bluuebunny/crossref_metadata_2025 huggingface dataset:
A new combination in Tulista, T. minor (Alooideae, Asphodelaceae)
Authors: SMITH GIDEON F. , FIGUEIREDO ESTRELA , MOLTENO STEVEN
Published: April 2018

Tulista Rafinesque (1840: 137) is the smallest of the three haworthioid genera recognised in the Asphodelaceae subfam. Alooideae, and widely considered to include four, or five, species [depending on whether T. opalina (Hayashi 2001: 17) Breuer (2016: 7) is accepted] (Smith et al. 2017).
Contribution to the taxonomy of Paracloeodes Day 1955 (Ephemeroptera: Baetidae) from South America
Authors: CRUZ PAULO VILELA , SALLES FREDERICO FALCÃO , HAMADA NEUSA
Published: April 2018

In recent decades, major advances in the systematics of the Western Hemisphere genus Paracloeodes Day have been made in South America. Despite the taxonomic progress, uncertainties in identification remain due to the morphological similarities among some nymphs and due to the general lack of knowledge of the imago stages (only 4 of 20 are described from throughout the range of the genus). This study addresses these impediments in part through description of the male imagoes of six species (P. atroari Nieto & Salles, P. binodulus Lugo-Ortiz & McCafferty, P. ibicui Lugo-Ortiz & McCafferty, P. pacawara Nieto & Salles, P. peri Nieto & Salles, P. waimiri Nieto & Salles), description of two new species based on morphologically distinct nymphs (P. aristotelesi sp. n. and P. carolinae sp. n.), description of one new species based on morphologically distinct nymph and male imago (P. prismatobranchus sp. n.); redescription of three species based on type material (P. ibicui Lugo-Ortiz & McCafferty, P. leptobranchus Lugo-Ortiz & McCafferty and P. eurybranchus Lugo-Ortiz & McCafferty); proposal of one new synonym based on morphological analyses of specimens from Bolivia, Brazil and Uruguay, including type specimens (P. pacawara = P. morellii Emmerich & Nieto); and the presentation of a new key to identify nymphs from South America to the species level.
New contributions to the knowledge of Chinese flea beetle fauna (III): revision of Meishania Chen & Wang with description of five new species (Coleoptera: Chrysomelidae: Galerucinae)
Authors: RUAN YONGYING , KONSTANTINOV ALEXANDER S. , PRATHAPAN K. D. , ZHANG MENGNA , JIANG SHIHONG , YANG XINGKE
Published: April 2018

The flea beetle genus Meishania Chen & Wang is revised and five new species—M. cangshanensis sp. nov., M. flavipennis sp. nov., M. fulvotigera sp. nov., and M. sichuanica sp. nov. from China and M. bhutanensis sp. nov. from Bhutan—are described. All species of Meishania are illustrated and a key to species is provided.
Phylogenetic and morphological resolution of the Helobdella stagnalis species-complex (Annelida: Clitellata: Hirudinea)
Authors: SAGLAM NAIM , KUTSCHERA ULRICH , SAUNDERS RALPH , SAIDEL WILLIAM M. , BALOMBINI KATHERINE L.W. , SHAIN DANIEL H.
Published: April 2018

The glossiphoniid freshwater leech, Helobdella stagnalis, was described by Linnaeus 1758 based on common European specimens. The presence of a brown, chitinous scute on the dorsal-anterior surface, as observed on leeches elsewhere in the world, has generally led to the classification of all scute-bearing members of the genus as H. stagnalis. Here we describe the morphology and behavior of the type species from Europe, and analyze H. stagnalis-like specimens collected worldwide. We present evidence for at least four distinct scute-bearing Helobdella species that can be morphologically resolved. Maximum Parsimony (MP) and Bayesian Inference (BI) analyses at the mitochondrial cytochrome c oxidase subunit I (COI) locus further supported this notion, with divergence values suggesting a mid-Miocene ancestor of this successful group of cosmopolitan hirudineans. New species, Helobdella echoensis nov. sp., Helobdella eriensis nov. sp., and Helobdella serendipitious nov. sp., are described, based on morphological, anatomical and molecular data. Current distribution patterns of Helobdella spp. suggest a robust, global dispersal mechanism, as well as local pockets of endemism.
A review of Newportia species in the subgenus Newportides Chamberlin, 1921 (Scolopendromorpha, Scolopocryptopidae, Newportiinae)
Authors: CHAGAS-JR AMAZONAS
Published: April 2018

Five Newportia species with a claw-shaped pretarsus of the ultimate legs are revised. Newportia amazonica Brolemann, 1904, N. unguifer Chamberlin, 1921, and N. pilosa González-Sponga, 1997 are redescribed; N. tetraspinae González-Sponga, 1997 is considered to be a junior synonym of N. unguifer, and N. guaiquinimensis González-Sponga, 2000 is considered to be a junior synonym of N. pilosa. All synonyms proposed are based on the structure of ultimate legs. The subgenus Newportides is revalidated based on the presence of claw-shaped pretarsus of ultimate legs.
Professional Development Quality in U.S. Music Education: An Analysis of the 2011–2012 Schools and Staffing Survey
Authors: Gallo Donna J.
Published: April 2018

The purpose of this study was to compare differences in the quality of professional development between U.S. music educators and teachers of other disciplines. Data were drawn from the 2011–2012 Schools and Staffing Survey. Factors such as types of professional development, quantity of activities, and levels of satisfaction were analyzed through a series of multiple regressions to determine the relationships between professional development quality for teachers of music and non-music disciplines. Results indicated that music educators were significantly less likely to collaborate with other educators on issues of instruction and engaged in significantly less technology-related professional activity; however, music educators reported significantly higher levels of satisfaction with content-specific professional activity and engaged in significantly more content-specific activity than some higher-stakes disciplines. In light of educational policies and trends, the common assumption that music educators are generally less supported within their schools does not hold true. Implications of this study include the need for music educators to participate in more collaborative forms of professional development. This study also suggests that all educators should receive more time spent in professional learning congruent to the level of engagement espoused by research literature.
Naming Institutionalized Racism in the Public Health Literature: A Systematic Literature Review
Authors: Hardeman Rachel R. , Murphy Katy A. , Karbeah J’Mag , Kozhimannil Katy Backes
Published: April 2018

Objectives:

Although a range of factors shapes health and well-being, institutionalized racism (societal allocation of privilege based on race) plays an important role in generating inequities by race. The goal of this analysis was to review the contemporary peer-reviewed public health literature from 2002-2015 to determine whether the concept of institutionalized racism was named (ie, explicitly mentioned) and whether it was a core concept in the article.

Methods:

We used a systematic literature review methodology to find articles from the top 50 highest-impact journals in each of 6 categories (249 journals in total) that most closely represented the public health field, were published during 2002-2015, were US focused, were indexed in PubMed/MEDLINE and/or Ovid/MEDLINE, and mentioned terms relating to institutionalized racism in their titles or abstracts. We analyzed the content of these articles for the use of related terms and concepts.

Results:

We found only 25 articles that named institutionalized racism in the title or abstract among all articles published in the public health literature during 2002-2015 in the 50 highest-impact journals and 6 categories representing the public health field in the United States. Institutionalized racism was a core concept in 16 of the 25 articles.

Conclusions:

Although institutionalized racism is recognized as a fundamental cause of health inequities, it was not often explicitly named in the titles or abstracts of articles published in the public health literature during 2002-2015. Our results highlight the need to explicitly name institutionalized racism in articles in the public health literature and to make it a central concept in inequities research. More public health research on institutionalized racism could help efforts to overcome its substantial, longstanding effects on health and well-being.
Festive Traditions in Modernity: The Public Sphere of the Festival of the ‘Fallas’ in Valencia (Spain)
Authors: Costa Xavier
Published: April 2018

Festive sociability is central for the transmission of tradition and is a fundamental field of interaction between the festive tradition and modernity. This sociability has a reflexivity and a public sphere of its own. The dominant modernist opposition between tradition and modernity is questioned with the help of a recent study of the Fire Festival of the ‘Fallas’ (Valencia, Spain).
Life Beyond the Screen: Embodiment and Identity through the Internet
Authors: Hardey Michael
Published: April 2018

This paper explores online and off-line identities and how relationships are formed and negotiated within internet environments that offer opportunities to meet people online and move into relationships off-line. To do this it draws on an analysis of users experiences of internet dating sites that are designed for those who wish meet others in the hope of forming an intimate relationship. Locating analyses in the context of the individualised sociability of late modernity, it is argued that virtual interactions may be shaped by and grounded in the social, bodily and cultural experiences of users. It is shown that disembodied anonymity that characterises the internet acts as a foundation for the building of trust and establishing real world relationships rather than the construction of fantasy selves. The paper concludes with a discussion of the wider significance of this for understanding disembodied identities and interactions and the impact of cyberspace on off-line sociability.
War and the Contest over National Identity
Authors: Coles Roberta L.
Published: April 2018

This paper looks at a recent historical moment in which the American national identity was defined and contested in the public arena. The Persian Gulf crisis of 1990–91 presents a case in point in which official actors attempted to define the American character and in so doing prescribed particular actions necessary to fulfill what it means to be an American. President George Bush's discourse used the crisis to rejuvenate US prestige and American confidence. He described Americans as unique in esteemed values and America as the only country capable of leading the world. In so doing, he invited American participation in support for US military intervention. On the other side, the peace movement chose to emphasize American weaknesses, domestic problems, and the gullible nature of the American people. In so doing, it attempted to shame Americans into supporting the anti-war movement.
Dis-Embeddedness and De-Classification: Modernization Politics and the Greek Teacher Unions in the 1990s
Authors: Athanasiades Harris , Patramanis Alexandros
Published: April 2018

During the 90s, PASOK, in common with the other European social democratic parties, has advocated Third Way revisionism and has placed the ‘modernization’ of the Greek society high on its political agenda. By focusing on a series of conflictual incidents between the teacher unions and the Greek government, this paper exemplifies the repercussions of this process on teachers-state relations. Building upon the dialectics of path shaping and path dependency, we suggest that the particular development of the modernization project and the reactions it has triggered are to be attributed to the historically determined, nationally specific, contingently activated institutional legacies and structures that, on the one hand, stand in the way of the incorporation of Greece to the EMU/ESM and, on the other, are employed by the unions to defend industrial and social citizenship.
Multilevel Modeling of Cognitive Diagnostic Assessment: The Multilevel DINA Example
Authors: Wang Wen-Chung , Qiu Xue-Lan
Published: April 2018

Many multilevel linear and item response theory models have been developed to account for multilevel data structures. However, most existing cognitive diagnostic models (CDMs) are unilevel in nature and become inapplicable when data have a multilevel structure. In this study, using the log-linear CDM as the item-level model, multilevel CDMs were developed based on the latent continuous variable approach and the multivariate Bernoulli distribution approach. In a series of simulations, the newly developed multilevel deterministic input, noisy, and gate (DINA) model was used as an example to evaluate the parameter recovery and consequences of ignoring the multilevel structures. The results indicated that all parameters in the new multilevel DINA were recovered fairly well by using the freeware Just Another Gibbs Sampler (JAGS) and that ignoring multilevel structures by fitting the standard unilevel DINA model resulted in poor estimates for the student-level covariates and underestimated standard errors, as well as led to poor recovery for the latent attribute profiles for individuals. An empirical example using the 2003 Trends in International Mathematics and Science Study eighth-grade mathematical test was provided.
Predictors of Complications in Patients Receiving Head and Neck Free Flap Reconstructive Procedures
Authors: Eskander Antoine , Kang Stephen , Tweel Ben , Sitapara Jigar , Old Matthew , Ozer Enver , Agrawal Amit , Carrau Ricardo , Rocco James W. , Teknos Theodoros N.
Published: April 2018

Objective

To (1) determine the overall complication rate, wound healing, and wound infection complications and (2) identify preoperative, intraoperative, and postoperative predictors of these complications.

Study Design

Case series with chart review.

Setting

Tertiary academic cancer hospital.

Subjects and Methods

All head and neck free flap patients at The Ohio State University (2006‐2012) were assessed. Multivariable logistic regression assessed the impact of patient factors, flap and wound factors, and intraoperative factors on the aforementioned quality metric outcomes.

Results

Of the 515 patients identified, 54% had a complication predicted by longer operating room (OR) time, higher comorbidity index, and oral cavity and pharyngeal tumor sites. Predictors of wound‐healing complications (15%) were longer OR time, volume of crystalloid given intraoperatively, and oral cavity and pharyngeal tumor sites. Predictors of wound infection (12%) were younger age, diabetes mellitus, and malnutrition.

Conclusions

Wound healing and infectious complications account for most complications in patients with head and neck cancer undergoing free flap reconstruction. Clean contaminated wounds are a significant predictor of wound complications. Advanced OR time, advanced age, and comorbidity status, including diabetes mellitus and malnutrition, are other important predictors. Crystalloid administration is also an important predictor of wound‐healing complications, and this warrants further study.
Impact of HPV Status on the Prognostic Potential of the AJCC Staging System for Larynx Cancer
Authors: Davidson Stacey M. , Ko Huasing C. , Harari Paul M. , Wieland Aaron M. , Chen Shuai , Baschnagel Andrew M. , Kimple Randall J. , Witek Matthew E.
Published: April 2018

Objective

We evaluated the ability of the American Joint Committee on Cancer (AJCC) seventh edition staging system to prognosticate the overall survival of patients with human papillomavirus (HPV)–positive laryngeal squamous cell carcinoma.

Study Design

Retrospective analysis.

Setting

National Cancer Database.

Subjects and Methods

Patients diagnosed with laryngeal squamous cell carcinoma who were treated with curative intent were identified in the National Cancer Database. Multivariate analysis was utilized to determine factors correlated with overall survival in the HPV‐negative and HPV‐positive cohorts. Unadjusted and propensity score–weighted Kaplan‐Meier estimation was used to determine overall survival of HPV‐negative and HPV‐positive patients across AJCC stage groupings.

Results

We identified 3238 patients with laryngeal squamous cell carcinoma, of which 2812 were HPV negative and 426 were HPV positive. Overall survival adjusted for age, sex, and comorbidity status confirmed significant differences among all consecutive stage groupings (I vs II, P <. 001; II vs III, P <. 05; III vs IVA, P <. 001; IVA vs IVB, P <. 05) in the HPV‐negative cohort, whereas only stages IVAs and IVB (P <. 01) exhibited a significant difference in overall survival for HPV‐positive patients.

Conclusion

The current AJCC staging system does not accurately distinguish risk of mortality for patients with HPV‐positive disease. These data support the consideration of HPV status in estimating prognosis as well as clinical trial design and clinical decision making for patients with laryngeal squamous cell carcinoma.
A Personalized Approach of Patient–Health Care Provider Communication Regarding Colorectal Cancer Screening Options
Authors: Sava M. Gabriela , Dolan James G. , May Jerrold H. , Vargas Luis G.
Published: April 2018

Background. Current colorectal cancer screening guidelines by the US Preventive Services Task Force endorse multiple options for average-risk patients and recommend that screening choices should be guided by individual patient preferences. Implementing these recommendations in practice is challenging because they depend on accurate and efficient elicitation and assessment of preferences from patients who are facing a novel task. Objective. To present a methodology for analyzing the sensitivity and stability of a patient’s preferences regarding colorectal cancer screening options and to provide a starting point for a personalized discussion between the patient and the health care provider about the selection of the appropriate screening option. Methods. This research is a secondary analysis of patient preference data collected as part of a previous study. We propose new measures of preference sensitivity and stability that can be used to determine if additional information provided would result in a change to the initially most preferred colorectal cancer screening option. Results. Illustrative results of applying the methodology to the preferences of 2 patients, of different ages, are provided. The results show that different combinations of screening options are viable for each patient and that the health care provider should emphasize different information during the medical decision-making process. Conclusion. Sensitivity and stability analysis can supply health care providers with key topics to focus on when communicating with a patient and the degree of emphasis to place on each of them to accomplish specific goals. The insights provided by the analysis can be used by health care providers to approach communication with patients in a more personalized way, by taking into consideration patients’ preferences before adding their own expertise to the discussion.
Performance of Skew Reinforcing in Inverted-T Bridge Caps
Authors: Roy Satya Sapath , Sawab Jamshaid , Zhou Tianmin , Mo Y. L. , Hsu Thomas T. C.
Published: April 2018

Inverted-T bridge caps (ITBCs) have been widely used in most bridges in Texas in recent years. In some typical cases, the bridge caps are skew when two roads are not aligned in a perpendicular manner. The traditional method of flaring the transverse reinforcement out in skew ITBCs introduces significant complexity in design and during construction. An alternative is to provide skew reinforcing which will substantially reduce the design complexities and construction period. In this paper, three ITBC specimens were subjected to shear action to evaluate and compare the performance of ITBCs with traditional reinforcing with those with skew reinforcing. The three specimens include 0-degree skew, 30-degree skew with traditional reinforcing, and 30-degree skew with skew reinforcing, worthy of verification and quantification as demonstrated in this paper. The physical test results show that the skew reinforcement arrangement does not weaken the bridge cap’s capacity, and the structural performance remains almost the same as that of the traditional arrangement. In addition, the serviceability performance of skew reinforcements is better as compared with traditional reinforcements.
Development of Domain Analysis to Predict Multi-Axial Flexible Airfield Pavement Responses Due to Gear and Environmental Loadings
Authors: Gamez Angeli , Hernandez Jaime A. , Al-Qadi Imad L.
Published: April 2018

Flexible pavement design procedures use maximum mechanistic strains to predict service life via empirical transfer functions. The conventional method of using predefined point locations for potential damage may not accurately represent realistic pavement scenarios. For instance, flexible airfield pavement analysis mainly considers the critical strain at the bottom of the asphalt concrete (AC), which may not characterize near-surface cracking potential. In lieu of point strains, domain analysis, a new method, accounts for the multi-axial behavior of pavements, as inherently excited by three-dimensional (3-D) and nonuniform aircraft tire–pavement contact stresses. Initially applied on highway pavements considering truck tire loading, this approach is an initial breakthrough for implementing domain analysis on flexible airfield pavements; in this study, A-380 and F-16 landing gear tire loads were considered. As anticipated, speed and temperature had significant influence on cumulative domain stress and strain ratios. The decrease in speed and increase in temperature not only increased the cumulative ratios up to 1.81, but nonlinearity of the problem became more prevalent at worst loading conditions (8 kph and 45°C). Minimal difference in ratios for F-16 cases suggests that the National Airport Pavement Test Facility pavement structure became less sensitive to conditions under low loads. Point response analysis revealed that critical strains were not significantly influenced by the tire-inflation pressure, for example, tensile strain at the bottom of the AC only increased up to 13.6% (considering 8 kph speed), whereas domain analysis quantified the increase with respect to 3-D stress or strain states.
Life-Cycle Cost Adjustment Factors in Alternate Design/Alternative Bid Pavement Bids: Added Value or Added Controversy?
Authors: Gransberg Douglas D. , Karaca Ilker , Buss Ashley
Published: April 2018

Alternative design/alternative bids (ADAB) provides a mechanism for the asphalt and concrete paving industries to compete for the same paving project. It operates on the principle of the market pricing of each material determining which is most economical when the bids are opened, rather than selecting the pavement type during design based on a life-cycle cost analysis (LCCA). This paper reviews including LCC-based bid adjustment factors in the ADAB award decision. Data are from a survey that received responses from 40 U.S. Departments of Transportation (DOT) and the Canadian province of Ontario, and a content analysis of 55 ADAB project outcomes in 13 U.S. states and three Canadian provinces. Seven algorithms in use to calculate an ADAB bid adjustment factor were found, and six U.S. DOTs that award ADAB projects without an adjustment factor. The paper finds that the adjustment factor formula rarely influences the award decision and, generally, the pavement type with the lowest bid cost wins with or without the adjustment factor. The paper models the ADAB process in financial terms as an exercisable commodity option that accrues value from the differential rates of volatility between asphalt and concrete. It concludes that an LCC-based bid adjustment factor complicates the award process, creating potential for controversy over what the factor inputs are, and does not add value over bidding the pavement types head to head and awarding to the low bidder. The ADAB process increases the number of bidders and reduces unit bid prices for both pavement types.
Individual, Travel, and Bus Stop Characteristics Influencing Travelers’ Safety Perceptions
Authors: Abenoza Roberto F. , Ceccato Vania , Susilo Yusak O. , Cats Oded
Published: April 2018

Ensuring safety during door-to-door public transport trips is a fundamental challenge to service providers, as safety influences individuals’ mobility. Using reported safety perceptions of travelers waiting at six bus stops with different characteristics in Stockholm, this study investigates factors that have an impact on determining travelers’ perceived safety and crime perceptions. This is done by assessing the importance of real-time information provision and the environmental characteristics of bus stops during the day and at night for different types of crime, after controlling for travelers’ individual and trip characteristics, and their previous experiences of victimization. Interaction effects of age, gender, and travel frequency are also tested. The results suggest that bus shelter characteristics, natural surveillance, and trustworthy real-time information are the most important factors influencing safety and crime perceptions. Additionally, safety perceptions are strongly influenced by previous experiences of victimization. The effect of perceived feelings about crime and safety are found to be nuanced by age and gender. Unlike some common beliefs, travelers: (1) feel less worried about becoming a victim of crime at bus stops associated with high crime rates; (2) prefer opaque shelters at night; and (3) have higher safety perceptions when the stop is located in an area of mixed land use. The impact of a bus stop’s number of passers-by is found to be insignificant. No direct or indirect effects can be attributed to frequency of travel by bus, indicating that familiar places and routine behavior have no effect on declared crime and safety perceptions.
Exploiting a Natural Hub: Turning a Stopover into a Destination
Authors: Goldsberry Leah , Scavette Adam R.
Published: April 2018

In the mature aviation system of today, it is difficult to establish new hubs that focus solely on transfer traffic. This paper identifies a new type of hub—a natural tourism hub—one at which an airline and the surrounding metropolitan area can simultaneously benefit from a transportation hub and accompanying tourist destination, respectively. The study aims to identify existing airports for these stopover locations that are located on highly trafficked international flight routes. Using Iceland as an example, this country’s success in optimizing its stopover location to promote tourism and gain airline passenger demand is examined. The analysis is carried out by implementing a k-means clustering algorithm on total distance added for stopover locations, as well as flight leg symmetry to identify existing airports that are geographically located in an optimal stopover path for international routes across the Atlantic and Pacific oceans, and between Europe and East Asia. Airports in the clusters that minimize total added distance are then observed, and the clusters are ordered based on how symmetric the two flight legs of a stopover journey at an airport in that cluster tend to be. In addition, three airports near the top of this list are analyzed as potential stopover locations. In using this algorithm, not only is it possible to forecast which hubs may become major tourist destinations, but also to identify how airlines can shape people’s perception of their location as a tourist destination.
Incidence of Osteochondritis Dissecans in Adults
Authors: Weiss Jennifer M. , Shea Kevin G. , Jacobs John C. , Cannamela Peter C. , Becker Ian , Portman Mark , Kessler Jeffrey I.
Published: April 2018

Background:

Osteochondritis dissecans (OCD) has frequently been described in children and adolescents, but cases of OCD in adults are certainly encountered. Little has been published on the epidemiology of OCD in adult patients.

Purpose:

To assess the frequency of OCD lesions in adults and assess the risk by age, sex, and ethnicity.

Study Design:

Descriptive epidemiology study.

Methods:

The authors assessed all patients aged 20 to 45 years from the entire database of patients enrolled as members of Kaiser Permanente Southern California from January 2011 until December 2013. Kaiser Southern California is an integrated health care system serving a racially, ethnically, and socioeconomically diverse population of >3.5 million patients. A retrospective chart review was done on OCD during this period. Inclusion criteria included OCD of any joint. Exclusion criteria included traumatic osteochondral fractures and coexistence of intra-articular lesions other than OCD. Joint involvement/location, laterality, and all patient demographics were recorded.

Results:

Among 122 patients, a total of 124 OCD lesions were found. The majority of lesions were in the ankle (n = 76) and knee (n = 43), with 3 foot lesions and 2 elbow lesions identified. OCD lesions were identified in 75 men (62%) and 47 women (38%). Overall incidence rates per 100,000 person-years were 3.42 for all OCD, 2.08 for ankle OCD, and 1.21 for knee OCD. The relative risk of adult OCD for men was twice that of women. The relative risk of adult OCD for white patients was 2.3 that of Asians and 1.7 that of Hispanics. Risk of knee OCD was 3.6 times higher for men than women. As compared with women, men had a higher risk for lateral femoral condyle OCD lesions versus the medial femoral condyle ( P = .05; odds ratio [OR], 5.19).

Conclusion:

This large cohort study of Southern California adults with OCD demonstrated an increased OR for men (vs women) of OCD in all joints. The majority of symptomatic lesions were present in the ankle rather than the knee, as previously found in children. White and black patients had the highest OR of OCD; men had a significantly greater OR of lateral femoral condyle knee lesions as compared with women.
Development of a Novel Large Animal Model of Ischemic Heart Failure Using Autologous Platelet Aggregates
Authors: Kwiatkowski Pawel , Sai-Sudhakar Chittoor , Philips Angela , Parthasarathy Sampath , Sun Benjamin
Published: April 2018

Background

Current animal models of heart failure lack the biomass of thrombus that occurs in patients undergoing myocardial infarction. We propose a novel animal model of ischemic cardiomyopathy developed by sequential direct injections of autologous platelet aggregates into the coronary circulation resulting in development of ischemic cardiac insufficiency.

Methods

Autologous platelets from adult sheep were isolated and aggregated. Aggregated platelets were then injected into the coronary circulation of anesthetized animals under fluoroscopic guidance. Troponin I levels were monitored for first three days after embolization to validate cardiac tissue injury. Progression of heart failure was corroborated by monitoring changes in echo-based assessment of ejection fraction and left ventricular end-systolic and end-diastolic dimensions. Thrombus-based obstruction of coronary artery was confirmed with histopathology review by mepacrine labeling of pre-aggregated platelets.

Results

All experimental animals developed heart failure-like cardiac insufficiency confirmed by elevated levels of troponin I and associated with significant drop in the ejection fraction.

Conclusions

Sequential injections of aggregated platelets into coronary circulation lead to progressive development of ischemic cardiac insufficiency. This phenomenon seems to mimic development of ischemic heart failure seen in human patients and opens multiple research opportunities to fill the existing gap between basic research and clinical practice.
Synthesis and Characterization of a Laminated Hydroxyapatite/Gelatin Nanocomposite Scaffold with Controlled Pore Structure for Bone Tissue Engineering
Authors: Azami Mahmoud , Samadikuchaksaraei Ali , Poursamar Seyed Ali
Published: April 2018

In this study, a nanostructured scaffold was designed for bone repair using hydroxyapatite (HA) and gelatin (GEL) as its main components. Nanopowders of HA were synthesized, and together with GEL, used to engineer a 3-dimensional nanocomposite combining 3 techniques of layer solvent casting, freeze-drying, and lamination. The results show that the scaffold possesses a 3-dimensional interconnected homogenous porous structure with a porosity of 82% and pore sizes ranging from 300 to 500 μm. It has also been shown that mechanical indices are in the range of spongy bones. Cultured osteoblast-like cells (SaOS-2) have shown an excellent level of cell attachment, migration, and penetration into the porosities of the nanocomposite scaffold. Here, we have shown that by a combination of widely available methods with simple experimental operations, nano-HA powders can be synthesized and used to make 3-dimensional HA/GEL nanocomposites in any desired shape, with mechanical properties comparable to spongy bone.
Crush Syndrome after the Wenchuan Earthquake: New Experience with Regional Citrate Anticoagulation Continuous Veno-Venous Hemofiltration
Authors: Xie Hong-Lang , Ji Da-Xi , Hu Wei-Xin , Wu Yan , Ge Yong-Chun , Hou Jin-Hua , Li Lei-Shi , Liu Zhi-Hong
Published: April 2018

Purpose

Acute renal failure (ARF) related to crush syndrome is usually treated with hemodialysis. Continuous veno-venous hemofiltration (CVVH) has seldom been adopted in this situation due to the main drawback of continuous anticoagulation. The purpose of this study was to evaluate the effectiveness and safety of regional citrate anticoagulation (RCA)-CVVH in two crush syndrome patients following the Wenchaun earthquake.

Methods

Two victims from the Wenchuan earthquake in Southwest China were admitted to our hospital on May 23, 2008, 11 days after their injury. The total entrapment time under the rubble was 5.5 and 22.5 hrs respectively. They remained oliguric on admission, in spite of vigorous treatment in the local hospital including aggressive fluid infusion, fasciotomy and intermittent hemodialysis. On admission, their serum myoglobin levels were 765 and 829 ng/mL, respectively. Further debridement and drainage were performed. RCA-CVVH was conducted; the citrate containing substitution fluid was infused in a pre-dilution manner at a rate of 4 l/h; calcium was infused through a separate access to the venous inlet of the double lumen catheter. The infusion rate was adjusted according to the serum ionized calcium and whole blood activated clotting time (WBACT). A low dose of low molecular weight heparin (LMWH) was infused at the rate of 150∼300 U/h simultaneously for anticoagulation after anemia had been corrected and their wounds were stable. RCA-CVVH was substituted by conventional CVVH and LMWH anticoagulation when case 2 complicated with hypoxia.

Results

RCA-CVVH was well tolerated, hemodynamic status was stable, and no complications related with RCA-CVVH were noted. The body temperature and WBC decreased to normal range, while anemia and hypoalbuminia were corrected. The levels of serum myoglobin and creatine phosphokinase were also decreased to normal range. Their urine volume increased after 20 and 22 days of oliguria and the tubular function of the patients recovered well. Although the second case encountered acute cholecystitis and acute lung injury in the hospital, both the patients recuperated and neither of them underwent amputation.

Conclusions

The present two crush patients have been successfully treated, but due to the limits of the small sample, it is difficult to generalize whether RCA-CVVH is safe enough for crush syndrome with a high risk of bleeding diathesis. Additional investigation with a larger number of patients is required. Fluid equilibrium, nutritional support, prevention of bleeding and infection are fundamental in this situation.
A New Prognostic Index for One-Year Survival in Incident Hemodialysis Patients
Authors: Marinovich Sergio , Lavorato Carlos , Moriñigo Claudio , Celia Eduardo , Bisignano Liliana , Soratti Mariano , Hansen-Krogh Daniela
Published: April 2018

Purpose

Although scoring comorbidities for patients beginning chronic hemodialysis has proved significant and has led researchers to develop several indexes, none of them has been extensively accepted. The aim of this study was to: 1) develop a prognostic index for patients entering renal replacement therapy; and 2) identify which one of the available scores better predicts one-year survival.

Methods

Records from 5,360 incident dialysis-requiring ESRD individuals were studied and a novel comorbidity index (NI) was developed. The agreement of this NI with the Charlson age-comorbidity, Kahn-Wright, ACPI, and Hemmelgarn indexes was assessed to identify which one better predicts one-year survival. The Cox proportional hazard regression with time-dependent covariates was used to analyze survival and the area under the receiver operating characteristic (ROC) curve was calculated to assess the ability of this score to discriminate between prognoses and to compare this NI with indexes already in use.

Results

16 of the original 19 predictor variables displayed hazard ratios ≥1.2. Although the area under the ROC curves for all the indexes compared were significantly different from 0.5, the NI showed better performance characteristics (0.74 vs. 0.70 for Charlson's, 0.68 for ACPI, 0.67 for Khan-Wright's and 0.63 for Hemmelgarn's). Compared with the Charlson score, the z statistic was 7.78 (p<0.001). One-year survival estimate for the high-risk group was 43% with the NI and ranged from 66% to 72% when assessed through other indexes.

Conclusions

We recommend the use of this NI because it better predicts the one-year survival probability of incident hemodialysis-requiring ESRD individuals.
Study of Mechanical Properties of Engineered Cartilage in an in Vivo Culture for Design of a Biodegradable Scaffold
Authors: Komura Makoto , Komura Hiroko , Kanamori Yutaka , Tanaka Yujirou , Ohatani Yoshiyuki , Ishimaru Tetuya , Sugiyama Masahiko , Hoshi Kazuto , Iwanaka Tadashi
Published: April 2018

Introduction

An engineered trachea with an absorbable scaffold should be used to augment the repair of a stenotic tracheal section in infants and children because this type of engineered airway structure can grow as the child grows. Our strategy for relief of tracheal stenosis is tracheoplasty by engineered cartilage implantation in accordance with the concept of costal cartilage grafting to enlarge the lumen. This study investigated the mechanical properties of regenerative cartilage with a biodegradable scaffold, Neoveil®, to aid in design of a composite scaffold that maintained semi-rigid properties until cartilage could be generated.

Materials and methods

New Zealand White rabbit (n=3) chondrocytes were isolated from auricular cartilage with collagenase type 2 digestion. Then 10×106/cm3 chondrocytes in atelocollagen solution were seeded onto polyglycolic acid (PGA) mesh. A total of 36 constructs, 12 from each rabbit, were implanted into athymic mice (3 constructs/mouse). Constructs were retrieved after 8 weeks and evaluated by measurements of mechanical and biochemical properties as well as histological examination. Thirty-six PGA mesh sheets of the same size but without cells were implanted in control mice.

Results

After 6 weeks of implantation, staining of sections with Safranin O revealed cartilage accumulation. Glycosaminoglycan was gradually produced from chondrocytes in the engineered constructs, correlating with the duration of implantation. Mechanical parameters had the same values as those for rabbit tracheal cartilage 8 weeks after implantation.

Conclusions

Biodegradable Neoveil® had good biocompatibility and was able to support extracellular matrix formation in engineered cartilage in an animal model.
Internal Hemodiafiltration versus Low-Flux Bicarbonate Dialysis: Results from a Long-Term Prospective Study
Authors: Righetti Marco , Filiberti Oliviero , Ranghino Andrea , Ferrario Gianmichele , Milani Silvana , Serbelloni Paola , Guida Gian Enrico , Tommasi Adalberto
Published: April 2018

Introduction

About ten years ago it was discovered that changes in filter design which increase passive filtration improved dialysis efficiency. Later, these modified membranes showed similar intradialytic efficiency when used in on-line hemodiafiltration or in bicarbonate dialysis, called internal hemodiafiltration.

Aim and Methods

On the basis of these previous results, we studied the long-term effects of internal hemodiafiltration, in comparison with low-flux bicarbonate dialysis. The pre-dialysis beta2-microglobulin level was chosen as the primary outcome variable. A prospective multicenter study with a cross-over scheme, 2 treatments and 3 periods, was designed. Twenty-four patients, followed in two dialysis centers, were enrolled. Many other parameters were measured every month at the first dialysis session of the week. The intra-dialytic removal of urea, beta2-microglobulin and homocysteine was also calculated.

Results

The removal of uremic toxins was significantly higher in internal hemodiafiltration than in low-flux bicarbonate dialysis. The pre-dialysis value of urea, phosphorus, beta2-microglobulin and homocysteine was lower during internal hemodiafiltration as compared with low-flux bicarbonate dialysis. The mean pre-dialysis value of hemoglobin was significantly higher during internal hemodiafiltration than low-flux bicarbonate dialysis, with a trend towards a significantly lower consumption of erythropoiesis stimulating agents during internal hemodiafiltration as compared with low-flux bicarbonate dialysis.

Conclusions

Long-term treatment with internal hemodiafiltration improves the removal of small molecules and stops the continuous increase of middle molecules as seen in low-flux bicarbonate dialysis. Internal hemodiafiltration may substitute low-flux bicarbonate dialysis, but we need new prospective studies about long-term hard end-points.
Chronic Kidney Disease after Liver Transplantation: Recent Evidence
Authors: Fabrizi Fabrizio , Dixit Vivek , Martin Paul , Messa Piergiorgio
Published: April 2018

Chronic kidney disease is a common complication after liver transplantation with an incidence ranging between 20% and 80%. Studies of renal function after liver transplantation have yielded conflicting results: the wide range in incidence rates of chronic kidney disease (CKD) following liver transplantation is related to the methods for measuring kidney function, and various criteria for defining renal dysfunction, among others. An important cause of CKD among liver transplant recipients is calcineurin inhibitor-based immunosuppression. Additional predictors of CKD post-liver transplantation include pre-transplant kidney function, peri-operative acute kidney failure, age, and hepatitis C. A recent meta-analysis of observational studies revealed that, in the subgroup of studies provided with glomerular filtration rate at baseline, the summary estimate of relative risk and 95% confidence intervals (CI) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01–4.46, p=0.047). Acute renal insufficiency is common immediately after liver transplantation, whereas the course of CKD after liver transplantation appears progressive over time. Only preliminary information exists on kidney pathological findings in recipients of liver transplants with CKD. Introduction of the Model for End-stage Liver Disease for the allocation of liver grafts has not increased the occurrence of renal dysfunction following liver transplantation. Chronic kidney disease following liver transplantation increases cardiovascular burden dramatically. The use of mycophenolic acid- or sirolimus-based immunosuppression in calcineurin-inhibitors sparing protocols is an area of intense research.
Left Ventricular Assist Improves Autonomic Imbalance in Patients with Persistent Myocardial Dysfunction
Authors: Gardiwal Ajmal , Roentgen Philipp , Luesebrink Ulrich , Koenig Thorben , Klein Gunnar , Oswald Hanno
Published: April 2018

Background

Left ventricular assist devices (LVAD) are an effective therapeutic option for end-stage heart failure (HF). Reduced heart rate variability (HRV) as a result of autonomic derangement is evident in chronic heart failure and several studies have established the independent prognostic value of HRV in chronic heart failure.

Objective

In the present study we investigated whether autonomic function is restored in patients after LVAD implantation with persistent, severely depressed left ventricular function.

Methods

Ambulatory Holter ECG recordings were collected in heart failure patients with an LVAD (n=8) und age-matched heart failure patients without an LVAD (n=7) both on optimal medical therapy. Cardiac dimensions and function were assessed by echocardiography or angiography.

Results

Analysis for heart rate variability revealed reduced SDNN (67±4ms), SDANN (56±4ms) and triangular index (18±1) in heart failure patients on optimal medical therapy. However patients with LVAD demonstrated a restoration in heart rate variability with normal SDNN (108±9ms), SDANN (103±8ms) and triangular index (29±2). Compared to patients without LVAD this difference was statistically significant (p<0.01).

Conclusions

In end-stage heart failure patients autonomic imbalance indicated by severely reduced heart rate variability is restored after LVAD implantation with unloading of the failing heart.
Beat-rate Dependent Mitral Flow Patterns for in Vitro Hemodynamic Applications
Authors: Vismara Riccardo , Fiore Gianfranco B.
Published: April 2018

The conservative surgery approach for restoring the functionality of heart valves has predominated during the last two decades, particularly for the mitral valve. In vitro pulsatile testing is a key methodology for the investigation of heart valve hemodynamics, and particularly for the ideation, validation and optimization of novel techniques in heart valve surgery. Traditionally, however, pulsatile mock loops have been developed for the study of aortic valve substitutes, and scarce attention has been paid in replicating the mitral flow patterns with due hemodynamic fidelity. In this work we provide detailed analytical expressions to produce beat-rate dependent, physiologic-like mitral flow patterns for in vitro applications. The approach we propose is based on a biomechanical analysis of the factors which govern hemodynamic changes in the mitral flow pattern, namely in terms of E and A wave contours and E/A peaks ratio, when switching from rest to mild exercise conditions. The patterns from the model we obtained were in good agreement with clinical literature data in terms of i) gradual superimposition of the E and A wave, which yielded a single peak at 96 bpm; ii) decrease in the E/A ratio with increasing heart rate; iii) amount of flow delivered by each of the two waves. The proposed method provides a physiologically representative, beat-rate dependent analytical expression of the mitral flow pattern, which can be used in in vitro hydrodynamic investigations to accurately replicate the changes that the flow waves experience when the heart rate shifts from rest to mild exercise conditions.