bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Rational Guide to Reducing Fracture Risk in Dialysis Patients
Authors: Toussaint Nigel D. , Elder Grahame J. , Kerr Peter G. 
Published: February 2010

AbstractExtrapolation of evidence‐based management of disorders in the general population to patients with chronic kidney disease (CKD) is not always appropriate, and the prevention of bone fracture and reduction of fracture risk in CKD stages 3–5 is one example. Compared to the general population, fracture risk is greater in CKD patients, especially those on dialysis (CKD‐5D). Fractures in CKD‐5D are associated with a marked increase in morbidity and mortality and with an aging dialysis population the burden of disease caused by fracture is likely to increase. Patients with CKD‐5D have distinct risks for fracture, as well as sharing risks identified in the general population. The development of the CKD mineral and bone disorder constitutes a significant cause for these differences. Literature addressing the determination of fracture risk and the efficacy of treatments to reduce fracture in patients on dialysis is limited. While some tools used for the diagnosis and monitoring of osteoporosis are applicable to patients on dialysis, bone mineral density measurement by dual‐energy X‐ray absorptiometry is generally not helpful and therapeutic interventions that reduce fracture risk in the nonuremic population cannot be generalized to patients on dialysis. This review outlines available evidence on the incidence, risk factors, and management of fractures in CKD‐5D with recommendations for strategies to reduce fracture risk.
Controversies and Concerns in Hemodialysis Series Editor: Marcello Tonelli: Calcific Uremic Arteriolopathy Should Be Treated Conservatively
Authors: Courtney Mark J. , Pannu Neesh 
Published: February 2010

AbstractCalcific uremic arteriolopathy (CUA) is a small vessel vasculopathy affecting mainly stage IV and V renal failure patients. It is characterized typically by non‐healing, painful skin ulcerations and carries a poor prognosis. Little is known about the pathogenesis, but abnormal mechanisms of vascular calcification have been postulated to contribute. Available therapies target promotion of wound healing and lowering of elevated parathyroid hormone levels and the calcium‐phosphate product. There are no prospective or randomized controlled trials to guide choice of therapeutic agents, yet available therapies may subject patients to adverse side effects, and/or increase program expenditures. Therefore, we favor a graded approach to treatment of CUA, commencing conservatively with the least harmful and most cost‐efficient measures available.
Salvage of Malpositioned and Malfunctioning Peritoneal Dialysis Catheters by Manipulation with a Modified Malecot Introducer
Authors: Santos Catarina R. , Branco Patrícia Q. , Martinho António , Gonçalves Margarida S. , Gaspar Augusta , Messias Humberto , Barata José D. 
Published: February 2010

AbstractPercutaneous peritoneal dialysis (PD) catheter manipulation successfully corrects displacement and contributes to catheter salvage. We describe a new device for the percutaneous treatment of malpositioned PD catheters, the modified Malecot introducer technique, which is an improvement over previous methods because its flexible consistency also allows the manipulation of swan‐neck catheters. Twenty‐one patients experienced catheter displacement managed by the new introducer: 12 males, average time in PD 13.7 ± 23.2 months, six with “swan‐neck” catheter, seven obese, and six with previous abdominal surgery. Catheter manipulation was technically successful in 19 of 21 cases (90.4%) by the end of the first week and in 15 cases (71.4%) at 1 month. An additional eight episodes of malposition occurred ranging from 10 to 300 days after the first manipulation. A second manipulation using the same introducer was performed and resulted in long‐term patency in seven patients. No complications were reported. In the long‐term follow‐up, only one patient removed PD catheter for mechanical dysfunction. Overall survival of manipulated catheters was 32.7 ± 23.4 months. Function at 1 month correlated with function by the first week (r = 0.513; p = 0.017) and the need of a second manipulation with age (r = 0.494; p = 0.027) but not with obesity or previous abdominal surgery. We conclude that manipulation using the modified Malecot introducer is a simple and effective procedure for the correction of malpositioned PD catheters. It also represents a new alternative for the management of displaced “swan‐neck” catheters.
Venous Elastography: Validation of a Novel High‐Resolution Ultrasound Method for Measuring Vein Compliance Using Finite Element Analysis
Authors: Biswas Rohan , Patel Prashant , Park Dae W. , Cichonski Thomas J. , Richards Michael S. , Rubin Jonathan M. , Hamilton James , Weitzel William F. 
Published: February 2010

AbstractUltrasonography for the noninvasive assessment of tissue properties has enjoyed widespread success. With the growing emphasis in recent years on arteriovenous fistulae (AVFs) for dialysis vascular access in patients with end‐stage renal disease, and on reducing AVF failures, there is increasing interest in ultrasound for the preoperative evaluation of the mechanical and elastic properties of arteries and veins. This study used high‐resolution ultrasound with phase‐sensitive speckle tracking to obtain in vivo vein elasticity measurements during dilation. The results of this novel ultrasound technique were then compared to a computer model of venous strain. The computer model and ultrasound analysis of the vessel wall demonstrated internally consistent positive and negative longitudinal strain values as the vein wall underwent dilation. These results support further investigation of the use of phase‐sensitive speckle tracking for ultrasound venous mapping for preoperative vascular access evaluation.
Insight: Effects of Reduced Intradialytic Urea Generation Rate and Residual Renal Clearance on Modeled Urea Distribution Volume and Kt/V in Conventional, Daily, and Nocturnal Dialysis
Authors: Daugirdas John T. , Depner Thomas A. , Greene Tom , Levin Nathan W. , Chertow Glenn M. , Rocco Michael V. , Stokes John B. ,   the Frequent Hemodialysis Network (FHN) Trial Group
Published: February 2010

AbstractClassic urea modeling assumes that both urea generation rate (G) and residual renal urea clearance (Kru) are constant throughout the week, but this may not be true. Reductions in intradialysis G could be caused by lower plasma amino acid levels due to predialysis/intradialysis fasting and also to losses of amino acids into the dialysate. Intradialytic reductions in Kru could be due to lower intravascular volume, blood pressure, or osmotic load. To determine the possible effects of reduced G or Kru during dialysis on the calculation of the volume of distribution (V) and Kt/Vurea, we modeled 3 and 6/week nocturnal, 6/week short daily, and 3/week conventional hemodialysis. A modified 2‐pool mathematical model of urea mass balance with a constant time‐averaged G was used, but the model was altered to allow adjustment of the ratio of dialytic/interdialytic G (Gd/Gid) and dialytic/total Kru (Krud/Kru) to vary from 1.0 down to near zero. In patients dialyzed six times per week for 400 minutes per session, when Gd/Gid was decreased from 1.0 to 0.05, the predicted urea reduction ratio (URR) increased from 68.9% to 80.2%. To achieve an increased URR of this magnitude under conditions of constant G (Gd/Gid = 1.0) required a decrease in modeled urea volume (V) of 36%. At Gd/Gid ratios of 0.8 or 0.6 (corresponding to 20% or 40% reductions in intradialysis G), the modeled URR was increased to 71.0% or 73.3%, causing a 7% or 15% factitious decrease in V. The error was intermediate for the 3/week nocturnal schedule, and was much less pronounced for the 6/week daily and 3/week conventional treatments. Reductions in intradialytic Kru had the opposite effect, lowering the predicted URR and increasing the apparent V, but here the errors were of much lesser amplitude. The results suggest that, particularly for nocturnal dialysis, the standard “constant G” urea kinetic model may need to be modified.
Brachiocephalic Vein Stent Fracture: Case Series and Literature Review
Authors: Kapoor Baljendra , Lockhart Mark , Sharma Deepak , Maya Ivan D. 
Published: February 2010

AbstractStent fractures are commonly seen in the arterial circulation and there is paucity of literature describing venous stent fractures particularly in the central venous circulation. In this case series, we describe three patients on hemodialysis who underwent right brachiocephalic vein (BCV) stent placement for severe stenosis in two patients and occlusion in one patient. Over the course of time, these patients clinically presented with arm swelling, pain, and difficulty in dialysis because of stenosis related to stent fracture and intimal hyperplasia. Two of these patients were successfully treated by restenting.
Obstacles for Clinical Monitoring in Hemodialysis Patients Because of Multiple Vascular Accesses
Authors: Vachharajani Tushar J. , Vachharajani Vidula 
Published: February 2010

AbstractThe increasing awareness of creating an arteriovenous fistula for maintenance hemodialysis in rapidly growing end‐stage renal disease population has created a new challenge not only for the nephrologist but also for the entire medical community. The construction of multiple vascular accesses limits the available sites for hemodynamic monitoring, creating a barrier in providing optimal patient care. The new management dilemmas that have been raised need to be better recognized. There is a critical need for creating tools to educate not only the chronic kidney disease patients but also medical personnel from other specialties regarding the value and care of dialysis vascular access.
Biopsychosocial Characteristics of Community‐Dwelling Older Adults with Limited Ability to Walk One‐Quarter of a Mile
Authors: Hardy Susan E. , McGurl David J. , Studenski Stephanie A. , Degenholtz Howard B. 
Published: February 2010

OBJECTIVES: To establish nationally representative estimates of the prevalence of self‐reported difficulty and inability of older adults to walk one‐quarter of a mile and to identify the characteristics independently associated with difficulty or inability to walk one‐quarter of a mile.DESIGN: Cross‐sectional analysis of data from the 2003 Cost and Use Medicare Current Beneficiary Survey.SETTING: Community.PARTICIPANTS: Nine thousand five hundred sixty‐three community‐dwelling Medicare beneficiaries aged 65 and older, representing an estimated total population of 34.2 million older adults.MEASUREMENTS: Self‐reported ability to walk one‐quarter of a mile, sociodemographics, chronic conditions, body mass index, smoking, functional status.RESULTS: In 2003, an estimated 9.5 million older Medicare beneficiaries had difficulty walking one‐quarter of a mile, and 5.9 million were unable to do so. Of the 20.2 million older adults with no difficulty in activities of daily living (ADLs) or instrumental activities of daily living (IADLs), an estimated 4.3 million (21%) had limited ability to walk one‐quarter of a mile. Having difficulty or being unable to walk one‐quarter of a mile was independently associated with older age, female sex, non‐Hispanic ethnicity, lower educational level, Medicaid entitlement, most chronic medical conditions, current smoking, and being overweight or obese.CONCLUSION: Almost half of older adults and 20% of those reporting no ADL or IADL limitations report limited ability to walk one‐quarter of a mile. For functionally independent older adults, reported ability to walk one‐quarter of a mile can identify vulnerable older adults with greater medical problems and fewer resources and may be a valuable clinical marker in planning their care. Future work is needed to determine the association between ability to walk one‐quarter of a mile walk and subsequent functional decline and healthcare use.
Does hepatocyte growth factor/c‐Met signal play synergetic role in lung cancer?
Authors: Wang Xiangdong , Li Ka , Chen Hong , Wang Diane , Zhang Yong , Bai Chunxue 
Published: February 2010

Abstract

Introduction
Does HGF/c‐Met signalIplay a role in lung cancer?
Can the HGF/c‐Met signal be blocked?
Does HGF/c‐Met regulate VEGF production?
Does HGF/c‐Met interact with MMPs?
Does HGF/c‐Met play a synergetic role?
Does HGF/c‐Met contribute to EGRFI therapeutic sensitivity?

There is growing evidence that the signal pathway between hepatocyte growth factor (HGF) and its receptor c‐Met plays an important role in the development of lung cancer, although the specificity of such role is to be clarified. It seems clear that the HGF/c‐Met signal contributes to the metastasis of cancer cells to the lung by stimulating the hyperproduction and overactivation of cytokines and enzymes, e.g. HGF, vascular endothelial growth factor and matrix metalloproteases. The HGF/c‐Met signal may act as the candidate responsible for the development of epidermal growth factor receptor (EGFR) kinase inhibitor resistance. Experimental evidence showed that the combination of both EGFR and c‐Met inhibitors had synergetic or additive therapeutic effects on lung cancer. Although the mechanism of interaction between HGF/c‐Met and transforming growth factor‐a/EGFR remains unclear, the cross‐talk and balance between those two signal pathways are critical and necessary in the development of new therapies for lung cancer.
Medium‐term vegetation dynamics and their association with edaphic conditions in two Hungarian saline grassland communities
Authors: Tóth Tibor 
Published: February 2010

AbstractMedium‐term (5.5 years) changes in the cover of major species in “Artemisia saline puszta” (Ass) and “Pannonic Puccinellia limosa hollow” (PPlh) grassland communities in the Kiskunság region, Hungary, were monitored and analyzed in relation to abiotic factors (e.g. air temperature, precipitation, soil moisture, salinity and alkalinity). Soil salinity varied considerably, indicating leaching and desalinization of surface layers as the most typical process occurring in the region. Yearly average covers of Artemisia santonicum and Plantago maritima were negatively and positively related to surface soil salinity, respectively, in accordance with their salt tolerance. Multiple regression analysis showed soil pH and salinity to be the most important factors determining yearly average cover of plants at Ass. Increasing pH increased the cover of A. santonicum and P. maritima, but decreased the cover of Podospermum canum. Increasing salinity decreased the cover of A. santonicum and P. canum. At PPlh, pH of groundwater had a positive effect and the lakewater level had a negative effect on the cover of Puccinellia limosa. The results provide information on the ongoing changes in the soil properties and the resulting changes in plant composition in these Hungarian salt‐affected grasslands.
Population dynamics of greenbug biotypes “E” and “F” on Texas bluegrass
Authors: Goldman Jason , Springer Tim 
Published: February 2010

AbstractCool‐season perennial forage grasses are known to serve as alternate hosts of the greenbug, Schizaphis graminum (Rondani) in the southern Great Plains of the USA. Texas bluegrass (Poa arachnifera Torr.) is a cool‐season perennial forage grass indigenous to this region and because of its persistence under grazing is being bred for improved forage production. An experiment was conducted to determine the population dynamics of greenbug biotype “E”, the predominant biotype found in this region and biotype “F” which is known to infest bluegrass species. Twenty‐five Texas bluegrass genotypes, three Kentucky bluegrass (Poa pratensis L.) genotypes, a Canada bluegrass (Poa compressa L.) genotype, two Texas × Kentucky bluegrass hybrids, and a Texas × Canada bluegrass hybrid were screened for their abilities to support greenbug population growth. Bluegrass species and genotypes varied significantly in their ability to support greenbug biotypes E and F. On the basis of higher aphid numbers, biotype E had a higher population growth rate as compared with biotype F on Texas bluegrass. Some Texas bluegrass genotypes were not included in both biotype trials due to lack of availability of uniform plant material for inoculation. Nine of 25 Texas bluegrass genotypes did not support biotype E greenbug population growth. Similarly, 13 of 22 Texas bluegrass genotypes did not support biotype F population growth. Both Canada and Kentucky bluegrass supported high populations of biotype F and interspecific hybrids varied in their host suitability to both biotypes.
Decomposition of grass leaves by ligninolytic litter‐decomposing fungi
Authors: Osono Takashi 
Published: February 2010

AbstractThe abilities of litter‐decomposing fungi (LDF) to remove lignin from leaves of a perennial grass, Miscanthus sinensis, were examined under pure culture conditions. A total of 12 fungal isolates were tested, including eight isolates of seven basidiomycete and one ascomycete species that are ligninolytic on tree leaf litter and four isolates of another ascomycete species, Nigrospora sphaerica, obtained from M. sinensis leaves. Mass loss of leaves caused by the 12 isolates ranged from 4.7 to 43.1% of the original leaf mass. Trametes versicolor caused the greatest mass loss of lignin, followed by Marasmius sp. and Gerronema nemorale, whereas Mycena polygramma and the four isolates of N. sphaerica had limited abilities to cause mass loss of lignin. Trametes versicolor caused the greatest mass loss of total carbohydrates, followed by Marasmius sp., two isolates of N. sphaerica, and G. nemorale, whereas Pseudoclitocybe cyathiformis, Coccomyces sp., and Clitocybe gibba had limited abilities to cause mass loss of total carbohydrates. Mass loss of lignin was significantly and positively correlated with mass loss of leaves for the seven isolates that showed marked ligninolytic activities. In separate experiments, leaves previously partly decomposed by three ligninolytic fungi were used in pure culture tests to evaluate the effects of the pretreatment of grass leaves by ligninolytic fungi on subsequent utilization of substrates by fungi with limited ligninolytic activities. The pretreatment of M. sinensis leaves with three ligninolytic fungi generally suppressed the subsequent decomposition of lignin, total carbohydrates, or both by N. sphaerica. The results demonstrate that ligninolytic LDF are capable of removing lignin effectively from grass leaves.
Succession of lactic acid bacteria in wilted rhodesgrass silage assessed by plate culture and denaturing gradient gel electrophoresis
Authors: Parvin Suraya , Nishino Naoki 
Published: February 2010

AbstractLactic acid bacteria (LAB) in low‐moisture rhodesgrass (Chrolis gayanaKunth) silage, involved in the fermentation process, were determined by plate culture and denaturing gradient gel electrophoresis (DGGE). The first harvest of rhodesgrass was wilted (581 g dry matter kg−1) and stored in laboratory silos for 15, 30, 90 and 180 days. The concentration of acetic acid was found to be more than that of lactic acid until day 30, while lactic acid was the major fermentation product after day 90. Both plate culture and DGGE analyses indicated thatLactobacillus plantarum,Lactobacillus brevisandLactococcus lactiswere the principal LAB present during the period of ensiling. Similar results were obtained with the two methods with respect to the LAB species, but neither of the methods could account for the change in the fermentation products over the period of ensiling.
Fecal acetone and isopropanol levels of wild sika deer (Cervus nippon yesoensis) in spring and winter
Authors: Sato Hiroshi 
Published: February 2010

AbstractRecently, the population of Cervus nippon yesoensis, a subspecies of sika deer, has been increasing in Hokkaido, Japan. The food habits and alimentary fermentation of sika deer change dramatically with season, with food primarily composed of bark in winter, and grasses and woody leaves for the remainder of the year. To investigate the relationship of colonic fermentation in the deer with food changes, fresh fecal samples were collected in March with lingering snow, and during a verdurous period in June. Fecal alcohol, acetone, ammonia and volatile fatty acids (VFAs) were analyzed after extracting the samples with water. With the change in food from winter to spring, ethanol level decreased while acetone and isopropanol levels increased in the majority of fecal samples. In June, higher n‐butyrate levels and a lower proportion of minor VFAs containing branched acids were found, with an accompanying tendency toward higher total VFA level. Thus, alterations of colonic fermentation occurred in conjunction with the transition from winter to spring food in wild sika deer.
Habitat and Life History Determinants of Antbird Occurrence in Variable‐Sized Amazonian Forest Fragments
Authors: Lees Alexander C. , Peres Carlos A. 
Published: February 2010

ABSTRACTThe highest avian species richness on Earth is found in the Neotropics, with the speciose antbird superfamily (Thamnophilidae, Formicariidae, Grallariidae and Conopophagidae) accounting for 15 percent of South American passerine diversity. Antbird species have divergent life histories and ecological requirements, resulting in considerable interspecific variation in responses to anthropogenic habitat modification. Here, we examine interspecific differences in antbird responses to both habitat fragmentation and perturbation in a region of the so‐called ‘Arc of Deforestation’ of southern Brazilian Amazonia in northern Mato Grosso. We surveyed the antbird community of 31 variable‐sized forest patches and found that antbird species richness was predominantly affected by patch size and isolation, although forest patch quality was also important. Life history predictors were less important overall in determining patch occupancy and minimum patch area requirements with body mass and geographic range size the most important predictors. Foraging niche was also important; mixed flock followers, bamboo specialists and army‐ant followers were all more prone to local extinction in small fragments. Although most Amazonian antbird species are not currently threatened, rates of interfluvial endemism are high and future forest loss may imperil many species currently considered to be of low conservation concern. Lessons learnt in the identification of fragmentation‐sensitive genera and guilds may be applicable to other antbird species outside Amazonia, such as those in the Brazilian Atlantic Forest. Ensuring future survival of antbirds across neotropical forest landscapes that retain only a small percentage of their original primary forest cover will rest on protecting remaining large forest patches and maintaining structural and functional connectivity between them.