bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interplay between Arabidopsis Activating Factors E2Fb and E2Fa in Cell Cycle Progression and Development
Authors: Sozzani Rosangela , Maggio Caterina , Varotto Serena , Canova Sabrina , Bergounioux Catherine , Albani Diego , Cella Rino 
Published: March 2006

AbstractEukaryotic E2Fs are conserved transcription factors playing crucial and antagonistic roles in several pathways related to cell division, DNA repair, and differentiation. In plants, these processes are strictly intermingled at the growing zone to produce postembryonic development in response to internal signals and environmental cues. Of the six AtE2F proteins found in Arabidopsis (Arabidopsis thaliana), only AtE2Fa and AtE2Fb have been clearly indicated as activators of E2F-responsive genes. AtE2Fa activity was shown to induce S phase and endoreduplication, whereas the function of AtE2Fb and the interrelationship between these two transcription factors was unclear. We have investigated the role played by the AtE2Fb gene during cell cycle and development performing in situ RNA hybridization, immunolocalization of the AtE2Fb protein in planta, and analysis of AtE2Fb promoter activity in transgenic plants. Overexpression of AtE2Fb in transgenic Arabidopsis plants led to striking modifications of the morphology of roots, cotyledons, and leaves that can be ascribed to stimulation of cell division. The accumulation of the AtE2Fb protein in these lines was paralleled by an increased expression of E2F-responsive G1/S and G2/M marker genes. These results suggest that AtE2Fa and AtE2Fb have specific expression patterns and play similar but distinct roles during cell cycle progression.
Temperament and character dimensions in patients with atopic dermatitis
Authors: KIM Tae‐Suk , PAE Chi‐Un , JEONG Jeung‐Tae , KIM Sang‐Dong , CHUNG Kyoo‐In , LEE Chul 
Published: March 2006

ABSTRACTThe aim of this study was to assess the personality traits of young male patients with atopic dermatitis (AD), and to examine the correlations between temperament and character dimensions with clinical and other psychological factors. Fifty young adult male AD patients and 83 healthy controls were examined using the temperament and character inventory, the Beck depression inventory and the state‐trait anxiety inventory. The AD patients scored higher on harm avoidance and lower on reward dependence, self‐directedness and cooperativeness than the healthy controls. The illness duration and anxiety correlated negatively with the self‐directedness score, and depression correlated negatively with reward dependence and the persistence scores in AD patients. These results suggest that AD patients have distinctive temperament and character dimensions compared to healthy controls. Moreover, illness duration and anxiety might be associated with some personality problems, and some temperament dimensions (e.g. reward dependence, persistence) may be linked to depressive symptoms in AD patients.
Granulomas induced by subcutaneous injection of leuprorelin acetate
Authors: SAKAMOTO Ryoko , HIGASHI Yuko , MERA Kentaro , KANEKURA Takuro , KANZAKI Tamotsu 
Published: March 2006

ABSTRACTLeuprorelin acetate, a chemotherapeutic agent used to treat prostate cancer, is a synthetic luteinizing hormone‐releasing hormone (LHRH) agonist. We report a 75‐year‐old man who presented with several large subcutaneous nodules at the site of leuprorelin acetate injections for his prostatic cancer. A biopsy of the nodules disclosed epithelioid granulomatous inflammation and resulted in a diagnosis of drug‐induced granulomatous reaction to leuprorelin acetate.
A case of Sister Mary Joseph's nodule from prostatic cancer
Authors: FUKUDA Hidetsugu , SAITO Ryuzo 
Published: March 2006

ABSTRACTThe metastasis of a visceral malignancy to the umbilicus is known as “Sister Mary Joseph's nodule” (SMJN). We recently encountered an 80‐year‐old man in whom umbilical metastasis of prostatic cancer was revealed during the course of treatment. The lesion was a red, firm, elastic nodule, 2.5 cm in diameter, with a bumpy, irregular surface, but without subjective symptoms. In histopathological examination, atypical cells with intensely stained, small quasi‐circular nuclei and weakly eosinophilic cytoplasm were found in all layers of the dermis. In some parts of these tumor cells, a gland‐like structure was observed. Immunohistochemical investigation of the invading tumor cells disclosed immunoreactivity for prostate specific antigen and prostatic acid phosphatase, supporting a diagnosis of SMJN from prostatic cancer. His general condition gradually deteriorated, and he died 2 months later. Prostate cancer often metastasizes to bones and lymph nodes, but rarely to the skin. Of all the cases of cutaneous metastasis of prostate cancer reported in Japan, only three metastases have occurred to the umbilical region. The present case is therefore an example of a very rare condition.
A case of Papillon–Lefevre syndrome associated with xanthogranulomatous pyelonephritis and hepatitis
Authors: MANSUR A. Tülin , GÖKTAY Fatih , DEMİROK Nüket 
Published: March 2006

ABSTRACTPapillon–Lefevre syndrome (PLS) is an autosomally recessive palmoplantar keratoderma accompanied by psoriasiform plaques on the extensor surfaces of extremities and leading to premature loss of deciduous and permanent teeth by progressive periodontitis. Patients with PLS may exhibit mental retardation, intracranial ectopic calcifications, nail dystrophies and a tendency to various infectious disorders, in addition to skin and oral findings. Herein, we report a 26‐year‐old man with PLS, who had experienced xanthogranulomatous pyelonephritis and hepatitis during childhood and adolescence. To the best of our knowledge, this is the first report of PLS associated with xanthogranulomatous inflammation.
Can haematological tests predict cardiovascular risk? The 2005 Kettle Lecture*
Authors: Lowe Gordon D. O. 
Published: March 2006

SummaryThe risk of venous or arterial thrombosis is routinely assessed by clinical variables (risk factors) supplemented by measurement of blood lipids and glucose for arterial thrombotic events. Haematological tests that might play a role in risk prediction include haemostatic variables, haematocrit and inflammatory markers (erythrocyte sedimentation rate, plasma viscosity, white cell count). Recent epidemiological studies of these phenotypes and related genotypes are reviewed. For the risk prediction of first venous thrombosis, screening for thrombophilias in ‘high‐risk’ situations does not appear clinically effective or cost‐effective; with the possible exception of women considering oral hormone replacement therapy. General screening after a first venous event to predict recurrence (or risk in asymptomatic relatives) does not appear effective; with the possible exception of d‐dimer, which requires further study. For risk prediction of first arterial thrombosis, screening adds little to prediction by current clinical risk scores. Screening of persons after a first arterial event, or with atrial fibrillation (e.g. with d‐dimer for stroke prediction), requires further study. In conclusion, haematological tests have very limited roles in the prediction of cardiovascular risk, and should only be used according to evidence‐based guidelines. The need for management studies is highlighted.
How are soil use and management reflected by soil organic matter characteristics: a spectroscopic approach
Authors: Gerzabek M. H. , Antil R. S. , Kögel‐Knabner I. , Knicker H. , Kirchmann H. , Haberhauer G. 
Published: March 2006

SummaryWe studied the quantitative and qualitative changes of soil organic matter (SOM) due to different land uses (arable versus grassland) and treatments (organic manure and mineral fertilizer) within an agricultural crop rotation in a long‐term field experiment, conducted since 1956 at Ultuna, Sweden, on a Eutric Cambisol. The organic carbon (OC) content of the grassland plot was 1.8 times greater than that of the similarly fertilized Ca(NO3)2 treated cropped plots. The comparison of two dispersion techniques (a low‐energy sonication and a chemical dispersion which yield inherent soil aggregates) showed that increasing OC contents of the silt‐sized fractions were not matched by a linear increase of silt‐sized aggregates. This indicated saturation of the aggregates with OC and a limited capacity of particles to protect OC physically. Thermogravimetric analyses suggested an increase of free organic matter with increasing OC contents. Transmission FT‐IR spectroscopy showed relative enrichment of carboxylic, aromatic, CH and NH groups in plots with increasing OC contents. The silt‐sized fractions contained the largest SOM pool and, as revealed by 13C NMR spectroscopy, were qualitatively more influenced by the plant residue versus manure input than the clay fractions. Alkyl and O‐alkyl C in the silt‐sized fractions amounted to 57.4% of organic carbon in the animal manure treated plots and 50–53% in the other treatments.
Lignin degradation controls the production of dissolved organic matter in decomposing foliar litter
Authors: Kalbitz K. , Kaiser K. , Bargholz J. , Dardenne P. 
Published: March 2006

SummaryLignin is considered to be a crucial component controlling litter decomposition but its role in the production of dissolved organic matter (DOM) from litter is not well understood. Our main objective therefore was to examine the amounts and properties of DOM produced in decomposing litter, with special emphasis on the role of lignin degradation. We exposed litter of five different tree species (Sycamore maple, Mountain ash, European beech, Norway spruce, Scots pine) in litterbags at the soil surface of two neighbouring sites to degradation under field conditions. Litterbags were sampled eight times during 27 months of exposure in the field. We determined mass loss and characterized the lignin fraction by two different methods (van Soest procedure, acid‐detergent lignin: ADL, CuO oxidation). Litter was irrigated in the laboratory and leachates were analysed for dissolved organic carbon (DOC) and characterized by UV and fluorescence spectroscopy. Litter decomposition followed a two‐stage model characterized by initially rapid and then decreasing degradation with time. In the initial phase of litter decomposition, leached amounts of DOM decreased with time and no effects of lignin degradation were found. The contents of ADL in the litter residues and CuO oxidation products suggest larger degradation and oxidation of lignin in beech, spruce and pine litter than in maple and ash litter. The production of DOM from litter with larger lignin degradation increased in the second phase of decomposition, when mass loss exceeded 10–20%. In contrast, DOM produced from litter showing weak lignin degradation (maple, ash) did not increase further in the second phase of decomposition. In the leachates of litter with large lignin degradation (beech, spruce, pine), UV absorbance and fluorescence spectroscopy indicated a larger increase in the contribution of lignin‐derived compounds to DOM with increasing mass loss than for litter species with relatively stable lignin. We conclude that degradation of lignin is an important control on DOM production during the second phase of litter decomposition.
The role of wood density and stem support costs in the growth and mortality of tropical trees
Authors: KING DAVID A. , DAVIES STUART J. , TAN SYLVESTER , NOOR NUR SUPARDI MD. 
Published: March 2006

SummaryThe rapid growth rates of light‐demanding tree species have been attributed in part to their low‐density, low‐cost stems. We evaluated the influence of light and biomass support costs on growth rates of trees 8–25 cm in diameter at breast height (d.b.h.) among 21 species differing in wood density in two aseasonal rain forests.Measurements of crown width, tree height, d.b.h. and wood density (ρ) were used to estimate the stem biomass (Ms) of a standard‐sized tree (17 m tall and 16 m2in crown area), i.e. the cost in stem biomass of supporting a given sized crown at a given height.The species showed a three‐fold range in support cost, which was highly correlated with wood density (Ms ∝ ρ0.77,r2 = 0.72 for the log‐transformed relationship). This relationship is due to the high interspecific variation in wood density and the fact that the stem diameter of the standard‐sized tree increased only slightly with decreasing wood density, i.e. light‐wooded species did not compensate for their lighter, weaker wood by substantially increasing stem thickness.Mean growth rate per species showed a 10‐fold range and increased with the fraction of trees at least partly in gaps (gap fraction), the reciprocal of support cost (1/Ms), and the reciprocal of wood density (1/ρ). The relationship between mean growth rate and 1/Mswas particularly strong when one outlier was excluded (r2 = 0.88) and among the Dipterocarpaceae (r2 = 0.89).Log(mortality rate), as determined for all trees per species ≥ 1 cm d.b.h., increased linearly with 1/Ms, 1/ρ and gap fraction.These results suggest an important role for wood density and support costs in the classic tradeoff between rapid growth and increased risks of damage and death.
Ecosystem science and human–environment interactions in the Hawaiian archipelago
Authors: VITOUSEK PETER 
Published: March 2006

Summary
Tansley's ecosystem concept remains a vital framework for ecological research in part because the approach facilitates interdisciplinary analyses of ecological systems.
Features of the Hawaiian Islands – particularly the nearly orthogonal variation in many of the factors that control variation among ecosystems elsewhere – make the archipelago a useful model system for interdisciplinary research designed to understand fundamental controls on the state and dynamics of ecosystems, and their consequences for human societies.
Analyses of rain forest sites arrayed on a substrate age gradient from c. 300 years to over 4 million years across the Hawaiian archipelago demonstrate that the sources of calcium and other essential cations shift from > 80% rock‐derived in young sites to > 80% derived from marine aerosol on substrates older than 100 000 years. Rock‐derived phosphorus is retained longer within ecosystems, but eventually long‐distance transport of continental dust from Asia becomes the most important source of phosphorus.
A biogeochemical feedback from low nutrient availability to efficient resource use by trees to slow decomposition and nutrient regeneration accentuates the geochemically driven pattern of low phosphorus availability and phosphorus limitation to net primary productivity in the oldest site.
Variations in ecosystem biogeochemistry across the archipelago shaped the development and sustainability of Polynesian agricultural systems in the millennium between their discovery of Hawai’i and contact by Europeans. Irrigated pondfields were largely confined to stream valleys on the older islands, while rain‐fed dryland systems occupied a narrow zone of fertile, well‐watered soils on the younger islands.
The ecosystem approach often represents the most appropriate level of organization for analyses of human influences on ecological systems; it can play a central role in the design and analysis of alternative agricultural, industrial and residential systems that could reduce the human footprint on the Earth.
PerR controls Mn‐dependent resistance to oxidative stress inNeisseria gonorrhoeae
Authors: Wu Hsing‐Ju , Seib Kate L. , Srikhanta Yogitha N. , Kidd Stephen P. , Edwards Jennifer L. , Maguire Tina L. , Grimmond Sean M. , Apicella Michael A. , McEwan Alastair G. , Jennings Michael P. 
Published: March 2006

SummaryIn previous studies it has been established that resistance to superoxide byNeisseria gonorrhoeaeis dependent on the accumulation of Mn(II) ions involving the ABC transporter, MntABC. A mutant strain lacking the periplasmic binding protein component (MntC) of this transport system is hypersensitive to killing by superoxide anion. In this study themntCmutant was found to be more sensitive to H2O2killing than the wild‐type. Analysis of regulation of MntC expression revealed that it was de‐repressed under low Mn(II) conditions. TheN. gonorrhoeae mntABClocus lacks themntRrepressor typically found associated with this locus in other organisms. A search for a candidate regulator ofmntABCexpression revealed a homologue of PerR, a Mn‐dependent peroxide‐responsive regulator found in Gram‐positive organisms. AperRmutant expressed more MntC protein than wild‐type, and expression was independent of Mn(II), consistent with a role for PerR as a repressor ofmntABCexpression. The PerR regulon ofN. gonorrhoeaewas defined by microarray analysis and includes ribosomal proteins, TonB‐dependent receptors and an alcohol dehydrogenase. Both themntCandperRmutants had reduced intracellular survival in a human cervical epithelial cell model.
Characterizing the flagellar filament and the role of motility in bacterial prey‐penetration by Bdellovibrio bacteriovorus
Authors: Lambert Carey , Evans Katy J. , Till Rob , Hobley Laura , Capeness Michael , Rendulic Snjezana , Schuster Stephan C. , Aizawa Shin‐Ichi , Sockett R. Elizabeth 
Published: March 2006

SummaryThe predatory bacterium Bdellovibrio bacteriovorus swims rapidly by rotation of a single, polar flagellum comprised of a helical filament of flagellin monomers, contained within a membrane sheath and powered by a basal motor complex. Bdellovibrio collides with, enters and replicates within bacterial prey, a process previously suggested to firstly require flagellar motility and then flagellar shedding upon prey entry. Here we show that flagella are not always shed upon prey entry and we study the six fliC flagellin genes of B. bacteriovorus, finding them all conserved and expressed in genome strain HD100 and the widely studied lab strain 109J. Individual inactivation of five of the fliC genes gave mutant Bdellovibrio that still made flagella, and which were motile and predatory. Inactivation of the sixth fliC gene abolished normal flagellar synthesis and motility, but a disordered flagellar sheath was still seen. We find that this non‐motile mutant was still able to predate when directly applied to lawns of YFP‐labelled prey bacteria, showing that flagellar motility is not essential for prey entry but important for efficient encounters with prey in liquid environments.
Two aerobic pathways for the formation of unsaturated fatty acids in Pseudomonas aeruginosa
Authors: Zhu Kun , Choi Kyoung‐Hee , Schweizer Herbert P. , Rock Charles O. , Zhang Yong‐Mei 
Published: March 2006

SummaryThe double bond in anaerobic unsaturated fatty acid (UFA) biosynthesis is introduced by the FabA dehydratase/isomerase of the bacterial type II fatty acid biosynthetic pathway. A ΔfabA mutant of Pseudomonas aeruginosa grew aerobically, but required a UFA supplement for anaerobic growth. Wild‐type cells produced 18:1Δ11 as the principal UFA, whereas the ΔfabA strain produced only 16:1Δ9. The double bond in the 16:1Δ9 was introduced after phospholipid formation and was localized in the sn‐2 position. Two predicted membrane proteins, DesA and DesB, possessed the conserved histidine clusters characteristic of fatty acid desaturases. The ΔfabAΔdesA double mutant required exogenous fatty acids for growth but the ΔfabAdesB double mutant did not. Exogenous stearate was converted to 18:1Δ9 and supported the growth of ΔfabAΔdesA double mutant. A ΔfabAΔdesAdesB triple mutant was unable to desaturate exogenous stearate and was an UFA auxotroph. We detected a 2.5‐fold increase in desA expression in ΔfabA mutants, whereas desB expression was derepressed by the deletion of the gene encoding a transcriptional repressor DesT. These data add two aerobic desaturases to the enzymes used for fatty acid metabolism in proteobacteria: DesA, a 2‐position phospholipid Δ9‐desaturase that supplements the anaerobic FabA pathway, and DesB, an inducible acyl‐CoA Δ9‐desaturase whose expression is repressed by DesT.
Bradyrhizobium japonicum senses iron through the status of haem to regulate iron homeostasis and metabolism
Authors: Yang Jianhua , Sangwan Indu , Lindemann Andrea , Hauser Felix , Hennecke Hauke , Fischer Hans‐Martin , O'Brian Mark R. 
Published: March 2006

SummaryThe Irr protein from the bacterium Bradyrhizobium japonicum is expressed under iron limitation to mediate iron control of haem biosynthesis. The regulatory input to Irr is the status of haem and its precursors iron and protoporphyrin at the site of haem synthesis. Here, we show that Irr controls the expression of iron transport genes and many other iron‐regulated genes not directly involved in haem synthesis. Irr is both a positive and negative effector of gene expression, and in at least some cases the control is direct. Loss of normal iron responsiveness of those genes in an irr mutant, as well as a lower total cellular iron content, suggests that Irr is required for the correct perception of the cellular iron status. Degradation of Irr in iron replete cells requires haem. Accordingly, control of Irr‐regulated genes by iron was aberrant in a haem‐defective strain, and iron replete mutant cells behave as if they are iron‐limited. In addition, the haem mutant had an abnormally high cellular iron content. The findings indicate that B. japonicum senses iron via the status of haem biosynthesis in an Irr‐dependent manner to regulate iron homeostasis and metabolism.
Characterization of the Staphylococcus aureus CidR regulon: elucidation of a novel role for acetoin metabolism in cell death and lysis
Authors: Yang Soo‐Jin , Dunman Paul M. , Projan Steven J. , Bayles Kenneth W. 
Published: March 2006

SummaryThe Staphylococcus aureus cid and lrg operons encode a novel regulatory system that affects murein hydrolase activity, stationary‐phase survival and antibiotic tolerance. Expression of the lrgAB operon is positively regulated by a two‐component regulatory system encoded by the lytSR operon located immediately upstream to lrgAB. By comparison, the cidABC operon lies downstream from the cidR gene, encoding a protein homologous to the LysR‐type family of transcriptional regulators. Transcription analysis of a cidR mutant revealed that CidR enhances cidABC expression in the presence of acetic acid generated by the metabolism of excess glucose. Microarray studies identified additional CidR‐regulated operons including the IrgAB and alsSD encoding proteins involved in acetoin production. Surprisingly, Northern blot analyses revealed that cidABC and lrgAB transcription was uninducible in an alsSD mutant grown in the presence of excess glucose, suggesting that the CidR‐mediated upregulation of cidABC and lrgAB transcription is dependent on the presence of intact alsSD genes. Zymographic and quantitative analyses of murein hydrolase activity also revealed that disruption of the alsSD genes results in significantly decreased extracellular murein hydrolase activity compared with that of the parental strain, UAMS‐1. Furthermore, the alsSD mutant displayed decreased stationary‐phase survival relative to UAMS‐1, both in the presence and absence of glucose. The results of this study define the CidR regulon and demonstrate that the generation of acetoin is linked to the control of cell death and lysis in S. aureus.