bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistin contributes to neointimal formation via oxidative stress after vascular injury
Authors: Shyu Kou-Gi , Lien Li-Ming , Wang Bao-Wei , Kuan Peiliang , Chang Hang
Published: August 2010

Resistin may play a major potential role in vascular remodelling and may contribute to atherogenesis. However, the role of VSMC (vascular smooth muscle cell)-derived resistin in neointimal formation is not well understood. We hypothesize that endogenous resistin derived from VSMCs may contribute to neointimal formation after vascular injury. VSMCs from thoracic aorta of adult Wistar rats were cultured. The carotid artery from adult Wistar rats was injured by balloon catheter. Resistin significantly increased migration and proliferation of VSMCs. Resistin siRNA (small interfering RNA) and resistin antibody significantly inhibited migration and proliferation of VSMCs induced by conditioned medium from stretched VSMCs. Resistin protein and mRNA expression significantly increased at 14 days after carotid injury. Resistin siRNA and NAC (N-acetylcysteine) significantly reduced resistin protein and mRNA expression induced by balloon injury. Carotid artery injury increased ROS (reactive oxygen species) production. Treatment with NAC and resistin siRNA decreased ROS production. The neointimal area was significantly increased after carotid injury and was significantly reduced by resistin siRNA and NAC. In conclusion, resistin increases migration and proliferation of VSMCs, and expression of resistin in carotid artery significantly increases after injury. Resistin siRNA attenuates neointimal formation after carotid injury partly through an antioxidative mechanism. Resistin may play a pivotal role in the pathogenesis of neointimal thickening after mechanical injury.
Spoken Word Recognition in School-Age Children With SLI: Semantic, Phonological, and Repetition Priming
Authors: Velez Melinda , Schwartz Richard G.
Published: August 2010

Purpose

The purpose of this study was to contribute to the current understanding of how children with specific language impairment (SLI) organize their mental lexicons. The study examined semantic and phonological priming in children with and without SLI.

Method

Thirteen children (7;0–11;3 [years;months]) with SLI and 13 age-matched children with typical language development participated in this study. Prime–target pairs (semantic, phonological, and repetition) were embedded within a running list of words so that the actual pairs were imperceptible. Reaction times to an animacy judgment (alive vs. not alive) were analyzed. The experiment featured 500-ms and 1,000-ms interstimulus intervals (ISIs) between primes and targets.

Results

Children with SLI exhibited priming effects in the repetition condition at both ISIs; however, phonological and semantic effects were absent. Typically developing children exhibited effects in the repetition at both ISIs. Semantic and phonological effects were absent at 500 ms ISIs, but present at 1,000 ms ISIs.

Conclusions

Although children with SLI have priming mechanisms similar to those of their age-matched peers, the absence of semantic and phonological priming suggests that these connections are not strong enough by themselves to yield priming effects. These findings are discussed in the context of semantic and phonological priming, representation, and generalized slowing.
A Treatment for Dysprosody in Childhood Apraxia of Speech
Authors: Ballard Kirrie J. , Robin Donald A. , McCabe Patricia , McDonald Jeannie
Published: August 2010

Purpose

Dysprosody is considered a core feature of childhood apraxia of speech (CAS), especially impaired production of lexical stress. Few studies have tested the effects of intervention for dysprosody. This Phase II study with 3 children investigated the efficacy of a treatment targeting improved control of relative syllable durations in 3-syllable nonwords representing strong-weak (SW) and weak-strong (WS) stress patterns (e.g., BAtigu or baTIgu). Treatment sessions were structured along the principles of motor learning (PML) approach.

Method

Three children, age 7 to 10 years, with mild to moderate CAS and normal language development participated in an intensive 3-week treatment. Within-participant designs with multiple baselines across participants and behaviors were used to examine acquisition, generalization, and maintenance of skill.

Results

All children improved in their ability to control relative duration of syllables in SW and WS nonwords. Improvement was also noted in control of loudness and pitch contrasts. Treatment effects generalized to untreated nonword stimuli, but minimal change was seen in production of real words.

Conclusion

Findings support the efficacy of this approach for improving production of lexical stress contrasts. Structuring the intervention according to the PML approach likely stimulated strong maintenance and generalization effects.
X-ray characterization of composition and relaxation of AlxGa1−xN(≤x≤1) layers grown on GaN/sapphire templates by low pressure organometallic vapor phase epitaxy
Authors: Tweedie James , Collazo Ramon , Rice Anthony , Xie Jinqiao , Mita Seiji , Dalmau Rafael , Sitar Zlatko
Published: August 2010

A characterization procedure was developed to determine the alloy composition and strain state of AlxGa1−xN/GaN(0<x<1) heterostructures deposited on c-plane sapphire substrates by low pressure organometalic vapor phase epitaxy. Motivated by a method suggested by Bowen and Tanner for separating the contributions of strain and composition in cubic crystals, we extended the technique to the case of hexagonal crystals by first principles derivation from elastic strain theory. The technique was evaluated using double-axis and triple-axis reciprocal space maps of 200 and 30 nm AlxGa1−xN layers. The procedure did not require absolute lattice parameter measurements and relied instead on relative measurements of the layer and substrate peak positions. Symmetric and asymmetric reflections of the film and substrate were measured in the double-axis configuration with ω–2θ scans. From the peak separation, the strained lattice parameters were determined. Assuming biaxial strain and linear variation of the relaxed lattice parameter with alloy composition, an equation was derived for composition in terms of the strained lattice parameters. The relaxation distribution in the AlGaN was found to be bimodal. Films with mole fraction of Al greater than 0.4 were completely relaxed and thoroughly cracked, while films with mole fraction of Al less than 0.4 exhibited compositionally dependent relaxation about the fully strained state.
Investigations of the polymer alignment, the nonradiative resonant energy transfer, and the photovoltaic response of poly(3-hexylthiophene)/TiO2 hybrid solar cells
Authors: Park Young Ran , Lee You-Jin , Yu Chang-Jae , Kim Jae-Hoon
Published: August 2010

We report the effects of annealing on the performance of hybrid photovoltaic (PV) cells containing poly(3-hexylthiophene) (P3HT) coated onto TiO2/Sn doped In2O3 (ITO) and ITO substrates. In the optimized device, which exhibits a higher efficiency, the backbone axes of the P3HT chains were found to lie within the substrate plane, their conjugated planes are slightly tilted, and their side chains are substantially tilted. The carboxylate group is attached via bidentate or bridging coordination to the TiO2 surface and enables photoinduced charge transfer between TiO2 and P3HT. The observed large quenching (with excitation at 488 nm) and enhanced emission (with excitation at 325 nm) indicates that efficient Förster resonance energy transfer occurs between TiO2 and P3HT. Thus, the main influences on the high efficiency of the hybrid PV cells are the photon-mediated electronic transition and the photoinduced charge transfer.
Single-molecule binding experiments on long time scales
Authors: Elenko Mark P. , Szostak Jack W. , van Oijen Antoine M.
Published: August 2010

We describe an approach for performing single-molecule binding experiments on time scales from hours to days, allowing for the observation of slower kinetics than have been previously investigated by single-molecule techniques. Total internal reflection fluorescence microscopy is used to image the binding of labeled ligand to molecules specifically coupled to the surface of an optically transparent flow cell. Long-duration experiments are enabled by ensuring sufficient positional, chemical, thermal, and image stability. Principal components of this experimental stability include illumination timing, solution replacement, and chemical treatment of solution to reduce photodamage and photobleaching; and autofocusing to correct for spatial drift.
Absorption in the Q-band region by isolated ferric heme+ and heme+(histidine) in vacuo
Authors: Wyer Jean Ann , Nielsen Steen Brøndsted
Published: August 2010

Absorption by heme proteins is determined by the heme microenvironment that is often vacuumlike (hydrophobic pocket). Here we provide absorption spectra in the Q-band region of isolated ferric heme+ and heme+(histidine) ions in vacuo to be used as references in protein biospectroscopy. Ions were photoexcited in an electrostatic storage ring and their decay monitored in time. Both ions display a triple band structure with maxima at 500, 518, and 530 nm. Previous attempts to study four-coordinate Fe(III)-heme+ were hampered by the strong affinity of Fe3+ for water and anions. Absorption at higher wavelengths is also measured, which is ascribed to charge-transfer transitions from the porphyrin to the iron. Finally, our data serve to benchmark theoretical calculations.
Embryo biotechnology in the dog: a review
Authors: Chastant-Maillard Sylvie , Chebrout Martine , Thoumire Sandra , Saint-Dizier Marie , Chodkiewicz Marc , Reynaud Karine
Published: August 2010

Canine embryos are a scarce biological material because of difficulties in collecting in vivo-produced embryos and the inability, to date, to produce canine embryos in vitro. The procedure for the transfer of in vivo-produced embryos has not been developed adequately, with only six attempts reported in the literature that have resulted in the birth of 45 puppies. In vitro, the fertilisation rate is particularly low (∼10%) and the incidence of polyspermy particularly high. So far, no puppy has been obtained from an in vitro-produced embryo. In contrast, cloning of somatic cells has been used successfully over the past 4 years, with the birth of 41 puppies reported in the literature, a yield that is comparable to that for other mammalian species. Over the same period, canine embryonic stem sells and transgenic cloned dogs have been obtained. Thus, the latest reproductive technologies are further advanced than in vitro embryo production. The lack of fundamental studies on the specific features of reproductive physiology and developmental biology in the canine is regrettable in view of the increasing role of dogs in our society and of the current demand for new biological models in biomedical technology.
Neonatal superior ovarian nerve transection inhibits follicle development by enhancing follicular atresia and suppressing granulosa cell proliferation in rats
Authors: Zhang Xiaoxin , Zhang Lei , Huo Shuying , Wang Jianlin , Cui Sheng
Published: August 2010

The ovarian sympathetic nerves participate in the regulation of mammalian ovarian function, but it is still not known whether the neonatal ovarian sympathetic nerve is involved in follicular development and related mechanisms. In the present study, the superior ovarian nerve (SON) of the neonatal rat was transected on postnatal day (PD) 2, and follicle development, ovarian hormone secretion, ovulation rate, granulosa cell proliferation and apoptosis were analysed on PD 30 and PD 90. The results demonstrate that SON transection decreases follicle number and size, reduces ovulation induced by gonadotrophin and enhances follicular atresia. Bromodeoxyuridine (BrdU) and cleaved caspase-3 immunohistochemistry staining provide evidence that SON transection inhibits granulosa cell proliferation and promotes granulosa cell apoptosis. In addition, SON transection increases serum oestradiol levels, but has no influence on serum progesterone levels. These results suggest that the sympathetic nerve supply to the ovaries is important in regulating follicle development and ovary function. These results are critical for further understanding of the neuroendocrine regulation of ovary development and function, although the mechanism needs to be elucidated in future studies.
Relationship between cumulus cell apoptosis, progesterone production and porcine oocyte developmental competence: temporal effects of follicular fluid during IVM
Authors: Grupen Christopher G. , Armstrong David T.
Published: August 2010

The objective of the present study was to determine the temporal effects of sow follicular fluid (FF) in vitro on cumulus cell viability and function, as well as oocyte nuclear and cytoplasmic maturation. Cumulus–oocyte complexes (COCs) recovered from the ovaries of prepubertal pigs were matured in medium with (+FF) or without (–FF) follicular fluid for the first 22 h of IVM. At 22 h of IVM, each group of COCs was then transferred to medium with or without FF and matured for another 22 h, forming four treatment groups (–FF/–FF, –FF/+FF, +FF/–FF and +FF/+FF). The concentration of progesterone in spent IVM medium and the incidence of cumulus cell apoptosis in individual COCs were determined at 22 and 44 h of IVM. Cumulus expansion was also recorded at 44 h of IVM. Finally, the ability of oocytes to complete meiosis to the MII stage and form blastocysts after IVF and embryo culture was assessed. Maturation with FF for part or the whole of IVM increased cumulus expansion and progesterone production and decreased the incidence of cumulus cell apoptosis compared with the –FF/–FF group (P < 0.05). The changes were greatest for the +FF/+FF group and intermediate for the –FF/+FF and +FF/–FF groups. Regression analysis revealed a negative association between cumulus cell progesterone production and the incidence of cumulus cell apoptosis (P < 0.001). Meiotic maturation was enhanced when FF was present during the first half of IVM. Oocytes matured in the presence of FF during the first and/or second half of IVM displayed an increased ability to form blastocysts compared with the –FF/–FF group (P < 0.05). The extent of the increase was similar for all FF-supplemented groups. The results show that FF exerts several beneficial effects at different times during IVM and suggest that a major role of FF is to provide protection from oxidative stress. We propose that the incidence of cumulus cell apoptosis in COCs must be kept below a certain threshold to ensure adequate functionality, including steroidogenic activity, is maintained for the acquisition of oocyte developmental competence.
Crystal engineering of lattice metrics of perhalometallate salts and MOFs
Authors: Adams Christopher J. , Haddow Mairi F. , Lusi Matteo , Orpen A. Guy
Published: August 2010

The synthesis of the salt

3
and metallo-organic framework (MOF) [{(4,4
′
-bipy)CoBr
2
}

n

]
4
by a range of solid state (mechanochemical and thermochemical) and solution methods is reported; they are isostructural with their respective chloride analogues
1
and
2
.
3
and
4
can be interconverted by means of HBr elimination and absorption. Single phases of controlled composition and general formula [4,4
′
-H
2
bipy][CoBr

4-
x

Cl

x

]

5

x

may be prepared from
2
and
4
by solid—gas reactions involving HBr or HCl respectively. Crystalline single phase samples of

5

x

and [{(4,4
′
-bipy)CoBr

2-
x

Cl

x

}

n

]

6

x

were prepared by solid-state mechanochemical routes, allowing fine control over the composition and unit cell volume of the product. Collectively these methods enable
continuous
variation of the unit cell dimensions of the salts [4,4
′
-H
2
bipy][CoBr

4-
x

Cl

x

] (

5

x

) and the MOFs [{(4,4
′
-bipy)CoBr

2-
x

Cl

x

}

n

] (

6

x

) by varying the bromide to chloride ratio and establish a means of controlling MOF composition and the lattice metrics, and so the physical and chemical properties that derive from it.
Signatures of founder effects, admixture, and selection in the Ashkenazi Jewish population
Authors: Bray Steven M. , Mulle Jennifer G. , Dodd Anne F. , Pulver Ann E. , Wooding Stephen , Warren Stephen T.
Published: August 2010

The Ashkenazi Jewish (AJ) population has long been viewed as a genetic isolate, yet it is still unclear how population bottlenecks, admixture, or positive selection contribute to its genetic structure. Here we analyzed a large AJ cohort and found higher linkage disequilibrium (LD) and identity-by-descent relative to Europeans, as expected for an isolate. However, paradoxically we also found higher genetic diversity, a sign of an older or more admixed population but not of a long-term isolate. Recent reports have reaffirmed that the AJ population has a common Middle Eastern origin with other Jewish Diaspora populations, but also suggest that the AJ population, compared with other Jews, has had the most European admixture. Our analysis indeed revealed higher European admixture than predicted from previous Y-chromosome analyses. Moreover, we also show that admixture directly correlates with high LD, suggesting that admixture has increased both genetic diversity and LD in the AJ population. Additionally, we applied extended haplotype tests to determine whether positive selection can account for the level of AJ-prevalent diseases. We identified genomic regions under selection that account for lactose and alcohol tolerance, and although we found evidence for positive selection at some AJ-prevalent disease loci, the higher incidence of the majority of these diseases is likely the result of genetic drift following a bottleneck. Thus, the AJ population shows evidence of past founding events; however, admixture and selection have also strongly influenced its current genetic makeup.
Resolving postglacial phylogeography using high-throughput sequencing
Authors: Emerson Kevin J. , Merz Clayton R. , Catchen Julian M. , Hohenlohe Paul A. , Cresko William A. , Bradshaw William E. , Holzapfel Christina M.
Published: August 2010

The distinction between model and nonmodel organisms is becoming increasingly blurred. High-throughput, second-generation sequencing approaches are being applied to organisms based on their interesting ecological, physiological, developmental, or evolutionary properties and not on the depth of genetic information available for them. Here, we illustrate this point using a low-cost, efficient technique to determine the fine-scale phylogenetic relationships among recently diverged populations in a species. This application of restriction site-associated DNA tags (RAD tags) reveals previously unresolved genetic structure and direction of evolution in the pitcher plant mosquito,
Wyeomyia smithii
, from a southern Appalachian Mountain refugium following recession of the Laurentide Ice Sheet at 22,000–19,000 B.P. The RAD tag method can be used to identify detailed patterns of phylogeography in any organism regardless of existing genomic data, and, more broadly, to identify incipient speciation and genome-wide variation in natural populations in general.
Paracrinology of islets and the paracrinopathy of diabetes
Authors: Unger Roger H. , Orci Lelio
Published: August 2010

New results have brought to light the importance of the regulation of glucagon by β-cells in the development of diabetes. In this perspective, we examine the normal paracrinology of α- and β-cells in nondiabetic pancreatic islets. We propose a Sherringtonian model of coordinated reciprocal secretory responses of these juxtaposed cells that secrete glucagon and insulin, hormones with opposing actions on the liver. As insulin is a powerful inhibitor of glucagon, we propose that within-islet inhibition of α-cells by β-cells creates an insulin-to-glucagon ratio that maintains glycemic stability even in extremes of glucose influx or efflux. By contrast, in type 1 diabetes mellitus, α-cells lack constant action of high insulin levels from juxtaposed β-cells. Replacement with exogenous insulin does not approach paracrine levels of secreted insulin except with high doses that “overinsulinize” the peripheral insulin targets, thereby promoting glycemic volatility. Based on the stable normoglycemia of mice with type 1 diabetes during suppression of glucagon with leptin, we conclude that, in the absence of paracrine regulation of α-cells, tonic inhibition of α-cells improves the dysregulated glucose homeostasis. These results have considerable medical implications, as they suggest new approaches to normalize the extreme volatility of glycemia in diabetic patients.
Mammalian endoplasmic reticulum stress sensor IRE1 signals by dynamic clustering
Authors: Li Han , Korennykh Alexei V. , Behrman Shannon L. , Walter Peter
Published: August 2010

Accumulation of misfolded proteins in the endoplasmic reticulum (ER) triggers the unfolded protein response (UPR), an intracellular signaling pathway that adjusts the protein folding capacity of the ER according to need. If homeostasis in the ER protein folding environment cannot be reestablished, cells commit to apoptosis. The ER-resident transmembrane kinase-endoribonuclease inositol-requiring enzyme 1 (IRE1) is the best characterized UPR signal transduction molecule. In yeast, Ire1 oligomerizes upon activation in response to an accumulation of misfolded proteins in the ER. Here we show that the salient mechanistic features of IRE1 activation are conserved: mammalian IRE1 oligomerizes in the ER membrane and oligomerization correlates with the onset of IRE1 phosphorylation and RNase activity. Moreover, the kinase/RNase module of human IRE1 activates cooperatively in vitro, indicating that formation of oligomers larger than four IRE1 molecules takes place upon activation. High-order IRE1 oligomerization thus emerges as a conserved mechanism of IRE1 signaling. IRE1 signaling attenuates after prolonged ER stress. IRE1 then enters a refractive state even if ER stress remains unmitigated. Attenuation includes dissolution of IRE1 clusters, IRE1 dephosphorylation, and decline in endoribonuclease activity. Thus IRE1 activity is governed by a timer that may be important in switching the UPR from the initially cytoprotective phase to the apoptotic mode.
A Spoonful of Sugar Helps the Medicine Go Down: the Relationship Between Food Prices and Medical Expenditures on Diabetes
Authors: Meyerhoefer Chad D. , Leibtag Ephraim S.
Published: August 2010

We investigate the impact of changes in the relative price of low‐ and high‐carbohydrate foods on medical expenditures for diabetes care using Nielsen Homescan price data merged to the 2000–2005 Medical Expenditure Panel Survey. We find that an increase in low‐(high‐)carbohydrate food price increases (decreases) both the likelihood of a diabetes diagnosis and the level of medical expenditures among those with diabetes. We also find small impacts of food prices on body mass index that differ by gender. Policy simulations suggest that subsidizing the low‐carbohydrate food purchases of people with diabetes could result in significant reductions in health care costs.
The Economics of Nested Names: Name Specificity, Reputations, and Price Premia
Authors: Costanigro Marco , McCluskey Jill J. , Goemans Christopher
Published: August 2010

A good can be identified by its region or country of origin, the firm that produces it, and its product name. In other words, names can nest within each other to categorize goods with increasing specificity. This article develops a conceptual framework for jointly analyzing the effect of product, firm, and collective reputations on market price. The model is estimated via quantile regression with California wine market data. The results portray how the structure and relative importance of reputations change as product prices vary. Specifically, reputation premia migrate from collective to specific names as prices increase.
Universal scaling of production rates across mammalian lineages
Authors: Hamilton Marcus J. , Davidson Ana D. , Sibly Richard M. , Brown James H.
Published: August 2010

Over many millions of years of independent evolution, placental, marsupial and monotreme mammals have diverged conspicuously in physiology, life history and reproductive ecology. The differences in life histories are particularly striking. Compared with placentals, marsupials exhibit shorter pregnancy, smaller size of offspring at birth and longer period of lactation in the pouch. Monotremes also exhibit short pregnancy, but incubate embryos in eggs, followed by a long period of post-hatching lactation. Using a large sample of mammalian species, we show that, remarkably, despite their very different life histories, the scaling of production rates is statistically indistinguishable across mammalian lineages. Apparently all mammals are subject to the same fundamental metabolic constraints on productivity, because they share similar body designs, vascular systems and costs of producing new tissue.
Diagnostic and therapeutic approach in a rare case of primary bilateral adrenal tuberculosis
Authors: Del Borgo Cosmo , Urigo Carlo , Marocco Raffaella , Belvisi Valeria , Pisani Luisa , Citton Rita , Cianni Roberto , Soscia Fabrizio , Lichtner Miriam , Mastroianni Claudio Maria
Published: August 2010

Here, we report a case of a febrile patient with primary bilateral adrenalitis who was successfully treated with an antituberculous regimen. Primary isolated tubercular adrenalitis is a very rare clinical entity but it should be considered in cases of fever and enlargement of the adrenal glands. Integration of radiological pattern data with epidemiological, clinical and immunological data has high accuracy and specificity, even without histological examination.
Influence of particle size on the pathology and efficacy of vaccination in a murine model of inhalational anthrax
Authors: Thomas Richard , Davies Carwyn , Nunez Alejandro , Hibbs Stephen , Flick-Smith Helen , Eastaugh Lin , Smither Sophie , Gates Amanda , Oyston Petra , Atkins Timothy , Eley Steve
Published: August 2010

Deposition of Bacillus anthracis endospores within either the lungs or nasal passages of A/J mice after aerosol exposure was influenced by different particle sized aerosols and resulted in different infection kinetics. The infection resulting from the inhalation of endospores within a 12 μm particle aerosol was prolonged compared to that from a 1 μm particle aerosol with a mean time-to-death of 161±16.1 h and 101.6±10.4 h, respectively. Inhalation of endospores within 1 μm or 12 μm particle aerosols resulted in a median lethal dose of 2432 and 7656 c.f.u., respectively. Initial involvement of the upper respiratory tract lymph nodes was observed in 75–83 % of mice exposed to either the 1 μm or 12 μm particle inhalational infections. Lung deposition was significantly greater after inhalation of the 1 μm particle aerosol with pronounced involvement of the mediastinal lymph node. Gastrointestinal involvement was observed only in mice exposed to 12 μm particle aerosols where bacteriological and histopathological analysis indicated primary gastritis (17 %), activation of the Peyer's patches (72 %) and colonization and necrosis of the mesenteric lymph nodes (67 %). Terminal disease was characterized by bacteraemia in both inhalational infections with preferential dissemination to spleen, liver, kidneys and thymus. Immunization with 1 μg recombinant protective antigen vaccine was equally efficacious against B. anthracis infections arising from the inhalation of 1 and 12 μm particle aerosols, providing 73–80 % survival under a suboptimum immunization schedule.
Role of Hcp, a type 6 secretion system effector, of Aeromonas hydrophila in modulating activation of host immune cells
Authors: Suarez Giovanni , Sierra Johanna C. , Kirtley Michelle L. , Chopra Ashok K.
Published: August 2010

Recently, we reported that the type 6 secretion system (T6SS) of Aeromonas hydrophila SSU plays an important role in bacterial virulence in a mouse model, and immunization of animals with the T6SS effector haemolysin co-regulated protein (Hcp) protected them against lethal infections with wild-type bacteria. Additionally, we showed that the mutant bacteria deleted for the vasH gene within the T6SS gene cluster did not express the hcp gene, while the vasK mutant could express and translocate Hcp, but was unable to secrete it into the extracellular milieu. Both of these A. hydrophila SSU mutants were readily phagocytosed by murine macrophages, pointing to the possible role of the secreted form of Hcp in the evasion of the host innate immunity. By using the ΔvasH mutant of A. hydrophila, our in vitro data showed that the addition of exogenous recombinant Hcp (rHcp) reduced bacterial uptake by macrophages. These results were substantiated by increased bacterial virulence when rHcp was added along with the ΔvasH mutant in a septicaemic mouse model of infection. Analysis of the cytokine profiling in the intraperitoneal lavage as well as activation of host cells after 4 h of infection with the ΔvasH mutant supplemented with rHcp indicated that this T6SS effector inhibited production of pro-inflammatory cytokines and induced immunosuppressive cytokines, such as interleukin-10 and transforming growth factor-β, which could circumvent macrophage activation and maturation. This mechanism of innate immune evasion by Hcp possibly inhibited the recruitment of cellular immune components, which allowed bacterial multiplication and dissemination in animals, thereby leading to their mortality.
Antisense-RNA-mediated plasmid copy number control in pCG1-family plasmids, pCGR2 and pCG1, in Corynebacterium glutamicum
Authors: Okibe Naoko , Suzuki Nobuaki , Inui Masayuki , Yukawa Hideaki
Published: August 2010

pCGR2 and pCG1 belong to different subfamilies of the pCG1 family ofCorynebacterium glutamicumplasmids. Nonetheless, they harbour homologous putative antisense RNA genes,crrIandcgrI, respectively. The genes in turn share identical positions complementary to the leader region of their respectiverepA(encoding plasmid replication initiator) genes. Determination of their precise transcriptional start- and end-points revealed the presence of short antisense RNA molecules (72 bp, CrrI; and 73 bp, CgrI). These short RNAs and their target mRNAs were predicted to form highly structured molecules comprising stem–loops with known U-turn motifs. Abolishing synthesis of CrrI and CgrI by promoter mutagenesis resulted in about sevenfold increase in plasmid copy number on top of an 11-fold (CrrI) and 32-fold (CgrI) increase inrepAmRNA, suggesting that CrrI and CgrI negatively control plasmid replication. This control is accentuated byparB,a gene that encodes a small centromere-binding plasmid-partitioning protein, and is located upstream ofrepA. Simultaneous deactivation of CrrI andparBled to a drastic 87-fold increase in copy number of a pCGR2-derived shuttle vector. Moreover, the fact that changes in the structure of the terminal loops of CrrI and CgrI affected plasmid copy number buttressed the important role of the loop structure in formation of the initial interaction complexes between antisense RNAs and their target mRNAs. Similar antisense RNA control systems are likely to exist not only in the twoC. glutamicumpCG1 subfamilies but also in related plasmids acrossCorynebacteriumspecies.
Lack of α-Xylosidase Activity in Arabidopsis Alters Xyloglucan Composition and Results in Growth Defects
Authors: Sampedro Javier , Pardo Brenda , Gianzo Cristina , Guitián Esteban , Revilla Gloria , Zarra Ignacio
Published: August 2010

Xyloglucan is the main hemicellulose in the primary cell walls of most seed plants and is thought to play a role in regulating the separation of cellulose microfibrils during growth. Xylose side chains block the degradation of the backbone, and α-xylosidase activity is necessary to remove them. Two Arabidopsis (Arabidopsis thaliana) mutant lines with insertions in the α-xylosidase gene AtXYL1 were characterized in this work. Both lines showed a reduction to undetectable levels of α-xylosidase activity against xyloglucan oligosaccharides. This reduction resulted in the accumulation of XXXG and XXLG in the liquid growth medium of Atxyl1 seedlings. The presence of XXLG suggests that it is a poor substrate for xyloglucan β-galactosidase. In addition, the polymeric xyloglucan of Atxyl1 lines was found to be enriched in XXLG subunits, with a concomitant decrease in XXFG and XLFG. This change can be explained by extensive exoglycosidase activity at the nonreducing ends of xyloglucan chains. These enzymes could thus have a larger role than previously thought in the metabolism of xyloglucan. Finally, Atxyl1 lines showed a reduced ability to control the anisotropic growth pattern of different organs, pointing to the importance of xyloglucan in this process. The promoter of AtXYL1 was shown to direct expression to many different organs and cell types undergoing cell wall modifications, including trichomes, vasculature, stomata, and elongating anther filaments.
Crystallographic study of wild-type carbonic anhydrase αCA1 fromChlamydomonas reinhardtii
Authors: Suzuki Kaoru , Shimizu Satoru , Juan Ella Czarina Magat , Miyamoto Takahiro , Fang Zhang , Hoque Md. Mominul , Sato Yoshiteru , Tsunoda Masaru , Sekiguchi Takeshi , Takénaka Akio , Yang Shi-Yuan
Published: August 2010

Carbonic anhydrases (CAs) are ubiquitously distributed and are grouped into three structurally independent classes (αCA, βCA and γCA). Most αCA enzymes are monomeric, but αCA1 fromChlamydomonas reinhardtiiis a dimer that is uniquely stabilized by disulfide bonds. In addition, during maturation an internal peptide of 35 residues is removed and three asparagine residues are glycosylated. In order to obtain insight into the effects of these structural features on CA function, wild-typeC. reinhardtiiαCA1 has been crystallized in space groupP65, with unit-cell parametersa=b= 134.3,c = 120.2 Å. The crystal diffracted to 1.88 Å resolution and a preliminary solution of its crystal structure has been obtained by the MAD method.
Crystallization and preliminary X-ray analysis of a glucansucrase from the dental caries pathogenStreptococcus mutans
Authors: Ito Keisuke , Ito Sohei , Shimamura Tatsuro , Kawarasaki Yasuaki , Abe Keiko , Misaka Takumi , Kobayashi Takuya , Iwata So
Published: August 2010

Glucansucrases encoded byStreptococcus mutansplay essential roles in the synthesis of sticky dental plaques. Based on amino-acid sequence similarity, glucansucrases are classified as members of glycoside hydrolase family 70 (GH 70). Data on the crystal structure of GH 70 glucansucrases have yet to be reported. Here, the GH 70 glucansucrase GTF-SI fromS. mutanswas overexpressed inEscherichia colistrain BL21 (DE3), purified to homogeneity and crystallized using the hanging-drop vapour-diffusion method. Orthorhombic GTF-SI crystals belonging to space groupP21212 were obtained. A diffraction data set was collected to 2.1 Å resolution.
Expression, purification and crystallization ofChaetomium thermophilumCu,Zn superoxide dismutase
Authors: Wakadkar Sachin , Zhang Li-Qing , Li Duo-Chuan , Haikarainen Teemu , Dhavala Prathusha , Papageorgiou Anastassios C.
Published: August 2010

Cu,Zn superoxide dismutase (Cu,ZnSOD) from the thermophilic fungusChaetomium thermophilumwas expressed inPichia pastorisand purified. Crystals were grown in over 120 conditions but only those produced with 1.4 Msodium potassium phosphate pH 8.2 as precipitant were suitable for structural studies. Data were collected to 1.9 Å resolution at 100 K from a single crystal using a synchrotron-radiation source. The crystals belonged to space groupP61/P65, with unit-cell parametersa= 90.2,c= 314.5 Å and eight molecules in the asymmetric unit. Elucidation of the crystal structure will provide insights into the active site of the enzyme and a better understanding of the structure–activity relationship, assembly and thermal stability of Cu,ZnSODs.
Preliminary crystallographic study of theStreptococcus agalactiaesortases, sortase A and sortase C1
Authors: Khare Baldeep , Samal Alexandra , Vengadesan Krishnan , Rajashankar K. R. , Ma Xin , Huang I-Hsiu , Ton-That Hung , Narayana Sthanam V. L.
Published: August 2010

Sortases are cysteine transpeptidases that are essential for the assembly and anchoring of cell-surface adhesins in Gram-positive bacteria. InStreptococcus agalactiae(GBS), the pilin-specific sortase SrtC1 catalyzes the polymerization of pilins encoded by pilus island 1 (PI-1) and the housekeeping sortase SrtA is necessary for cell-wall anchoring of the resulting pilus polymers. These sortases are known to utilize different substrates for pilus polymerization and cell-wall anchoring; however, the structural correlates that dictate their substrate specificity have not yet been clearly defined. This report presents the expression, purification and crystallization of SrtC1 (SAG0647) and SrtA (SAG0961) fromS. agalactiaestrain 2603V/R. The GBS SrtC1 has been crystallized in three crystal forms and the GBS SrtA has been crystallized in one crystal form.
Crystallization and preliminary X-ray crystallographic analysis of a bacterial tyrosinase fromBacillus megaterium
Authors: Sendovski Mor , Kanteev Margarita , Shuster Ben-Yosef Vered , Adir Noam , Fishman Ayelet
Published: August 2010

Tyrosinases are type 3 copper enzymes that are involved in the production of melanin and have two copper ions in the active site. Here, the crystallization and primary analysis of a tyrosinase fromBacillus megateriumis reported. The purified protein was crystallized in the absence or presence of zinc ions and the crystals diffracted to a resolution of 2.0 Å. Crystals obtained in the presence of zinc belonged to space groupP212121, while crystals grown in the absence of zinc belonged to space groupP21. In both space groups the asymmetric unit contained a dimer, with minor differences in the crystal density and in packing interactions.
Preliminary crystallographic analysis of the N-terminal domain of FILIA, a protein essential for embryogenesis
Authors: Wang Juke , Zhang Tong-Cun , Liu Xinqi
Published: August 2010

FILIA is a component of the subcortical maternal complex that is essential for early stage embryogenesis. Its 6×His-tagged N-terminal domain was expressed inEscherichia coliand purified to homogeneity. Two types of crystals formed under different crystallization conditions during screening. Orthorhombic crystals appeared in a solution containing 1.4 Mammonium sulfate, 0.1 MTris pH 8.2 and 12% glycerol, while tetragonal crystals were obtained using 15% PEG 4000 mixed with 0.1 MHEPES pH 7.5 and 15% 2-propanol. High-quality diffraction data were collected from the two crystal forms to resolutions of 1.8 and 2.2 Å, respectively, using synchrotron radiation. The Matthews coefficients indicated that theP212121andP41212 crystals contained two molecules and one molecule per asymmetric unit, respectively. A selenomethionine-substituted sample failed to crystallize under the native conditions, but another orthorhombic crystal form was obtained under different conditions and anomalous diffraction data were collected.
Crystallization and preliminary X-ray crystallographic study of GenX, a lysyl-tRNA synthetase paralogue fromEscherichia coli, in complex with translation elongation factor P
Authors: Sumida Tomomi , Yanagisawa Tatsuo , Ishii Ryohei , Yokoyama Shigeyuki
Published: August 2010

GenX, a lysyl-tRNA synthetase paralogue fromEscherichia coli, was overexpressed inE. coli, purified by three chromatographic steps and cocrystallized with a lysyl adenylate analogue (LysAMS) by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The GenX–LysAMS crystals belonged to the triclinic space groupP1, with unit-cell parametersa = 54.80,b= 69.15,c = 94.08 Å, α = 95.47, β = 106.51, γ = 90.46°, and diffracted to 1.9 Å resolution. Furthermore, GenX was cocrystallized with translation elongation factor P (EF-P), which is believed to be a putative substrate of GenX, and LysAMS using PEG 4000 and ammonium sulfate as precipitants. The GenX–EF-P–LysAMS crystals belonged to the monoclinic space groupP21, with unit-cell parametersa = 105.93,b= 102.96,c= 119.94 Å, β = 99.4°, and diffracted to 2.5 Å resolution. Structure determination of theE. coliGenX–LysAMS and GenX–EF-P–LysAMS complexes by molecular replacement was successful and structure refinements are now in progress.
Crystallization and preliminary crystallographic characterization of the iron-regulated outer membrane lipoprotein FrpD fromNeisseria meningitidis
Authors: Sviridova Ekaterina , Bumba Ladislav , Rezacova Pavlina , Prochazkova Katerina , Kavan Daniel , Bezouska Karel , Kuty Michal , Sebo Peter , Kuta Smatanova Ivana
Published: August 2010

Fe-regulated protein D (FrpD) is aNeisseria meningitidisouter membrane lipoprotein that may be involved in the anchoring of the secreted repeat in toxins (RTX) protein FrpC to the outer bacterial membrane. However, the function and biological roles of the FrpD and FrpC proteins remain unknown. Native and selenomethionine-substituted variants of recombinant FrpD43–271protein were crystallized using the sitting-drop vapour-diffusion method. Diffraction data were collected to a resolution of 2.25 Å for native FrpD43–271protein and to a resolution of 2.00 Å for selenomethionine-substituted FrpD43–271(SeMet FrpD43–271) protein. The crystals of native FrpD43–271protein belonged to the hexagonal space groupP62orP64, while the crystals of SeMet FrpD43–271protein belonged to the primitive orthorhombic space groupP212121.
Clinical application of transthoracic ultrasonography in inpatients with pneumonia
Authors: Sperandeo Marco , Carnevale Vincenzo , Muscarella Silvana , Sperandeo Giuseppe , Varriale Antonio , Filabozzi Paola , Piattelli Maria L. , D’Alessandro Vito , Copetti Massimiliano , Pellegrini Fabio , Dimitri Lucia , Vendemiale Gianluigi
Published: August 2010

Eur J Clin Invest 2010; 41 (1): 1–7

Purpose  The aim of this study was to investigate the clinical applicability of transthoracic ultrasound (TUS) in the diagnosis and follow‐up of community acquired pneumonia (CAP).

Methods  We designed a pilot study in 15 patients and subsequently investigated 342 patients (206 men and 136 women) consecutively admitted to our Department from September 2005 to November 2009 because of radiographically diagnosed CAP. All patients underwent standard chest radiography, and consequently TUS. Follow‐up TUS were performed at 4th and 8–10th day, in most patients.

Results  Concerning the reproducibility of TUS method, no reader’s bias was present (P = 0·18), overall variability and between‐subject variability (inter‐reader agreement) did not show any difference between readers (P = 0·62 and P = 0·32 respectively), and estimated within‐subject variabilities (intra‐reader agreement) suggested a very high repeatability of the method (P ∼ 1). Of 342 patients with Rx diagnosis of CAP, in 314 patients (92% of cases) a pulmonary consolidation was also detected using TUS, whose ultrasonographic patterns were studied. Pleural effusion was detected in 120/342 (35%) patients using ultrasound and in 111/342 (32%) patients using chest radiography. Overall dimensional changes of the lung consolidated areas assessed with TUS method showed highly significant results. (1st day mean ± SD: 66·34 ± 19·25; 4th day: 39·92 ± 14·61; 8–10th day: 7·41 ± 1·50; P < 0·0001).

Conclusions  TUS is easily reproducible and we proved it to be a useful complementary diagnostic tool for the diagnosis and the follow‐up of CAP.
Patient's decision making in selecting a hospital for elective orthopaedic surgery
Authors: Moser Albine , Korstjens Irene , van der Weijden Trudy , Tange Huibert
Published: August 2010

Rationale, aims and objectives  The admission to a hospital for elective surgery, like arthroplasty, can be planned ahead. The elective nature of arthroplasty and the increasing stimulus of the public to critically select a hospital raise the issue of how patients actually take such decisions. The aim of this paper is to describe the decision‐making process of selecting a hospital as experienced by people who underwent elective joint arthroplasty and to understand what factors influenced the decision‐making process.

Methods  Qualitative descriptive study with 18 participants who had a hip or knee replacement within the last 5 years. Data were gathered from eight individual interviews and four focus group interviews and analysed by content analysis.

Results  Three categories that influenced the selection of a hospital were revealed: information sources, criteria in decision making and decision‐making styles within the GP– patient relationship. Various contextual aspects influenced the decision‐making process. Most participants gave higher priority to the selection of a medical specialist than to the selection of a hospital.

Conclusion  Selecting a hospital for arthroplasty is extremely complex. The decision‐making process is a highly individualized process because patients have to consider and assimilate a diversity of aspects, which are relevant to their specific situation. Our findings support the model of shared decision making, which indicates that general practitioners should be attuned to the distinct needs of each patient at various moments during the decision making, taking into account personal, medical and contextual factors.
Leadership development of individuals with developmental disabilities in the self‐advocacy movement
Authors: Caldwell J.
Published: August 2010

Background  Exploring the life stories of leaders in the self‐advocacy movement can expand our knowledge about leadership development of individuals with developmental disabilities. A better understanding of this process may assist with supporting the movement and leadership development of youth with disabilities.

Methods  In‐depth qualitative interviews were conducted with 13 leaders in the self‐advocacy movement within the USA in order to explore their life stories. Purposeful sampling contributed to a diverse sample of leaders. A grounded theory approach led to the identification of major themes and factors associated with their leadership development.

Findings  Four major themes emerged: (1) disability oppression and resistance; (2) environmental supports and relationships; (3) leadership skills; and (4) advanced leadership opportunities. Findings have conceptual and practical relevance for future interventions and research.
Efficiency and economies of scale of large Canadian banks
Authors: Allen Jason , Liu Ying
Published: August 2010

Abstract.  This paper measures the economies of scale of Canada's six largest banks and their cost‐efficiency over time. Using a unique panel data set from 1983 to 2003, we estimate pooled cost functions and derive measures of relative efficiency and economies of scale. The disaggregation of the data allows us to include non‐traditional outputs as well as time‐varying, bank‐specific effects. Our model leads us to reject constant returns to scale. These findings suggest there are potential scale benefits in the Canadian banking industry. We also find that technological and regulatory changes have had significant positive effects on the banks' cost structure.
Viewpoint: Replication in economics
Authors: Hamermesh Daniel S.
Published: August 2010

Abstract.  This examination of the role and potential for replication in economics points out the paucity of both pure replication – checking on others' published papers using their data – and scientific replication – using data representing different populations in one's own work or in a comment. Several controversies in empirical economics are used to illustrate how and how not to behave when replicating others' work. The incentives for replication are examined, and proposals aimed at journal editors and authors are advanced that might stimulate an activity that most economists applaud but few perform.