cultured cells of Nicotiana plumbaginifolia, when deprived of exogenous cytokinin, arrest in G2 phase prior to mitosis and then contain cyclin-dependent protein kinase (CDK) that is inactive because phosphorylated on tyrosine (Tyr). The action of cytokinin in stimulating the activation of CDK by removal of inhibitory phosphorylation from Tyr is not a secondary downstream consequence of other hormone actions but is the key primary effect of the hormone in its stimulation of cell proliferation, since cytokinin could be replaced by expression of cdc25, which encodes the main Cdc2 (CDK)-Tyr dephosphorylating enzyme of yeast (Saccharomyces cerevisiae). The cdc25 gene, under control of a steroid-inducible promoter, induced a rise in cdc25 mRNA, accumulation of p67Cdc25 protein, and increase in Cdc25 phosphatase activity that was measured in vitro with Tyr-phosphorylated Cdc2 as substrate. Cdc25 phosphatase activity peaked during mitotic prophase at the time CDK activation was most rapid. Mitosis that was induced by cytokinin also involved increase in endogenous plant CDK Tyr phosphatase activity during prophase, therefore indicating that this is a normal part of plant mitosis. These results suggest a biochemical mechanism for several previously described transgene phenotypes in whole plants and suggest that a primary signal from cytokinin leading to progression through mitosis is the activation of CDK by dephosphorylation of Tyr.
Identification in Pea Seed Mitochondria of a Late-Embryogenesis Abundant Protein Able to Protect Enzymes from Drying
Authors: Grelet Johann , Benamar Abdelilah , Teyssier Emeline , Avelange-Macherel Marie-Hélène , Grunwald Didier , Macherel David 
Published: December 2004

Abstract
Late-embryogenesis abundant (LEA) proteins are hydrophilic proteins that accumulate to a high level in desiccation-tolerant tissues and are thus prominent in seeds. They are expected to play a protective role during dehydration; however, functional evidence is scarce. We identified a LEA protein of group 3 (PsLEAm) that was localized within the matrix space of pea (Pisum sativum) seed mitochondria. PsLEAm revealed typical LEA features such as high hydrophilicity and repeated motifs, except for the N-terminal transit peptide. Most of the highly charged protein was predicted to fold into amphiphilic α-helixes. PsLEAm was expressed during late seed development and remained in the dry seed and throughout germination. Application of the stress hormone abscisic acid was found to reinduce the expression of PsLEAm transcripts during germination. PsLEAm could not be detected in vegetative tissues; however, its expression could be reinduced in leaves by severe water stress. The recombinant PsLEAm was shown to protect two mitochondrial matrix enzymes, fumarase and rhodanese, during drying in an in vitro assay. The overall results constitute, to our knowledge, the first characterization of a LEA protein in mitochondria and experimental evidence for a beneficial role of a LEA protein with respect to proteins during desiccation.
Site Preferences of Insertional Mutagenesis Agents in Arabidopsis
Authors: Pan Xiaokang , Li Yong , Stein Lincoln 
Published: December 2004

Abstract
We have performed a comparative analysis of the insertion sites of engineered Arabidopsis (Arabidopsis thaliana) insertional mutagenesis vectors that are based on the maize (Zea mays) transposable elements and Agrobacterium T-DNA. The transposon-based agents show marked preference for high GC content, whereas the T-DNA-based agents show preference for low GC content regions. The transposon-based agents show a bias toward insertions near the translation start codons of genes, while the T-DNAs show a predilection for the putative transcriptional regulatory regions of genes. The transposon-based agents also have higher insertion site densities in exons than do the T-DNA insertions. These observations show that the transposon-based and T-DNA-based mutagenesis techniques could complement one another well, and neither alone is sufficient to achieve the goal of saturation mutagenesis in Arabidopsis. These results also suggest that transposon-based mutagenesis techniques may prove the most effective for obtaining gene disruptions and for generating gene traps, while T-DNA-based agents may be more effective for activation tagging and enhancer trapping. From the patterns of insertion site distributions, we have identified a set of nucleotide sequence motifs that are overrepresented at the transposon insertion sites. These motifs may play a role in the transposon insertion site preferences. These results could help biologists to study the mechanisms of insertions of the insertional mutagenesis agents and to design better strategies for genome-wide insertional mutagenesis.
Endoplasmic Reticulum-Associated Degradation of Ricin A Chain Has Unique and Plant-Specific Features
Authors: Di Cola Alessandra , Frigerio Lorenzo , Lord J. Michael , Roberts Lynne M. , Ceriotti Aldo 
Published: December 2004

AbstractProteins that fail to fold in the endoplasmic reticulum (ER) or cannot find a pattern for assembly are often disposed of by a process named ER-associated degradation (ERAD), which involves transport of the substrate protein across the ER membrane (dislocation) followed by rapid proteasome-mediated proteolysis. Different ERAD substrates have been shown to be ubiquitinated during or soon after dislocation, and an active ubiquitination machinery has been found to be required for the dislocation of certain defective proteins. We have previously shown that, when expressed in tobacco (Nicotiana tabacum) protoplasts, the A chain of the heterodimeric toxin ricin is degraded by a pathway that closely resembles ERAD but is characterized by an unusual uncoupling between the dislocation and the degradation steps. Since lysine (Lys) residues are a major target for ubiquitination, we have investigated the effects of changing the Lys content on the retrotranslocation and degradation of ricin A chain in tobacco protoplasts. Here we show that modulating the number of Lys residues does not affect recognition events within the ER lumen nor the transport of the protein from this compartment to the cytosol. Rather, the introduced modifications have a clear impact on the degradation of the dislocated protein. While the substitution of the two Lys residues present in ricin A chain with arginine slowed down degradation, the introduction of four extra lysyl residues had an opposite effect and converted the ricin A chain to a standard ERAD substrate that is disposed via a process in which dislocation and degradation steps are tightly coupled.
Can Insider Power Affect Employment?
Authors: Díaz-Vázquez Pilar , Snower Dennis J. 
Published: December 2004

Abstract
Do firms reduce employment when their insiders (established, incumbent employees) claim higher wages? The conventional answer in the theoretical literature is that insider power has no influence on employment, provided that the newly hired employees (entrants) receive their reservation wages. The reason given is that an increase in insider wages gives rise to a countervailing fall in reservation wages, leaving the present value of wage costs unchanged. Our analysis contradicts this conventional answer. We show that, in the context of a stochastic model of the labor market, an increase in insider wages promotes firing in recessions, while leaving hiring in booms unchanged. Thereby insider power reduces average employment.
Association of single nucleotide polymorphisms in klotho with priapism in sickle cell anaemia
Authors: Nolan Vikki G. , Baldwin Clinton , Ma Qianli , Wyszynski Diego F. , Amirault Yvonne , Farrell John J. , Bisbee Alice , Embury Stephen H. , Farrer Lindsay A. , Steinberg Martin H. 
Published: December 2004

SummaryThe complications of sickle cell disease are probably determined by genes whose products modify the pathophysiology initiated by the sickle haemoglobin mutation. Priapism, one vaso‐occlusive manifestation of sickle cell disease, affects more than 30% of males with the disease. We examined the possible association of single nucleotide polymorphisms (SNPs) in 44 candidate genes of different functional classes for an association with the occurrence of priapism. One hundred and forty‐eight patients with sickle cell anaemia and incident or a confirmed history of priapism were studied, along with 529 controls that had not developed priapism. Polymorphisms in the KLOTHO gene (KL; 13q12) showed an association with priapism by genotypic [reference SNP cluster identifier number (rs)2249358; odds ratio (OR) = 2·6 (1·4–5·5); rs211239; OR = 1·7 (1·2–2·6)] and haplotype analyses [rs211234 and rs211239; OR = 2·3 (1·5–3·4)]. These findings may have broader implications in sickle cell disease, as KL encodes a membrane protein that regulates many vascular functions, including vascular endothelial growth factor expression and endothelial nitric oxide release.
Syndecan‐1 and angiogenic cytokines in multiple myeloma: correlation with bone marrow angiogenesis and survival
Authors: Andersen Niels Frost , Standal Therese , Nielsen Johan Lanng , Heickendorff Lene , Borset Magne , Sørensen Flemming Brandt , Abildgaard Niels 
Published: December 2004

SummaryAngiogenesis is a complex process involved in the proliferation and metastasis of malignant tumours, and partly triggered by the secretion of various angiogenic factors by tumour cells or cells in the stromal environment. We investigated the correlation between bone marrow angiogenesis, estimated as microvessel density (MVD), and interleukin‐6 (IL‐6), basic fibroblastic growth factor (bFGF), hepatocyte growth factor (HGF) and syndecan‐1 in 67 patients with newly diagnosed multiple myeloma, and evaluated the prognostic value of these parameters. Circulating levels of IL‐6, bFGF, HGF and syndecan‐1 were significantly higher in patients than in controls. Moreover, in patients, bone marrow levels of bFGF, HGF and syndecan‐1 were higher than peripheral blood levels. Positive correlations were found between MVD and syndecan‐1 blood levels (r = 0·33,P = 0·017), syndecan‐1 bone marrow levels (r = 0·49,P = 0·046) and HGF blood levels (r = 0·36,P = 0·008) respectively. High MVD and high blood levels of IL‐6, HGF and syndecan‐1 were predictive of a shorter survival. In a multivariate survival analysis MVD and blood levels of IL‐6 retained independent prognostic significance, while in a survival analysis without MVD the peripheral blood levels of HGF and syndecan‐1 were strong independent prognostic factors.
Presence of anti‐kinectin and anti‐PMS1 antibodies in Japanese aplastic anaemia patients
Authors: Hirano Naoto , Butler Marcus O. , Guinan Eva C. , Nadler Lee M. , Kojima Seiji 
Published: December 2004

SummaryWhile anti‐kinectin antibodies are frequently found in aplastic anaemia (AA) patients from the US (39%), we detected antibodies in only three of 30 (10%) of Japanese AA cases. Additionally, population differences in anti‐postmeiotic segregation increased 1 (PMS1) responses were seen, with detectable antibody in 10% Japanese and 0% US AA patients. In one of the Japanese AA patients with detectible anti‐kinectin antibodies, the autoantibody disappeared coincidentally with the partial resolution of pancytopenia. These results support the hypothesis that the epidemiology of AA is heterogeneous and suggest that anti‐kinectin autoantibody titre may serve as a surrogate maker for the disease activity of AA.
Gall initiation enhances the availability of food resources for herbivorous insects
Authors: Nakamura M. , Miyamoto Y. , Ohgushi T. 
Published: December 2004

Summary

Insect herbivory may have not only negative but also positive plant‐mediated effects on other insect herbivores. We investigated plant‐mediated effects of the stem gall midge Rabdophaga rigidae on other insect herbivores through regrowth response of the willow Salix eriocarpa.
Gall initiation on current‐year shoots stimulated the development of lateral shoots, followed by a secondary leaf flush. Lateral shoots and upper leaves on galled shoots were less tough and had a higher water and nitrogen content.
Colonization rates by the aphid Aphis farinosa were significantly higher on galled shoots than on ungalled shoots, because this aphid frequently colonized lateral shoots.
Adults of two leaf beetles, Plagiodera versicolora and Smaragdina semiaurantiaca, were more abundant on galled than on ungalled shoots; they preferentially fed on young leaves produced during the secondary leaf flush.
Gall initiation positively affected aphids and leaf beetles by enhancing the availability of food resources as a result of the regrowth responses of S. eriocarpa. This indicates that the regrowth responses of plants to insect herbivory provide an important mechanism responsible for positive effects on other insect herbivores.
Long‐term patterns of leaf, shoot and wood production after insect herbivory in the Mountain Birch
Authors: Karlsson P. S. , Weih M. 
Published: December 2004

Summary

The pattern of responses of adult trees of Mountain Birch (Betula pubescens ssp. czerepanovii) to an outbreak of a folivorous insect (Epirrita autumnata) causing ≈90% defoliation was studied over 8 years in a subarctic area in northern Sweden.
Tree recovery was monitored in terms of the numbers, area, mass and nitrogen content of leaves, the numbers of leaf‐carrying long and short shoots, and the widths of annual tree rings in stems.
The most prominent characteristic of defoliated trees was a threefold increase in the proportion of long shoots 1 year after defoliation. These shoots subsequently produced many new leaf‐carrying short shoots, resulting in shoot populations ≈50% larger than those of control trees. Thereafter the most strongly defoliated trees showed decreasing leaf area.
Defoliated trees produced more female catkins but fewer male catkins than control trees.
Released apical dominance did not result in any overcompensation in terms of growth or leaf area production. However, it presumably increased the rate of recovery from herbivory. For the most strongly defoliated trees, the benefits from increased production of long shoots was not sustainable.
Comparative fire ecology of tropical savanna and forest trees
Authors: Hoffmann William A. , Orthen Birgit , Nascimento Paula Kielse Vargas do 
Published: December 2004

SummaryFire is important in the dynamics of savanna–forest boundaries, often maintaining a balance between forest advance and retreat.We performed a comparative ecological study to understand how savanna and forest species differ in traits related to fire tolerance. We compared bark thickness, root and stem carbohydrates, and height of reproductive individuals within 10 congeneric pairs, each containing one savanna and one forest species.Bark thickness of savanna species averaged nearly three times that of forest species, thereby reducing the risk of stem death during fire. The allometric relationship between bark thickness and stem diameter differed between these two tree types, with forest species tending to have a larger allometric coefficient.The height of reproductive individuals of forest species averaged twice that of congeneric savanna species. This should increase the time necessary for forest species to reach reproductive size, thereby reducing their capacity to reach maturity in the time between consecutive fires.There was no difference in total non‐structural carbohydrate content of stems or roots between savanna and forest species, though greater allocation to total root biomass by savanna species probably confers greater capacity to resprout following fire.These differences in fire‐related traits may largely explain the greater capacity of savanna species to persist in the savanna environment.