bluuebunny/crossref_metadata_2025_split huggingface dataset:
A long‐term study on hyperlipidemia in stable renal transplant recipients
Authors: Tse Kai‐Chung , Lam Man‐Fai , Yip Pok‐Siu , Li Fu‐Keung , Lai Kar‐Neng , Chan Tak‐Mao 
Published: May 2004

Abstract: Objectives: Hyperlipidemia is a common and important risk factor after renal transplantation, but there is little long‐term data on its incidence, pattern, and evolution in stable renal allograft recipients on low dose maintenance immunosuppression.Patients and methods: A retrospective study was conducted on all patients who received kidney transplants from April 1, 1990 to March 31, 2000 at a single center, on their serial lipid profile during the first 3 yr after kidney transplantation.Results: A total of 221 (122 male, 99 female; mean age 37.8 ± 10.0 yr at the time of transplantation) Chinese adult renal allograft recipients were included. A 95.3% of patients were on cyclosporine and prednisolone based immunosuppression. Increases in total cholesterol (TC), low density lipoprotein (LDL), and high density lipoprotein (HDL) were noted, while the level of triglyceride (TG) decreased after renal transplant. The incidence of hypercholesterolemia (defined as TC ≥ 6.3 mmol/L or LDL ≥ 4.2 mmol/L) within the first year was 28.2 and 20.3%, respectively. The incidence rate decreased significantly in the second (5.4%, p = 0.000 and 6.4%, p = 0.003) and third year (9.5%, p = 0.003 and 4.9%, p = 0.021), but the incidence of patients having a high risk‐ratio (defined as TC/HDL ≥ 5) remained unchanged (6.9, 4.9 and 10.3% within the first, second, and third year, respectively). Treatment with statin was necessitated in 6.8, 13.6 and 21.7% of the patients at 1, 2, and 3 yr after transplantation, respectively. The prevalence rates of elevated TC and LDL were 18.3 and 18.9% at baseline, 40.6 and 33.3% after 1 yr, 32.8 and 27.3% after 2 yr, and 24.8 and 19.0% after 3 yr, despite treatment. The prevalence of patients with a high risk‐ratio was 45.0% at baseline, 30.5% after 1 yr (p = 0.002), 22.6% after 2 yr (p = 0.000) and 21.8% after 3 yr (p = 0.000). Hypercholesterolemia at the time of transplantation was an independent predictor for post‐transplant hypercholesterolemia (odds ratio 3.76, 95% confidence interval 1.47–9.62, p = 0.006).Conclusion: Renal transplantation is associated with a characteristic pattern of dyslipidemia, with increased TC, LDL and HDL, and a decrease in TG. Patients with pre‐existing hypercholesterolemia were at higher risk for post‐transplant hypercholesterolemia. Although the incidence of hypercholesterolemia peaks within the first year after transplantation, this remains a long‐term complication in a significant proportion of patients on low dose immunosuppressive medications.
Apolipoprotein E gene polymorphism in renal transplant recipients: effects on lipid metabolism, atherosclerosis and allograft function
Authors: Kahraman Serkan , Kiykim Ahmet Alper , Altun Bülent , Gençtoy Gültekin , Arici Mustafa , Gulsun Meltem , Erdem Yunus , Yasavul Unal , Turgan Çetin , Çağlar Şali 
Published: May 2004

Abstract:  Introduction:  Atherosclerosis is a serious complication and leading cause of mortality in renal transplant recipients (RTRs). Hyperlipidemia may be associated with progression of renal disease and chronic allograft dysfunction. Similarities in the pathogenesis of glomerulosclerosis and atherosclerosis have been proposed. Apolipoprotein (apo) E gene code forms three major isoforms (E2, E3, and E4) with variable effects on lipid metabolism.Patients and Methods:  A total of 118 patients, at a mean age of 40 ± 8 yr, were included in the study. Apo E genotyping was carried out on genomic DNA using polymerase chain reaction and restriction enzyme. Carotid artery intima media thickness and atherosclerotic plaques were evaluated by B‐mode ultrasonography. The plasma levels of lipids and lipoproteins and acute phase reactants were also studied. Allograft function was evaluated by measuring serum creatinine and creatinine clearance values.Results:  The frequencies of E2, E3, and E4 alleles were 0.10, 0.78, and 0.12 respectively. Carotid artery atherosclerosis was found in 25% of E2 carriers, 30% of E3 carriers, and 57% of E4 carriers. Total cholesterol, total triglyceride, low‐density lipoprotein, very low‐density lipoprotein, apo B 100 levels were found to be higher in apo E4 carriers. Median apo A1 level was higher and allograft functions were better in apo E2 carriers (p < 0.05). Multiple regression analysis showed that allograft functions were negatively correlated with elevated acute phase reactants (p < 0.01) and only the age, but not the apo E genotypes, was an independent risk factor for atherosclerotic vascular disease (p < 0.01).Discussion:  The pathogenetic events linking lipid metabolism and allograft functions and development of atherosclerosis are complex and multifactorial in RTRs. Our results showed that apo E genotypes have influences on lipids, lipoproteins and allograft functions. The ultimate role of apo E4 gene polymorphism as a risk factor for development and progression of atherosclerosis in RTRs should be sought in further studies.
Outcome of lamivudine resistant hepatitis B virus mutant post‐liver transplantation on lamivudine monoprophylaxis
Authors: Chan Henry Lik‐Yuen , Chui Albert Ka‐Keung , Lau Wan‐Yee , Chan Francis Ka‐Leung , Hui Alex Yui , Rao Araga Ramesha Nitin , Wong John , Lai Eric Chun‐Hung , Sung Joseph Jao‐Yiu 
Published: May 2004

Abstract: Background: We aimed to investigate the clinical outcome of patients who develop lamivudine resistant hepatitis B virus mutants (YMDD mutants) after liver transplantation.Methods: Patients who received liver transplantation for hepatitis B‐related liver diseases from 1999 to 2002 were studied. All patients received lamivudine monotherapy before and after liver transplantation. HBsAg and HBV DNA were regularly monitored, and YMDD mutation was detected by direct sequencing.Results: Twenty patients were followed up for median 94 wk (range: 15–177 wk) post‐liver transplantation. Six patients developed YMDD mutants, and the cumulative probability of developing YMDD mutations post‐liver transplantation was 21% in 1 yr and 34% in 2 yr. One patient developed YMDD mutants before liver transplantation and died of hepatitis reactivation and liver failure 15 wk post‐transplantation. The other five patients developed YMDD mutants 32–72 wk after liver transplantation. Two of them developed severe hepatitis which responded promptly to adefovir dipivoxil. The remaining three patients with YMDD mutants had minimal to mild hepatitis. The cumulative survival for patients with YMDD mutants was 83% and 28% at 1 and 2 yr, respectively. Only one patient who did not develop YMDD mutants died at week 119 due to chronic rejection. The post‐transplant survival for patients with YMDD mutants was significantly poorer than those without YMDD mutants (log rank test p = 0.083).Conclusions: The emergence of YMDD mutants after liver transplantation on lamivudine monoprophylaxis had wide range of clinical presentations and was associated with increased mortality.
A decision‐analytic economic evaluation of valaciclovir prophylaxis for the prevention of cytomegalovirus infection and disease in renal transplantation
Authors: Tilden Dominic P , Chapman Jeremy , Davey Peter J , Solly Michaela L , Crowley Steven 
Published: May 2004

Abstract: Objective: This analysis evaluates the cost‐effectiveness of valaciclovir prophylaxis using clinically and economically important health outcomes including graft failure, life‐years, and quality‐adjusted life‐years (QALYs).Methods: A Markov model was developed using a randomized, placebo‐controlled trial of valaciclovir prophylaxis, together with a published epidemiological study and national renal transplant registry data. The model's population was stratified into two risk groups by donor/recipient cytomegalovirus (CMV) serostatus at transplantation: donor‐positive/recipient‐negative (D+R−) and recipient‐positive (R+) patients. The model estimated costs and health outcomes over a 30‐yr period from the perspective of Australian health care providers.Results: The total health care cost was $3619 lower for D+R− patients receiving valaciclovir prophylaxis compared with those not receiving prophylaxis. D+R− patients receiving valaciclovir gained an extra 0.33 yr of life and 0.27 QALYs. R+ patients receiving valaciclovir prophylaxis gained an extra 0.07 yr of life and 0.05 QALYs, with an incremental cost of $914. This equates to $17 127 per QALY gained, which is highly cost‐effective compared with other drugs and health interventions.Conclusions: Valaciclovir for the prophylaxis of CMV disease in renal transplant recipients is a cost‐effective intervention, significantly reducing the burden of CMV disease to patients and health care providers.
Tree–grass coexistence in savannas revisited – insights from an examination of assumptions and mechanisms invoked in existing models
Authors: Sankaran Mahesh , Ratnam Jayashree , Hanan Niall P. 
Published: May 2004

AbstractSeveral explanations for the persistence of tree–grass mixtures in savannas have been advanced thus far. In general, these either concentrate on competition‐based mechanisms, where niche separation with respect to limiting resources such as water lead to tree–grass coexistence, or demographic mechanisms, where factors such as fire, herbivory and rainfall variability promote tree–grass persistence through their dissimilar effects on different life‐history stages of trees. Tests of these models have been largely site‐specific, and although different models find support in empirical data from some savanna sites, enough dissenting evidence exists from others to question their validity as general mechanisms of tree–grass coexistence. This lack of consensus on determinants of savanna structure and function arises because different models: (i) focus on different demographic stages of trees, (ii) focus on different limiting factors of tree establishment, and (iii) emphasize different subsets of the potential interactions between trees and grasses. Furthermore, models differ in terms of the most basic assumptions as to whether trees or grasses are the better competitors. We believe an integration of competition‐based and demographic approaches is required if a comprehensive model that explains both coexistence and the relative productivity of the tree and grass components across the diverse savannas of the world is to emerge. As a first step towards this end, we outline a conceptual framework that integrates existing approaches and applies them explicitly to different life‐history stage of trees.
Increase of atmospheric CO2 promotes phytoplankton productivity
Authors: Schippers Peter , Lürling Miquel , Scheffer Marten 
Published: May 2004

AbstractIt is usually thought that unlike terrestrial plants, phytoplankton will not show a significant response to an increase of atmospheric CO2. Here we suggest that this view may be biased by a neglect of the effects of carbon (C) assimilation on the pH and the dissociation of the C species. We show that under eutrophic conditions, productivity may double as a result of doubling of the atmospheric CO2 concentration. Although in practice productivity increase will usually be less, we still predict a productivity increase of up to 40% in marine species with a low affinity for bicarbonate. In eutrophic freshwater systems doubling of atmospheric CO2 may result in an increase of the productivity of more than 50%. Freshwaters with low alkalinity appeared to be very sensitive to atmospheric CO2 elevation. Our results suggest that the aquatic C sink may increase more than expected, and that nuisance phytoplankton blooms may be aggravated at elevated atmospheric CO2 concentrations.
Recovery of copepod, but not cladoceran, zooplankton from severe and chronic effects of multiple stressors
Authors: Yan Norman D. , Girard Robert , Heneberry Jocelyne H. , Keller W. Bill , Gunn John M. , Dillon Peter J. 
Published: May 2004

AbstractIn the mid‐twentieth century, many lakes near Sudbury, Canada, were severely contaminated by acid and metal emissions from local smelters. For example, in the early 1970s, Middle Lake had pH of 4.2, and Cu and Ni levels both >0.5 mg L−1 . To determine if crustacean zooplankton could recover from such severe and chronic damage, Middle Lake was neutralized in 1973. A comparison of its zooplankton with that of 22 reference (pH > 6) lakes indicates that the planktonic Copepoda completely recovered by 2001. In contrast, the cladoceran assemblage improved but did not recover. Colonist sources existed – Cladocera and Copepoda occurred with equal frequency in area lakes – but six separate colonizations by cladoceran species failed. We argue that local factors, metal toxicity and predation by yellow perch, have, to date, prevented cladoceran recovery. Nonetheless, the complete copepod recovery is encouraging, given the severity and duration of pre‐neutralization stress.
Moving from pattern to process: coexistence mechanisms under intermediate disturbance regimes
Authors: Shea Katriona , Roxburgh Stephen H. , Rauschert Emily S. J. 
Published: May 2004

AbstractCoexistence mechanisms that require environmental variation to operate contribute importantly to the maintenance of biodiversity. One famous hypothesis of diversity maintenance under disturbance is the intermediate disturbance hypothesis (IDH). The IDH proposes patterns of peaked diversity under intermediate disturbance regimes, based on a tension between competitively superior species and species which can rapidly colonize following disturbance. We review the literature, and describe recent research that suggests that more than one underlying mechanism can generate this unimodal diversity pattern in disturbed environments. Several exciting emerging research areas are identified, including interactions between disturbance types, operation of the IDH in multi‐trophic systems, and changes in disturbance regimes. However, empirical work is still focussed on describing the IDH pattern, with little emphasis on identifying its mechanistic basis. We discuss how to extend methods for identifying different coexistence mechanisms, developed in the theoretical literature, to experimental research. In an attempt to operationalize these various ideas we outline a hypothetical IDH research programme. A solid understanding of the life history attributes of the component species and their responses to disturbance will facilitate identification of the coexistence mechanism(s) underlying the IDH pattern, and provide a framework by which empirical and theoretical results can be more fully integrated.
Abrupt community change on a rocky shore – biological mechanisms contributing to the potential formation of an alternative state
Authors: Paine Robert T. , Trimble Alan C. 
Published: May 2004

AbstractThe 1997/1998 El Niño initiated a major shift in the intertidal assemblage on the Washington State outer coast. A 25 year time series (1978–2003) shows stands of dominant canopy algae replaced by mussel beds. A prior experiment had indicated that mussels can become too large to be eaten by starfish; newly initiated starfish removals predict mussel attainment of a size refuge. Such escapes inhibit recovery towards prior community composition and enhance development of alternative community states which may persist long after the originating forcing has lessened or disappeared.
Removal of a specialization‐associated symbiont does not affect aphid fitness
Authors: Leonardo Teresa E. 
Published: May 2004

AbstractSymbioses are ubiquitous in nature. However, these interactions, in particular those which are facultative from the perspective of the host, are still poorly understood. One major question is whether facultative symbionts affect host fitness, and in particular whether they can benefit the host. In pea aphid, host plant specialization was found to be associated with the presence of Pea Aphid U‐type Symbiont [Proc. R. Soc. Lond. B 270 (2003) S209]. Host and symbiont genomes are normally co‐transmitted, making it difficult to determine which is responsible for causing this variation in fitness. Here antibiotic treatment is used to selectively remove the symbiont, thus partitioning symbiont and host genomes. I find that PAUS is not responsible for causing host plant specialization. Examination of aphids in which PAUS presence has been naturally manipulated also supports this conclusion. Additional work will be necessary to determine the forces maintaining this symbiont in host populations, and whether it benefits the host insect under different conditions.
Bayesian inference in ecology
Authors: Ellison Aaron M. 
Published: May 2004

AbstractBayesian inference is an important statistical tool that is increasingly being used by ecologists. In a Bayesian analysis, information available before a study is conducted is summarized in a quantitative model or hypothesis: the prior probability distribution. Bayes’ Theorem uses the prior probability distribution and the likelihood of the data to generate a posterior probability distribution. Posterior probability distributions are an epistemological alternative toP‐values and provide a direct measure of the degree of belief that can be placed on models, hypotheses, or parameter estimates. Moreover, Bayesian information‐theoretic methods provide robust measures of the probability of alternative models, and multiple models can be averaged into a single model that reflects uncertainty in model construction and selection. These methods are demonstrated through a simple worked example. Ecologists are using Bayesian inference in studies that range from predicting single‐species population dynamics to understanding ecosystem processes. Not all ecologists, however, appreciate the philosophical underpinnings of Bayesian inference. In particular, Bayesians and frequentists differ in their definition of probability and in their treatment of model parameters as random variables or estimates of true values. These assumptions must be addressed explicitly before deciding whether or not to use Bayesian methods to analyse ecological data.
Tree physiological responses to above‐ground herbivory directly modify below‐ground processes of soil carbon and nitrogen cycling
Authors: Ayres Edward , Heath James , Possell Malcolm , Black Helaina I. J. , Kerstiens Gerhard , Bardgett Richard D. 
Published: May 2004

AbstractAbove‐ground herbivory is ubiquitous in terrestrial ecosystems, yet its impacts on below‐ground processes and consequences for plants remain ambiguous. To examine whether physiological responses of individual trees may potentially modify soil nutrient availability, we subjectedFagus sylvaticaL. (European beech) andAbies albaMill. (silver fir) to simulated foliar herbivory over two growing seasons. Above‐ground herbivory enhanced N mineralization and inorganic N availability in the soil. The total input of C from the plant roots to the soil is not known; however, carbon sequestration in the soil, measured using stable isotopic techniques, was unaffected by herbivory.Fagusresponded to herbivory by producing larger leaves, with increased photosynthetic capacity and N content, which largely compensated for the loss of biomass;Abiesexhibited no such response. We conclude that despite large interspecific differences in the growth response, tree physiological responses to foliar herbivory are capable of directly modifying soil biological processes.
Characterization of 15 polymorphic microsatellite loci in an endangered tropical tree Hopea bilitonensis (Dipterocarpaceae) in Peninsular Malaysia
Authors: Lee S. L. , Tani N. , Ng K. K. S. , Tsumura Y. 
Published: May 2004

AbstractThis study reports the isolation and characterization of 15 polymorphic microsatellite loci in an endangered tropical tree Hopea bilitonensis (Dipterocarpaceae). The primers were designed from a genomic library enriched for dinucleotide (CT) repeats and screened on 24 adult trees from a natural population. The number of alleles ranged from two to eight, and the observed heterozygosity ranged from 0.042 to 1.000. These loci will allow mating system and population analyses to be carried out in this species.
Isolation and characterization of Brachymystax lenok microsatellite loci and cross‐species amplification in Hucho spp. and Parahucho perryi
Authors: Froufe E. , Sefc K. M. , Alexandrino P. , Weiss S. 
Published: May 2004

AbstractWe isolated and characterized eight polymorphic microsatellite markers for Brachymystax lenok (Pallas, 1773) from genomic libraries enriched for (GATA)n, (GACA)n and (ATG)n microsatellites. The number of alleles per locus ranged from two to 17. Heterozygosity ranged from 0.2 to 0.95. In addition, cross‐species amplification was successful for seven loci in Hucho hucho, eight in H. taimen and seven in Parahucho perryi.
Isolation and characterization of microsatellite loci in the Caribbean gorgonian Pseudopterogorgia elisabethae
Authors: Gutiérrez‐Rodríguez Carla , Lasker Howard R. 
Published: May 2004

AbstractWe report on the isolation and characterization of five polymorphic microsatellites in the gorgonian Pseudopterogorgia elisabethae from genomic DNA‐enriched libraries. Forty‐four microsatellites were screened from the libraries with the oligonucleotide probe (CA)12. Five of the screened microsatellites were polymorphic. The levels of polymorphism found in 50 genotyped individuals from a single population suggest that microsatellites are useful tools for the study of genetic variation in gorgonians. These are the first microsatellite loci reported from any gorgonian species.
Microsatellite DNA markers for parental assignment in hybrid striped bass (Morone saxatilis × Morone chrysops)
Authors: Ross Kirstin , Wang Xiaoxue , O'Malley Kathleen G. , Gatlin Delbert M. , Gold John R. 
Published: May 2004

AbstractDevelopment of nine polymorphic microsatellites from a genomic library of hybrid striped bass (female Morone chrysops × male Morone saxatilus) DNA is described. Breeding of hybrid striped bass for aquaculture is based largely on breeding wild fish. Molecular markers such as microsatellites will be useful tools for developing broodstock, estimating heritability for production traits, and selective breeding via marker‐assisted selection. The nine polymorphic microsatellites include six dinucleotide and three complex repeat motifs. The number of alleles detected among a sample of 10 individuals of each species was relatively low. All polymerase chain reaction primer pairs also amplified products in the sea bass Dicentrarchus labrax.
convert: A user‐friendly program to reformat diploid genotypic data for commonly used population genetic software packages
Authors: Glaubitz Jeffrey C. 
Published: May 2004

Abstract convert is a user‐friendly, 32‐bit Windows program that facilitates ready transfer of codominant, diploid genotypic data amongst commonly used population genetic software packages. convert reads input files in its own ‘standard’ data format, easily produced from an excel file of diploid, codominant marker data, and can convert these to the input formats of the following programs: gda, genepop, arlequin, popgene, microsat, phylip, and structure. convert can also read input files in genepop format. In addition, convert can produce a summary table of allele frequencies in which private alleles and the sample sizes at each locus are indicated.
Characterization and PCR multiplexing of novel highly variable tetranucleotide Atlantic salmon (Salmo salar L.) microsatellites
Authors: Paterson S. , Piertney S. B. , Knox D. , Gilbey J. , Verspoor E. 
Published: May 2004

AbstractSeven novel and highly variable tetranucleotide microsatellite markers, and conditions for multiplexing and simultaneous genotyping six of these in a single run, are described for Atlantic salmon. These provide a highly informative and cost‐effective set of molecular markers for genetic studies on cultured and wild populations of the species. The primers sets showed cross‐species amplification of appropriately sized amplified products in a number of other salmonid species and suggests the primer sets may have wider application.