bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma homocysteine and microvascular and macrovascular complications in type 1 diabetes: a cross‐sectional nested case–control study
Authors: SOEDAMAH‐MUTHU S. S. , CHATURVEDI N. , TEERLINK T. , IDZIOR‐WALUS B. , FULLER J. H. , STEHOUWER C. D. A. ,   THE EURODIAB PROSPECTIVE COMPLICATIONS STUDY GROUP
Published: October 2005

Abstract.Objectives.  To examine the independent relationship between plasma total homocysteine (tHcy) and microvascular and macrovascular complications.Design.  We performed a cross‐sectional nested case–control study from the EURODIAB Prospective Complications Study.Setting.  A hospital‐based multicentre study at 24 centres in 13 European countries.Subjects.  A total of 533 type 1 diabetic patients, diagnosed at <36 years of age. Cases (n = 359) were defined as those with one or more complications of diabetes and control subjects (n = 174) were all those with no evidence of any complication.Main outcome measures.  Retinopathy, albumin excretion rate (AER), glomerular filtration rate (GFR) estimated by Cockcroft–Gault formula, hypertension and cardiovascular disease (CVD) were assessed.Results.  In unadjusted models, tHcy (per 5 μmol L−1) was significantly associated with nonproliferative retinopathy (OR = 1.45, 95% CI: 1.10–1.91), proliferative retinopathy (OR = 1.74, 95% CI: 1.34–2.27), macroalbuminuria (OR = 1.90, 95% CI: 1.49–2.42), hypertension (OR = 2.23, 95% CI: 1.69–2.93) and CVD (OR = 1.59, 95% CI: 1.18–2.14). In multivariate models, tHcy was significantly related to macroalbuminuria (OR = 1.66, 95% CI: 1.24–2.24) and hypertension (OR = 1.57, 95% CI: 1.19–2.07), independent of age, sex, diabetes duration, GFR, microvascular and macrovascular complications and cardiovascular risk factors. There was a significant relationship between tHcy and decreased GFR, independent of established risk factors. The relationship between tHcy and retinopathy was not independent of albuminuria or GFR. The initial positive relationship with CVD was explained by cardiovascular risk factors.Conclusion.  In this large study of European type 1 diabetic subjects, increased concentrations of tHcy were independently related to macroalbuminuria, renal function and hypertension, which suggests that tHcy might play an important role in the pathogenesis of vascular complications in type 1 diabetes.
Refugia, dispersal and divergence in a forest archipelago: a study of Streptocarpus in eastern South Africa
Authors: HUGHES M. , MÖLLER M. , BELLSTEDT D. U. , EDWARDS T. J. , DE VILLIERS M. 
Published: October 2005

AbstractWe describe a scenario of plant speciation across a relict forest archipelago in South Africa involving Pleistocene habitat expansion‐contraction cycles, dispersal and adaptation to lower temperatures. This is the first population level study using molecular data in South African forests and has significant implications for conservation efforts in this area. Populations of the mesophytic forest floor herbs Streptocarpus primulifolius sensu lato and Streptocarpus rexii were sampled throughout their range in the naturally fragmented forests of eastern South Africa in order to investigate population genetic and phylogenetic patterns within the species complex, using nuclear microsatellites, nuclear ribosomal ITS (internal transcribed spacer) sequences and chloroplast genome sequences. S. primulifolius harbours high levels of genetic diversity at both the nuclear (mean HE = 0.50) and the chloroplast level (each population fixed for a unique haplotype). This is consistent with populations of these coastal species being Pleistocene relicts. In contrast, populations of S. rexii in cooler habitats at higher altitudes and lower latitudes harbour little or no nuclear genetic diversity (mean HE = 0.09) and most share a common chloroplast haplotype. The split of S. rexii from populations intermediate between the two species (S. cf. primulifolius) occurred between 0 and 0.44 million years ago according to the calibrated ITS phylogeny of the taxa. The low genetic diversity and homogeneity of S. rexii is congruent with this species having reached its current range during the Holocene. We found no evidence of monophyly of any of the taxa in this study, which we consider a consequence of recent evolution in a fragmented habitat.
Direct and indirect estimates of gene flow among wild and managed populations of Polaskia chichipe, an endemic columnar cactus in Central Mexico
Authors: OTERO‐ARNAIZ ADRIANA , CASAS ALEJANDRO , HAMRICK JAMES L. 
Published: October 2005

AbstractMicrosatellite markers were used to obtain direct and indirect estimates of gene flow in populations of Polaskia chichipe under different management regimes, in order to understand the genetic consequences of gene flow in the evolutionary process of domestication. P. chichipe is a columnar cactus endemic to the Tehuacan Valley, Central Mexico, and has come under domestication for its edible fruit. Morphological, phenological, physiological, and reproductive differences, apparently attributable to artificial selection, exist between wild and managed populations, which grow sympatrically. However, strong gene flow may counteract the effects of this selection. In this study, we used paternity analysis to demonstrate that although most of the pollinations occur among individuals within the same population at distances < 40 m, pollen flow from other populations is considerable (27 ± 5%). Heterogeneity in pollen clouds sampled by mother plants (FST = 0.12) indicated nonrandom mating, which is probably due to temporal heterogeneity in pollen movement. Spatial structure on local and regional scales is consistent with an isolation‐by‐distance model. The similarity of indirect, direct and demographic estimates of neighbourhood size (74–250 individuals) suggests that this genetic structure is representative of an equilibrium state. These results suggest that traditional management practices have conserved the genetic resources of this species in situ, but also that gene flow is counteracting the effect of domestication to some degree. We discuss our results in the general context of genetic exchange between cultivated and wild populations during the domestication process.
Effects of historical climate change, habitat connectivity, and vicariance on genetic structure and diversity across the range of the red tree vole (Phenacomys longicaudus) in the Pacific Northwestern United States
Authors: MILLER MARK P. , BELLINGER M. RENEE , FORSMAN ERIC D. , HAIG SUSAN M. 
Published: October 2005

AbstractPhylogeographical analyses conducted in the Pacific Northwestern United States have often revealed concordant patterns of genetic diversity among taxa. These studies demonstrate distinct North/South genetic discontinuities that have been attributed to Pleistocene glaciation. We examined phylogeographical patterns of red tree voles (Phenacomys longicaudus) in western Oregon by analysing mitochondrial control region sequences for 169 individuals from 18 areas across the species’ range. Cytochromebsequences were also analysed from a subset of our samples to confirm the presence of major haplotype groups. Phylogenetic network analyses suggested the presence of two haplotype groups corresponding to northern and southern regions ofP. longicaudus’ range. Spatial genetic analyses (samovaand Genetic Landscape Shapes) of control region sequences demonstrated a primary genetic discontinuity separating northern and southern sampling areas, while a secondary discontinuity separated northern sampling areas into eastern and western groups divided by the Willamette Valley. The North/South discontinuity likely corresponds to a region of secondary contact between lineages rather than an overt barrier. Although the Cordilleran ice sheet (maximum ∼12 000 years ago) did not move southward to directly affect the region occupied byP. longicaudus, climate change during glaciation fragmented the forest landscape that it inhabits. Signatures of historical fragmentation were reflected by positive associations between latitude and variables such as Tajima'sDand patterns associated with location‐specific alleles. Genetic distances between southern sampling areas were smaller, suggesting that forest fragmentation was reduced in southern vs. northern regions.
Molecular evidence for a founder effect in invasive house finch (Carpodacus mexicanus) populations experiencing an emergent disease epidemic
Authors: HAWLEY DANA M. , HANLEY DANIEL , DHONDT ANDRÉ A. , LOVETTE IRBY J. 
Published: October 2005

AbstractThe impact of founder events on levels of genetic variation in natural populations remains a topic of significant interest. Well‐documented introductions provide a valuable opportunity to examine how founder events influence genetic diversity in invasive species. House finches (Carpodacus mexicanus) are passerine birds native to western North America, with the large eastern North American population derived from a small number of captive individuals released in the 1940s. Previous comparisons using amplified fragment length polymorphism (AFLP) markers found equivalent levels of diversity in eastern and western populations, suggesting that any genetic effects of the founder event were ameliorated by the rapid growth of the newly established population. We used an alternative marker system, 10 highly polymorphic microsatellites, to compare levels of genetic diversity between four native and five introduced house finch populations. In contrast to the AFLP comparisons, we found significantly lower allelic richness and heterozygosity in introduced populations across all loci. Three out of five introduced populations showed significant reductions in the ratio of the number of alleles to the allele size range, a within‐population characteristic of recent bottlenecks. Finally, native and introduced populations showed significant pairwise differences in allele frequencies in every case, with stronger isolation by distance within the introduced than native range. Overall, our results provide compelling molecular evidence for a founder effect during the introduction of eastern house finches that reduced diversity levels at polymorphic microsatellite loci and may have contributed to the emergence of theMycoplasmaepidemic which recently swept the eastern range of this species.
Molecular architecture and function of the Omp85 family of proteins
Authors: Gentle Ian E. , Burri Lena , Lithgow Trevor 
Published: October 2005

SummaryOmp85 is a protein found in Gram‐negative bacteria where it serves to integrate proteins into the bacterial outer membrane. Members of the Omp85 family of proteins are defined by the presence of two domains: an N‐terminal, periplasmic domain rich in POTRA repeats and a C‐terminal beta‐barrel domain embedded in the outer membrane. The widespread distribution of Omp85 family members together with their fundamental role in outer membrane assembly suggests the ancestral Omp85 arose early in the evolution of prokaryotic cells. Mitochondria, derived from an ancestral bacterial endosymbiont, also use a member of the Omp85 family to assemble proteins in their outer membranes. More distant relationships are seen between the Omp85 family and both the core proteins in two‐partner secretion systems and the Toc75 family of protein translocases found in plastid outer envelopes. Aspects of the ancestry and molecular architecture of the Omp85 family of proteins is providing insight into the mechanism by which proteins might be integrated and assembled into bacterial outer membranes.
A proteomic analysis of penicillin resistance in Streptococcus pneumoniae reveals a novel role for PstS, a subunit of the phosphate ABC transporter
Authors: Soualhine Hafid , Brochu Vicky , Ménard François , Papadopoulou Barbara , Weiss Karl , Bergeron Michel G. , Légaré Danielle , Drummelsmith Jolyne , Ouellette Marc 
Published: October 2005

SummaryResistance to penicillin is widespread in the Gram‐positive bacterium Streptococcus pneumoniae, and while several mutations are known to be implicated in resistance other mechanisms are likely to occur. We used a proteomic screen of two independent mutants in which resistance was selected in vitro. We found a number of differentially expressed proteins including PstS, a subunit of the phosphate ABC transporter of S. pneumoniae. This protein was increased in both mutants, a phenotype correlated to increased RNA expression of the entire phosphate ABC transporter operon. Inactivation of the pstS gene led to increased susceptibility to penicillin in the wild‐type strain. To further link the expression of the ABC phosphate transporter with penicillin resistance, we looked at pstS mRNA levels in 12 independent clinical isolates sensitive and resistant to penicillin and found an excellent correlation between resistance and increased expression of pstS. Inactivation of pstS in one of the clinical isolates significantly reduced penicillin resistance. Global approaches are ideally suited for the discovery of novel factors in the biology of resistance.
Adjustments in hydraulic architecture ofPinus palustrismaintain similar stomatal conductance in xeric and mesic habitats
Authors: ADDINGTON R. N. , DONOVAN L. A. , MITCHELL R. J. , VOSE J. M. , PECOT S. D. , JACK S. B. , HACKE U. G. , SPERRY J. S. , OREN R. 
Published: October 2005

ABSTRACTWe investigated relationships between whole‐tree hydraulic architecture and stomatal conductance inPinus palustrisMill. (longleaf pine) across habitats that differed in soil properties and habitat structure. Trees occupying a xeric habitat (characterized by sandy, well‐drained soils, higher nitrogen availability and lower overstory tree density) were shorter in stature and had lower sapwood‐to‐leaf area ratio (AS:AL) than trees in a mesic habitat. The soil‐leaf water potential gradient (ΨS − ΨL) and leaf‐specific hydraulic conductance (kL) were similar between sites, as was tissue‐specific hydraulic conductivity (KS) of roots. Leaf and canopy stomatal conductance (gSandGS, respectively) were also similar between sites, and they tended to be somewhat higher at the xeric site during morning hours when vapour pressure deficit (D) was low. A hydraulic model incorporating tree height,AS:ALandΨS − ΨLaccurately described the observed variation in individual treeGSref(GSatD = 1 kPa) across sites and indicated that tree height was an important determinant ofGSrefacross sites. This, combined with a 42% higher root‐to‐leaf area ratio (AR:AL) at the xeric site, suggests that xeric site trees are hydraulically well equipped to realize equal – and sometimes higher – potential for conductance compared with trees on mesic sites. However, a slightly more sensitive stomatal closure response to increasingDobserved in xeric site trees suggests that this potential for higher conductance may only be reached whenDis low and when the capacity of the hydraulic system to supply water to foliage is not greatly challenged.
Identification of cold acclimation‐responsiveRhododendrongenes for lipid metabolism, membrane transport and lignin biosynthesis: importance of moderately abundant ESTs in genomic studies
Authors: WEI HUI , DHANARAJ ANIK L. , ARORA RAJEEV , ROWLAND LISA J. , FU YAN , SUN LI 
Published: October 2005

ABSTRACTWe have previously analysed expressed sequence tags (ESTs) from non‐acclimated (NA) and cold‐acclimated (CA)Rhododendronleaves, and identified highly abundant complementary DNAs (cDNAs) possibly involved in cold acclimation. A potentially significant, but relatively unexplored, application of these EST data sets is the study of moderately abundant cDNAs, such as those picked only 1–3 times from eachRhododendronEST library containing ∼ 430 ESTs. Using statistical tests and Northern blots, we established that the probability of differential expression of moderately abundant cDNAs based on the EST data is, indeed, a reasonably accurate predictor of their ‘true’ upregulation or downregulation as 11 out of 13 cDNAs (85%) studied fit this criterion. The analyses also revealed four aspects of cold acclimation inRhododendronleaf tissues. Firstly, the concomitant upregulation of long‐chain acyl‐coenzyme A (acyl‐CoA) synthetase, CTP:cholinephosphate cytidylyltransferase and delta‐12 fatty acid desaturase in CA leaf tissues suggests that phospholipid biosynthesis and desaturation are important components of cold hardening inRhododendron. Secondly, upregulation of plastidic nicotinamide adenine dinucleotide phosphate‐malic enzyme (NADP‐ME) in CA tissues suggests that malate is an important source of acetyl‐CoA used for fatty acid biosynthesis during cold acclimation. Thirdly, downregulation of plasma membrane intrinsic protein (PIP)2‐1 aquaporin and upregulation of gated outward rectifying K+channel (GORK) in CA tissues may be associated with the protection of overwintering leaves from freeze‐induced cellular dehydration. Fourthly, upregulation of coumarate 3‐hydroxylase may be associated with cell wall thickening in CA tissues. Physiological implications of these results, which reveal potentially novel regulations of cold acclimation in overwintering woody evergreens, are discussed. This work highlights the importance of also investigating low/moderately abundant ESTs (in addition to highly abundant ones) in genomic studies, in that it offers an effective strategy for identifying stress‐related genes, especially when large‐scale cDNA sequencing/microarray studies are not possible.
Higher rates of leaf gas exchange are associated with higher leaf hydrodynamic pressure gradients
Authors: FRANKS PETER J. 
Published: October 2005

ABSTRACTSteady‐state leaf gas‐exchange parameters and leaf hydraulic conductance were measured on 10 vascular plant species, grown under high light and well‐watered conditions, in order to test for evidence of a departure from hydraulic homeostasis within leaves as hydraulic conductance varied across species. The plants ranged from herbaceous crop plants to mature forest trees. Across species, under standardized environmental conditions (saturating light, well watered), mean steady‐state stomatal conductance to water vapour (gw) was highly correlated with mean rate of CO2 assimilation (A) and mean leaf hydraulic conductance normalized to leaf area (kleaf). The relationship between A and gw was well described by a power function, while that between A and kleaf was highly linear. Non‐linearity in the relationship between gw and kleaf contributed to an increase in the hydrodynamic (transpiration‐induced) water potential drawdown across the leaf (ΔΨleaf) as kleaf increased across species, although across the 10 species the total increase in ΔΨleaf was slightly more than twofold for an almost 30‐fold increase in gw. Higher rates of leaf gas exchange were therefore associated with higher kleaf and higher leaf hydrodynamic pressure gradients. A mechanistic model incorporating the stomatal hydromechanical feedback loop is used to predict the relationship between ΔΨleaf and kleaf, and to explore the coordination of stomatal and leaf hydraulic properties in supporting higher rates of leaf gas exchange.
Effects of nitrogen nutrition on the relationships between the levels of rbcS and rbcL mRNAs and the amount of ribulose 1·5‐bisphosphate carboxylase/oxygenase synthesized in the eighth leaves of rice from emergence through senescence
Authors: IMAI KAZUHIRO , SUZUKI YUJI , MAKINO AMANE , MAE TADAHIKO 
Published: October 2005

ABSTRACTSoon after the emergence of the eighth leaf blades, rice plants were grown with two (1 and 4 mm) levels of nitrogen (N) supply, and the relationships between the levels of rbcS and rbcL mRNAs, the amount of ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) synthesized and the N influx were examined in the eighth leaf blades from emergence through senescence. The levels of both rbcS and rbcL mRNAs, the amount of Rubisco synthesized and the N influx were greater for the 4 mm N treatment than for the 1 mm N treatment throughout the experiment. The amount of Rubisco synthesized was well correlated with the levels of both mRNAs during leaf expansion, but not after the completion of leaf expansion in both N treatments. The ratio of the amount of Rubisco synthesized to the levels of both mRNAs dramatically declined after full expansion. On the other hand, the amount of Rubisco synthesized was well correlated with the N influx in both N treatments. These results indicate that the N influx, namely, N availability, rather than the levels of rbcS and rbcL mRNAs, is more closely related to the amount of Rubisco synthesized in the leaf blade of rice throughout the lifespan of a leaf.
Effects of intravascular volume therapy using hydroxyethyl starch (130/0.4) on post‐operative bleeding and transfusion requirements in children undergoing cardiac surgery: a randomized clinical trial
Authors: Chong Sung K. , Kum Suk P. , Mi Ja Y. , Kyoung Ok K. 
Published: October 2005

Background:  Hydroxyethyl starch (HES) used for intravascular volume expansion may cause coagulation abnormalities, especially in cardiac patients. Although low molecular weight HES (130/0.4) has been developed to minimize its influence on coagulation, experience with HES (130/0.4) in children is limited. Therefore, we evaluated the effects of a HES (130/0.4) infusion on post‐operative blood loss in children undergoing cardiac surgery.Methods:  Forty‐two children undergoing cardiac surgery were assigned at random to receive either 10 ml/kg fresh frozen plasma (FFP group; n = 21) or HES (130/0.4) (HES group; n = 21) shortly after cardiopulmonary bypass termination. Activated partial thromboplastin time (aPTT) and international normalization ratio (INR) were measured. In addition, post‐operative transfusion requirements and blood loss until the end of the first post‐operative day were compared.Results:  INR was significantly prolonged after HES infusion in comparison to the FFP group (P < 0.05). During the first 24 h after surgery, post‐operative blood loss, the use of allogenic blood/blood products and aPTT were similar in all children.Conclusions:  Our study shows that the administration of a moderate dose of HES (130/0.4) in children undergoing cardiac surgery does not cause more bleeding or a higher transfusion requirement than a FFP infusion, and suggests that the administration of 10 ml/kg HES (130/0.4) is a safe alternative to plasma for intravascular volume replacement in this patient population.
Postoperative outcome among elderly patients after general anesthesia
Authors: Kojima Y. , Narita M. 
Published: October 2005

Background:  Preoperative decision‐making for elderly patients requires a long‐term perspective. The aim of this study was to identify preoperative risk factors for decreased 1‐ to 5‐year survival rates and to compare the survival rates of stratified risk groups with those of the sex‐ and age‐matched general population.Methods:  Subjects were 406 patients, aged 80 years or older, who underwent surgery with general anesthesia. Higher age, male sex, dependency in daily living, low serum albumin level, malignancy, abdominal surgery, emergency surgery and high ASA class were analyzed for survival using univariate and multivariate analysis with Cox's proportional hazard model. One‐ to 5‐year survival rates were estimated using life table analysis for patients divided by risk factors. The survival data were also compared with the cumulative survival rates of the sex‐ and age‐matched general population.Results:  Multivariate analysis identified three factors that were significantly associated with decreased survival rates: male sex, dependency in daily living and abdominal surgery. Long‐term survival among patients older than 90 years was comparable to those of the general population. Although improved in recent years, overall survival rates were much lower than expected due to poor outcome among patients dependent in daily living and those who underwent abdominal surgery.Conclusions:  In patients 80 years or older who underwent surgery with general anesthesia, independent risk factors for decreased survival are male sex, dependency in daily living and abdominal surgery. Only patients independent in daily living who underwent non‐abdominal surgery had survival rates comparable to those of the general population.