bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size‐mediated ageing reduces vigour in trees
Authors: Mencuccini M. , Martínez‐Vilalta J. , Vanderklein D. , Hamid H. A. , Korakaki E. , Lee S. , Michiels B. 
Published: September 2005

AbstractThere is increasing interest in understanding the costs and benefits of increased size and prolonged lifespan for plants. Some species of trees can grow more than 100 m in height and can live for several millennia, however whether these achievements are obtained at the cost of some other physiological functions is currently unclear. As increases in size are usually associated with ageing, it is also unclear whether observed reductions in growth rates and increased mortality rates are a function of size or of age per se. One theory proposes that reduced growth after the start of the reproductive phase is caused by cellular senescence. A second set of theories has focussed instead on plant size and the increased respiratory burdens or excessive height. We report on experimental manipulations to separate the effects of extrinsic factors such as size from those of intrinsic factors such as age for four tree species of contrasting phylogeny and life history. For each species, we measured growth, gas exchange and leaf biochemical properties for trees of different ages and sizes in the field and on propagated material obtained from the same genetic individuals but now all of small similar size in our common gardens. For all species, evidence indicated that size, not cellular senescence, accounted for the observed age‐related declines in relative growth rates and net assimilation rates. Two species exhibited evidence of genetic control on leaf characters such as specific leaf area, although size also exerted an independent, and stronger, effect. We found partial support for the theory of hydraulic limitations to tree growth. The lack of a marked separation of soma and germline, an unlimited proliferation potential of meristem cells and the exponential increase in reproductive effort with size all help explain the lack of a senescence‐induced decline in trees. It is possible that trees much older than the ones we sampled exhibit senescence symptoms.
Novel genes for nitrite reductase and Amo‐related proteins indicate a role of uncultivated mesophilic crenarchaeota in nitrogen cycling
Authors: Treusch Alexander H. , Leininger Sven , Kletzin Arnulf , Schuster Stephan C. , Klenk Hans‐Peter , Schleper Christa 
Published: September 2005

SummaryMesophilic crenarchaeota are frequently found in terrestrial and marine habitats worldwide, but despite their considerable abundance the physiology of these as yet uncultivated archaea has remained unknown. From a 1.2 Gb large‐insert environmental fosmid library of a calcareous grassland soil, a 43 kb genomic fragment was isolated with a ribosomal RNA that shows its affiliation to group 1.1b of crenarchaeota repeatedly found in soils. The insert encoded a homologue of a copper‐containing nitrite reductase with an unusual C‐terminus that encoded a potential amicyanin‐like  electron  transfer  domain  as  well  as  two proteins related to subunits of ammonia monooxygenases or particulate methane monooxygenases (AmoAB/PmoAB) respectively. Expression of nirK and the amoA‐like gene was shown by reverse transcription polymerase chain reaction (PCR) analyses in soil samples, the latter being found at higher levels when the soil was incubated with ammonia (measured by quantitative PCR). Further variants of both genes were amplified from soil samples and were found in the environmental database from the Sargasso Sea plankton. Taken together, our findings suggest that mesophilic terrestrial and marine crenarchaeota might be capable of ammonia oxidation under aerobic and potentially also under anaerobic conditions.
Lateral gene transfer and phylogenetic assignment of environmental fosmid clones
Authors: Nesbø Camilla L. , Boucher Yan , Dlutek Marlena , Doolittle W. Ford 
Published: September 2005

SummaryMetagenomic data, especially sequence data from large insert clones, are most useful when reasonable inferences about phylogenetic origins of inserts can be made. Often, clones that bear phylotypic markers (usually ribosomal RNA genes) are sought, but sometimes phylogenetic assignments have been based on the preponderance of blast hits obtained with predicted protein coding sequences (CDSs). Here we use a cloning method which greatly enriches for ribosomal RNA‐bearing fosmid clones to ask two questions: (i) how reliably can we judge the phylogenetic origin of a clone (that is, its RNA phylotype) from the sequences of its CDSs? and (ii) how much lateral gene transfer (LGT) do we see, as assessed by CDSs of different phylogenetic origins on the same fosmid? We sequenced 12 rRNA containing fosmid clones, obtained from libraries constructed using DNA isolated from Baltimore harbour sediments. Three of the clones are from bacterial candidate divisions for which no cultured representatives are available, and thus represent the first protein coding sequences from these major bacterial lineages. The amount of LGT was assessed by making phylogenetic trees of all the CDSs in the fosmid clones and comparing the phylogenetic position of the CDS to the rRNA phylotype. We find that the majority of CDSs in each fosmid, 57–96%, agree with their respective rRNA genes. However, we also find that a significant fraction of the CDSs in each fosmid, 7–44%, has been acquired by LGT. In several cases, we can infer co‐transfer of functionally related genes, and generate hypotheses about mechanism and ecological significance of transfer.
Patient‐centred and professional‐directed implementation strategies for diabetes guidelines: a cluster‐randomized trial‐based cost‐effectiveness analysis
Authors: Dijkstra R. F. , Niessen L. W. , Braspenning J. C. C. , Adang E. , Grol R. T. P. M. 
Published: September 2005

AbstractAims  Economic evaluations of diabetes interventions do not usually include analyses on effects and cost of implementation strategies. This leads to optimistic cost‐effectiveness estimates. This study reports empirical findings on the cost‐effectiveness of two implementation strategies compared with usual hospital outpatient care. It includes both patient‐related and intervention‐related cost.Patients and methods  In a clustered‐randomized controlled trial design, 13 Dutch general hospitals were randomly assigned to a control group, a professional‐directed or a patient‐centred implementation programme. Professionals received feedback on baseline data, education and reminders. Patients in the patient‐centred group received education and diabetes passports. A validated probabilistic Dutch diabetes model and the UKPDS risk engine are used to compute lifetime disease outcomes and cost in the three groups, including uncertainties.Results  Glycated haemoglobin (HbA1c) at 1 year (the measure used to predict diabetes outcome changes over a lifetime) decreased by 0.2% in the professional‐change group and by 0.3% in the patient‐centred group, while it increased by 0.2% in the control group. Costs of primary implementation were < 5 Euro per head in both groups, but average lifetime costs of improved care and longer life expectancy rose by 9389 Euro and 9620 Euro, respectively. Life expectancy improved by 0.34 and 0.63 years, and quality‐adjusted life years (QALY) by 0.29 and 0.59. Accordingly, the incremental cost per QALY was 32 218 Euro for professional‐change care and 16 353 for patient‐centred care compared with control, and 881 Euro for patient‐centred vs. professional‐change care. Uncertainties are presented in acceptability curves: above 65 Euro per annum the patient‐directed strategy is most likely the optimum choice.Conclusion  Both guideline implementation strategies in secondary care are cost‐effective compared with current care, by Dutch standards, for these patients. Additional annual costs per patient using patient passports are low. This analysis supports patient involvement in diabetes in the Netherlands, and probably also in other Western European settings.
The Lem2 gene promoter of barley directs cell‐ and development‐specific expression of gfp in transgenic plants
Authors: Abebe Tilahun , Skadsen Ron , Patel Minesh , Kaeppler Heidi 
Published: September 2005

SummaryTransgenic approaches to combating fungal pathogens, such as Fusarium graminearum, require the targeting of antifungal gene expression in tissues of developing seed spikes of cereal grains, especially lemmas and epicarps. The Lem2 gene of barley encodes a lectin‐like protein that is strongly up‐regulated by salicylic acid and is preferentially expressed in lemmas, paleas (lemma/palea) and coleoptiles. Transient expression studies have indicated that the proximal −75/+70 region (relative to the transcription start site) determines organ specificity. In the present study, Golden Promise barley stably transformed with Morex Lem2 promoter/gfp reporter constructs displayed cell‐ and development‐specific expression of gfp (green fluorescent protein gene). This expression corresponded to the expression seen in Northern blots of Morex organs. Under the full‐length promoter, strong GFP fluorescence was observed in the lemma/palea, glumes, coleoptile, auricle and ligule. Weak GFP fluorescence was also observed in the rachis, tips of primary leaves and the leaf sheath. Unexpectedly, strong expression occurred in the epicarp, even though Lem2 is not expressed in this organ in Morex. Studies showed that the Lem2 promoter is more highly methylated in the epicarp than in the lemma of Morex. In the lemma/palea, gfp underwent a temporal shift in expression from the mesophyll to specialized epidermal cork cells. Similar to the lemma/palea, expression in the leaf sheath was localized in the cork cells. Progressive 5′ deletions of the promoter to nucleotide −75 gradually reduced the level of gfp expression, but tissue‐ and cell‐specific expression was retained.
A novel alternative splicing form of excitatory amino acid transporter 1 is a negative regulator of glutamate uptake
Authors: Vallejo‐Illarramendi Ainara , Domercq María , Matute Carlos 
Published: September 2005

AbstractEAAT1 is a major glutamate transporter in the CNS and is required for normal neurotransmission and neuroprotection from excitotoxicity. In the present study, we have identified a novel form of the human EAAT1, named here as EAAT1ex9skip, which lacks the entire exon 9. Quantitative PCR analysis indicates that this variant is expressed throughout the CNS, both in grey matter and axonal tracts, at levels ranging between 10% and 20% of the full‐length EAAT1 form. When expressed in HEK293 cells, EAAT1ex9skip mRNA is translated into a truncated protein localized in the endoplasmic reticulum. EAAT1ex9skip has no functional glutamate uptake activity but instead, exerts a dominant negative effect over full‐length EAAT1 function. In turn, co‐expression of full‐length EAAT1 and EAAT1ex9skip variants reduces the insertion of the former into the plasma membrane. Together, these results indicate that the EAAT1ex9skip splice variant is a negative regulator of full‐length EAAT1 function in the human brain.
Characterization of glial cell line‐derived neurotrophic factor family receptor α‐1 in peripheral nerve Schwann cells
Authors: Hase Asako , Saito Fumiaki , Yamada Hiroki , Arai Ken , Shimizu Teruo , Matsumura Kiichiro 
Published: September 2005

AbstractGlial cell line‐derived neurotrophic factor (GDNF) family receptor α‐1 (GFRα‐1) is a receptor component of GDNF that associates with and activates the tyrosine kinase receptor Ret. To further understand GDNF and its receptor system in the PNS, we first characterized the expression of GFRα‐1 in bovine peripheral nerve in vivo. GFRα‐1 immunoreactivity was localized adjacent to the outermost layer of myelin sheath, as well as in the endoneurium and axoplasm. In a fractionation study, GFRα‐1 was recovered mostly in the soluble fraction, although a small amount was recovered in the membrane fraction. A substantial amount of GFRα‐1 in the membrane fraction was extractable by detergent and alkaline conditions. To further clarify the expression of GFRα‐1 in Schwann cells, we examined cultured rat Schwann cells and the Schwannoma cell line RT4. Schwann cells expressed GFRα‐1 in both the soluble/cytosolic and membrane fractions, and the membrane form of GFRα‐1 was expressed at the outer surface of the Schwann cell plasma membrane. We also confirmed the secretion of the soluble form of GFRα‐1 from Schwannoma cells in a metabolic labeling experiment. These data contribute to our knowledge of the production, expression and functions of GFRα‐1 in the PNS.
Regulation of hippocampal cholesterol metabolism by apoE and environmental stimulation
Authors: Levi Ofir , Lütjohann Dieter , Devir Aliza , Von Bergmann Klaus , Hartmann Tobias , Michaelson Daniel M. 
Published: September 2005

AbstractAlzheimer's disease is associated with genetic risk factors, of which the allele E4 of apolipoprotein E (apoE4) is the most prevalent, and it is also affected by environmental factors such as early life education. We have recently shown, utilizing apoE‐deficient and apoE transgenic mice, that synaptogenesis in the hippocampus following environmental stimulation is affected by apoE. In view of the pivotal role of cholesterol in synaptic plasticity, and of its suggested role in synaptogenesis, we presently examined the effects of apoE and environmental stimulation on brain cholesterol homeostasis. The hippocampal levels of cholesterol and its precursors and metabolites in control mice were not affected by exposure to environmental stimulation. In contrast, the hippocampal levels of cholesterol and its precursors lathosterol and desmosterol and metabolite 24S‐hydroxycholesterol were lower in apoE‐deficient mice that were maintained in a regular environmental than those of corresponding control mice, whereas they were markedly elevated following environmental stimulation. Histological and immunohistochemical experiments revealed that the combined stimulatory effects of apoE deficiency and environmental stimulation on cholesterol metabolism were associated with marked activation of hippocampal astrocytes and with the abnormal accumulation of cholesterol in neurons and astrocytes. These effects were rescued similarly in apoE3 and apoE4 transgenic mice. These findings suggest that apoE plays an important role in the translocation of cholesterol from astrocytes to neurons in vivo and in the regulation and homeostasis of this process.
A nonlethal method of identification of Ambystoma laterale, A. jeffersonianum and sympatric unisexuals
Authors: RAMSDEN C. , BÉRIAULT K. , BOGART J. P. 
Published: September 2005

AbstractUnisexual salamanders in the genus Ambystoma live in obligate sympatry with the sexual species Ambystoma laterale or Ambystoma jeffersonianum, from which they are not easily distinguished. Because the sexual species are protected in many parts of their range, accurate identification of sexual and unisexual individuals is required for conservation purposes. Unisexual individuals are currently identified using isozyme electrophoresis, which requires sacrificing the animal. Here we present a nonlethal method of identification for members of the A. laterale–jeffersonianum part of the Ambystoma complex utilizing genome‐specific microsatellites with or without the addition of flow cytometry.
Constraining the P–T path of a MORB‐type eclogite using pseudosections, garnet zoning and garnet‐clinopyroxene thermometry: an example from the Bohemian Massif
Authors: ŠTÍPSKÁ P. , POWELL R. 
Published: September 2005

AbstractA mid‐ocean ridge basalt (MORB)‐type eclogite from the Moldanubian domain in the Bohemian Massif retains evidence of its prograde path in the form of inclusions of hornblende, plagioclase, clinopyroxene, titanite, ilmenite and rutile preserved in zoned garnet. Prograde zoning involves a flat grossular core followed by a grossular spike and decrease at the rim, whereas Fe/(Fe + Mg) is also flat in the core and then decreases at the rim. In a pseudosection for H2O‐saturated conditions, garnet with such a zoning grows along an isothermal burial path at c. 750 °C from 10 kbar in the assemblage plagioclase‐hornblende‐diopsidic clinopyroxene‐quartz, then in hornblende‐diopsidic clinopyroxene‐quartz, and ends its growth at 17–18 kbar. From this point, there is no pseudosection‐based information on further increase in pressure or temperature. Then, with garnet‐clinopyroxene thermometry, the focus is on the dependence on, and the uncertainties stemming from the unknown Fe3+ content in clinopyroxene. Assuming no Fe3+ in the clinopyroxene gives a serious and unwarranted upward bias to calculated temperatures. A Fe3+‐contributed uncertainty of ±40 °C combined with a calibration and other uncertainties gives a peak temperature of 760 ± 90 °C at 18 kbar, consistent with no further heating following burial to eclogite facies conditions. Further pseudosection modelling suggests that decompression to c. 12 kbar occurred essentially isothermally from the metamorphic peak under H2O‐undersaturated conditions (c. 1.3 mol.% H2O) that allowed the preservation of the majority of garnet with symplectitic as well as relict clinopyroxene. The modelling also shows that a MORB‐type eclogite decompressed to c. 8 kbar ends as an amphibolite if it is H2O saturated, but if it is H2O‐undersaturated it contains assemblages with orthopyroxene. Increasing H2O undersaturation causes an earlier transition to SiO2 undersaturation on decompression, leading to the appearance of spinel‐bearing assemblages. Granulite facies‐looking overprints of eclogites may develop at amphibolite facies conditions.
Juvenile Xanthogranuloma Associated with Contralateral Lymphadenopathy
Authors: Kirke Sandra , Windebank Kevin , Wood Katrina , Taylor Aileen E. M. 
Published: September 2005

Abstract:  Juvenile xanthogranuloma is an uncommon, benign histiocytic condition, primarily affecting children less than 1 year of age. Although usually only cutaneous lesions are found, systemic manifestations of the disease have been reported. We present a child with juvenile xanthogranuloma of the right cheek associated with contralateral cervical lymph node histiocytic infiltration.
Acquired Ichthyosis and Hypertrichosis due to Autoimmune Thyroiditis: Therapeutic Response to Thyroxine Replacement
Authors: Brazzelli Valeria , Prestinari Francesca , Barbagallo Tania , Bellani Eleonora , Calcaterra Valeria , Larizza Daniella , Lauriola Maria M. , Borroni Giovanni 
Published: September 2005

Abstract:  Thyroid diseases may be associated with a wide variety of dermatologic disorders. We report a 15‐year‐old girl with acquired ichthyosis and hypertrichosis associated with hypothyroidism resulting from autoimmune thyroiditis. Her skin lesions progressively resolved after 8 months of replacement therapy with L‐thyroxine. This result supports the hypothesis that hypothyroidism in our patient can be directly related to the pathogenesis of acquired ichthyosis and hypertrichosis.
Obesity is Associated with Genetic Variants That Alter Dopamine Availability
Authors: Need A. C. , Ahmadi K. R. , Spector T. D. , Goldstein D. B. 
Published: September 2005

SummaryHuman and animal studies have implicated dopamine in appetite regulation, and family studies have shown that BMI has a strong genetic component. Dopamine availability is controlled largely by three enzymes: COMT, MAOA and MAOB, and by the dopamine transporter SLC6A3, and each gene has a well‐characterized functional variant. Here we look at these four functional polymorphisms together, to investigate how heritable variation in dopamine levels influences the risk of obesity in a cohort of 1150, including 240 defined as obese (BMI ≥ 30). The COMT and SLC6A3 polymorphisms showed no association with either weight, BMI or obesity risk. We found, however, that both MAOA and MAOB show an excess of the low‐activity genotypes in obese individuals (MAOA:χ2= 15.45, p = 0.004; MAOB:χ2= 8.05, p = 0.018). Additionally, the MAOA genotype was significantly associated with both weight (p = 0.0005) and BMI (p = 0.001). When considered together, the ‘at risk genotype’ ‐ low activity genotypes at both the MAOA and MAOB loci ‐ shows a relative risk for obesity of 5.01. These results have not been replicated and, given the experience of complex trait genetics, warrant caution in interpretation. In implicating both the MAOA and MOAB variants, however, this study provides the first indication that dopamine availability (as opposed to other effects of MAOA) is involved in human obesity. It is therefore a priority to assess the associations in replication datasets.
Detecting linkage disequilibrium in the presence of locus heterogeneity
Authors: Wang D. , Huang J. 
Published: September 2005

SummaryLocus heterogeneity is a common phenomenon in complex diseases and is one of the most important factors that affect the power of either linkage or linkage disequilibrium (LD) analysis. In linkage analysis, the heterogeneity LOD score (HLOD) rather than LOD itself is often used. However, the existing methods for detecting linkage disequilibrium, such as the TDT and many of its variants, do not take into account locus heterogeneity. We propose two novel likelihood‐based methods, an LD‐Het likelihood and an LD‐multinomial likelihood, to test linkage disequilibrium (LD) that explicitly incorporate locus heterogeneity in the analysis. The LD‐Het is applicable to general nuclear family data but requires a working penetrance model. The LD‐multinomial is only applicable to affected sib‐pair data but does not require specification of a trait model. For affected sib‐pair data, both methods have similar power to detect LD under the recessive model, but the LD‐multinomial model has greater power when the underlying model is dominant or additive.
Cardiovascular Risk Factors Predictive for Survival and Morbidity‐Free Survival in the Oldest‐Old Framingham Heart Study Participants
Authors: Terry Dellara F. , Pencina Michael J. , Vasan Ramachandran S. , Murabito Joanne M. , Wolf Philip A. , Hayes Margaret Kelly , Levy Daniel , D'Agostino Ralph B. , Benjamin Emelia J. 
Published: September 2005

Objectives:To examine whether midlife cardiovascular risk factors predict survival and survival free of major comorbidities to the age of 85.Design:Prospective community‐based cohort study.Setting:Framingham Heart Study, Massachusetts.Participants:Two thousand five hundred thirty‐one individuals (1,422 women) who attended at least two examinations between the ages of 40 and 50.Measurements:Risk factors were classified at routine examinations performed between the ages of 40 and 50. Stepwise sex‐adjusted logistic regression models predicting the outcomes of survival and survival free of morbidity to age 85 were selected from the following risk factors: systolic and diastolic blood pressure, total serum cholesterol, glucose intolerance, cigarette smoking, education, body mass index, physical activity index, pulse pressure, antihypertensive medication, and electrocardiographic left ventricular hypertrophy.Results:More than one‐third of the study sample survived to age 85, and 22% of the original study sample survived free of morbidity. Lower midlife blood pressure and total cholesterol levels, absence of glucose intolerance, nonsmoking status, higher educational attainment, and female sex predicted overall and morbidity‐free survival. The predicted probability of survival to age 85 fell in the presence of accumulating risk factors: 37% for men with no risk factors to 2% with all five risk factors and 65% for women with no risk factors to 14% with all five risk factors.Conclusion:Lower levels of key cardiovascular risk factors in middle age predicted overall survival and major morbidity‐free survival to age 85. Recognizing and modifying these factors may delay, if not prevent, age‐related morbidity and mortality.