bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stimulation of regulatory volume increase (RVI) in avian articular chondrocytes by gadolinium chloride
Authors: Ong Sang-Bing , Shah Dinesh , Qusous Ala , Jarvis Simon M. , Kerrigan Mark J.P. 
Published: May 2010

Chondrocytes, the resident cell-type of articular cartilage, are responsible for the regulation of the extracellular matrix (ECM) in response to their physico-chemical environment. Due to the nature of cartilage loading, chondrocytes are exposed to constant changes in extracellular osmolality with a gradual increase throughout the day. As an increase in osmolality attenuates matrix synthesis, we have studied cell volume regulation (regulatory volume increase (RVI)) after hypertonic challenge and the regulation of RVI by the actin cytoskeleton. Using freshly isolated avian articular chondrocytes, changes in actin organisation were studied by confocal laser scanning microscopy following a 43% increase in extracellular osmolality. Using calcein-loading chondrocytes, the capacity for RVI was determined and the rate of volume recovery (t1/2) mathematically extrapolated. Following an increase in extracellular osmolality there was a significant increase (p < 0.05) in cortical actin, inhibited by the removal of extracellular calcium EGTA or by the addition of 100 µmol·L–1 gadolinium chloride. Most cells exhibited slow RVI (t1/2 = 55.5 ± 5.5 min), whereby inhibition of actin polymerisation by gadolinium chloride or the removal of extracellular calcium significantly increased the rate of volume recovery via a bumetanide-sensitive pathway (t1/2 of 29.6 ± 6.5 min and 13.8 ± 3.1 min, respectively). These data suggest the Na+–K+–2Cl– (NKCC) co-transporter regulated by the actin cytoskeleton is involved in avian chondrocyte RVI.
Plasma membrane subdomain partitioning of Lck in primary human T lymphocytes
Authors: Irles Claudine , Arias-Martinez Joel , Guzmán-Bárcenas José , Ortega Alicia 
Published: May 2010

Uncovering the plasma membrane distribution of tyrosine kinase Lck is crucial to understanding T lymphocyte triggering. Several studies of Lck species partitioning have given contradictory results. We decided to re-address this point by using phospho-specific antibodies to characterize active and inactive Lck partitioning in raft and non-raft membranes from primary human peripheral blood T lymphocytes. We show that most inactive Lck was localized in rafts and was associated with nearly all CD4 coreceptors and its negative regulator Csk in resting cells, while T cell receptor (TCR) engagement promoted a sustained dephosphorylation of inactive Lck. In contrast, active Lck had a more discrete distribution interacting with only a small number of CD4 coreceptors, and the kinase showed a rapid and short phosphorylation after TCR triggering. The differences in distribution and kinetics may be related to T lymphocyte signalling threshold modulation by Lck species and suggest how TCR triggering is first initiated. This study furthers our knowledge of the TCR activation model in primary human T lymphocytes.
Cilostazol attenuates ventricular arrhythmia induction and improves defibrillation efficacy in swine
Authors: Kanlop Natnicha , Shinlapawittayatorn Krekwit , Sungnoon Rattapong , Weerateerangkul Punate , Chattipakorn Siriporn , Chattipakorn Nipon 
Published: May 2010

Previous reports demonstrated that cilostazol, a phosphodiesterase 3 inhibitor, affected cellular electrophysiology and reduced episodes of ventricular fibrillation (VF) in patients with Brugada syndrome. However, its effects on VF induction and defibrillation efficacy have never been investigated. We tested the hypothesis that cilostazol increases the VF threshold (VFT) and decreases the upper limit of vulnerability (ULV) and the defibrillation threshold (DFT). A total of 48 pigs were randomly assigned to defibrillation and VF induction studies. The diastolic pacing threshold (DPT), VFT, ULV, DFT, and effective refractory period were determined before and after the infusion of cilostazol at 6 mg/kg, 3 mg/kg, or vehicle. The DPT was significantly increased after administration of 3 and 6 mg/kg cilostazol. The ULV and DFT were significantly decreased after administration of 6 mg/kg cilostazol only. The ULV in the 6 mg/kg group had 12% lower peak voltage and 25% lower total energy, and the DFT had 13% lower peak voltage and 25% lower total energy. The VFT was not altered in any experimental group. This study shows that cilostazol administration significantly increased the DPT, which was associated with significantly reduced DFT and ULV.
Effects of genistein and daidzein on erythrocyte membrane fluidity: an electron paramagnetic resonance study
Authors: Ajdžanović Vladimir , Spasojević Ivan , Filipović Branko , Šošić-Jurjević Branka , Sekulić Milka , Milošević Verica 
Published: May 2010

The maintenance of erythrocyte membrane fluidity at the physiological level is an important factor affecting the ability of erythrocytes to pass through blood vessels of small luminal diameter. Genistein and daidzein, which are used as alternative therapeutics in cardiovascular conditions, can be incorporated into the cell membrane and change its fluidity. The aim of this study was to examine the effects of genistein and daidzein on erythrocyte membrane fluidity at graded depths. We used electron paramagnetic resonance (EPR) spectroscopy and fatty acid spin probes (5-DS and 12-DS) where EPR spectra were dependent on fluidity. The results showed that genistein significantly (p < 0.05) decreased erythrocyte membrane fluidity near the hydrophilic surface, while daidzein significantly (p < 0.05) increased the same parameter in deeper regions of the membrane. These data suggest that the deep fluidizing effects of daidzein on erythrocyte membranes make it a better therapeutic choice than genistein in some cardiovascular conditions.
Association of Left Atrial Endothelin-1 With Atrial Rhythm, Size, and Fibrosis in Patients With Structural Heart Disease
Authors: Mayyas Fadia , Niebauer Mark , Zurick Andrew , Barnard John , Gillinov A. Marc , Chung Mina K. , Van Wagoner David R. 
Published: May 2010

Background—
Atrial fibrillation (AF) promotes atrial remodeling and can develop secondary to heart failure or mitral valve disease. Cardiac endothelin-1 (ET-1) expression responds to wall stress and can promote myocyte hypertrophy and interstitial fibrosis. We tested the hypothesis that atrial ET-1 is elevated in AF and is associated with AF persistence.

Methods and Results—
Left atrial appendage tissue was studied from coronary artery bypass graft, valve repair, and/or Maze procedure in patients in sinus rhythm with no history of AF (SR, n=21), with history of AF but in SR at surgery (AF/SR, n=23), and in AF at surgery (AF/AF, n=32). The correlation of LA size with atrial protein and mRNA expression of ET-1 and ET-1 receptors (ETAR and ETBR)was evaluated. LA appendage ET-1 content was higher in AF/AF than in SR, but receptor levels were similar. Immunostaining revealed that ET-1 and its receptors were present both in atrial myocytes and in fibroblasts. ET-1 content was positively correlated with LA size, heart failure, AF persistence, and severity of mitral regurgitation. Multivariate analysis confirmed associations of ET-1 with AF, hypertension, and LA size. LA size was associated with ET-1 and MR severity. ET-1 mRNA levels were correlated with genes involved in cardiac dilatation, hypertrophy, and fibrosis.

Conclusions—
Elevated atrial ET-1 content is associated with increased LA size, AF rhythm, hypertension, and heart failure. ET-1 is associated with atrial dilatation, fibrosis, and hypertrophy and probably contributes to AF persistence. Interventions that reduce atrial ET-1 expression and/or block its receptors may slow AF progression.
Myocardial Infarction Does Not Preclude Electrical and Hemodynamic Benefits of Cardiac Resynchronization Therapy in Dyssynchronous Canine Hearts
Authors: Rademakers Leonard M. , van Kerckhoven Roeland , van Deursen Caroline J.M. , Strik Marc , van Hunnik Arne , Kuiper Marion , Lampert Anniek , Klersy Catherine , Leyva Francisco , Auricchio Angelo , Maessen Jos G. , Prinzen Frits W. 
Published: May 2010

Background—
Several studies suggest that patients with ischemic cardiomyopathy benefit less from cardiac resynchronization therapy. In a novel animal model of dyssynchronous ischemic cardiomyopathy, we investigated the extent to which the presence of infarction influences the short-term efficacy of cardiac resynchronization therapy.

Methods and Results—

Experiments were performed in canine hearts with left bundle branch block (LBBB, n=19) and chronic myocardial infarction, created by embolization of the left anterior descending or left circumflex arteries followed by LBBB (LBBB+left anterior descending infarction [LADi; n=11] and LBBB+left circumflex infarction [LCXi; n=7], respectively). Pacing leads were positioned in the right atrium and right ventricle and at 8 sites on the left ventricular (LV) free wall. LV pump function was measured using the conductance catheter technique, and synchrony of electrical activation was measured using epicardial mapping and ECG. Average and maximal improvement in electric resynchronization and LV pump function by right ventricular+LV pacing was similar in the 3 groups; however, the site of optimal electrical and mechanical benefit was LV apical in LBBB hearts, LV midlateral in LBBB+LCXi hearts and LV basal-lateral in LBBB+LADi hearts. The best site of pacing was not the site of latest electrical activation but that providing the largest shortening of the QRS complex. During single-site LV pacing the range of atrioventricular delays yielding ≥70% of maximal hemodynamic effect was approximately 50% smaller in infarcted than noninfarcted LBBB hearts (
P
<0.05).

Conclusions—
Cardiac resynchronization therapy can improve resynchronization and LV pump function to a similar degree in infarcted and noninfarcted hearts. Optimal lead positioning and timing of LV stimulation, however, require more attention in the infarcted hearts.
Reduced End-Systolic Pressure-Volume Ratio Response to Exercise
Authors: Jellis Christine L. , Jenkins Carly , Leano Rodel , Martin Jennifer H. , Marwick Thomas H. 
Published: May 2010

Background—
Limitations in the predictive value of negative exercise echocardiography in type 2 diabetes mellitus has been linked to a reduced end-systolic pressure-volume response (ESPVR). We sought whether abnormal ESPVR reflected subclinical diabetic heart disease by examining the association between the ESPVR and markers of myocardial dysfunction and to establish if the change (Δ) or peak systolic blood pressure/end-systolic left ventricular volume ratio (SP/ESV) is a better marker of contractile reserve in type 2 diabetes mellitus.

Methods and Results—

Resting and exercise echocardiography was performed in 167 apparently healthy patients with type 2 diabetes mellitus (97 men; age, 55±10 years) without ischemia, other cardiac disease, or noncardiac complications of diabetes. Standard echocardiographic and color tissue Doppler measures (early diastolic tissue velocity, strain, and strain rate) were acquired at baseline and peak stress in apical long-axis views. Calibrated integrated backscatter was calculated from a resting parasternal long-axis view. ΔSP/ESV was calculated as [(peak stress SP/ESV)−(rest SP/ESV)]. The 83 subjects who demonstrated a ΔSP/ESV ≤12 mm Hg/mL/m
2
after exercise were older and had lower peak heart rate, resting diastolic and stress systolic tissue velocity, stress ejection fraction, and exercise capacity than the remainder. There was no significant association between ΔSP/ESV and metabolic derangement or echocardiographic measures of deformation or backscatter. Change in Sm and stress ejection fraction were independent correlates of ΔSP/ESV.

Conclusions—
ΔSP/ESV ratio is associated with established features of subclinical diabetic heart disease as well as determinants of contractile reserve (peak hemodynamic response and stress systolic function). Peak ESPVR is poorly associated with markers of myocardial dysfunction.
Powdery mildew fungal effector candidates share N-terminal Y/F/WxC-motif
Authors: Godfrey Dale , Böhlenius Henrik , Pedersen Carsten , Zhang Ziguo , Emmersen Jeppe , Thordal-Christensen Hans 
Published: May 2010

AbstractBackgroundPowdery mildew and rust fungi are widespread, serious pathogens that depend on developing haustoria in the living plant cells. Haustoria are separated from the host cytoplasm by a plant cell-derived extrahaustorial membrane. They secrete effector proteins, some of which are subsequently transferred across this membrane to the plant cell to suppress defense.ResultsIn a cDNA library from barley epidermis containing powdery mildew haustoria, two-thirds of the sequenced ESTs were fungal and represented ~3,000 genes. Many of the most highly expressed genes encoded small proteins with N-terminal signal peptides. While these proteins are novel and poorly related, they do share a three-amino acid motif, which we named "Y/F/WxC", in the N-terminal of the mature proteins. The first amino acid of this motif is aromatic: tyrosine, phenylalanine or tryptophan, and the last is always cysteine. In total, we identified 107 such proteins, for which the ESTs represent 19% of the fungal clones in our library, suggesting fundamental roles in haustoria function. While overall sequence similarity between the powdery mildew Y/F/WxC-proteins is low, they do have a highly similar exon-intron structure, suggesting they have a common origin. Interestingly, searches of public fungal genome and EST databases revealed that haustoria-producing rust fungi also encode large numbers of novel, short proteins with signal peptides and the Y/F/WxC-motif. No significant numbers of such proteins were identified from genome and EST sequences from either fungi which do not produce haustoria or from haustoria-producing Oomycetes.ConclusionIn total, we identified 107, 178 and 57 such Y/F/WxC-proteins from the barley powdery mildew, the wheat stem rust and the wheat leaf rust fungi, respectively. All together, our findings suggest the Y/F/WxC-proteins to be a new class of effectors from haustoria-producing pathogenic fungi.
The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant
Authors: Zhao Zhi-Gang , Du Guo-Zhen , Huang Shuang-Quan 
Published: May 2010

Abstract

Background
Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module) in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb Aconitum gymnandrum (Ranunculaceae).

Results
We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers), showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position.

Conclusions
This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites.
Seroprevalence of Bartonella in Eastern China and analysis of risk factors
Authors: Sun Jimin , Fu Guiming , Lin Junfen , Song Xiuping , Lu Liang , Liu Qiyong 
Published: May 2010

Abstract

Background

Bartonella infections are emerging in the Zhejiang Province of China. However, there has been no effort to date to explore the epidemiology of these infections in this region, nor to identify risk factors associated with exposure to Bartonella. The aim of this study was to investigate the seroprevalence of Bartonella in both patients bitten by dogs and blood donors (for control) in Eastern China, and to identify risk factors associated with exposure to Bartonella. As no previous data for this region have been published, this study will provide baseline data useful for Bartonella infection surveillance, control, and prevention.

Methods
Blood samples were collected from industrial rabies clinic attendees and blood donors living in eight areas of the Zhejiang Province of China, between December 2005 and November 2006. An indirect immunofluorescent antibody test was used to determine the presence of Bartonella in these samples. Risk factors associated with Bartonella exposure were explored using Chi-square tests and logistic regression analysis of epidemiological data relating to the study's participants.

Results

Bartonella antibodies were detected in 19.60% (109/556) of blood samples. Seroprevalence varied among the eight areas surveys, ranging from over 32% in Hangzhou to only 2% in Jiangshan (X2 = 28.22, P < 0.001). We detected a significantly higher prevalence of Bartonella antibodies in people who had been bitten by dogs than in blood donors (X2 = 13.86, P < 0.001). Seroprevalence of Bartonella was similar among males (18.61%, n = 317) and females (20.92%, n = 239).

Conclusions

Bartonella antibodies were encountered in people living across Zhejiang Province and the seropositivity rate among those exposed to dog bites was significantly higher than that among blood donors, indicating that dog bites may be a risk factor for Bartonella infection.
Improving capacity for evidence-based practice in South East Asia: evaluating the role of research fellowships in the SEA-ORCHID Project
Authors: Short Jacki , McDonald Steve , Turner Tari , Martis Ruth ,   the SEA-ORCHID Study Group
Published: May 2010

Abstract

Background
Fellowships are a component of many professional education programs. They provide opportunities to develop skills and competencies in an environment where time is protected and resources and technical support are more readily available. The SEA-ORCHID fellowships program aimed to increase capacity for evidence-based practice and research synthesis, and to encourage fellows to become leaders in these areas.

Methods
Fellows included doctors, nurses, midwives and librarians working in the maternal and neonatal areas of nine hospitals in South East Asia. Fellowships were undertaken in Australia and involved specific outputs related to evidence-based practice or research synthesis. Training and support was tailored according to the type of output and the fellow's experience and expertise. We evaluated the fellowships program quantitatively and qualitatively through written evaluations, interviews and follow-up of fellowship activities.

Results
During 2006-07, 23 fellows from Thailand, Indonesia, Malaysia and the Philippines undertook short-term fellowships (median four weeks) in Australia. The main outputs were drafts of Cochrane systematic reviews, clinical practice guidelines and protocols for randomised trials, and training materials to support evidence-based practice. Protocols for Cochrane systematic reviews were more likely to be completed than other outcomes. The fellows identified several components that were critical to the program's overall success; these included protected time, tailored training, and access to technical expertise and resources. On returning home, fellows identified a lack of time and limited access to the internet and evidence-based resources as barriers to completing their outputs. The support of colleagues and senior staff was noted as an important enabler of progress, and research collaborators from other institutions and countries were also important sources of support.

Conclusions
The SEA-ORCHID fellowships program provided protected time to work on an output which would facilitate evidence-based practice. While the fellows faced substantial barriers to completing their fellowship outputs once they returned home, these fellowships resulted in a greater understanding, enthusiasm and skills for evidence-based practice. The experience of the SEA-ORCHID fellowships program may be useful for other initiatives aiming to build capacity in evidence-based practice.
Novel approach of high cell density recombinant bioprocess development: Optimisation and scale-up from microlitre to pilot scales while maintaining the fed-batch cultivation mode of E. coli cultures
Authors: Šiurkus Juozas , Panula-Perälä Johanna , Horn Uwe , Kraft Mario , Rimšeliene Renata , Neubauer Peter 
Published: May 2010

AbstractBackgroundBioprocess development of recombinant proteins is time consuming and laborious as many factors influence the accumulation of the product in the soluble and active form. Currently, in most cases the developmental line is characterised by a screening stage which is performed under batch conditions followed by the development of the fed-batch process. Performing the screening already under fed-batch conditions would limit the amount of work and guarantee that the selected favoured conditions also work in the production scale.ResultsHere, for the first time, high throughput multifactorial screening of a cloning library is combined with the fed-batch technique in 96-well plates, and a strategy is directly derived for scaling to bioreactor scale. At the example of a difficult to express protein, an RNase inhibitor, it is demonstrated that screening of various vector constructs and growth conditions can be performed in a coherent line by (i) applying a vector library with promoters and ribosome binding sites of different strength and various fusion partners together with (ii) an early stage use of the fed-batch technology. It is shown that the EnBase®technology provides an easy solution for controlled cultivation conditions in the microwell scale. Additionally the high cell densities obtained provide material for various analyses from the small culture volumes. Crucial factors for a high yield of the target protein in the actual case were (i) the fusion partner, (ii) the use of of a mineral salt medium together with the fed-batch technique, and (iii) the preinduction growth rate. Finally, it is shown that the favorable conditions selected in the microwell plate and shake flask scales also work in the bioreactor.ConclusionsCultivation media and culture conditions have a major impact on the success of a screening procedure. Therefore the application of controlled cultivation conditions is pivotal. The consequent use of fed-batch conditons from the first screening phase not only shortens the developmental line by guarantying that the selected conditions are relevant for the scale up, but in our case also standard batch cultures failed to select the right clone or conditions at all.