bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathogenesis of β2‐Microglobulin Amyloidosis: Role of Monocytes/Macrophages
Authors: Hou Fan Fan , Reddan Donal N. , Seng Wong Kok , Owen William F. 
Published: March 2003

ABSTRACTβ2‐microglobulin (β2M) amyloidosis (Aβ2M) is a serious, often incapacitating complication for patients undergoing long‐term hemodialysis. Amyloid deposits composed of β2M fibrils as the major constituent protein are mainly localized in joints and periarticular bone and lead to chronic arthralgias, carpal tunnel syndrome, and eventually destructive arthropathy. Although recent histologic studies have shown the accumulation of monocytes/macrophages around amyloid deposits, the factor(s) causing their infiltration and pathologic involvement have yet to be fully elucidated. Immunohistochemical staining reveals that macrophages in tenosynovial tissues express CD13, CD14, CD33, HLA‐DR, and CD68 antigens on their surfaces and express interleukin (IL)‐1β, tumor necrosis factor (TNF)‐α, and IL‐6. Many of these cells also express LFA‐1 (CD11a/CD18), Mac‐1 (CD11b/CD18), and VLA‐4 (CD49d/CD29) on their surfaces. AGE‐modified β2M enhances chemotaxis of monocytes and stimulates macrophages to release bone‐resorbing cytokines, such as IL‐1β, TNF‐α and IL‐6. Via a RAGE‐mediated pathway, AGE‐modified, but not unmodified β2M, significantly delays constitutive apoptosis of human peripheral blood monocytes. Monocytes survival in an advanced glycation end product (AGE) β2M‐containing microenvironment is associated with their phenotypic alteration into macrophage‐like cells that generate more reactive oxygen species and elaborate greater quantities of IL‐1β and TNF‐α. Thus through regulation of their survival and differentiation, AGE β2M in amyloid deposits may be able to influence the presence and quantity of infiltrated monocytes, and hence their biologic effects.
Alternative Medicine and Nephrology Series Editor: Naomi V. Dahl: Herbs and Supplements in Dialysis Patients: Panacea or Poison?
Authors: Dahl Naomi V. 
Published: March 2003

ABSTRACTThe safety of herbal remedies and supplement use is of particular concern in patients with renal disease, and reliable information is not always easy to find. Predialysis patients may be drawn to complementary and alternative medicine (CAM) because they believe it can help prevent the progression of their renal disease. The purpose of this series of articles on alternative medicine for nephrologists is to address concerns and issues specific to CAM use in dialysis patients and to provide a guide to reliable sources of information. This introductory article emphasizes safety issues with a focus primarily on herbal medicine. Lack of regulation means that patients may not actually be taking what they think they are. Independent laboratory analyses have shown a lack of stated label ingredients and many instances of supplements and traditional remedies being contaminated with pesticides, poisonous plants, heavy metals, or conventional drugs. While certain supplements are always unsafe (carcinogenic, hepatotoxic, glandular extracts), others are specifically contraindicated in renal disease. Supplement use may be especially hazardous in renal disease because of unpredictable pharmacokinetics, drug interactions, negative effects on kidney function, nephrotoxicity, hemodynamic alterations, unpredictable effects on blood pressure or blood glucose, or potentiation of electrolyte abnormalities. There are no data on potential dialyzability of either active compounds, or their potentially active or toxic metabolites. Many supplements contain metal ions and other minerals. Transplant recipients are also at risk from potential unpredictable effects on immune function. Recommendations and information resources are listed.
Chronic Dialysis and Dialysis Doctors in the United States: A Nephrologist‐Historian's Perspective
Authors: Peitzman Steven J. 
Published: March 2003

ABSTRACTIn an earlier article in Seminars in Dialysis (9:276–281, 1996), the author described the invention of clinical hemodialysis for acute renal failure and its initially equivocal reception by the emerging specialty of nephrology in the United States. A similar story of blunted enthusiasm played out following the invention of the Quinton–Scribner shunt (whose idea “came in the night”), which allowed maintenance treatment for chronic renal failure. Few centers at first could match Belding Scribner's early successes, and some physiology‐oriented university nephrologists envisioned how routine dialysis might swamp other activities. Nonetheless, increasingly complex and successful inventions appeared and prevailed: the chronic dialysis unit, the national dialysis chain. A unique federal entitlement program fostered the spread of maintenance dialysis, but so did the emergence of disposable off‐the‐shelf supplies and many new nephrologists trained in academia but seeking positions in practice. Indeed, the spread of end‐stage renal disease (ESRD) care transformed American nephrology. The essay concludes by considering what nephrologists of the ESRD era share with their patients.
L‐Carnitine in Dialysis Patients
Authors: Ahmad Suhail 
Published: March 2003

ABSTRACTHemodialysis (HD) patients often have low serum concentrations of free L‐carnitine and decreased skeletal muscle stores. As L‐carnitine is an essential cofactor in fatty acid and energy metabolism, it is possible that abnormal carnitine metabolism in dialysis patients may be associated with clinical problems such as skeletal myopathies, intradialytic symptoms, reduced cardiac function, and anemia. Studies have shown that L‐carnitine supplementation in HD patients improves several complications seen in dialysis patients, including cardiac complications (arrhythmias, reduced output, low cardiothoracic ratio), limitation of exercise capacity, increased intradialytic hypotension, and muscle symptoms. The most promising results have been noted in the treatment of erythropoietin‐resistant anemia. Routine administration of L‐carnitine to all dialysis patients is not recommended at this time; however, a therapeutic trial of L‐carnitine can be useful in symptomatic patients with certain clinical features unresponsive to the usual measures. These include intradialytic muscle cramps and hypotension, asthenia, cardiomyopathy, lowered ejection fraction, muscle weakness or myopathy, reduced oxygen consumption, and anemia requiring large doses of EPO.
Photosynthetic Responses to Light for Rainforest Seedlings Planted in Abandoned Pasture, Costa Rica
Authors: Loik Michael E. , Holl Karen D. 
Published: March 2003

AbstractEfforts to reforest tropical pasture with native tree species have increased in recent years, yet little is known about the physiology of most tropical trees. The goal of this study was to assess the effect of habitat on photosynthetic responses to light for seedlings of four native rainforest species (Calophyllum brasiliense, Ocotea glaucosericea, Ocotea whitei, and Sideroxylon portoricense) planted to facilitate tropical rainforest recovery in southern Costa Rica. Seedlings were planted in primary forest, in open abandoned pasture, and in the shade of remnant trees within the pasture. Growth, morphology, photosynthetic gas exchange responses to light, and chlorophyll fluorescence (an indication of the integrity of photosynthetic processes) were measured in the three habitats. Height and leaf area were generally greater for seedlings in tree shade compared to those in the forest and open pasture. Photosynthetic rates were higher for plants in open pasture and tree shade compared to those in the forest for two of the four species. Chlorophyll fluorescence results indicated flexibility in the photosynthetic processing of light energy that may help plants tolerate the bright light of the pasture. This study demonstrates that, for certain species, seedlings under remnant pasture trees do not exhibit the level of photosynthetic stress experienced in open abandoned pasture. Seedling responses to light, in combination with other factors such as increased nutrient input through litterfall, help explain the enhanced growth of seedlings under remnant pasture trees. Planting seedlings under remnant trees may increase the success of future efforts to restore tropical forest in abandoned agricultural land.
Restoring Savanna Using Fire: Impact on the Breeding Bird Community
Authors: Davis Mark A. , Peterson David W. , Reich Peter B. , Crozier Michelle , Query Toby , Mitchell Eliot , Huntington Josh , Bazakas Paul 
Published: March 2003

AbstractRestoration of many terrestrial plant communities involves the reintroduction of fire. However, there have been few studies of the effects of fire on the avifauna during the restoration process. To study the effects of oak savanna restoration on avian communities, breeding birds were censused and the vegetation structure documented in seven experimental burn units (8–18 ha) that had experienced different frequencies of controlled burns during the past 31 years (0–26 burns). Data were analyzed with both direct and indirect gradient analyses using multivariate techniques. The results showed that, as savanna restoration proceeded, there was a general decline in predominantly insectivorous species, particularly those that feed in the upper canopy region (leaves and air space), and a general increase in omnivorous species, particularly those that feed on the ground and in the lower canopy. Insectivorous bark gleaners (woodpeckers) also increased during restoration and were correlated with the increase in standing dead trees resulting from the fires. Overall, savanna restoration resulted in increases in the abundance of many open country bird species, including many species that have been declining in central and eastern North America, including red‐headed woodpecker, Baltimore oriole, eastern kingbird, vesper sparrow, field sparrow, lark sparrow, brown thrasher, American goldfinch, and brown‐headed cowbird. The shifts in species and guilds were correlated with changes in burn frequency and the macro vegetation structure—tree and shrub density, leaf area index, and relative proportion of standing dead trees. The findings show that savanna restoration can increase bird diversity and provide important habitat for uncommon or declining bird species. These birds are most likely attracted to one or more of the distinctive habitat features of the restored savanna environments, including scattered mature trees, standing dead trees and snags, and presence of both shrubby and grassland vegetation. The findings also suggest that restoration ecologists and wildlife biologists will need to work together to achieve desired goals, since different types of savanna restoration efforts may produce different effects on the breeding bird community.
Restoring the Vegetation of Mined Peatlands in the Southern Rocky Mountains of Colorado, U.S.A.
Authors: Cooper David J. , MacDonald Lee H. 
Published: March 2003

AbstractSouth Park is a high‐elevation, semi‐arid, treeless intermountain basin in central Colorado. A few extreme rich fens occur on the western margin and in the center of South Park where regional and local groundwater flow systems discharge to the ground surface. Over the past 40 years there has been extensive peat mining in these fens, but restoration methods have yet to be developed and successfully applied. The first part of this study compared the naturally reestablished vegetation on six mined peatlands with six pristine sites, while the second part of the study tested different revegetation techniques in 27 plots with varying depths to the water table. The six mined sites had only 30 plant species as compared with 122 species in the unmined sites; 43% of the species in the mined sites were not present in the undisturbed fens. Even after 40 years the sedges and willows that dominate the undisturbed sites were largely absent on the mined sites. The revegetation experiments seeded eight species, transplanted Carex aquatilis (water sedge) seedlings, transplanted rhizomes from six species, and transplanted four species of willow cuttings. Of the eight species seeded, only Triglochin maritima (arrowgrass) germinated and established seedlings. C. aquatilis seedlings, rhizome transplants of C. aquatilis, Kobresia simpliciuscula (elk sedge), and Juncus arcticus (arctic rush), and willow cuttings all had differing patterns of survival with respect to the annual maximum height of the water table. These results indicate that the dominant species can be successfully reintroduced to mined surfaces with the appropriate hydrologic conditions, but human intervention will be necessary to rapidly re‐establish these species. The slow rate of peat accumulation means that restoration of the mined fens will require hundreds, if not thousands, of years.
The Influence of Rewetting on Vegetation Development and Decomposition in a Degraded Fen
Authors: Richert Maja , Dietrich Ottfried , Koppisch Dorothea , Roth Siegfried 
Published: March 2003

AbstractThe rewetting technique border irrigation was installed in a degraded fen peatland in northeastern Germany. Because of the prevailing site conditions, the technique resulted in two different rewetting variants (surface irrigation and temporary inundation) at the study site. This paper reports on the practicability of this technique and the influence of rewetting on vegetation development, decomposition processes and soil nutrient availability, and the possibilities for renewed peat accumulation. The technique proved to be suited for rewetting fen sites with a continuous slope, deep peat layer with low hydraulic conductivity, and upstream water recharge facilities. A subsidence of the ground‐water levels during the summer months, however, could not be avoided in dry years. The vegetation changed slowly from species‐poor grassland into typical fen plant communities, despite rewetting and soil tillage. Species richness, however, was higher in the surface irrigation than in the temporary inundation variant. A sufficient water supply proved to be absolutely necessary to retard decomposition processes because higher decomposition of root materials (i.e., higher k values) occurred under temporary inundated conditions. Generally, the higher water content in the soil after rewetting led to a lower nitrate‐N–to–ammonium‐N ratio in the topsoil in both rewetting variants. In the surface irrigation variant the mineral nitrogen content (Nmin) of the topsoil decreased from 7.8 to 4.4 g N/m2, which is also correlated with the increase in water content of the soil. The low Nmin levels of fens which were never deeply drained (0.9–2.8 g N/m2), however, were not reached within the observation period of 3 years.
Revegetation of Roadcut Slopes in Mesa Verde National Park, U.S.A.
Authors: Paschke Mark W. , DeLeo Claire , Redente Edward F. 
Published: March 2003

AbstractThe geology of Mesa Verde National Park (MVNP) poses unique problems to road construction and maintenance. Major geologic formations of the Park consist of an overlying resistant sandstone cap underlain by highly erodable shales. Once this sandstone cap is removed, the shales are easily eroded away, creating the notable mesas of the region. In many places, road construction has removed the sandstone layer and vegetation resulting in unaesthetic barren slopes that require continual maintenance and have proven difficult to revegetate. An experiment was conducted to evaluate the effectiveness of several cultural techniques combined with seeding and transplanting indigenous plants for revegetation of these roadcut slopes. Techniques evaluated were fertilization, mulching, soil pitting, and polyacrylamide amendments. Replicated test plots were established at three roadcut sites in MVNP to evaluate these techniques by measuring percent plant cover by species over a 4‐year period. A combination of seeding grasses and transplanting forbs and shrubs appeared to be the optimal way to maintain species diversity and structure on the roadcuts while accomplishing the goal of revegetating these difficult sites. The perennial forb Aster glaucodes and the shrub Artemisia ludoviciana showed high survival when transplanted in the experimental roadcut sites. These species, as well as the perennial grass Pascopyrum smithii, also established well from seed. The addition of an organic fertilizer, in combination with mulch, proved to be the most effective method of improving vegetation cover for these and other transplanted species.
Restoration of Wet Fen Meadows by Topsoil Removal: Vegetation Development and Germination Biology of Fen Species
Authors: Patzelt Annette , Wild Ulrich , Pfadenhauer Jörg 
Published: March 2003

AbstractThe present investigation was part of a fen restoration project, which deals with the rehabilitation of a deeply drained peat land used for intensive agriculture for more than 200 years. Consequently, the conditions for restoration are unfavorable. The hay of well‐developed fen meadows from nature reserves in the region appeared to contain enough viable seeds to act as a source for the development of target communities when spread out on bare peat after topsoil removal. Repeated vegetation analysis showed that a combination of topsoil removal and hay transfer resulted in the establishment of new populations in the target area for 70% of the species of the donor area. Germination conditions of fen species were investigated to determine the optimal combination for stimulating germination rates. Most fen species were found to be dormant, and it was shown that dormancy could be broken with fluctuating light and temperature cycles and stratification pre‐treatment.
Comparing the Importance of Seedbed and Canopy Type in the Restoration of Upland Thuja occidentalis Forests of Northeastern Minnesota
Authors: Cornett Meredith W. , Puettmann Klaus J. , Frelich Lee E. , Reich Peter B. 
Published: March 2003

AbstractIn cold‐temperate ecosystems of the upper Great Lakes Region, evergreen conifer‐dominated forests were once common. As a result of past management practices, early‐successional deciduous forests now dominate the landscape. Embedded in this matrix are stands of shade‐tolerant conifers, including Thuja occidentalis. For the past several decades, large‐scale T. occidentalis regeneration in remnant T. occidentalis and adjacent Betula papyrifera forests has not occurred. Using a combination of restoration experiments and field surveys at three study sites on the Lake Superior Highlands, Minnesota, U.S.A., we examined safe sites for T. occidentalis regeneration under both Thuja and Betula canopy types. This study focused on the colonization and establishment phases of regeneration, differentiating among safe‐site components for T. occidentalis. Seedbed type determined colonization success, with higher rates on conifer logs than on B. papyrifera logs, mounds, or pits. Mortality rates for seedlings on natural decayed wood seedbeds were higher under Thuja canopy than under Betula canopy, but the reverse was true for seedlings on manipulated seedbeds, suggesting that seedbed type was more important than the dominant canopy type. Growth rates for seedlings on moved log segments were greater under the Betula than the Thuja canopy type, but seedlings on natural decayed wood seedbeds did not exhibit this difference. Results indicated that T. occidentalis regeneration was more limited in Betula forest by seedbed availability, while in Thuja forest canopy conditions were more limiting.
Forest Development, Wood Jams, and Restoration of Floodplain Rivers in the Puget Lowland, Washington
Authors: Collins Brian D. , Montgomery David R. 
Published: March 2003

AbstractHistorically in Puget Lowland rivers, wood jams were integral to maintaining an anastomosing channel pattern and a dynamic channel–floodplain connection; they also created deep pools. In the late 1800s, wood was removed from most rivers, rivers were isolated from their floodplains, and riparian forests were cut down, limiting wood recruitment. An exception to this history is an 11‐km‐long reach of the Nisqually River, which has natural banks and channel pattern and a mature floodplain forest. We use field and archival data from the Nisqually River to explore questions relevant to restoring large rivers in the Pacific Northwest and other forested temperate regions. In particular, we focus on the relation between recovery of in‐channel wood accumulations and valley bottom forest conditions and explore implications for river restoration strategies. We find that restoring large rivers depends on establishing riparian forests that can provide wood large enough to function as key pieces in jams. Although the frequency of large trees in the Nisqually valley bottom in 2000 is comparable with that of 1873 land surveys, many formerly more abundant Thuja plicata (western red cedar) were cut down in the late 1800s, and now hardwoods, including Populus trichocarpa (black cottonwood) and Acer macrophyllum (bigleaf maple), are also abundant. Pseudotsuga menziesii (Douglas fir) and fast‐growing P. trichocarpa commonly form key pieces that stabilize jams, suggesting that reforested floodplains can develop naturally recruited wood jams within 50 to 100 years, faster than generally assumed. Based on the dynamic between riparian forests, wood recruitment, and wood jams in the Nisqually River, we propose a planning framework for restoring self‐sustaining dynamic river morphology and habitat to forested floodplain rivers.
Does Facilitation of Faunal Recruitment Benefit Ecosystem Restoration? An Experimental Study of Invertebrate Assemblages in Wetland Mesocosms
Authors: Brady Valerie J. , Cardinale Bradley J. , Gathman Joseph P. , Burton Thomas M. 
Published: March 2003

AbstractWe used wetland mesocosms (1) to experimentally assess whether inoculating a restored wetland site with vegetation/sediment plugs from a natural wetland would alter the development of invertebrate communities relative to unaided controls and (2) to determine if stocking of a poor invertebrate colonizer could further modify community development beyond that due to simple inoculation. After filling mesocosms with soil from a drained and cultivated former wetland and restoring comparable hydrology, mesocosms were randomly assigned to one of three treatments: control (a reference for unaided community development), inoculated (received three vegetation/sediment cores from a natural wetland), and stocked + inoculated (received three cores and were stocked with a poorly dispersing invertebrate group—gastropods). All mesocosms were placed 100 m from a natural wetland and allowed to colonize for 82 days. Facilitation of invertebrate colonization led to communities in inoculated and stocked + inoculated treatments that contrasted strongly with those in the unaided control treatment. Control mesocosms had the highest taxa richness but the lowest diversity due to high densities and dominance of Tanytarsini (Diptera: Chironomidae). Community structure in inoculated and stocked + inoculated mesocosms was more similar to that of a nearby natural wetland, with abundance more evenly distributed among taxa, leading to diversity that was higher than in the control treatment. Inoculated and stocked + inoculated communities were dominated by non‐aerial invertebrates, whereas control mesocosms were dominated by aerial invertebrates. These results suggest that facilitation of invertebrate recruitment does indeed alter invertebrate community development and that facilitation may lead to a more natural community structure in less time under conditions simulating wetland restoration.