bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered ion transport by thyroid epithelia from CFTR−/− pigs suggests mechanisms for hypothyroidism in cystic fibrosis
Authors: Li Hui , Ganta Suhasini , Fong Peying
Published: August 2010

Subclinical hypothyroidism has been linked to cystic fibrosis, and the cystic fibrosis transmembrane conductance regulator (CFTR) shown to be expressed in the thyroid. The thyroid epithelium secretes Cl− and absorbs Na+ in response to cAMP. Chloride secretion may provide a counter‐ion for the SLC26A4 (pendrin)‐mediated I− secretion which is required for the first step of thyroid hormonogenesis, thyroglobulin iodination. In contrast, few models exist to explain a role for Na+ absorption. Whether CFTR mediates the secretory Cl− current in thyroid epithelium has not been directly addressed. We used thyroids from a novel pig CFTR−/− model, generated primary pig thyroid epithelial cell cultures (pThECs), analysed these cultures for preservation of thyroid‐specific transcripts and proteins, and monitored the following parameters: (1) the Cl− secretory response to the cAMP agonist, isoprenaline; and (2) the amiloride‐sensitive Na+ current. Baseline short‐circuit current (Isc) did not differ between CFTR+/+ and CFTR−/− cultures. Serosal isoprenaline increased Isc in CFTR+/+, but not CFTR−/−, monolayers. Compared with CFTR+/+ thyroid cultures, amiloride‐sensitive Na+ absorption measured in CFTR−/− pThECs represented a greater fraction of the resting Isc. However, levels of transcripts encoding epithelial sodium channel (ENaC) subunits did not differ between CFTR+/+ and CFTR−/− pThECs. Immunoblot analysis verified ENaC subunit protein expression, but quantification indicated no difference in expression levels. Our studies definitively demonstrate that CFTR mediates cAMP‐stimulated Cl− secretion in a well‐differentiated thyroid culture model and that knockout of CFTR promotes increased Na+ absorption by a mechanism other than increased ENaC expression. These findings suggest several models for the mechanism of cystic fibrosis‐associated hypothyroidism.
Randomly Amplified Polymorphic DNA Reveals Tight Links between Viruses and Microbes in the Bathypelagic Zone of the Northwestern Mediterranean Sea
Authors: Winter Christian , Weinbauer Markus G.
Published: August 2010

The study site located in the Mediterranean Sea was visited eight times in 2005 and 2006 to collect samples from the epipelagic (5 m), mesopelagic (200 m, 600 m), and bathypelagic (1,000 m, 2,000 m) zones. Randomly amplified polymorphic DNA PCR (RAPD-PCR) analysis was used to obtain fingerprints from microbial and viral size fractions using two different primers each. Depending on the primer used, the number of bands in the water column varied between 12 to 24 and 6 to 19 for the microbial size fraction and between 16 to 26 and 8 to 22 for the viral size fraction. The majority of sequences from the microbial fraction was related to
Alphaproteobacteria
,
Cyanobacteria
,
Gammaproteobacteria
,
Firmicutes
, and
Eukaryota
. Only 9% of sequences obtained from the viral fraction were of identifiable viral origin; however, 76% of sequences had no close relatives in the nr database of GenBank. Only 20.1% of complete phage genomes tested
in silico
resulted in potential RAPD-PCR products, and only 12% of these were targeted by both primers. Also,
in silico
analysis indicated that RAPD-PCR profiles obtained by the two different primers are largely representative of two different subsets of the viral community. Also, correlation analyses and Mantel tests indicate that the links between changes in the microbial and viral community were strongest in the bathypelagic. Thus, these results suggest a strong codevelopment of virus and host communities in deep waters. The data also indicate that virus communities in the bathypelagic zone can exhibit substantial temporal dynamics.
Characterization of
Thermobifida fusca
Cutinase-Carbohydrate-Binding Module Fusion Proteins and Their Potential Application in Bioscouring
Authors: Zhang Yao , Chen Sheng , Xu Meng , Cavoco-Paulo Artur , Wu Jing , Chen Jian
Published: August 2010

Cutinase from
Thermobifida fusca
is thermally stable and has potential application in the bioscouring of cotton in the textile industry. In the present study, the carbohydrate-binding modules (CBMs) from
T. fusca
cellulase Cel6A (CBM
Cel6A
) and
Cellulomonas fimi
cellulase CenA (CBM
CenA
) were fused, separately, to the carboxyl terminus of
T. fusca
cutinase. Both fusion enzymes, cutinase-CBM
Cel6A
and cutinase-CBM
CenA
, were expressed in
Escherichia coli
and purified to homogeneity. Enzyme characterization showed that both displayed similar catalytic properties and pH stabilities in response to
T. fusca
cutinase. In addition, both fusion proteins displayed an activity half-life of 53 h at their optimal temperature of 50°C. Compared to
T. fusca
cutinase, in the absence of pectinase, the binding activity on cotton fiber was enhanced by 2% for cutinase-CBM
Cel6A
and by 28% for cutinase-CBM
CenA
, whereas in the presence of pectinase, the binding activity was enhanced by 40% for the former and 45% for the latter. Notably, a dramatic increase of up to 3-fold was observed in the amount of released fatty acids from cotton fiber by both cutinase-CBM fusion proteins when acting in concert with pectinase. This is the first report of improving the scouring efficiency of cutinase by fusing it with CBM. The improvement in activity and the strong synergistic effect between the fusion proteins and pectinase suggest that they may have better applications in textile bioscouring than the native cutinase.
Curli Produced by
Escherichia coli
PHL628 Provide Protection from Hg(II)
Authors: Hidalgo Gabriela , Chen Xincai , Hay Anthony G. , Lion Leonard W.
Published: August 2010

The role of curli, amyloid extracellular fibers, in the tolerance of
Escherichia coli
PHL628 to Hg(II) was examined. Our findings indicate that by sorbing Hg(II) extracellularly, curli protect the cells. To our knowledge, this is the first time a protective role of curli against toxic metals has been demonstrated.
Prm1 Targeting to Contact Sites Enhances Fusion during Mating in Saccharomyces cerevisiae
Authors: Olmo Valerie N. , Grote Eric
Published: August 2010

Prm1 is a pheromone-regulated membrane glycoprotein involved in the plasma membrane fusion event of
Saccharomyces cerevisiae
mating. Although this function suggests that Prm1 should act at contact sites in pairs of mating yeast cells where plasma membrane fusion occurs, only a small percentage of the total Prm1 was actually detected on the plasma membrane. We therefore investigated the intracellular transport of Prm1 and how this transport contributes to cell fusion. Two Prm1 chimeras that were sorted away from the contact site had reduced fusion activity, indicating that Prm1 indeed functions at contact sites. However, most Prm1 is located in endosomes and other cytoplasmic organelles and is targeted to vacuoles for degradation. Mutations in a putative endocytosis signal in a cytoplasmic loop partially stabilized the Prm1 protein and caused it to accumulate on the plasma membrane, but this endocytosis mutant actually had reduced mating activity. When Prm1 was expressed from a galactose-regulated promoter and its synthesis was repressed at the start of mating, vanishingly small amounts of Prm1 protein remained at the time when the plasma membranes came into contact. Nevertheless, this stable pool of Prm1 was retained at polarized sites on the plasma membrane and was sufficient to promote plasma membrane fusion. Thus, the amount of Prm1 expressed in mating yeast is far in excess of the amount required to facilitate fusion.
The bZIP Transcription Factor MeaB Mediates Nitrogen Metabolite Repression at Specific Loci
Authors: Wagner Dominik , Schmeinck Anne , Mos Magdalena , Morozov Igor Y. , Caddick Mark X. , Tudzynski Bettina
Published: August 2010

InFusarium fujikuroi, bikaverin (BIK) biosynthesis is subject to repression by nitrogen. Unlike most genes subject to nitrogen metabolite repression, it has been shown that transcription ofbikbiosynthetic genes is not AreA dependent. Searching for additional transcription factors that may be involved in nitrogen regulation, we cloned and characterized the orthologue ofAspergillus nidulansmeaB, which encodes a bZIP transcription factor. Two transcripts are derived fromF. fujikuroimeaB: the large transcript (meaBL) predominates under nitrogen-sufficient conditions and the smaller transcript (meaBS) under nitrogen limitation, in an AreA-dependent manner. MeaB is specifically translocated to the nucleus under nitrogen-sufficient conditions in bothF. fujikuroiandA. nidulans. Deletion ofmeaBresulted in partial upregulation of several nitrogen-regulated genes, but only in the ΔmeaBΔareAdouble mutant were the bikaverin genes significantly upregulated in the presence of glutamine. These data demonstrate that MeaB and AreA coordinately mediate nitrogen metabolite repression and, importantly, that independently of AreA, MeaB can mediate nitrogen metabolite repression at specific loci inF. fujikuroi.
Roles of Multiple Acetoacetyl Coenzyme A Reductases in Polyhydroxybutyrate Biosynthesis in
Ralstonia eutropha
H16
Authors: Budde Charles F. , Mahan Alison E. , Lu Jingnan , Rha ChoKyun , Sinskey Anthony J.
Published: August 2010

The bacterium
Ralstonia eutropha
H16 synthesizes polyhydroxybutyrate (PHB) from acetyl coenzyme A (acetyl-CoA) through reactions catalyzed by a β-ketothiolase (PhaA), an acetoacetyl-CoA reductase (PhaB), and a polyhydroxyalkanoate synthase (PhaC). An operon of three genes encoding these enzymatic steps was discovered in
R. eutropha
and has been well studied. Sequencing and analysis of the
R. eutropha
genome revealed putative isologs for each of the PHB biosynthetic genes, many of which had never been characterized. In addition to the previously identified
phaB1
gene, the genome contains the isologs
phaB2
and
phaB3
as well as 15 other potential acetoacetyl-CoA reductases. We have investigated the roles of the three
phaB
isologs by deleting them from the genome individually and in combination. It was discovered that the gene products of both
phaB1
and
phaB3
contribute to PHB biosynthesis in fructose minimal medium but that in plant oil minimal medium and rich medium,
phaB3
seems to be unexpressed. This raises interesting questions concerning the regulation of
phaB3
expression. Deletion of the gene
phaB2
did not result in an observable phenotype under the conditions tested, although this gene does encode an active reductase. Addition of the individual reductase genes to the genome of the Δ
phaB1
Δ
phaB2
Δ
phaB3
strain restored PHB production, and in the course of our complementation experiments, we serendipitously created a PHB-hyperproducing mutant. Measurement of the PhaB and PhaA activities of the mutant strains indicated that the thiolase reaction is the limiting step in PHB biosynthesis in
R. eutropha
H16 during nitrogen-limited growth on fructose.
Molecular Basis of Vancomycin Dependence in VanA-Type
Staphylococcus aureus
VRSA-9
Authors: Meziane-Cherif Djalal , Saul Frederick A. , Moubareck Carole , Weber Patrick , Haouz Ahmed , Courvalin Patrice , Périchon Bruno
Published: August 2010

The vancomycin-resistant
Staphylococcus aureus
VRSA-9 clinical isolate was partially dependent on glycopeptide for growth. The responsible
vanA
operon had the same organization as that of Tn
1546
and was located on a plasmid. The chromosomal
d
-Ala:
d
-Ala ligase (
ddl
) gene had two point mutations that led to Q260K and A283E substitutions, resulting in a 200-fold decrease in enzymatic activity compared to that of the wild-type strain VRSA-6. To gain insight into the mechanism of enzyme impairment, we determined the crystal structure of VRSA-9 Ddl and showed that the A283E mutation induces new ion pair/hydrogen bond interactions, leading to an asymmetric rearrangement of side chains in the dimer interface. The Q260K substitution is located in an exposed external loop and did not induce any significant conformational change. The VRSA-9 strain was susceptible to oxacillin due to synthesis of pentadepsipeptide precursors ending in
d
-alanyl-
d
-lactate which are not substrates for the β-lactam-resistant penicillin binding protein PBP2′. Comparison with the partially vancomycin-dependent VRSA-7, whose Ddl is 5-fold less efficient than that of VRSA-9, indicated that the levels of vancomycin dependence and susceptibility to β-lactams correlate with the degree of Ddl impairment. Ddl drug targeting could therefore be an effective strategy against vancomycin-resistant
S. aureus
.
Genome Sequence of the Solvent-Producing Bacterium
Clostridium carboxidivorans
Strain P7
T
Authors: Paul Debarati , Austin Frank W. , Arick Tony , Bridges Susan M. , Burgess Shane C. , Dandass Yoginder S. , Lawrence Mark L.
Published: August 2010

Clostridium carboxidivorans
strain P7
T
is a strictly anaerobic acetogenic bacterium that produces acetate, ethanol, butanol, and butyrate. The
C. carboxidivorans
genome contains all the genes for the carbonyl branch of the Wood-Ljungdahl pathway for CO
2
fixation, and it encodes enzymes for conversion of acetyl coenzyme A into butanol and butyrate.
Complete Genome Sequence of
Staphylococcus aureus
Strain JKD6159, a Unique Australian Clone of ST93-IV Community Methicillin-Resistant
Staphylococcus aureus
Authors: Chua Kyra , Seemann Torsten , Harrison Paul F. , Davies John K. , Coutts Scott J. , Chen Honglei , Haring Volker , Moore Robert , Howden Benjamin P. , Stinear Timothy P.
Published: August 2010

Community methicillin-resistant
Staphylococcus aureus
(cMRSA) is an emerging issue that has resulted in multiple worldwide epidemics. We report the first complete genome sequence of an ST93-MRSA-IV clinical isolate that caused severe invasive infection and a familial outbreak of skin infection. This isolate is a representative of the most common Australian clone of cMRSA that is more distantly related to the previously sequenced genomes of
S. aureus.
Altered in vivo left ventricular torsion and principal strains in hypothyroid rats
Authors: Chen Yong , Somji Aleefia , Yu Xin , Stelzer Julian E.
Published: August 2010

The twisting and untwisting motions of the left ventricle (LV) lead to efficient ejection of blood during systole and filling of the ventricle during diastole. Global LV mechanical performance is dependent on the contractile properties of cardiac myocytes; however, it is not known how changes in contractile protein expression affect the pattern and timing of LV rotation. At the myofilament level, contractile performance is largely dependent on the isoforms of myosin heavy chain (MHC) that are expressed. Therefore, in this study, we used MRI to examine the in vivo mechanical consequences of altered MHC isoform expression by comparing the contractile properties of hypothyroid rats, which expressed only the slow β-MHC isoform, and euthyroid rats, which predominantly expressed the fast α-MHC isoform. Unloaded shortening velocity ( Vo) and apparent rate constants of force development ( ktr) were measured in the skinned ventricular myocardium isolated from euthyroid and hypothyroid hearts. Increased expression of β-MHC reduced LV torsion and fiber strain and delayed the development of peak torsion and strain during systole. Depressed in vivo mechanical performance in hypothyroid rats was related to slowed cross-bridge performance, as indicated by significantly slower Vo and ktr, compared with euthyroid rats. Dobutamine infusion in hypothyroid hearts produced smaller increases in torsion and strain and aberrant transmural torsion patterns, suggesting that the myocardial response to β-adrenergic stress is compromised. Thus, increased expression of β-MHC alters the pattern and decreases the magnitude of LV rotation, contributing to reduced mechanical performance during systole, especially in conditions of increased workload.
Defining new insight into atypical arrhythmia: a computational model of ankyrin-B syndrome
Authors: Wolf Roseanne M. , Mitchell Colleen C. , Christensen Matthew D. , Mohler Peter J. , Hund Thomas J.
Published: August 2010

Normal cardiac excitability depends on the coordinated activity of specific ion channels and transporters within specialized domains at the plasma membrane and sarcoplasmic reticulum. Ion channel dysfunction due to congenital or acquired defects has been linked to human cardiac arrhythmia. More recently, defects in ion channel-associated proteins have been associated with arrhythmia. Ankyrin-B is a multifunctional adapter protein responsible for targeting select ion channels, transporters, cytoskeletal proteins, and signaling molecules in excitable cells, including neurons, pancreatic β-cells, and cardiomyocytes. Ankyrin-B dysfunction has been linked to cardiac arrhythmia in human patients and ankyrin-B heterozygous (ankyrin-B+/−) mice with a phenotype characterized by sinus node dysfunction, susceptibility to ventricular arrhythmias, and sudden death (“ankyrin-B syndrome”). At the cellular level, ankyrin-B+/− cells have defects in the expression and membrane localization of the Na+/Ca2+ exchanger and Na+-K+-ATPase, Ca2+ overload, and frequent afterdepolarizations, which likely serve as triggers for lethal cardiac arrhythmias. Despite knowledge gathered from mouse models and human patients, the molecular mechanism responsible for cardiac arrhythmias in the setting of ankyrin-B dysfunction remains unclear. Here, we use mathematical modeling to provide new insights into the cellular pathways responsible for Ca2+ overload and afterdepolarizations in ankyrin-B+/− cells. We show that the Na+/Ca2+ exchanger and Na+-K+-ATPase play related, yet distinct, roles in intracellular Ca2+ accumulation, sarcoplasmic reticulum Ca2+ overload, and afterdepolarization generation in ankyrin-B+/− cells. These findings provide important insights into the molecular mechanisms underlying a human disease and are relevant for acquired human arrhythmia, where ankyrin-B dysfunction has recently been identified.
Upregulation of eNOS and unchanged energy metabolism in increased susceptibility of the aging type 2 diabetic GK rat heart to ischemic injury
Authors: Desrois Martine , Clarke Kieran , Lan Carole , Dalmasso Christiane , Cole Mark , Portha Bernard , Cozzone Patrick J. , Bernard Monique
Published: August 2010

We investigated the tolerance of the insulin-resistant diabetic heart to ischemic injury in the male Goto-Kakizaki (GK) rat, a model of type 2 diabetes. Changes in energy metabolism, nitric oxide (NO) pathway, and cardiac function were assessed in the presence of physiological substrates. Age-matched control Wistar ( n = 19) and GK ( n = 18) isolated rat hearts were perfused with 0.4 mM palmitate, 3% albumin, 11 mM glucose, 3 U/l insulin, 0.2 mM pyruvate, and 0.8 mM lactate for 24 min before switching to 1.2 mM palmitate (11 rats/group) during 32 min low-flow (0.5 ml·min−1·g wet wt−1) ischemia. Next, flow was restored with 0.4 mM palmitate buffer for 32 min. A subset of hearts from each group ( n = 8 for control and n = 7 for GK groups) were freeze-clamped for determining baseline values after the initial perfusion of 24 min. ATP, phosphocreatine (PCr), and intracellular pH (pHi) were followed using31P magnetic resonance spectroscopy with simultaneous measurement of contractile function. The NO pathway was determined by nitric oxide synthase (NOS) isoform expression and total nitrate concentration (NOx) in hearts. We found that coronary flow was 26% lower ( P < 0.05) during baseline conditions and 61% lower ( P < 0.05) during reperfusion in GK vs. control rat hearts. Rate pressure product was lower during reperfusion in GK vs. control rat hearts ( P < 0.05). ATP, PCr, and pHiduring ischemia-reperfusion were similar in both groups. Endothelial NOS expression was increased in GK rat hearts during baseline conditions ( P < 0.05). NOx was increased during baseline conditions ( P < 0.05) and after reperfusion ( P < 0.05) in GK rat hearts. We report increased susceptibility of type 2 diabetic GK rat heart to ischemic injury that is not associated with impaired energy metabolism. Reduced coronary flow, upregulation of eNOS expression, and increased total NOx levels confirm NO pathway modifications in this model, presumably related to increased oxidative stress. Modifications in the NO pathway may play a major role in ischemia-reperfusion injury of the type 2 diabetic GK rat heart.
Antenatally administered PPAR-γ agonist rosiglitazone prevents hyperoxia-induced neonatal rat lung injury
Authors: Rehan Virender K. , Sakurai Reiko , Corral Julia , Krebs Melissa , Ibe Basil , Ihida-Stansbury Kaori , Torday John S.
Published: August 2010

The physiological development and homeostasis of the lung alveolus is determined by the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) by the interstitial lipofibroblast. We have recently shown (Dasgupta C et al., Am J Physiol Lung Cell Mol Physiol 296: L1031–L1041, 2009.) that PPAR-γ agonists administered postnatally accelerate lung maturation and prevent hyperoxia-induced lung injury. However, whether the same occurs antenatally is not known. The objective of this study was to test the hypothesis that the potent PPAR-γ agonist rosiglitazone (RGZ), administered antenatally, enhances fetal lung maturation and protects against hyperoxia-induced neonatal lung injury. Sprague-Dawley rat dams were administered either diluent or RGZ (3 mg/kg), at late gestation, to determine its effect on lung maturation and on hyperoxia (95% O2exposure for 24 h)-induced neonatal lung injury. The lungs were examined for the expression of specific markers of alveolar development (surfactant proteins A and B, cholinephosphate cytidylyltransferase-α, leptin receptor, triglyceride uptake, and [3H]choline incorporation into saturated phosphatidylcholine) and injury/repair, in particular, the markers of transforming growth factor-β signaling (activin receptor-like kinase-5, SMAD3, lymphoid enhancer factor-1, fibronectin, and calponin). Overall, antenatal RGZ accelerated lung maturation and blocked the inhibition of alveolar sacculation and septal wall thinning by hyperoxia. RGZ specifically stimulated the development of the alveolar epithelial type II cell, the lipofibroblast, and the vasculature. The increased expression of the transforming growth factor-β intermediates, such as SMAD3 and lymphoid enhancer factor-1, implicated in hyperoxic lung injury, was also blocked by antenatal RGZ treatment. In conclusion, PPAR-γ agonists can enhance fetal lung maturation and can effectively prevent hyperoxia-induced neonatal lung injury.
Gender influences the response to experimental silica-induced lung fibrosis in mice
Authors: Brass David M. , McGee Sean P. , Dunkel Mary K. , Reilly Sarah M. , Tobolewski Jacob M. , Sabo-Attwood Tara , Fattman Cheryl L.
Published: August 2010

Accumulating evidence suggests that gender can have a profound effect on incidence and severity of a variety of pulmonary diseases. To address the influence of gender on the development of silica-induced pulmonary fibrosis, we instilled 0.2 g/kg silica into male and female C57BL/6 mice and examined the fibrotic and inflammatory response at 14 days postexposure. Both silica-exposed male and female mice had significant increases in total lung hydroxyproline compared with saline controls. However, silica-exposed female mice had significantly less total lung hydroxyproline than silica-exposed male mice. This observation was confirmed by color thresholding image analysis. Interestingly, silica-exposed female mice had significantly more inflammatory cells, the majority of which were macrophages, as well as higher levels of the macrophage-specific chemokines MCP-1 and CCL9 in whole lung lavage compared with silica-exposed male mice. We also show that at baseline, estrogen receptor α (ERα) mRNA expression is lower in female mice than in males and that ERα mRNA expression is decreased by silica exposure. Finally, we show that the response of ovariectomized female mice to silica instillation is similar to that of male mice. These observations together show that gender influences the lung response to silica.
Expression of IL-4/IL-13 receptors in differentiating human airway epithelial cells
Authors: White Steven R. , Martin Linda D. , Stern Randi , Laxman Bharathi , Marroquin Bertha A.
Published: August 2010

IL-4 and IL-13 elicit several important responses in airway epithelium including chemokine secretion and mucous secretion that may contribute to airway inflammation, cell migration, and differentiation. These cytokines have overlapping but not identical effector profiles likely due to shared subunits in their receptor complexes. These receptors are variably described in epithelial cells, and the relative expression, localization, and function of these receptors in differentiated and repairing epithelial cells are not clear. We examined IL-4/IL-13 receptor expression and localization in primary airway epithelial cells collected from normal human lungs and grown under conditions yielding both undifferentiated and differentiated cells inclusive of basal, goblet, and ciliated cell phenotypes. Gene expression of the IL-4Rα, IL-2Rγc, IL-13Rα1, and IL-13Rα2 receptor subunits increased with differentiation, but different patterns of localization and protein abundance were seen for each subunit based on both differentiation and the cell subtypes present. Increased expression of receptor subunits observed in more differentiated cells was associated with more substantial functional responses to IL-4 stimulation including increased eotaxin-3 expression and accelerated migration after injury. We demonstrate substantial differences in IL-4/IL-13 receptor subunit expression and responsiveness to IL-4 based on the extent of airway epithelial cell differentiation and suggest that these differences may have functional consequences in airway inflammation.
Lead Extraction in Pediatric and Congenital Heart Disease Patients
Authors: Cecchin Frank , Atallah Joseph , Walsh Edward P. , Triedman John K. , Alexander Mark E. , Berul Charles I.
Published: August 2010

Background—

Transvenous pacemaker and defibrillator implantation is an expanding practice in pediatric and congenital heart disease patients, and given the finite longevity of current lead designs, lead extraction is an eventuality for a significant subset of these patients. Data on the safety and efficacy of different lead extraction techniques in this specific patient population are limited.

Methods and Results—

We report our experience from a single-center cohort study with a retrospective review of prospectively collected data on all lead extractions performed between January 2002 and December 2008. Lead extraction procedures involved a total of 144 patients and 203 leads. Of these, 61 patients (42%) were female and 86 (60%) had structural heart disease. Successful simple extraction, requiring the use of only a nonlocking stylet, was achieved in 59 (29%) leads. Of the remaining leads, 35 were abandoned and 109 underwent complex extraction techniques, including a radiofrequency-powered sheath used in 78 of 109 leads. Successful extraction was achieved in 80% (162/203) of all leads and 94% (103/109) of leads undergoing a complex extraction. On multivariable analysis, older lead age (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.48 to 0.82;
P
<0.0001), ventricular lead position (OR, 0.40; 95% CI, 0.20 to 0.79;
P
=0.015), and polyurethane insulation (OR, 0.34; 95% CI, 0.14 to 0.80;
P
=0.017) were found to be associated with a decreased likelihood of simple extraction. There were 4 major and 4 minor procedural complications involving 8 patients and no procedure-related deaths. On univariate analysis, lead age (OR, 1.28; 95% CI, 1.09 to 1.50;
P
=0.002) was the only factor associated with procedural complications.

Conclusions—

The majority of leads implanted in pediatric and congenital heart disease patients can be extracted successfully; however, the procedure carries a risk of serious complications. Older lead age, ventricular leads, and polyurethane insulation were independent predictors of the decreased likelihood of an extraction by simple traction.
Genes Within the MHC Region Have a Dramatic Influence on Radiation-Enhanced Atherosclerosis in Mice
Authors: Shi Weibin , Zhang Zhimin , Chen Mei-Hua , Angle John F. , Matsumoto Alan H.
Published: August 2010

Background—

C3H/HeJ (C3H) mice develop much smaller atherosclerotic lesions than C57BL/6 (B6) mice when deficient in apolipoprotein E (apoE
−/−
) or fed an atherogenic diet. The 2 strains differ in H2 haplotypes, with B6 having H2
b
and C3H having H2
k
. C3.SW-H2
b
/SnJ (C3.SW) is a congenic strain of C3H/HeJ in which H2
k
is replaced with H2
b
.

Methods and Results—

We performed bone marrow transplantation and found that atherosclerosis-resistant C3.SW.apoE
−/−
mice reconstituted with bone marrow from either C3.SW.apoE
−/−
or B6.apoE
−/−
mice after lethal irradiation had significantly larger atherosclerotic lesions than B6.apoE
−/−
mice receiving identical treatments and much larger lesions than C3H.apoE
−/−
mice reconstituted with syngeneic bone marrow. For syngeneic transplantation, C3.SW.apoE
−/−
mice exhibited a 21-fold increase in lesion size over C3H.apoE
−/−
mice (152 800±21 937 versus 7060±2290 μm
2
/section) and a near 4-fold increase over B6.apoE
−/−
mice (40 529±4675 μm
2
/section). C3.SW.apoE
−/−
mice reconstituted with syngeneic marrow exhibited enhanced lesion formation relative to those reconstituted with B6 marrow (152 800±21 937 versus 107 000±9374 μm
2
/section;
P
=0.067). Sublethal irradiation led to a 6-fold increase of lesion size in C3.SW.apoE
−/−
mice (9795±2804 versus 1550±607 μm
2
/section;
P
=0.008). Wild-type C3.SW mice reconstituted with apoE
+/+
or apoE
−/−
bone marrow had significantly larger atherosclerotic lesions than C3H mice receiving identical treatments on an atherogenic diet.

Conclusions—

These results indicate that gene(s) within the H2 region have a dramatic impact on radiation-enhanced atherosclerosis, and their effect is conveyed partially through bone marrow–derived cells.
The Effects of Critical Thinking Instruction on Training Complex Decision Making
Authors: Helsdingen Anne S. , van den Bosch Karel , van Gog Tamara , van Merriënboer Jeroen J. G.
Published: August 2010

Objective: Two field studies assessed the effects of critical thinking instruction on training and transfer of a complex decision-making skill.

Background: Critical thinking instruction is based on studies of how experienced decision makers approach complex problems.

Method: Participants conducted scenario-based exercises in both simplified (Study 1) and high-fidelity (Study 2) training environments. In both studies, half of the participants received instruction in critical thinking. The other half conducted the same exercises but without critical thinking instruction. After the training, test scenarios were administered to both groups.

Results: The first study showed that critical thinking instruction enhanced decision outcomes during both training and the test. In the second study, critical thinking instruction benefited both decision outcomes and processes, specifically on the transfer to untrained problems.

Conclusion:The results suggest that critical thinking instruction improves decision strategy and enhances understanding of the general principles of the domain.

Application: The results of this study warrant the implementation of critical thinking instruction in training programs for professional decision makers that have to operate in complex and highly interactive, dynamic environments.
Social Threats, Happiness, and the Dynamics of Meaning in Life Judgments
Authors: Hicks Joshua A. , Schlegel Rebecca J. , King Laura A.
Published: August 2010

Four studies examined social relatedness and positive affect (PA) as alternate sources of information for judgments of meaning in life (MIL). In Studies 1 through 3 (total N = 282), priming loneliness increased reliance on PA and decreased reliance on social functioning in MIL judgments. In Study 4 ( N = 138), daily assessments of PA, relatedness needs satisfaction (RNS), and MIL were obtained every 5 days over 20 days. Multilevel modeling showed that on days when RNS was low, PA was strongly related to MIL. Results suggest the dynamic ways that social relationships and PA inform judgments of MIL. Informational and motivational accounts of these results are discussed.
How Much Information Can Metabolic Syndrome Provide?
Authors: Beckstead Jason W. , Beckie Theresa M.
Published: August 2010

The purpose of this article is to show, using principles from Shannon’s information theory, that it is possible to estimate the amount of information loss that occurs, in relative terms, when multiple continuous biological traits are dichotomized and aggregated, as is the case with many diagnostic definitions. We use metabolic syndrome as a case in point. It is our position that this type of information loss can impede the progress of medical research. This argument will first be made on theoretical grounds and then be supplemented using data from a clinical trial involving 252 women enrolled in cardiac rehabilitation. After laying out relevant principles, we conduct analyses to show how such information loss occurs during data transformation. Our analyses demonstrate that transforming the multiple traits that comprise metabolic syndrome into a single binary indicator discarded over 98% of the potential information contained in the original measurements. We go on to illustrate how such information loss impedes the establishment of meaningful statistical relationships with an indicator of cardiovascular health, time on an exercise tolerance test.
Genotype-Phenotype Correlations in a Group of 15 SCN1A-Mutated Italian Patients with GEFS+ Spectrum (Seizures plus, Classical and Borderline Severe Myoclonic Epilepsy of Infancy)
Authors: Nicita Francesco , Spalice Alberto , Papetti Laura , Ursitti Fabiana , Parisi Pasquale , Gennaro Elena , Zara Federico , Iannetti Paola
Published: August 2010

Mutations in SCN1A gene have been associated with the spectrum of generalized/genetic epilepsy with febrile seizures plus. Recently, databases reporting SCN1A mutations and clinical details of patients have been created to facilitate genotype— phenotype correlations, actually not completely defined, particularly if a specific mutation underlies phenotypes. We report on a group of 15 patients with clinical features of GEFS+ (3), classical (7), or borderline severe myoclonic epilepsy of infancy (5), in whom genetic analysis of patients and parents and follow-up period were performed to establish genotype—phenotype correlations, to enrich literature and databases data. We found 11 pathogenic mutations (5 novel: c.80 G>C exon 1; c.187 T>C exon 1; c.3061 G>T exon 16; c.4297 G>A exon 22; c.5579 delA ins TCTCC exon 26) and 4 novel nucleotidic variants (IVS5+38 C>T intron 5; IVS8-19 C>T intron 18; c.4945 C>T exon 25; c.5127 C>A exon 26). Paternal inheritance was observed in 4/4 cases.
An analysis of modern pollen representation and climatic conditions on the Galápagos Islands
Authors: Collins A. , Bush M.B.
Published: August 2010

In the first modern pollen trapping study conducted in the Galápagos Islands, 58 clusters of pollen traps were established on four islands: Genovesa, Rocas Bainbridge, Santa Cruz, and San Cristobal. HOBO data loggers collected temperature, humidity, and dew point every 30 min for 1 year at eight locations. The trapping locations were selected to provide a wide diversity of Galápagos habitat types and to support active or future analyses from bog and lake core records recovered from the islands. Pollen influx to the traps was generally low (<100 grains/cm 2 per yr), but broad habitat types were clearly identifiable based on the pollen collected. More precise identification of trapping sites and vegetation zones within the islands were identified using ordinations of the pollen and climate data. Long-distance dispersal from the mainland and neighboring islands were found to be significant elements of pollen records, particularly those where local pollen production was low (<150 grains/cm 2 per yr). Over-representation and under-representation of ecological dominants was documented, as was the significant representation of invasive exotic species in some settings. Temperature and relative humidity data were used to reconstruct the presence of ground-level cloud (garúa). Garúa caused substantial cooling, beyond what would be expected from adiabatic lapse rate, in the highlands. The cloud formation associated with garúa caused low-elevation temperatures to be cooler than maximum sea-surface temperatures. The data emphasize the importance of garúa to the endemic flora of the islands and their long-term conservation.
The National DNA Database on trial
Authors: Anderson Claudine , Stackhouse Rebecca , Shaw Anita , Iredale Rachel
Published: August 2010

While there has been research conducted on public views about ethical and social aspects of the National DNA Database (NDNAD), there is little which focuses on views of young people, in particular those whose details are held on the NDNAD. We describe an engagement activity developed in South Wales to engage young offenders with ethical and social issues surrounding the NDNAD – a Mock Trial – and how we facilitated the presentation of their views to policy makers. We discuss the successes and challenges we encountered with engaging young offenders, decisions that the young people reached about possible future policies for the NDNAD at the Mock Trial, and their contribution to the decision-making process.
Visual Storytelling: A Beneficial But Challenging Method for Health Research With Young People
Authors: Drew Sarah E. , Duncan Rony E. , Sawyer Susan M.
Published: August 2010

Visual storytelling is a new research approach drawing on established methods of photovoice and photo elicitation. It appears well suited to research with young people. We explored the feasibility of this approach, reflecting on benefits and challenges encountered while using it during a study of chronic disease self-management in adolescents. During in-depth interviews, 68 participants were questioned about the value of visual storytelling. Thematic analysis was applied. Visual storytelling was valued for (a) being a draw card during recruitment and increasing positive feelings about the research; (b) being fun; (c) promoting self-understanding; and (d) promoting expression, communication, and focus during interviews. Deciding what to photograph was difficult. More time and effort was required by researchers than for a standard qualitative interview study. The technique facilitated rich interviews, drawing into focus details of young peoples’ lives that otherwise might not have been discussed.
Successful clinical trial research in nursing homes: the Improving Decision-Making Study
Authors: Hanson Laura C , Gilliam Robin , Tae Joon Lee
Published: August 2010

Background One in four Americans, and 70% of people who have dementia, will spend their final days in nursing home care. Clinical research, particularly clinical trials, rarely includes this population due to unique challenges in research methods and ethics. Families of advanced dementia patients make choices about tube feeding and other feeding options with limited access to information or communication. The cluster randomized trial, Improving Decision Making about Feeding Options for Dementia Patients, tests a decision aid intervention to improve the quality of decision making for this choice.

Purpose Our objectives are (1) to describe the methods used in this trial; (2) to describe challenges and strategies for effective nursing home and nursing home resident recruitment and retention; and (3) to describe research ethics approaches to minimize harms and maximize benefits for this population.

Methods The study is a cluster randomized trial of a decision aid to inform and support the choice between tube feeding and assisted oral feeding in advanced dementia. Study subjects are paired surrogate decision makers and residents with advanced dementia and feeding problems, enrolled from nursing homes in North Carolina.

Results This trial enrolled 256 paired surrogate decision makers and residents in 24 nursing home sites, and 99% completed participation through the 3-month study period. The research team had prior clinical and investigative experience in this setting, and used multiple strategies to recruit and retain nursing home sites, providers, surrogates, and the residents for whom they spoke. Informed consent and human subjects’ protections were designed to address the vulnerability of this population.

Limitations Cluster randomization was necessary to avoid contamination between control and intervention subjects, but may introduce confounding by site and intracluster correlation effects in analyses.

Conclusions Strategies that facilitate nursing home recruitment, participant recruitment and protection of human subjects for a vulnerable population may be used by future investigators to expand the research evidence base for nursing home and dementia care. Clinical Trials 2010; 7: 735—743. http:// ctj.sagepub.com
Effect of Smoking on the Association Between Environmental Triggers and Asthma Severity Among Adults in New England
Authors: Nguyen Kimberly , Peng Justin , Boulay Eileen
Published: August 2010

To identify environmental triggers associated with asthma severity and the potential modifying effect of cigarette smoke, the authors examined the relationship between sociodemographic characteristics, controller medication use, environmental triggers, and actions taken to reduce triggers on asthma severity among adults (≥18 years) residing in New England using the Behavior Risk Factor Surveillance Survey (BRFSS) Asthma Call-Back data. Asthma severity was categorized as intermittent, mild persistent, moderate persistent, and severe persistent according to the National Asthma Education and Prevention Program guidelines. In weighted logistic regression models, asthma severity was analyzed for 3075 adults with active asthma in Connecticut, Massachusetts, Maine, New Hampshire, and Vermont from 2006 to 2007. The odds of more severe asthma were 1.8 for smokers as compared with nonsmokers (95% confidence interval [CI] = 1.1, 3.1). Among current smokers, the odds of more severe asthma among those who were exposed to wood stoves was 2.4 (95% CI = 1.1, 5.7) as compared with those who were not exposed to wood stoves. Among nonsmokers, those who had a high school education or less (odds ratio [OR] = 2.0, 95% CI = 1.2, 3.3), had some college or technical school education (OR = 2.1, 95% CI = 1.2, 3.7), or had any comorbidity factors such as chronic obstructive pulmonary disease, emphysema, or bronchitis (OR = 2.5, 95% CI = 1.6, 3.8) were significantly associated with more severe asthma. Furthermore, the odds for more severe asthma were 2.1 (95% CI = 1.1, 4.0) among nonsmokers who were exposed to environmental tobacco smoke (ETS) as compared with those who were not exposed to ETS. The effect of environmental triggers on asthma severity differs among smokers and nonsmokers, even after controlling for sociodemographic factors, medication use, and actions taken to reduce triggers. Targeting smokers with asthma and making modifications to the environment may be important for reducing asthma severity among a high-risk population.
Acquired genomic copy number aberrations and survival in adult acute myelogenous leukemia
Authors: Parkin Brian , Erba Harry , Ouillette Peter , Roulston Diane , Purkayastha Anjali , Karp Judith , Talpaz Moshe , Kujawski Lisa , Shakhan Sajid , Li Cheng , Shedden Kerby , Malek Sami N.
Published: August 2010

Genomic aberrations are of predominant importance to the biology and clinical outcome of patients with acute myelogenous leukemia (AML), and conventional karyotype-based risk classifications are routinely used in clinical decision making in AML. One of the known limitations of cytogenetic analysis is the inability to detect genomic abnormalities less than 5 Mb in size, and it is currently unclear whether overcoming this limitation with high-resolution genomic single-nucleotide polymorphism (SNP) array analysis would be clinically relevant. Furthermore, given the heterogeneity of molecular mechanisms/aberrations that underlie the conventional karyotype-based risk classifications, it is likely that further refinements in genomic risk prognostication can be achieved. In this study, we analyzed flow cytometer–sorted, AML blast-derived, and paired, buccal DNA from 114 previously untreated prospectively enrolled AML patients for acquired genomic copy number changes and loss of heterozygosity using Affymetrix SNP 6.0 arrays, and we correlated genomic lesion load and specific chromosomal abnormalities with patient survival. Using multivariate analyses, we found that having ≥ 2 genomic lesions detected through SNP 6.0 array profiling approximately doubles the risk of death when controlling for age- and karyotype-based risk. Finally, we identified an independent negative prognostic impact of p53 mutations, or p53 mutations and 17p-loss of heterozygosity combined on survival in AML.
Down syndrome and GATA1 mutations in transient abnormal myeloproliferative disorder: mutation classes correlate with progression to myeloid leukemia
Authors: Kanezaki Rika , Toki Tsutomu , Terui Kiminori , Xu Gang , Wang RuNan , Shimada Akira , Hama Asahito , Kanegane Hirokazu , Kawakami Kiyoshi , Endo Mikiya , Hasegawa Daisuke , Kogawa Kazuhiro , Adachi Souichi , Ikeda Yasuhiko , Iwamoto Shotaro , Taga Takashi , Kosaka Yoshiyuki , Kojima Seiji , Hayashi Yasuhide , Ito Etsuro
Published: August 2010

Twenty percent to 30% of transient abnormal myelopoiesis (TAM) observed in newborns with Down syndrome (DS) develop myeloid leukemia of DS (ML-DS). Most cases of TAM carry somatic GATA1 mutations resulting in the exclusive expression of a truncated protein (GATA1s). However, there are no reports on the expression levels of GATA1s in TAM blasts, and the risk factors for the progression to ML-DS are unidentified. To test whether the spectrum of transcripts derived from the mutant GATA1 genes affects the expression levels, we classified the mutations according to the types of transcripts, and investigated the modalities of expression by in vitro transfection experiments using GATA1 expression constructs harboring mutations. We show here that the mutations affected the amount of mutant protein. Based on our estimates of GATA1s protein expression, the mutations were classified into GATA1s high and low groups. Phenotypic analyses of 66 TAM patients with GATA1 mutations revealed that GATA1s low mutations were significantly associated with a risk of progression to ML-DS (P < .001) and lower white blood cell counts (P = .004). Our study indicates that quantitative differences in mutant protein levels have significant effects on the phenotype of TAM and warrants further investigation in a prospective study.