bluuebunny/crossref_metadata_2025 huggingface dataset:
Analyzing Cognitive Interview Data Using the Constant Comparative Method of Analysis to Understand Cross-Cultural Patterns in Survey Data
Authors: Ridolfo Heather , Schoua-Glusberg Alisú
Published: August 2011

The rise in multilingual surveys within the U.S. federal government and around the world has led to an increased need for assurance of comparable survey questions and resulting data. Cognitive interviewing (CI) is one method that allows us to examine how different language versions are interpreted and thus detects ways in which translated questions are not comparable. However, despite being a well-established question evaluation methodology, CI findings have been limited due to a lack of standards for analyzing interview data. The authors contend that cognitive interview findings can be strengthened by using existing qualitative analysis methods. In this article, the authors demonstrate how to conduct analysis of CI data using the constant comparative method and present the resulting findings.
Using Cognitive Interviewing and Behavioral Coding to Determine Measurement Equivalence across Linguistic and Cultural Groups
Authors: Thrasher James F. , Quah Anne C. K. , Dominick Gregory , Borland Ron , Driezen Pete , Awang Rahmat , Omar Maizurah , Hosking Warwick , Sirirassamee Buppha , Boado Marcelo
Published: August 2011

This study examined and compared results from two questionnaire pretesting methods (i.e., behavioral coding and cognitive interviewing [CI]) to assess systematic measurement bias in survey questions for adult smokers across six countries (United States, Australia, Uruguay, Mexico, Malaysia, and Thailand). Protocol development and translation involved multiple bilingual partners in each linguistic/cultural group. The study was conducted with convenience samples of 20 adult smokers in each country. Behavioral coding and CI methods produced similar conclusions regarding measurement bias for some questions; however, CI was more likely to identify potential response errors than behavioral coding. Coordinated qualitative pretesting of survey questions (or postsurvey evaluation) is feasible across cultural groups and can provide important information on comprehension and comparability. The CI appears to be a more robust technique than behavioral coding, although combinations of the two might be even better.
National Sentiment and Economic Behavior
Authors: Braun Sebastian , Kvasnicka Michael
Published: August 2011

National sentiment can have major implications for individual consumption and investment choices but has been researched little by economists. This article studies how national sentiment in the form of a perception or loyalty bias of bettors may affect pricing patterns on national wagering markets for European football. The authors show theoretically that both biases can be profitably exploited by domestic bookmakers through price adjustment. Analyzing empirically a unique data set of betting odds from online bookmakers in Europe, the authors find evidence of systematic biases in the pricing of own national teams, deviations that can be explained by the aforementioned two biases.
Upsets
Authors: Osborne Evan
Published: August 2011

The article models the upset—a low-probability outcome of a periodic competition. It is assumed that the upset is an independent component of consumer preferences, whose marginal willingness to pay grows with time. The decision rule for a league on upset timing is a competitive-balance problem but is unlike standard models of competitive balance. Upset timing is likened partially to the optimal redemption time of a growing asset, and implications for competitive balance in this environment are derived.
Testing the Developmental Nature of Work Motivation Using Kegan’s Constructive-Development Theory
Authors: Bugenhagen Marilyn J. , Barbuto John E.
Published: August 2011

This article reports a field study testing the relationship between individuals’ constructive-development level and their sources of work motivation. Constructive development was assessed using the Subject–Object Interview for 53 community and educational leaders. Motivation was assessed using the Motivation Sources Inventory. Results indicated that constructive-development progression was significantly related to instrumental motivation. No other significant relationships were found, indicating that the other four sources of work motivation exist independent of individuals’ constructive development. Implications for research and practice are addressed.
Factors Influencing Food Buying Practices in Residents of a Low-Income Food Desert and a Low-Income Food Oasis
Authors: Walker Renee E. , Fryer Craig S. , Butler James , Keane Christopher R. , Kriska Andrea , Burke Jessica G.
Published: August 2011

Studies suggest that proximity to a supermarket influences access to healthy foods. However, little is known about factors that influence food buying practices within areas with limited supermarket access. This study identified these factors and explored how they are related and influence healthy eating. Twenty-five men and women engaged in the concept mapping process, a mixed methods approach allowing participants to identify, sort, and rate ideas. Participants generated 121 unique (nonduplicate) statements of factors that influence food buying practices and sorted them into 12 clusters that represented their perceptions. Average cluster ratings for residents with poor supermarket access were higher than residents with supermarket access. Awareness of these factors is important for increasing access to and consumption of healthy foods.
An Innovative Mixed Methods Approach to Studying the Online Health Information Seeking Experiences of Adults With Chronic Health Conditions
Authors: Mayoh Joanne , Bond Carol S , Todres Les
Published: August 2011

This article presents an innovative sequential mixed methods approach to researching the experiences of U.K. adults with chronic health conditions seeking health information online. The use of multiple methods integrated within a single study ensured that the focus of the research was emergent and relevant and ultimately provided a more complete picture of the experience of online health information seeking through joint discussion. This was achieved by communicating both breadth and depth of data relating to the phenomenon. Findings indicate that if the study had used a single research method in isolation, something would have been lost or misunderstood regarding the phenomenon, thus demonstrating the value of each stage within the research design and of the integration of these findings.
Do the dimensions of the distal phalanges allow suture anchor fixation of the flexor digitorum profundus? A cadaver study
Authors: Jain D. K. , Kakarala G. , Compson J. , Singh R.
Published: August 2011

This study was done to identify whether the dimensions of the distal phalanges allow suture anchor fixation of the flexor digitorum profundus tendon. Forty pairs of hands were dissected to measure the anteroposterior and lateral dimensions of distal phalanges of all digits. The mean anteroposterior depth of the distal phalanx at the insertion of the tendon was found to be 4.7 mm for the little finger, 5.4 mm for the ring finger, 5.9 mm for the middle finger, 5.4 mm for the index finger and 6.9 mm for the thumb respectively. The commonly available anchors and drill bits for fingers were found to be suboptimal for anchoring the flexor digitorum profundus tendon to the distal phalanx of the little finger. The drill bits used for these anchors were found to be too long for the little fingers and some ring and index fingers.
Expansile aneurysmal bone cyst in the tubular bones of the hand treated with en bloc excision and autograft reconstruction: a report of 12 cases
Authors: Jafari D. , Jamshidi K. , Najdmazhar F. , Shariatzade H. , Liaghat O.
Published: August 2011

Primary aneurysmal bone cysts (ABCs) in the small tubular bones of the hands are rare and optimal treatment is not yet established. Between August 1997 and June 2009, 12 patients with biopsy-proven expansile primary ABCs of the small tubular bones of the hand were treated with en bloc tumor excision and strut autograft reconstruction. The adjacent joint was preserved if feasible, otherwise it was fused. Patients were followed for at least 2 years (mean = 7 years). All grafts were incorporated except for partial resorption in one. There was only one tumor recurrence about 1 year after the operation. Other complications included premature physeal arrest in one case and limitation of adjacent joint motion in three. A relatively low rate of recurrence and other complications indicates that this technique would serve as a good strategy for patients with expansile ABCs in the hand in terms of safety, simplicity and reduced number of re-operations.
Steady state determination using bond graphs for systems with singular state matrix
Authors: González A G , Galindo R
Published: August 2011

A bond graph procedure to get the steady state value for linear time-invariant systems is presented. The general case of a singular state matrix is considered. The procedure is based on a junction structure configuration with derivative causality assignment, and on relationships of the bond graphs with integral and derivative causality assignments. It is shown that the structurally null modes, i.e. the poles at the origin, are cancelled for steady state. The key to cancel the poles at the origin is that the adjugate matrix of sIn −  Ap multiplies Bp yielding the zeros at the origin with the same order that the structurally null modes, where ( Ap, Bp, Cp, Dp) is a state space realization of a linear time-invariant system, s is the Laplace operator and In, is an n ×  n identity matrix. Hence, this unstable part of the system is cancelled and the steady state can be obtained. Thus, the singularity of the state space matrix is avoided, and the steady state is obtained from the bond graph with derivative causality assignment. Since the singular state matrix is considered, it is shown that by using the bond graph with derivative causality assignment, an equivalent system with linearly independent state variables can be obtained. An example of an electrical system with an electrical transformer modelled by an I-field whose state matrix is singular is presented. Also, the proposed methodology for a load driven by two DC motors is applied.
Antithrombotic medicines following intracerebral haemorrhage: where's the evidence?
Authors: Flynn Robert , Doney Alexander
Published: August 2011

The use of antithrombotic medicines in patients who have a history of intracerebral haemorrhage is widely perceived as being contraindicated. However, many patients with intracerebral haemorrhage may suffer from conditions for which antithrombotic medicines are indicated. Such scenarios represent a therapeutic dilemma whereby treating infers an increased risk of recurrent intracerebral haemorrhage, but not treating infers an increase of thrombotic complications. Despite the importance of this dilemma, there is very little guidance for prescribers. This perspective review considered previous systematic reviews that addressed this issue, together with recently published research findings from the Tayside Stroke Cohort. Systematic reviews of experimental and observational studies have concluded that there is a marked lack of data on which to judge the safety of oral anticoagulant agents following intracerebral haemorrhage. In addition, the limited data available regarding the use of antiplatelet medicines following intracerebral haemorrhage provide no evidence that they are harmful, and again further data are required. In the absence of such data, a decision analysis approach has been proposed. This considers the findings of other studies to infer the likely impact of using antithrombotic agents in patients with intracerebral haemorrhage. The success of this approach is contingent on the availability of reliable data that describe the rate of recurrent intracerebral haemorrhage; however, published data on this varies widely. There are a number of factors that conspire against researchers addressing this issue. The current paucity of evidence to guide prescribers faced with this therapeutic dilemma seems likely to remain for some time.
The Pitch-Matching Ability of High School Choral Students
Authors: Riegle Aaron M. , Gerrity Kevin W.
Published: August 2011

The purpose of this study was to determine the pitch-matching ability of high school choral students. Years of piano experience, middle school performance experience, and model were considered as variables that might affect pitch-matching ability. Gender of participants was also considered when identifying the effectiveness of each model. Participants (N = 164) were students of a rural school corporation in Northern Indiana and were enrolled in auditioned and nonauditioned choral ensembles. Results indicated that the study population had poor pitch-matching skills based on the rubric used by the researchers. Significant associations between pitch-matching ability and years of piano experience and middle school performance experience were revealed. At a 95% confidence interval, the female model elicited more accurate responses from participants than the male or piano model.
Hepcidin regulation by innate immune and infectious stimuli
Authors: Armitage Andrew E. , Eddowes Lucy A. , Gileadi Uzi , Cole Suzanne , Spottiswoode Natasha , Selvakumar Tharini Ashtalakshmi , Ho Ling-Pei , Townsend Alain R. M. , Drakesmith Hal
Published: August 2011

Hepcidin controls the levels and distribution of iron, an element whose availability can influence the outcome of infections. We investigated hepcidin regulation by infection-associated cytokines, pathogen-derived molecules, and whole pathogens in vitro and in vivo. We found that IL-22, an effector cytokine implicated in responses to extracellular infections, caused IL-6–independent hepcidin up-regulation in human hepatoma cells, suggesting it might represent an additional inflammatory hepcidin agonist. Like IL-6, IL-22 caused phosphorylation of STAT3 and synergized with BMP6 potentiating hepcidin induction. In human leukocytes, IL-6 caused potent, transient hepcidin up-regulation that was augmented by TGF-β1. Pathogen-derived TLR agonists also stimulated hepcidin, most notably the TLR5 agonist flagellin in an IL-6–dependent manner. In contrast, leukocyte hepcidin induction by heat-killed Candida albicans hyphae was IL-6–independent, but partially TGF-β–dependent. In a murine acute systemic candidiasis model, C albicans strongly stimulated hepcidin, accompanied by a major reduction in transferrin saturation. Similarly, hepcidin was up-regulated with concomitant lowering of serum iron during acute murine Influenza A/PR/8/34 virus (H1N1) infection. This intracellular pathogen also stimulated hepcidin expression in leukocytes and hepatoma cells. Together, these results indicate that hepcidin induction represents a component of the innate immune response to acute infection, with the potential to affect disease pathogenesis.
TMPRSS6 rs855791 modulates hepcidin transcription in vitro and serum hepcidin levels in normal individuals
Authors: Nai Antonella , Pagani Alessia , Silvestri Laura , Campostrini Natascia , Corbella Michela , Girelli Domenico , Traglia Michela , Toniolo Daniela , Camaschella Clara
Published: August 2011

The iron hormone hepcidin is inhibited by matriptase-2 (MT2), a liver serine protease encoded by the TMPRSS6 gene. Cleaving the bone morphogenetic protein (BMP) coreceptor hemojuvelin (HJV), MT2 impairs the BMP/son of mothers against decapentaplegic homologs (SMAD) signaling pathway, down-regulates hepcidin, and facilitates iron absorption. TMPRSS6 inactivation causes iron-deficiency anemia refractory to iron administration both in humans and mice. Genome-wide association studies have shown that the SNP rs855791, which causes the MT2 V736A amino acid substitution, is associated with variations of serum iron, transferrin saturation, hemoglobin, and erythrocyte traits. In the present study, we show that, in vitro, MT2 736A inhibits hepcidin more efficiently than 736V. Moreover, in a genotyped population, after exclusion of samples with iron deficiency and inflammation, hepcidin, hepcidin/transferrin saturation, and hepcidin/ferritin ratios were significantly lower and iron parameters were consistently higher in homozygotes 736A than in 736V. Our results indicate that rs855791 is a TMPRSS6 functional variant and strengthen the idea that even a partial inability to modulate hepcidin influences iron parameters and, indirectly, erythropoiesis.
Treating limited-stage nodular lymphocyte predominant Hodgkin lymphoma similarly to classical Hodgkin lymphoma with ABVD may improve outcome
Authors: Savage Kerry J. , Skinnider Brian , Al-Mansour Mubarak , Sehn Laurie H. , Gascoyne Randy D. , Connors Joseph M.
Published: August 2011

The appropriate therapy for limited-stage nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is unclear. In contrast to classical Hodgkin lymphoma (CHL), chemotherapy is often omitted; however, it is unknown whether this impacts the risk of relapse. Herein, we compared the outcome of patients with limited-stage NLPHL treated in an era in which ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy was routinely incorporated into the primary therapy to an earlier era in which radiotherapy (RT) was used as a single modality. Using the British Columbia Cancer Agency Lymphoid Cancer Database, 88 patients with limited-stage NLPHL (stage 1A/1B or 2A, nonbulky disease < 10 cm) were identified. Treatment followed era-specific guidelines: before 1993, (n = 32) RT alone; and 1993 to present (n = 56), ABVD-like chemotherapy for 2 cycles followed by RT with the exception of 14 patients who received ABVD chemotherapy alone. Most patients were male (75%) with stage I disease (61%). In an era-to-era comparison, the 10-year time to progression (98% vs 76% P = .0074), progression-free survival (91% vs 65% P = .0024), and OS (93% vs 84%, P = .074) favored the ABVD treatment era compared with the RT alone era. Treating limited-stage NLPHL similarly to CHL may improve outcome compared with the use of radiation alone.
Citramalic acid and salicylic acid in sugar beet root exudates solubilize soil phosphorus
Authors: Khorassani Reza , Hettwer Ursula , Ratzinger Astrid , Steingrobe Bernd , Karlovsky Petr , Claassen Norbert
Published: August 2011

Background

In soils with a low phosphorus (P) supply, sugar beet is known to intake more P than other species such as maize, wheat, or groundnut. We hypothesized that organic compounds exuded by sugar beet roots solubilize soil P and that this exudation is stimulated by P starvation.

Results

Root exudates were collected from plants grown in hydroponics under low- and high-P availability. Exudate components were separated by HPLC, ionized by electrospray, and detected by mass spectrometry in the range of mass-to-charge ratio (m/z) from 100 to 1000. Eight mass spectrometric signals were enhanced at least 5-fold by low P availability at all harvest times. Among these signals, negative ions with an m/z of 137 and 147 were shown to originate from salicylic acid and citramalic acid. The ability of both compounds to mobilize soil P was demonstrated by incubation of pure substances with Oxisol soil fertilized with calcium phosphate.

Conclusions

Root exudates of sugar beet contain salicylic acid and citramalic acid, the latter of which has rarely been detected in plants so far. Both metabolites solubilize soil P and their exudation by roots is stimulated by P deficiency. These results provide the first assignment of a biological function to citramalic acid of plant origin.
Walnut oil increases cholesterol efflux through inhibition of stearoyl CoA desaturase 1 in THP-1 macrophage-derived foam cells
Authors: Zhang Jun , Grieger Jessica A , Kris-Etherton Penny M , Thompson Jerry T , Gillies Peter J , Fleming Jennifer A , Vanden Heuvel John P
Published: August 2011

Background

Walnuts significantly decrease total and low-density lipoprotein cholesterol in normo- and hypercholesterolemic individuals. No study to date has evaluated the effects of walnuts on cholesterol efflux, the initial step in reverse cholesterol transport, in macrophage-derived foam cells (MDFC). The present study was conducted to investigate the mechanisms by which walnut oil affects cholesterol efflux.

Methods

The extract of English walnuts (walnut oil) was dissolved in DMSO and applied to cultured THP-1 MDFC cells (0.5 mg/mL). THP-1 MDFC also were treated with human sera (10%, v:v) taken from subjects in a walnut feeding study. Cholesterol efflux was examined by liquid scintillation counting. Changes in gene expression were quantified by real time PCR.

Results

Walnut oil treatment significantly increased cholesterol efflux through decreasing the expression of the lipogenic enzyme stearoyl CoA desaturase 1 (SCD1) in MDFC. Alpha-linolenic acid (ALA), the major n-3 polyunsaturated fatty acids found in walnuts, recaptured SCD1 reduction in MDFC, a mechanism mediated through activation of nuclear receptor farnesoid-X-receptor (FXR). Postprandial serum treatment also increased cholesterol efflux in MDFC. When categorized by baseline C-reactive protein (CRP; cut point of 2 mg/L), subjects in the lower CRP sub-group benefited more from dietary intervention, including a more increase in cholesterol efflux, a greater reduction in SCD1, and a blunted postprandial lipemia.

Conclusion

In conclusion, walnut oil contains bioactive molecules that significantly improve cholesterol efflux in MDFC. However, the beneficial effects of walnut intake may be reduced by the presence of a pro-inflammatory state.

Trial Registration

ClinicalTrials.gov: NCT00938340
Clinical evaluation of cardiac effects of experimental doxycycline overdosing in healthy calves
Authors: Brihoum Mounir , Rollin Frédéric , Desmecht Daniel , Detilleux Johann , Amory Hélène
Published: August 2011

Background

Cardiac morphologic and functional changes consistent with cardiomyopathy have been reported in field cases of calves with accidental doxycycline overdosing. The purpose of this study was to evaluate clinically the cardiac effects of an experimentally-induced doxycycline overdosing in healthy calves.

Twelve 2 months-old healthy Belgian Blue calves were studied. Six of them (group 1) received the normal dose (5 mg/kg, BID) and the six others (group 2) received five times the normal dose (25 mg/kg, BID) of oral doxycycline for five consecutive days (D1 to D5). Each calf was clinically examined daily. Measurement of serum AST, CK, Iso-CKs and LDH activities and an echocardiographic examination were performed before (D0) and one day after (D6) the last doxycycline administration. An ECG tracing was recorded at D0, D4, and D6.

Results

In both groups, no clinical, blood, echocardiographic or electrocardiographic changes suggestive of a cardiomyopathy were observed. Only a decreased appetite was observed in the calves of the group 2 between D3 and D6.

Conclusions

This trial failed to reproduce cardiac changes reported in accidental doxycycline-poisoning in calves, suggesting that high doses of doxycycline may not be the only etiologic factor of the cardiomyopathy reported in the field cases.
Defective eosinophil hematopoiesis ex vivo in inbred Rocky Mountain White (IRW) mice
Authors: Dyer Kimberly D , Garcia-Crespo Katia E , Percopo Caroline M , Bowen Aaron B , Ito Tomonobu , Peterson Karin E , Gilfillan Alasdair M , Rosenberg Helene F
Published: August 2011

We examine the proliferation and differentiation of bone marrow (BM) progenitors from inbred Rocky Mountain White (IRW) mice, a strain used primarily for retrovirus infection studies. In contrast to findings with BALB/c and C57BL/6 strains, IRW BM cells cannot proliferate or generate pure eosinophil cultures ex vivo in response to a defined cytokine regimen. Analysis of IRW BM at baseline was unremarkable, including 0.08 ± 0.03% Lin–Sca-1+c-kit+ (LSK) hematopoietic stem cells and 5.2 ± 0.3% eosinophils; the percentage of eosinophil progenitors (EoPs; Lin–Sca-1–c-kit+CD34+IL-5Rα+) was similar in all three mouse strains. Transcripts encoding GM-CSFRα and the IL-3/IL-5/GM-CSF common β chain were detected at equivalent levels in IRW and BALB/c BM, whereas expression of transcripts encoding IL-5Rα, IL-3Rα, and GATA-2 was diminished in IRW BM compared with BALB/c. Expression of membrane-bound IL-5Rα and intracellular STAT5 proteins was also diminished in IRW BM cells. Diminished expression of transcripts encoding IL-5Rα and GATA-2 and immunoreactive STAT5 in IRW BM persisted after 4 days in culture, along with diminished expression of GATA-1. Western blot revealed that cells from IRW BM overexpress nonsignaling soluble IL-5Rα protein. Interestingly, OVA sensitization and challenge resulted in BM and airway eosinophilia in IRW mice; however, the responses were significantly blunted. These results suggest that IRW mice have diminished capacity to generate eosinophils in culture and in vivo, likely as a result of diminished signaling via IL-5Rα.
Deletion of cannabinoid receptors 1 and 2 exacerbates APC function to increase inflammation and cellular immunity during influenza infection
Authors: Karmaus Peer W F , Chen Weimin , Crawford Robert B , Harkema Jack R , Kaplan Barbara L F , Kaminski Norbert E
Published: August 2011

We and others have reported that simultaneous targeted deletion of CB1 and CB2 resulted in exacerbation of immune reactivity, suggesting a role of endocannabinoids in down-regulating immune function. In this study, we demonstrate that APC function is enhanced specifically in the absence of CB1 and CB2 signaling, resulting in an exacerbated immune response phenotype. After influenza infection, CB1−/−CB2−/− mice showed more pronounced pulmonary damage, increased inflammatory cell infiltrate, inflammation, and a greater cellular immune responses compared with WT mice, as evidenced by transcriptome analysis, more robust T cell activation, and effector cell cytokine production. After direct activation in vitro, there were no differences in the percentages of cytokine-producing CD4+ T cells between CB1−/−CB2−/− and WT mice. However, untreated CB1−/−CB2−/− mice routinely had fewer naïve T cells compared with WT, suggesting dysregulation of APC immune homeostasis. Moreover, bmDCs and AM isolated from CB1−/−CB2−/− mice exhibited a more mature phenotype, with and without TLR stimulation, and bmDCs elicited T cells more robustly than WT mice. Collectively, these findings implicate a role for CB1 and CB2 on APCs in regulating immune responses and immune homeostasis.
Differentiation of CD8+ T cells into effector cells is enhanced by physiological range hyperthermia
Authors: Mace Thomas A , Zhong Lingwen , Kilpatrick Casey , Zynda Evan , Lee Chen-Ting , Capitano Maegan , Minderman Hans , Repasky Elizabeth A
Published: August 2011

In this study, we asked whether exposure to different physiologically relevant temperatures (33°C, 37°C, and 39.5°C) could affect subsequent antigen-specific, activation-related events of naive CD8+ T cells. We observed that temporary exposure of CD62LhiCD44lo Pmel-1 CD8+ cells to 39.5°C prior to their antigen-dependent activation with gp10025–33 peptide-pulsed C57BL/6 splenocytes resulted in a greater percentage of cells, which eventually differentiated into CD62LloCD44hi effector cells compared with cells incubated at 33°C and 37°C. However, the proliferation rate of naive CD8+ T cells was not affected by mild heating. While exploring these effects further, we observed that mild heating of CD8+ T cells resulted in the reversible clustering of GM1+ CD-microdomains in the plasma membrane. This could be attributable to a decrease in line tension in the plasma membrane, as we also observed an increase in membrane fluidity at higher temperatures. Importantly, this same clustering phenomenon was observed in CD8+ T cells isolated from spleen, LNs, and peripheral blood following mild whole-body heating of mice. Further, we observed that mild heating also resulted in the clustering of TCRβ and the CD8 coreceptor but not CD71R. Finally, we observed an enhanced rate of antigen-specific conjugate formation with APCs following mild heating, which could account for the difference in the extent of differentiation. Overall, these novel findings may help us to further understand the impact of physiologically relevant temperature shifts on the regulation of antigen-specific CD8+ T cell activation and the subsequent generation of effector cells.
Bombesin Receptor Subtype-3 (BRS-3) Regulates Glucose-Stimulated Insulin Secretion in Pancreatic Islets across Multiple Species
Authors: Feng Yue , Guan Xiao-Ming , Li Jing , Metzger Joseph M. , Zhu Yonghua , Juhl Kirstine , Zhang Bei B. , Thornberry Nancy A. , Reitman Marc L. , Zhou Yun-Ping
Published: August 2011

Bombesin receptor subtype-3 (BRS-3) regulates energy homeostasis, and BRS-3 agonism is being explored as a possible therapy for obesity. Here we study the role of BRS-3 in the regulation of glucose-stimulated insulin secretion (GSIS) and glucose homeostasis. We quantified BRS-3 mRNA in pancreatic islets from multiple species and examined the acute effects of Bag-1, a selective BRS-3 agonist, on GSIS in mouse, rat, and human islets, and on oral glucose tolerance in mice. BRS-3 is highly expressed in human, mouse, rhesus, and dog (but not rat) pancreatic islets and in rodent insulinoma cell lines (INS-1 832/3 and MIN6). Silencing BRS-3 with small interfering RNA or pharmacological blockade with a BRS-3 antagonist, Bantag-1, reduced GSIS in 832/3 cells. In contrast, the BRS-3 agonist (Bag-1) increased GSIS in 832/3 and MIN6 cells. The augmentation of GSIS by Bag-1 was completely blocked by U73122, a phospholipase C inhibitor. Bag-1 also enhanced GSIS in islets isolated from wild-type, but not Brs3 knockout mice. In vivo, Bag-1 reduced glucose levels during oral glucose tolerance test in a BRS-3-dependent manner. BRS-3 agonists also increased GSIS in human islets. These results identify a potential role for BRS-3 in islet physiology, with agonism directly promoting GSIS. Thus, in addition to its potential role in the treatment of obesity, BRS-3 may also regulate blood glucose levels and have a role in the treatment of diabetes mellitus.
Dual energy CT for the assessment of reperfused chronic infarction – a feasibility study in a porcine model
Authors: Kerl J Matthias , Deseive Simon , Tandi Christa , Kaiser Christina , Kettner Mattias , Korkusuz Huedayi , Lehmann Ralf , Herzog Christopher , Schoepf U Joseph , Vogl Thomas J , Bauer Ralf W
Published: August 2011

Backround

Detection of myocardial infarction has been the focus of considerable research over the past few decades. Recently developed dual source computed tomography (DSCT) scanners with dual energy mode have been used to detect myocardial infarction, but the studies on this topic are few.

Purpose

To evaluate the feasibility and performance of dual energy CT (DECT) during arterial phase in coronary CT angiography for the detection of chronic infarction compared with late enhancement MRI (LE-MRI) and histopathology in a porcine model of reperfused myocardial infarction.

Material and Methods

Myocardial infarctions were induced by 30 min occlusion of the proximal left anterior descending coronary artery in eight minipigs. DECT, post-contrast LE-MRI and histopathology were performed 60 days after infarct induction. The CT scan was performed in dual energy mode using a dedicated protocol. Myocardial iodine distribution was superimposed as color maps on grey scale multiplanar reformats of the heart. Two radiologists in consensus interpreted all imaging studies for presence of gadolinium uptake at LE-MRI reduced iodine content at DECT and hypoenhanced areas in the initial 100 kV coronary CT angiography images that were acquired during the DECT-acquisition. Results were compared with histopathology.

Results

Based on evaluable segments, DECT showed a sensitivity and specificity of 0.72 and 0.88; LE-MRI showed a sensitivity and specificity of 0.78 and 0.92; and the 100 kV data-set of the DECT scan showed a sensitivity and specificity of 0.60 and 0.93, respectively, for the detection of histological proved ischemia.

Conclusion

DECT during arterial phase coronary CT angiography, which is ordinarily used for coronary artery evaluation, is feasible for the detection of a chronic reperfused myocardial infarction.
Non-invasive assessment of renal allograft fibrosis by dynamic sonographic tissue perfusion measurement
Authors: Syversveen Trygve , Brabrand Knut , Midtvedt Karsten , Strøm Erik H , Hartmann Anders , Berstad Audun Elnaes
Published: August 2011

Background

Chronic allograft nephropathy (CAN) characterized by interstitial fibrosis and tubular atrophy is a major cause of renal transplant failure. The diagnosis can currently only be verified by a graft biopsy.

Purpose

To evaluate whether non-invasive dynamic color Doppler sonographic parenchymal perfusion measurements are different in grafts with various degrees of biopsy proven renal transplant fibrosis.

Material and Methods

Forty-nine adult patients were prospectively included. Four patients were excluded. Color Doppler videos from the renal cortex were recorded. Perfusion in the renal cortex was evaluated using a software package which calculates color pixel area and flow velocity, encoded by each pixel inside a region of interest of a video sequence. The software calculates parameters that describe tissue perfusion numerically. Two of these, the perfusion intensity and tissue pulsatility index, were compared to grade of interstitial fibrosis (0–3) in biopsies. Observer agreement was evaluated in a subset of 12 patients.

Results

Of the 45 patients analyzed, 18 patients had grade 0, 18 had grade 1, seven had grade 2 and two had grade 3 fibrosis. The mean perfusion intensity of grade 0 was significantly higher than that of grade 2 and 3 fibrosis in the proximal cortical layer (1.65 m/s vs. 0.84 m/s, P = 0.008). No significant difference was found between grade 0 and grade 1 fibrosis. Perfusion intensity was correlated to estimated glomerular filtration rate (Pearson r 0.51, P = 0.001, R2 = 0.26 and 0.46, P = 0.001, R2 = 0.22 in the distal and proximal cortex, respectively). Inter-observer agreement of the perfusion intensity, expressed as intraclass correlation coefficient was 0.69 in the proximal part of the cortex. Intra-observer agreement was 0.85 for observer 1 and 0.82 for observer 2.

Conclusion

Perfusion intensity assessed by dynamic color Doppler measurements is significantly reduced in allografts with grade 2 and 3 fibrosis compared to allografts without fibrosis. Further studies involving longitudinal assessment of allografts undergoing protocol biopsies would be of interest.
Isoniazid-induced recurrent acute pancreatitis
Authors: Pandey Arvind S , Surana Ashish
Published: August 2011

Drug-induced acute pancreatitis should be considered in the differential diagnosis of acute abdomen occurring soon after the initiation of antitubercular treatment. Isoniazid-induced pancreatitis is potentially reversible: early recognition and drug withdrawal are warranted in the appropriate clinical setting. We present a case of reversible acute pancreatitis after isoniazid treatment of lymph node tuberculosis, followed by the recurrence of pancreatitis upon the reintroduction of the drug.
Time-Frequency Analysis of Aeroelastic Deflections of Flapping Wings
Authors: Love Robert D. , Lind Rick
Published: August 2011

The flight dynamics of flapping-wing micro air vehicles result from a complicated relationship between aerodynamics and structural dynamics. This relationship has both frequency-domain aspects and time-domain aspects that are each critical. As such, analyzing data from a flapping wing requires techniques that can process information related to both of these domains. This paper introduces wavelet analysis as a tool that determine the frequency content of time-varying deflections. The resulting wavelet map presents a time-frequency domain representation that relates both the time-domain aspects and frequency-domain aspects. Data is analyzed using wavelet processing from a set of wings with different structural dynamics and different flapping parameters whose responses in the vertical and span-wise directions are recorded using digital image correlation. The resulting wavelet maps demonstrate the variations in energy content and temporal distribution associated with the deflections.
Directional Bimodality in Nearshore, Surface Water Wave Energy Spectra, Georgia, USA
Authors: Work Paul A
Published: August 2011

Surface water wave measurements in coastal Georgia, USA are considered. The dataset includes non-directional wave energy spectra measured via pressure transducers at two locations; non-directional, wave buoy-derived observations at a third; and directional wave buoy observations at a fourth, closest to shore. Mean depths at the observation sites range from 14 to 44 m. Measurements of non-directional surface wave energy spectra and the resulting bulk wave parameters (height, period) are compared at the four locations to reveal spatial and temporal variations. Directional characteristics of the waves are investigated at the nearshore site. A new, simple definition for directionally bimodal spectra is proposed and applied. The importance of directional bimodality when considering problems that are sensitive to wave direction, such as longshore sediment transport, is demonstrated. Neglect of directional bimodality via the use of a single mean wave direction can lead to significant errors in computation of longshore sediment transport, and potentially even the incorrect sign on computed quantities.
Wind Speed Prediction by Using Different Wavelet Conjunction Models
Authors: Kisi Ozgur , Shiri Jalal , Makarynskyy Oleg
Published: August 2011

Three wavelet conjunction models, wavelet-genetic programming (WGEP), wavelet-neuro-fuzzy (WNF) and wavelet-neural network (WNN) were introduced in this paper for predicting hourly and daily wind speed values with three lag times. Hourly wind speed measurements from Darwin Airport synoptic station and daily wind speed data from Tabriz Station (North-western Iran) were used as inputs to the wavelet conjunction models to predict 1-, 2- and 3-hour and 1-, 2- and 3-days ahead wind speeds. First, conventional GEP, NF and ANN models were applied to the wind speed time series. Then WGEP, WNF and WANN conjunction models were also used for the same purpose and their results were compared with those of the conventional GEP, NF and ANNs. The correlation coefficient, root mean squared error, scatter index and mean absolute error were used to evaluate the performance of the models. Inter-comparisons of model results indicated that the use of wavelet conjunction models increased the performance of the conventional GEP, ANFIS and ANN in forecasting hourly and daily wind speeds.
Plasticity and diversity of tRNA anticodon determinants of substrate recognition by eukaryotic A37 isopentenyltransferases
Authors: Lamichhane Tek N. , Blewett Nathan H. , Maraia Richard J.
Published: August 2011

The N6-(isopentenyl)adenosine (i6A) modification of some tRNAs at position A37 is found in all kingdoms and facilitates codon-specific mRNA decoding, but occurs in different subsets of tRNAs in different species. Here we examine yeasts' tRNA isopentenyltransferases (i.e., dimethylallyltransferase, DMATase, members of the Δ2-isopentenylpyrophosphate transferase, IPPT superfamily) encoded by tit1+ in Schizosaccharomyces pombe and MOD5 in Saccharomyces cerevisiae, whose homologs are Escherichia coli miaA, the human tumor suppressor TRIT1, and the Caenorhabditis elegans life-span gene product GRO-1. A major determinant of miaA activity is known to be the single-stranded tRNA sequence, A36A37A38, in a stem–loop. tRNATrpCCA from either yeast is a Tit1p substrate, but neither is a Mod5p substrate despite the presence of A36A37A38. We show that Tit1p accommodates a broader range of substrates than Mod5p. tRNATrpCCA is distinct from Mod5p substrates, which we sort into two classes based on the presence of G at position 34 and other elements. A single substitution of C34 to G converts tRNATrpCCA to a Mod5p substrate in vitro and in vivo, consistent with amino acid contacts to G34 in existing Mod5p-tRNACysGCA crystal structures. Mutation of Mod5p in its G34 recognition loop region debilitates it differentially for its G34 (class I) substrates. Multiple alignments reveal that the G34 recognition loop sequence of Mod5p differs significantly from Tit1p, which more resembles human TRIT1 and other DMATases. We show that TRIT1 can also modify tRNATrpCCA consistent with broad recognition similar to Tit1p. This study illustrates previously unappreciated molecular plasticity and biological diversity of the tRNA-isopentenyltransferase system of eukaryotes.
Facile synthesis of nucleoside 5′-(α-P-seleno)-triphosphates and phosphoroselenoate RNA transcription
Authors: Lin Lina , Caton-Williams Julianne , Kaur Manindar , Patino Andres M. , Sheng Jia , Punetha Jaya , Huang Zhen
Published: August 2011

Phosphoroselenoate RNA (PSe-RNA) is nuclease resistant and has great potentials in X-ray crystal structure and function studies of noncoding RNAs and protein–RNA interactions. In order to conveniently synthesize PSe-RNA via transcription, we have developed a one-pot synthetic method for the nucleoside 5′-(α-P-seleno)-triphosphates (NTPαSe) analogs without protecting any functionality of the ribonucleosides. The NTPαSe diastereomers have been purified, fully characterized, and incorporated into RNAs by T7 RNA polymerase. The transcribed RNAs are diastereomerically pure, and the Se-derivatized ribozymes are generally active. Furthermore, we have established an affinity purification strategy by using immobilized boronate to conveniently purify NTPαSe analogs. Though the affinity-purified NTPαSe analogs are diastereomeric mixtures, they can be directly used in transcription without a significant impact on the transcription efficiency. Moreover, we found that the PSe-nucleotide is stable during polyacrylamide gel purification, indicating that the PSe-RNAs can be purified straightforwardly for crystal structural and functional studies.
The crystal structure of an oligo(U):pre-mRNA duplex from a trypanosome RNA editing substrate
Authors: Mooers Blaine H.M. , Singh Amritanshu
Published: August 2011

Guide RNAs bind antiparallel to their target pre-mRNAs to form editing substrates in reaction cycles that insert or delete uridylates (Us) in most mitochondrial transcripts of trypanosomes. The 5′ end of each guide RNA has an anchor sequence that binds to the pre-mRNA by base-pair complementarity. The template sequence in the middle of the guide RNA directs the editing reactions. The 3′ ends of most guide RNAs have ∼15 contiguous Us that bind to the purine-rich unedited pre-mRNA upstream of the editing site. The resulting U-helix is rich in G·U wobble base pairs. To gain insights into the structure of the U-helix, we crystallized 8 bp of the U-helix in one editing substrate for the A6 mRNA of Trypanosoma brucei. The fragment provides three samples of the 5′-AGA-3′/5′-UUU-3′ base-pair triple. The fusion of two identical U-helices head-to-head promoted crystallization. We obtained X-ray diffraction data with a resolution limit of 1.37 Å. The U-helix had low and high twist angles before and after each G·U wobble base pair; this variation was partly due to shearing of the wobble base pairs as revealed in comparisons with a crystal structure of a 16-nt RNA with all Watson–Crick base pairs. Both crystal structures had wider major grooves at the junction between the poly(U) and polypurine tracts. This junction mimics the junction between the template helix and the U-helix in RNA-editing substrates and may be a site of major groove invasion by RNA editing proteins.
Chitosan nanoparticles for tamoxifen delivery and cytotoxicity to MCF-7 and Vero cells
Authors: Ravikumara Neralakere Ramanna , Madhusudhan Basavaraj
Published: August 2011

In this study, tamoxifen citrate-loaded chitosan nanoparticles (tamoxcL-ChtNPs) and tamoxifen citrate-free chitosan nanoparticles (tamoxcF-ChtNPs) were prepared by an ionic gelation (IG) method. The physicochemical properties of the nanoparticles were analyzed for particle size, zeta (ζ) potential, and other characteristics using photon correlation spectroscopy (PCS), zeta phase analysis light scattering (PALS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC). The variation in particle size was assessed by changing the concentration of chitosan, pentasodium tripolyphosphate (TPP), and the pH of the solution. The optimized tamoxcL-ChtNPs showed mean diameter of 187 nm, polydispersity of 0.125, and ζ-potential of +19.1 mV. The encapsulation efficiency (EE) of tamoxifen citrate (tamoxc) increased at higher concentrations, and release of tamoxc from the chitosan matrix displayed controlled biphasic behavior. Those tamoxcL-ChtNPs tested for chemosensitivity showed dose- and time-dependent antiproliferative activity of tamoxc. Further, tamoxcL-ChtNPs were found to be hemocompatible with human red blood cells (RBCs) and safe by in vitro cytotoxicity tests, suggesting that they offer promise as drug delivery systems in therapy.
Relationship of serum fibroblast growth factor 23 with cardiovascular disease in older community-dwelling women
Authors: Dalal Mansi , Sun Kai , Cappola Anne R , Ferrucci Luigi , Crasto Candace , Fried Linda P , Semba Richard D
Published: August 2011

Objective

Although fibroblast growth factor 23 (FGF23) has been implicated in the pathogenesis of cardiovascular disease, the relationship between FGF23 and cardiovascular disease has not been well characterized in the general population. The aim of this study was to determine whether serum FGF23 is independently associated with cardiovascular disease in older community-dwelling women.

Design and methods

A cross-sectional design was used to examine the relationship between serum FGF23 and cardiovascular disease. The subjects consisted of a population-based sample of 659 women, aged 70–79 years, who participated in the Women's Health and Aging Studies in Baltimore, Maryland. Prevalent cardiovascular disease (coronary heart disease, stroke, congestive heart failure, and peripheral artery disease) was assessed through diagnostic algorithms and physician adjudication.

Results

Of the 659 women, 185 (28.1%) had cardiovascular disease. Median (25th, 75th percentile) intact serum FGF23 was 34.6 (25.2, 46.2) pg/ml. The prevalence of cardiovascular disease in the lowest, middle, and highest tertile of serum FGF23 was 22.6, 24.9, and 36.7% respectively (P=0.002). Serum log FGF23 was associated with cardiovascular disease (odds ratio per 1s.d.increase=1.23, 95% confidence interval 1.17, 1.30;P<0.0001) in a multivariable logistic regression model, adjusting for age, race, smoking, education, body mass index, cognition, diabetes, hypertension, physical activity, total cholesterol, high-density lipoprotein cholesterol, and renal function.

Conclusion

Elevated serum FGF23 concentrations are independently associated with prevalent cardiovascular disease in older community-dwelling women. Further studies are needed to elucidate the potential biological mechanisms by which FGF23 may be involved in the pathogenesis of cardiovascular disease.