bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological Grafts for Hemodialysis Access: Historical Lessons, State‐of‐the‐Art and Future Directions
Authors: Dukkipati Ramanath , Peck Marissa , Dhamija Rajiv , Hentschel Dirk M , Reynolds Tyler , Tammewar Gautam , McAllister Todd 
Published: August 2012

AbstractThe vast majority of arteriovenous grafts (AVG) have been constructed using expanded polytetrafluoroethylene (ePTFE). While ePTFE grafts have the advantage of being relatively inexpensive and easy to manufacture, distribute, ship, and store, their primary patency rates are disappointing when compared with the native AVF. Though use of arteriovenous fistulas (AVF) in the United States has increased substantially, approximately 25% of hemodialysis patients continue to use AVG as their vascular access. We present here a comprehensive review of biological grafts and their use in hemodialysis vascular access. In this review, we discuss the use of synthetics and then explore the evolution of biological grafts over the past 20 years, their clinical impact, and future challenges in widespread clinical use in hemodialysis patients. Provided are in depth descriptions of currently used nonbiological arteriovenous grafts and the recent approaches in increasing the patency of synthetic grafts. Recent technological advances using tissue‐engineered AVGs have shown promise for patients receiving hemodialysis and their potential to provide an attractive, viable option for vascular access have been discussed.
Arterial Micro‐Calcification of Vascular Access is Associated with Aortic Arch Calcification and Arterial Stiffness in Hemodialysis Patients
Authors: Kim Hyun Gyung , Park Sun Cheol , Lee Soo Lim , Shin Ok‐Ran , Yoon Sun Ae , Yang Chul Woo , Kim Yongsoo , Kim Young Ok 
Published: August 2012

AbstractVascular calcification of the coronary arteries or aorta is an independent risk factor for cardiovascular outcome, but clinical significance of arterial micro‐calcification (AMC) of vascular access is unclear in hemodialysis (HD) patients. Sixty‐five patients awaiting vascular access operation were enrolled. We compared surrogate markers of cardiovascular morbidity such as aortic arch calcification (AoAC) by chest radiography, arterial stiffness by brachial‐ankle pulse wave velocity (baPWV) and endothelial dysfunction by flow‐mediated dilatation (FMD) between patients with and without AMC of vascular access on von Kossa staining. AMC of vascular access was detected in 36 (55.4%). The AMC‐positive group had significantly higher incidence of AoAC (63.9% vs. 20.7%, p < 0.001) and higher baPWV (26.5 ± 9.4 m/s vs. 19.8 ± 6.6 m/s, p = 0.006) than the AMC‐negative group. There was no significant difference in FMD between the two groups (5.4 ± 2.6% vs. 5.7 ± 3.5%, p = 0.764). The AMC‐positive group had higher incidence of diabetes mellitus, higher systolic blood pressure and wider pulse pressure than the AMC‐negative group. This study suggests that AMC of vascular access may be associated with cardiovascular morbidity via AoAC and arterial stiffness in HD patients.
A Finite Element Model to Simulate Femoral Fractures in Calves: Testing Different Polymers for Intramedullary Interlocking Nails
Authors: Rodrigues Luciano B. , Las Casas Estevam B. , Lopes Daniel S. , Folgado João , Fernandes Paulo R. , Pires Eduardo A. C. B. , Alves Geraldo Eleno S. , Faleiros Rafael R. 
Published: August 2012

ObjectiveTo verify if the finite element method can correctly estimate the performance of polyacetal and polyamide 6 intramedullary nails in stabilizing a femoral fracture in calves and to estimate the performance of a polypropylene nail in same conditions.Study DesignComputational and experimental study.Sample PopulationFinite element models (FEMs).MethodsBased on a 3‐dimensional finite element method (FEM) of the femoral diaphysis, 3 models were constructed to simulate an oblique simple fracture stabilized by an intramedullary nail composed of 1 of 3 distinct polymers. Models were tested under 6 loading conditions that simulated a static calf or a calf in different walking phases. Maximum bone and implant stresses were compared to yield and rupture stresses of specific materials.ResultsUnder static conditions, all polymers were resistant to critical deformation and rupture because maximum von Mises stresses were lower than the respective yield and rupture stresses. However, during walking, maximum stresses exceeded the yield and rupture limits of the polymers, in agreement with a previous in vivo study, which used polyacetal and polyamide nails.ConclusionsFEM correctly estimated that polyacetal and polyamide 6 nails would fail to immobilize an oblique femoral diaphyseal fracture in calves that were allowed to walk freely during the early postoperative period. FEM can be useful in the development of new bovine orthopedic devices.
The Instantaneous Apparent Activation Energy of Cement Hydration Measured Using a Novel Calorimetry‐Based Method
Authors: Thomas Jeffrey J. 
Published: August 2012

A new calorimetry‐based method for calculating the activation energy of cement hydration is described. The method requires a scanning calorimeter that can change the sample temperature relatively quickly and has a stable baseline, but the technique is straightforward to perform. Activation energy values can be calculated at multiple hydration times from a single specimen, allowing any changes with time to be assessed. With this method, the measured activation energy at a given time does not depend on the previous microstructural development, as is the case with traditional methods of calculating the activation energy from parallel specimens hydrated isothermally at different temperatures. For tricalcium silicate (C3S) hydrated in pure water or in a calcium chloride solution, the activation energy remains statistically constant from the earliest times until the degree of hydration exceeds 0.65, with an overall average value of (51.1 ± 1.8) kJ/mol. For cement hydration, the activation energy is also constant until well past the main hydration peak, with slightly lower average values. These results suggest that the rate‐controlling step in the hydration process does not change during the early hydration period (the first few days after mixing), as different reaction steps tend to have different activation energies.
Peripheral Nerve Sheath Tumors. Benign or Malignant? The Role of MRI and Ultrasonography in A Case Report
Authors: Chatzistefanou Alexandros , Mantatzis Michalis , Deftereos Savas , Mintzopoulou Paraskevi , Prassopoulos Panos 
Published: August 2012

ABSTRACTA 31‐year‐old male patient admitted to another hospital for investigation of a localized painful hump in the medial surface of his left leg. The clinical examination revealed a painful palpable lump in the medial surface of left thigh that was initially thought to be a hematoma due to a history of recent trauma. However, an ultrasound was requested to exclude deep venous thrombosis (DVT). The US examination revealed a heterogeneous, fusiform lesion with elongated proximal and distal projections in close proximity to superficial femoral artery and vein and could not definitely exclude the DVT hypothesis. In a second ultrasound examination performed in our department, a neurogenic origin of the lesion was proposed. A consequent MRI examination confirmed the presence of a fusiform tumor in the anatomic path of the saphenous nerve. This was further confirmed intraoperatively, and pathologically was diagnosed as a malignant peripheral nerve sheath tumor (MPNST). In this present study the role of ultrasonography, the correlation between MRI and ultrasonographic findings are discussed and a review of the literature is presented.
Symptoms after obstetric sphincter injuries have little effect on quality of life
Authors: PALM ANNA , ISRAELSSON LEIF , BOLIN MARIE , DANIELSSON INGELA 
Published: August 2012

AbstractObjective. To compare the prevalence of anal incontinence and dyspareunia in women with or without obstetric sphincter injury after standardizing the suture technique. Design. Retrospective case–control study. Setting. Regional hospital, Sweden. Population. 305 women with an obstetric sphincter injury and 297 women with spontaneous vaginal delivery. Methods. In order to standardize and improve the repairing skills of sphincter injuries, collaboration between obstetricians and colorectal surgeons was begun in 2000. Inner and external sphincters were repaired in two layers with continuous monofilament polidioxane sutures. The participating women received a questionnaire with validated questions on anal incontinence, dyspareunia and quality of life. The follow‐up time was 15 months to 8 years. Main outcome measures. Anal incontinence, dyspareunia and quality of life. Results. Of the sphincter group, 72% returned the questionnaire, as did 67% in the control group. Significantly more women in the sphincter group suffered from incontinence of flatus and loose stool compared to controls (p < 0.05). There was no significant difference of incontinence of solid stool, soiling, or fecal urgency between the groups. The quality of life questions showed no significant difference between the groups. In the sphincter group, there was significantly more superficial coital pain compared to controls (p= 0.02). Significantly more women with complete sphincter injury reported anal incontinence than women with a partial sphincter injury. Conclusion. In spite of increased rate of anal incontinence and dyspareunia after anal sphincter rupture, there was no statistically significant reduction in the women's quality of life.
How to measure the cost‐effectiveness of periodontal treatments
Authors: Vernazza Chris , Heasman Peter , Gaunt Francesca , Pennington Mark 
Published: August 2012

AbstractThere is a need to measure efficiency of periodontal treatments. Efficiency questions can be addressed through a variety of economic evaluation techniques: cost minimization, cost‐effectiveness, cost utility and cost–benefit analysis. Each of these techniques is outlined in this article, including a detailed discussion of different preference‐based outcome (utility) measures. Despite the need, few analyses have been undertaken in periodontology. There are several issues in undertaking cost‐effectiveness analyses specific to periodontology and these are examined in detail: outcome measures including patient‐based vs. clinical measures of outcome; discounting or taking into account time preference for outcomes and costs; problems of costing, including the perspective taken in an analysis; interpreting the evidence, in particular using incremental cost‐effectiveness ratios; and global variation in periodontal care delivery, including healthcare systems and the use of hygienists. The need for cost‐effectiveness analysis in periodontology is explored further, and the need to involve a health economist in such an evaluation is underlined.
Recording and surveillance systems for periodontal diseases
Authors: Beltrán‐Aguilar Eugenio D. , Eke Paul I. , Thornton‐Evans Gina , Petersen Poul E. 
Published: August 2012

AbstractThis paper describes tools used to measure periodontal diseases and the integration of these tools into surveillance systems. Tools to measure periodontal diseases at the surveillance level have focussed on current manifestations of disease (e.g. gingival inflammation) or disease sequelae (e.g. periodontal pocket depth or loss of attachment). All tools reviewed in this paper were developed based on the state of the science of the pathophysiology of periodontal disease at the time of their design and the need to provide valid and reliable measurements of the presence and severity of periodontal diseases. Therefore, some of these tools are no longer valid. Others, such as loss of periodontal attachment, are the current de‐facto tools but demand many resources to undertake periodical assessment of the periodontal health of populations. Less complex tools such as the Community Periodontal Index, have been used extensively to report periodontal status. Laboratory tests for detecting putative microorganisms or inflammatory agents present in periodontal diseases have been used at the clinical level, and at least one has been tested at the population level. Other approaches, such as self‐report measures, are currently under validation. In this paper, we do not review indices designed to measure plaque or residual accumulation around the tooth, indices focussed only on gingival inflammation or radiographic approaches with limited applicability in surveillance systems. Finally, we review current case‐definitions proposed for surveillance of periodontal disease severity.
Periodontal health and global public health
Authors: Petersen Poul E. , Baehni Pierre C. 
Published: August 2012

AbstractChronic diseases are a growing burden to people, to health‐care systems and to societies across the world. The rapid increase in the burden of chronic diseases is particularly prevalent in the developing countries. Periodontal disease is one of the two most important oral diseases contributing to the global burden of chronic disease. In addition to social determinants, periodontal health status is related to several proximal factors. Modifiable risk factors, such as tobacco use, excessive alcohol consumption, poor diet and nutrition, obesity, psychological stress and insufficient personal/oral hygiene, are important and these principal risk factors for periodontal disease are shared by other chronic diseases. The present monograph is devoted to the existing evidence on the practice of public health related to periodontal health. Public health is defined as the process of mobilizing and engaging local, national and international resources to assure that people can be healthy. Social determinants of health, environmental hazards and unhealthy lifestyles are prioritized in modern public health‐care. Disease prevention and health promotion are cornerstones in actions for public health. This volume of Periodontology 2000 is entitled ‘Periodontal health and global public health’; the 12 articles of this volume discuss different aspects of this statement. It covers a range of subjects from public health issues to patient care. This monograph intends to stimulate community action research in the field of periodontology in order to help the development of appropriate public health intervention and relevant surveillance programs. It also expects to stimulate health authorities and professional organizations to initiate and support actions to promote periodontal health in their respective countries.
Is breastfeeding related to bone properties? A longitudinal analysis of associations between breastfeeding duration and pQCT parameters in children and adolescents
Authors: Kühn Tilman , Kroke Anja , Remer Thomas , Schönau Eckhard , Buyken Anette E. 
Published: August 2012

AbstractNutritive and bioactive components of human milk could be involved in programming metabolic systems that affect bone growth throughout the life course. Bone properties in childhood and adolescence might differ, depending on breastfeeding duration. Thus, breastfeeding could be a relevant factor in the context of primary osteoporosis prevention. The prospective association between breastfeeding duration and bone properties was investigated using the data of 284 participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study. Breastfeeding duration was assessed during infancy. Bone properties were measured by peripheral quantitative computed tomography (pQCT) at ages 5–23 years. Cortical volumetric bone mineral density, cortical bone mineral content, strength strain index, total cross‐sectional area of the bone and cross‐sectional area of the cortical bone were determined at the 65% site of the radius. Linear regression analyses were performed to check for differences in pQCT parameters of subjects who had not or shortly been breastfed (0–16 weeks) and subjects who had been breastfed for a long duration (≥17 weeks). Multivariable models adjusted for age, gender, forearm length, muscle cross‐sectional area, body mass index standard deviation score (SDS), height SDS and socio‐economic status did not yield associations between breastfeeding duration and pQCT parameters. These findings suggest neither protective nor adverse effects of prolonged breastfeeding on bone health in childhood and adolescence. Influences of early nutrition on bone growth might be overridden by current effects of mechanical loads on bone physiology.
Identification of potent small‐molecule inhibitors of STAT3 with anti‐inflammatory properties in RAW 264.7 macrophages
Authors: Capiralla Hemachander , Vingtdeux Valérie , Venkatesh Jeganathan , Dreses‐Werringloer Ute , Zhao Haitian , Davies Peter , Marambaud Philippe 
Published: August 2012

Signal transducer and activator of transcription 3 (STAT3) is a key mediator of the inflammatory response of macrophages and other immune cell types. The naturally occurring polyphenol resveratrol is associated with anti‐proliferative and anti‐inflammatory properties via mechanisms implicating inhibition of STAT3 signaling. Here, we report that the small‐molecule analogs of resveratrol, RSVA314 and RSVA405, are potent inhibitors of STAT3. RSVA314 and RSVA405 inhibited both constitutive and stimulated STAT3 activity in HEK293 cells and lipopolysaccharide‐stimulated RAW 264.7 macrophages, respectively. The small‐molecule analogs inhibited STAT3 nearly 50 times more potently than did resveratrol (apparent IC50 ~0.5 μm). We further show that RSVA405 interfered with the inflammatory response by RAW 264.7 cells upon lipopolysaccharide stimulation by inhibiting IκB kinase and IκBα phosphorylation and by decreasing the expression of several cytokines, including the NF‐κB target genes tumor necrosis factor α and interleukin‐6. Downstream activation of STAT1 upon lipopolysaccharide stimulation was also inhibited by RSVA405. Consequently, RSVA405 significantly interfered with the phagocytotic activity and proliferation of lipopolysaccharide‐activated RAW 264.7 macrophages. Finally, we found that the effect of the two small‐molecule analogs on STAT3 phosphorylation could be prevented by inhibitors of protein tyrosine phosphatases, indicating that the small molecules acted by promoting dephosphorylation of STAT3 by protein tyrosine phosphatases.
Fallibilism
Authors: Reed Baron 
Published: August 2012

AbstractAlthough recent epistemology has been marked by several prominent disagreements – e.g., between foundationalists and coherentists, internalists and externalists – there has been widespread agreement that some form of fallibilism must be correct. According to a rough formulation of this view, it is possible for a subject to have knowledge even in cases where the justification or grounding for the knowledge is compatible with the subject’s being mistaken. In this paper, I examine the motivation for fallibilism before providing a fully general account of the view. I conclude by looking at the two major difficulties for fallibilism: the Gettier problem and the lottery paradox.
Potassium channel activators differentially modulate the effect of sodium channel blockade on cardiac conduction
Authors: Veeraraghavan R. , Larsen A. P. , Torres N. S. , Grunnet M. , Poelzing S. 
Published: August 2012

AbstractAimsDiminished repolarization reserve contributes to the arrhythmogenic substrate in many disease states. Pharmacological activation of K+ channels has been suggested as a potential antiarrhythmic therapy in such conditions. Having previously demonstrated that IK1 and IKr can modulate cardiac conduction, we tested here the effects of pharmacological IKATP and IKs activation on cardiac conduction and its dependence on the sodium current (INa).Methods and ResultsBath electrocardiograms (ECGs) recorded from Langendorff‐perfused guinea pig ventricles revealed QRS prolongation during IKATP activation by pinacidil but not during IKs activation by R‐L3 relative to control. In contrast, when INa was partially blocked by flecainide, R‐L3 but not pinacidil prolonged the QRS relative to flecainide alone. Conduction velocity (θ) was quantified by optical mapping during epicardial pacing. Both longitudinal (θL) and transverse (θT) θ were reduced by pinacidil (by 10 ± 1 and 9 ± 3%, respectively) and R‐L3 (by 11 ± 2% and 15 ± 4%, respectively). Flecainide decreased θL by 33 ± 4% and θT by 36 ± 5%. Whereas pinacidil did not further slow θ relative to flecainide alone, R‐L3 decreased both θL and θT.ConclusionPharmacological activation of IKATP and IKs slows cardiac conduction; however, they demonstrate diverse effects on θ dependence on INa blockade. These findings may have significant implications for the use of K+ channel activators as antiarrhythmic drugs and for patients with Na+ channel abnormalities or being treated with Na+ channel blockers.
The effect of selected pre‐analytical phase variables on plasma thromboxane A2 measurements in humans
Authors: Sadilkova L. , Paluch Z. , Mottlova J. , Bednar F. , Alusik S. 
Published: August 2012

SummaryAimsPlatelet function testing is often affected by the existence of different pre‐analytical variables that can cause platelet activation. The aim of this study was to assess the effect of such variables that are present when samples are taken (different anticoagulants, incubation temperature, and storage conditions) to select those which enable to reach optimal range of measured plasma concentrations of the two stable thromboxane A2 metabolites, that is, thromboxane B2 (TxB2) and 11‐dehydrothromboxane B2 (11‐dTxB2).Materials and MethodsFor the purpose of this study, whole blood samples obtained from 20 volunteers were screened for TxB2 and 11‐dTxB2 concentrations using commercial EIA kits (Cayman Chemicals™; Neogen™) in relation to the effect of different anticoagulants, using different incubation temperatures and storage conditions.ResultsTrisodium citrate has been shown not to be affecting the TxB2 and 11‐dTxB2 concentrations compared with the values measured in the serum. Incubation of the samples for 1 h at 37 °C and freezing at −20 °C or −80 °C give the most suitable concentration range of both thromboxanes in the used EIA measurement.ConclusionThis study describes the setup of such pre‐analytical phase conditions that enable the screening of platelet function in terms of the plasma concentrations of TxB2 and 11‐dTxB2 in selected EIA measurement.
Overlapping generations can balance the fluctuations in the activity patterns of an endangered ground beetle species: long‐term monitoring of Carabus hungaricus in Hungary
Authors: Bérces Sándor , Elek Zoltán 
Published: August 2012

Abstract

Carabus hungaricus is a ground beetle inhabiting the Pannonian steppes. It is highly endangered by fragmentation and abandonment of its habitat.
For five consecutive years, from 2006 to 2010, we used the mark–release‐recapture technique in a grid of 270 live‐capture pitfall traps to study its population ecology in sandy grasslands on Szentendrei Island in the Northern vicinity of Budapest, Hungary.
In total, 3950 individuals of C. hungaricus (1874 females and 2076 males) were marked.
Population size was estimated at∼2000 individuals per year; the estimates for females were consistently higher than those for males. The minimum population size was 1317 ± 60.1 individuals in 2007, whereas the maximum was 2169.7 ± 108.8 individuals in 2008.
Adults older than a year formed∼32–42% of the population, whereas individuals surviving for 3 years formed∼10%, and those surviving for 4 years formed∼2% of the population. Individuals older than 4 years comprised <1% of the population. Female survival rate was higher than that of male, but the capture rate also differed between sexes.
Although the studied population showed considerable fluctuations in the pattern of activity during the 5 years, its size seemed to be relatively stable, underlining the importance of overlapping generations.