bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dialysis‐Related Amyloidosis: Pathogenesis Focusing on AGE Modification
Authors: Niwa Toshimitsu 
Published: March 2003

ABSTRACTDialysis‐related amyloidosis (DRA) is a serious complication in long‐term dialysis patients, and presents with carpal tunnel syndrome, cystic bone lesions, destructive spondylarthropathy, diffuse arthritis and periarthritis, systemic organ involvement, and dialysis‐related spinal canal stenosis (DSCS). Recently a new concept of DSCS has been proposed that includes both destructive spondylarthropathy and myeloradiculopathy induced by extradural thickness. β2‐microglobulin (β2M) amyloid was demonstrated to be modified with advanced glycation end products (AGEs) such as imidazolone, Nε‐(carboxymethyl)lysine (CML), and pentosidine. Imidazolone is a reaction product of arginine residue in proteins with 3‐deoxyglucosone (3‐DG), which is markedly accumulated in uremic serum. Imidazolone is generated under nonoxidative conditions, while CML and pentosidine are formed by oxidative processes. Immunoelectron microscopy demonstrated that AGEs were localized not only in dialysis amyloid but also in nonamyloid collagenous structures, supporting the hypothesis that AGE modification of collagen might have pathogenic relevance in the deposition of β2M on collagen. Serum levels of AGEs are increased in uremic patients. The dimeric form of β2M in the dialysate and urine of uremic patients is more susceptible to imidazolone modification as observed in dialysis amyloid. However, the major component of dialysis amyloid is a native form of β2M, while AGE‐modified β2M and truncated β2M are the minor components. Thus I propose that 3‐DG and the other dicarbonyl compounds accumulating in uremic serum promote the modification of β2M with AGEs mainly after deposition of β2M as amyloid. For the prevention and treatment of DRA, β2M should be efficiently eliminated from circulating blood by kidney transplantation, hemodialysis, or hemodiafiltration using high‐flux membranes and an adsorbent (Lixelle) column.
Significance of Distribution Volume in Dialysis Quantification
Authors: Sternby Jan 
Published: March 2003

ABSTRACTThe urea distribution volume is in several ways an important parameter in the treatment of end‐stage renal disease (ESRD) patients. It has a major impact on the relative dose of dialysis treatment as measured by Kt/V. It is also important in the assessment of fluid status, which has a direct influence on blood pressure. Nevertheless, urea distribution volume is usually not measured on a regular basis, probably because it has been perceived as a relatively complicated measurement. With the arrival of on‐line monitors for dialysate urea this situation has improved radically. In this article a number of volume determination methods are discussed, including some new methods based on on‐line dialysate urea monitoring, which are shown to perform well in comparison to reference methods.
Imaging in the Dialysis Patient: Contrast Agents in Patients on Dialysis
Authors: Dawson Peter 
Published: March 2003

AbstractContrast media are used to enhance the structural and functional information that is provided by imaging methods. They are used particularly in conventional radiographic (X‐ray) investigations, but are also used in magnetic resonance imaging (MRI) and increasingly in ultrasound (US). The water‐soluble, iodinated, intravascular radiographic agents are commonly used, and in large doses. They are excreted almost exclusively by the kidney and may have nephrotoxic effects. The use of these agents in patients with renal impairment may potentially be problematic. In this article the chemical composition and pharmacokinetics of these contrast agents are reviewed, as are their potentially toxic effects on the heart, neural tissues, kidney, and endothelium. Their safety for use in the patient with end‐stage renal disease (ESRD) and those on dialysis is discussed. This aspect is also addressed briefly for the contrast agents used to augment MRI and US.
Special Article: The Study of Treatment for Renal Insufficiency: Data and Evaluation (STRIDE), a National Registry of Chronic Kidney Disease
Authors: Rao Madhumathi , Kausz Annamaria T. , Mitchell Don , Ratican Sari Heller , Lin Francie , Burrows‐Hudson Sally , Port Fritz , Pereira Brian J. G. 
Published: March 2003

AbstractOptimization of care in patients with chronic kidney disease (CKD) could be the key to improved clinical and economic outcomes, both during the phase of CKD as well as in patients with end‐stage renal disease (ESRD). CKD is a major public health problem that has been insufficiently studied. There is little published information on outcomes among CKD patients, specifically, data on mortality, morbidity, and quality of life. Indeed, recent efforts by the National Kidney Foundation (NKF) have served to define the classification, evaluation, and approach to management of CKD in practice. The Study of Treatment for Renal Insufficiency: Data and Evaluation (STRIDE) registry is an initiative to study CKD patients in nephrology practices across the country. It is a prospective observational study whose objective is to profile demographic and clinical variables, practice patterns, comorbid conditions, quality of life, and outcomes in a nationally based sample of CKD patients. This article details the design, methodology, and process of enrollment into the registry.
Editorials: The ADEMEX Study and Its Implications for Peritoneal Dialysis Adequacy
Authors: Burkart John M. 
Published: March 2003

AbstractIn an attempt to improve patient outcomes in peritoneal dialysis (PD), national organizations (such as the National Kidney Foundation Dialysis Outcomes Quality Initiative [NKF‐DOQI] process) have formulated clinical practice guidelines based on clinical evidence available at the time of development. For “adequacy” of PD it was acknowledged that there was no prospective randomized interventional clinical trial that evaluated the effect of an increase in peritoneal clearance on outcome. The ADEMEX study is the first such study designed to do this. It was well done and adequately powered for the primary analysis. The study findings indicate that over the range of solute clearances studied, an increase in peritoneal clearance is not associated with an incremental improvement in patient outcome. However, it is noted that the cause of dropout was different between groups, with more dropout for “uremia” in the control group. There are also some limitations in the generalizability of the results. First, the exclusion criteria were likely to exclude patients who were small in body size or were high transporters, patients with the highest relative risk of death. Second, although there was an increase in small solute clearance between control and intervention groups, there was not likely to be an increase in clearance of other potential uremic solutes such as middle molecules. Third, the study did not examine outcomes for patients on cycler therapy. Nevertheless it was a provocative, well‐run clinical study which does have implications for clinical practice. It confirms that one prescription does not fit all patients, that many patients below current NKF‐DOQI targets for small solute clearance are likely to be adequately dialyzed, and provides evidence‐based clinical information for national societies to consider when preparing for the next revision of their guidelines.
Effects of Changes in Acidity on Aquatic Insects in Rocky Littoral Habitats of Lakes Near Sudbur y, Ontario
Authors: Carbone J. , Keller W. , Griffiths R. W. 
Published: March 2003

Benthic aquatic insects were collected from rocky nearshore areas (< 1 m deep) of 17 lakes near Sudbury, Ontario, with a pH range of 4.7–7.3 and a size range of less than 10 ha to over 10,000 ha. These insect communities were composed of taxa common to lake soft‐sediments and streams. Direct and indirect effects of lake acidity appeared to be major controls on the structure of these communities, implying that several factors may be involved in restructuring during acidification or recovery. Declines in abundances of several taxa of Ephemeroptera at pH below 5.5 were attributable to acid toxicity, while increases in the abundances of Odonata and Diptera at pH below 5.5 were associated with the absence of fish predators and other indirect effects of acidity. The communities of two experimentally neutralized lakes restructured rapidly within 5 years, approaching but not achieving community structures typical of our near‐neutral survey lakes. Neutralization led to recolonization or increased abundance of the acid‐sensitive mayfly, Stenacron interpunctatum, and the dragonfly, Boyeria grafiana; however, recolonization by other taxa expected to be present in near‐neutral lakes (Stenonema femoratum, Eurylophella, and Basiaeshna janata) was not observed. Consistent with results for the survey lakes, declines in the abundances of the dragonflies Aeshna interrupta, Aeshna eremita, and Leucorrhinia glacialis in the neutralized lakes were associated with reintroductions of Salvelinus fontinalis (aurora trout) and increased fish predation pressure, while reduced abundances of the dipterans Ceratopogonidae, Psectrocladius, and Stackelbergina may be related to indirect effects of acidity other than fish predation. Although community composition varied greatly across the acidity gradient, total species richness and abundance were not correlated with lake chemistry or number of fish species.
Shrub Densities on Pre‐1985 Reclaimed Mine Lands in Wyoming
Authors: Booth D. Terrance , Gores James K. , Schuman Gerald E. , Olson Richard A. 
Published: March 2003

AbstractThe reestablishment of native shrubs is part of the mandate under which mining companies extract mineral resources in Wyoming and other western states. Post‐mining shrub density and species mixtures have been topics debated by various mine reclamation stake holders. By law, coal‐mined lands in Wyoming must now meet a post‐mining shrub density of 1 shrub/m2 on 20% of the affected area. To better understand the long‐term results of shrub reclamation methods, we measured shrub density by species in 14 pre‐1985 seedings at eight mines in three geographic regions of Wyoming. The sites studied were selected as Atriplex canescens (Pursh) Nutt. (fourwing saltbush) and grass or as Artemisia tridentata Nutt. ssp. wyomingensis (Beetle and Young) (Wyoming big sagebrush), fourwing saltbush, and grass post‐mining communities. Shrub density and composition varied by site but typically reflected the seed mixtures used. Seedings that used a diversity of shrub species generally had greater 1994 shrub densities. Seeding rates between 60 and 1000 shrub seeds/m2 had a positive, linear relationship with shrub density up to 0.6 shrubs/m2 when sagebrush was part of the shrub seed mixture. We conclude that the likelihood of meeting the shrub standard can be enhanced by seeding diverse shrub mixtures at high seeding rates.
Effects of Soil Nitrogen Reduction on Nonnative Plants in Restored Grasslands
Authors: Morghan K. J. Reever , Seastedt T. R. 
Published: March 2003

AbstractWe studied the cumulative effects of 3 years of carbon amendments on previously disturbed mixed‐grass prairie sites near Boulder, Colorado. Analysis of soil inorganic nitrogen during the third field season indicated statistically significant but short‐term nitrogen reduction in response to addition of a combination of sugar and sawdust treatments. Plant foliage production was significantly reduced by these carbon amendments and averaged 377 g/m2/year on control plots versus 219 g/m2/year on treated plots. Undesirable species such as Centaurea diffusa (diffuse knapweed) exhibited a similar biomass response. But after three years of treatment there is little evidence to suggest a relative increase in desirable, reseeded species such as Agropyron smithii (western wheatgrass). We suggest that the carbon amendment treatment alone is an inadequate remediation technique in areas exposed to extensive seed rain by exotic species.
Protocols for Restoration Based on Recruitment Dynamics, Community Structure, and Ecosystem Function: Perspectives from South African Fynbos
Authors: Holmes Patricia M. , Richardson David M. 
Published: March 2003

AbstractSouth African fynbos ecosystems are under threat from alien plant invasions and transformations to alternative land uses. If large‐scale habitat loss and species extinction are to be halted, restoration actions are urgently required. We postulate that by adopting an approach in which an understanding of community and ecosystem dynamics is applied to restoration practices, protocols can be developed which will lead to more efficient restoration. This understanding is based on a review of the relevant ecological literature, focusing on recruitment dynamics, community structure, and ecosystem function, which are particularly relevant to restoration. We develop a conceptual framework for restoration and apply our protocols to a case study area on the Cape Peninsula. Before ecological restoration can begin, the cause of transformation must first be removed or ameliorated. The next step is to ensure that the important ecological processes are functioning. We contend that a fully functioning community requires a good balance of the major growth‐form, regeneration, and nutrient acquisition guilds. Fire is the natural disturbance event initiating recruitment in fynbos. It is, therefore, essential to either burn a site or provide fire‐related germination cues in order to stimulate recruitment. Where guilds are under‐represented, corrective reintroductions will further improve the long‐term resilience of the restored community. Many taxa have persistent soil‐stored seed banks, so it is important to conserve topsoil and optimize use of this local species pool. Seed dispersal distances are generally very short, and in highly transformed sites it will be necessary to reintroduce seed of the major guilds in order to restore community structure and functioning. Post‐fire succession in fynbos begins with the full complement of species; species gradually die out from the vegetation according to their respective life spans. In order to stimulate germination and promote successful establishment, it is important to sow seed after fire or site clearing in late summer or autumn. Introducing seed or plants at a later stage in the succession is very likely to fail. Because of the localized distributions of many taxa, extreme care must be taken when selecting species for reintroduction if local gene pools are to be conserved.
The Importance of Transplant Size and Gap Width in the Botanical Enrichment of Species‐Poor Grasslands in Britain
Authors: Davies Angus , Dunnett Nigel P. , Kendle Tony 
Published: March 2003

AbstractA series of five grasslands of differing agricultural productivity and species diversity was chosen for this study. Four of these areas were divided into three sub‐plots, each under a different management regime (either mown, sheep, or cattle grazed). Each sub‐plot was inoculated with 180 transplants comprised of 12 individuals of 15 perennial species. These species were chosen to provide a spectrum of ‘phytometers’ to evaluate the receptivity of the grasslands to species introduction. Half of the plants were 9‐cm pot‐grown transplants, the other half, 2‐cm plug plants. One‐third of each of the transplant sizes was inserted into either 0‐cm, 15‐cm, or 30‐cm‐diameter gaps. Evaluation of species enrichment success was made by monitoring the survivorship of the transplants over a three‐year study period. The fifth grassland was already species‐rich and, therefore, left untreated and used as a reference community. The species could be classified into three main groups on the basis of their survivorship: (a) species with higher survivorship for pot than plug transplants; (b) species that established significantly better as plug than as pot transplants; and (c) species that suffered equally high mortalities as either pot or plug transplants. For three out of the four grasslands, the size of competition‐free gaps was not significant in enhancing survivorship for either pot or plug transplants. Gap creation only aided survivorship for the set of plug plants inserted into the most productive grassland. Transplant survival was strongly negatively correlated with soil P and K concentrations, and peak biomass. In this, the establishment phase, the three management treatment regimes did not have a significant differential effect on transplant survival. The results are discussed in relation to practical techniques for restoring species‐poor grasslands using transplants.
Effects of Burning and Grazing on a Coastal California Grassland
Authors: Hatch Daphne A. , Bartolome James W. , Fehmi Jeffrey S. , Hillyard Deborah S. 
Published: March 2003

AbstractWe tested the effects of fall burning and protection from livestock grazing as management to enhance native grasses on a coastal grassland in central California. Plants from the Mediterranean, introduced beginning in the late 1700s, have invaded and now dominate most of California's grasslands. Coastal grasslands are generally less degraded than those inland and have higher potential for restoration and conservation. Productivity of the experimental plots varied annually and declined over the course of the study because of rainfall patterns. Foliar cover of the native Danthonia californica (California oatgrass) increased more under grazing than grazing exclusion and did not respond to burning. Two other natives, Nassella pulchra (purple needlegrass) and Nassella lepida (foothill needlegrass), responded variably to treatments. The response of N. pulchra differed from that reported on more inland sites in California. Restoring these grasslands is complicated by differing responses of target species to protection from grazing and burning. The current practice of managing to enhance single species of native plants (e.g., N. pulchra) may be detrimental to other equally important native species.
Restoration of Northwest Florida Sandhills Through Harvest of Invasive Pinus clausa
Authors: Provencher Louis , Herring Brenda J. , Gordon Doria R. , Rodgers H. LeRoy , Tanner George W. , Brennan Leonard A. , Hardesty Jeffrey L. 
Published: March 2003

AbstractAcross much of the southeastern U.S.A., sandhills have become dominated by hardwoods or invasive pine species following logging of Pinus palustris (longleaf pine) and fire suppression. At Eglin Air Force Base where this study was conducted, Pinus clausa (sand pine) has densely colonized most southeastern sandhill sites, suppressing groundcover vegetation. The objectives of this study were: to determine if suppressed groundcover vegetation recovers following the removal of P. clausa; to compare species composition and abundance in removal plots with that in reference, high quality sandhills; to test the assumption that recolonization by P. clausa seedlings decreases with proximity to the centers of removal plots; and to measure the survival of containerized P. palustris seedlings that were planted on P. clausa removal plots. One year post‐removal (1995), the number of plant species decreased by 50%, but then increased by 100% from 1995 to 1997, followed by a small reduction in 1998. The number of plant species was greater in reference plots than in removal plots prior to 1997. Eighty‐five percent of the original species were recorded 4 years post‐harvest in removal plots. Shrubs and large trees remained at low density after harvest. Densities of graminoids, legumes, other forbs, woody vines, and small trees increased after harvest. Plant densities of all life forms, except woody vines, were greater in reference plots than in removal plots. The density of recolonizing P. clausa seedlings 2–4 years post‐harvest significantly decreased with increasing proximity to the centers of removal plots. On average, 80% of planted P. palustris seedlings survived their first 2 years. Harvest of P. clausa followed by fire and the planting of P. palustris is a reasonably effective restoration approach in invaded sandhills. However, supplementary plantings of some herbaceous species may be necessary for full restoration.
Cattle and Weedy Shrubs as Restoration Tools of Tropical Montane Rainforest
Authors: Posada Juan M. , Aide T. Mitchell , Cavelier Jaime 
Published: March 2003

AbstractOver the last 150 years, a large proportion of forests in Latin America have been converted to pastures. When these pastures are abandoned, grasses may slow re‐establishment of woody species and limit forest regeneration. In this study, we explored the use of cattle in facilitating the establishment of woody vegetation in Colombian montane pastures, dominated by the African grasses Pennisetum clandestinum (Kikuyo) and Melinis minutiflora (Yaraguá). First, we described woody and herbaceous vegetation in grazed and non‐grazed pastures. Second, we tested the effect of grazing and seed addition on the establishment and growth of woody species. We also determined if the effect of grazing was different in P. clandestinum and M. minutiflora pastures. We found that low stocking density of cattle greatly increased density, number of branches per individual (a measure of “shrubiness”), and basal area of woody species, but also reduced woody plant species richness and diversity. In the grazed area, the shrubs Baccharis latifolia (Chilca) and Salvia sp. (Salvia) were the most abundant. The combined effect of grazing and shading from the shrubs reduced herbaceous vegetation by 52 to 92%. In the grazing/seed addition experiment, grazing increased establishment of woody seedlings, particularly of the shrub Verbesina arborea (camargo), but the largest effect was seed addition. Where grasses are an important barrier to regeneration, grazing can facilitate the establishment of shrubs that create a microhabitat more suitable for the establishment of montane forest tree species.
Structural and Floristic Heterogeneity in a 30‐Year‐Old Costa Rican Rain Forest Restored on Pasture Through Natural Secondary Succession
Authors: Finegan Bryan , Delgado Diego 
Published: March 2003

AbstractRelatively little information exists on neotropical secondary rain forests that have progressed beyond the pioneer stages of succession, or on the potential of natural regeneration to restore forest on large areas. We determined the structural and floristic characteristics (10 cm dbh) of a 30‐year‐old secondary forest developing on a 32.5 ha pasture on hilly terrain, abandoned after use of moderate intensity. Ten 0.24 ha sample plots covered the range of site conditions. The forest was dominated by long‐lived pioneer tree species; overall, the majority of species (70%) was vertebrate dispersed but the majority of individuals (52%) was of wind‐dispersed species. Tree species, including the dominants, were a mixture of those present in old‐growth and adventives colonizing from agricultural land. The forest was very heterogeneous. Vochysia ferruginea‐dominated stands characterized slopes with soils of high exchangeable acidity, while the adventive Cordia alliodora dominated sites with gentler topography and soils of lower acidity. Structural differences between the two forest types were slight, but Cordia forest had significantly greater species diversity and absolute and relative abundances of vertebrate‐dispersed tree species than Vochysia forest, which had significantly greater absolute and relative abundances of wind‐dispersed tree species. These latter differences between forest types, as well as the wide structural variation of the forest as a whole, were probably largely due to spatial and temporal variation in seed rains, some of it linked to the characteristics of the dominant species. Rain forest restoration on large pastures may depend greatly on wind dispersal and adventive tree species, and techniques for silvicultural diagnosis must be developed as a basis for the management of heterogeneous successional stands. Studies of early colonization of pastures should be expanded to focus on the causes of heterogeneity in older forests.