bluuebunny/crossref_metadata_2025 huggingface dataset:
Water’s role in the force-induced unfolding of ubiquitin
Authors: Li Jingyuan , Fernandez Julio M. , Berne B. J.
Published: October 2010

In atomic force spectroscopic studies of the elastomeric protein ubiquitin, the β-strands 1-5 serve as the force clamp. Simulations show how the rupture force in the force-induced unfolding depends on the kinetics of water molecule insertion into positions where they can eventually form hydrogen bonding bridges with the backbone hydrogen bonds in the force-clamp region. The intrusion of water into this region is slowed down by the hydrophobic shielding effect of carbonaceous groups on the surface residues of β-strands 1-5, which thereby regulates water insertion prior to hydrogen bond breakage. The experiments show that the unfolding of the mechanically stressed protein is nonexponential due to static disorder. Our simulations show that different numbers and/or locations of bridging water molecules give rise to a long-lived distribution of transition states and static disorder. We find that slowing down the translational (not rotational) motions of the water molecules by increasing the mass of their oxygen atoms, which leaves the force field and thereby the equilibrium structure of the solvent unchanged, increases the average rupture force; however, the early stages of the force versus time behavior are very similar for our “normal” and fictitious “heavy” water models. Finally, we construct six mutant systems to regulate the hydrophobic shielding effect of the surface residues in the force-clamp region. The mutations in the two termini of β-sheets 1-5 are found to determine a preference for different unfolding pathways and change mutant’s average rupture force.
Uterine epithelial estrogen receptor α is dispensable for proliferation but essential for complete biological and biochemical responses
Authors: Winuthayanon Wipawee , Hewitt Sylvia C. , Orvis Grant D. , Behringer Richard R. , Korach Kenneth S.
Published: October 2010

Female fertility requires estrogen to specifically stimulate estrogen receptor α (ERα)-dependent growth of the uterine epithelium in adult mice, while immature females show proliferation in both stroma and epithelium. To address the relative roles of ERα in mediating estrogen action in uterine epithelium versus stroma, a uterine epithelial-specific ERα knockout (UtEpiαERKO) mouse line was generated by crossing
Esr
mice with
Wnt7a
-Cre mice. Expression of
Wnt7a
directed Cre activity generated selective deletion of ERα in uterine epithelium, and female UtEpiαERKO are infertile. Herein, we demonstrate that 17β-estradiol (
E
2
)-induced uterine epithelial proliferation was independent of uterine epithelial ERα because DNA synthesis and up-regulation of mitogenic mediators were sustained in UtEpiαERKO uteri after
E
2
treatment. IGF-1 treatment resulted in ligand-independent ER activation in both wild-type (WT) and UtEpiαERKO and mimicked the
E
2
stimulatory effect on DNA synthesis in uterine epithelium. Uterine epithelial ERα was necessary to induce lactoferrin, an
E
2
-regulated secretory protein selectively synthesized in the uterine epithelium. However, loss of uterine epithelial ERα did not alter the
E
2
-dependent progesterone receptor (PR) down-regulation in epithelium. Strikingly, the uterine epithelium of UtEpiαERKO had robust evidence of apoptosis after 3 d of
E
2
treatment. Therefore, we surmise that estrogen induced uterine hyperplasia involves a dispensable role for uterine epithelial ERα in the proliferative response, but ERα is required subsequent to proliferation to prevent uterine epithelial apoptosis assuring the full uterine epithelial response, illustrating the differential cellular roles for ERα in uterine tissue and its contribution during pregnancy.
Optimal habits can develop spontaneously through sensitivity to local cost
Authors: Desrochers Theresa M. , Jin Dezhe Z. , Goodman Noah D. , Graybiel Ann M.
Published: October 2010

Habits and rituals are expressed universally across animal species. These behaviors are advantageous in allowing sequential behaviors to be performed without cognitive overload, and appear to rely on neural circuits that are relatively benign but vulnerable to takeover by extreme contexts, neuropsychiatric sequelae, and processes leading to addiction. Reinforcement learning (RL) is thought to underlie the formation of optimal habits. However, this theoretic formulation has principally been tested experimentally in simple stimulus-response tasks with relatively few available responses. We asked whether RL could also account for the emergence of habitual action sequences in realistically complex situations in which no repetitive stimulus-response links were present and in which many response options were present. We exposed naïve macaque monkeys to such experimental conditions by introducing a unique free saccade scan task. Despite the highly uncertain conditions and no instruction, the monkeys developed a succession of stereotypical, self-chosen saccade sequence patterns. Remarkably, these continued to morph for months, long after session-averaged reward and cost (eye movement distance) reached asymptote. Prima facie, these continued behavioral changes appeared to challenge RL. However, trial-by-trial analysis showed that pattern changes on adjacent trials were predicted by lowered cost, and RL simulations that reduced the cost reproduced the monkeys’ behavior. Ultimately, the patterns settled into stereotypical saccade sequences that minimized the cost of obtaining the reward on average. These findings suggest that brain mechanisms underlying the emergence of habits, and perhaps unwanted repetitive behaviors in clinical disorders, could follow RL algorithms capturing extremely local explore/exploit tradeoffs.
Imbalance of ionic conductances contributes to diverse symptoms of demyelination
Authors: Coggan Jay S. , Prescott Steven A. , Bartol Thomas M. , Sejnowski Terrence J.
Published: October 2010

Fast axonal conduction of action potentials in mammals relies on myelin insulation. Demyelination can cause slowed, blocked, desynchronized, or paradoxically excessive spiking that underlies the symptoms observed in demyelination diseases. The diversity and timing of such symptoms are poorly understood, often intermittent, and uncorrelated with disease progress. We modeled the effects of demyelination (and secondary remodeling) on intrinsic axonal excitability using Hodgkin–Huxley and reduced Morris–Lecar models. Simulations and analysis suggested a simple explanation for the breadth of symptoms and revealed that the ratio of sodium to leak conductance,

g
Na
/g
L

, acted as a four-way switch controlling excitability patterns that included spike failure, single spike transmission, afterdischarge, and spontaneous spiking. Failure occurred when this ratio fell below a threshold value. Afterdischarge occurred at

g
Na
/g
L

just below the threshold for spontaneous spiking and required a slow inward current that allowed for two stable attractor states, one corresponding to quiescence and the other to repetitive spiking. A neuron prone to afterdischarge could function normally unless it was switched to its “pathological” attractor state; thus, although the underlying pathology may develop slowly by continuous changes in membrane conductances, a discontinuous change in axonal excitability can occur and lead to paroxysmal symptoms. We conclude that tonic and paroxysmal positive symptoms as well as negative symptoms may be a consequence of varying degrees of imbalance between

g
Na

and

g
L

after demyelination. The KCNK family of

g
L

potassium channels may be an important target for new drugs to treat the symptoms of demyelination.
FcγRIV deletion reveals its central role for IgG2a and IgG2b activity in vivo
Authors: Nimmerjahn Falk , Lux Anja , Albert Heike , Woigk Melissa , Lehmann Christian , Dudziak Diana , Smith Patrick , Ravetch Jeffrey V.
Published: October 2010

Cellular Fcγ receptors are essential for IgG-dependent effector functions in vivo. There is convincing evidence that selective activating Fcγ receptors are responsible for the activity of individual IgG subclasses. Thus, IgG1 activity is absent in FcγRIII-deficient mice, and several studies suggest that the activity of the most potent IgG subclasses, IgG2a and IgG2b, might be dependent on either individual or a combination of activating FcγRs. To study the role of individual activating FcγRs for IgG subclass activity, we generated an FcγRIV-deficient mouse and showed that a variety of IgG2a- and IgG2b-dependent effector functions are impaired in the absence of this activating Fc receptor in models of autoimmunity and antibody-dependent cellular cytotoxicity.
Helping stem cells make a connection
Authors: Leslie Mitch
Published: October 2010

Protein network strengthens cell–cell contacts, promoting pluripotency.
Template-free 13-protofilament microtubule–MAP assembly visualized at 8 Å resolution
Authors: Fourniol Franck J. , Sindelar Charles V. , Amigues Béatrice , Clare Daniel K. , Thomas Geraint , Perderiset Mylène , Francis Fiona , Houdusse Anne , Moores Carolyn A.
Published: October 2010

Microtubule-associated proteins (MAPs) are essential for regulating and organizing cellular microtubules (MTs). However, our mechanistic understanding of MAP function is limited by a lack of detailed structural information. Using cryo-electron microscopy and single particle algorithms, we solved the 8 Å structure of doublecortin (DCX)-stabilized MTs. Because of DCX’s unusual ability to specifically nucleate and stabilize 13-protofilament MTs, our reconstruction provides unprecedented insight into the structure of MTs with an in vivo architecture, and in the absence of a stabilizing drug. DCX specifically recognizes the corner of four tubulin dimers, a binding mode ideally suited to stabilizing both lateral and longitudinal lattice contacts. A striking consequence of this is that DCX does not bind the MT seam. DCX binding on the MT surface indirectly stabilizes conserved tubulin–tubulin lateral contacts in the MT lumen, operating independently of the nucleotide bound to tubulin. DCX’s exquisite binding selectivity uncovers important insights into regulation of cellular MTs.
Pom121 links two essential subcomplexes of the nuclear pore complex core to the membrane
Authors: Mitchell Jana M. , Mansfeld Jörg , Capitanio Juliana , Kutay Ulrike , Wozniak Richard W.
Published: October 2010

Nuclear pore complexes (NPCs) control the movement of molecules across the nuclear envelope (NE). We investigated the molecular interactions that exist at the interface between the NPC scaffold and the pore membrane. We show that key players mediating these interactions in mammalian cells are the nucleoporins Nup155 and Nup160. Nup155 depletion massively alters NE structure, causing a dramatic decrease in NPC numbers and the improper targeting of membrane proteins to the inner nuclear membrane. The role of Nup155 in assembly is likely closely linked to events at the membrane as we show that Nup155 interacts with pore membrane proteins Pom121 and NDC1. Furthermore, we demonstrate that the N terminus of Pom121 directly binds the β-propeller regions of Nup155 and Nup160. We propose a model in which the interactions of Pom121 with Nup155 and Nup160 are predicted to assist in the formation of the nuclear pore and the anchoring of the NPC to the pore membrane.
On gas permeation in PDMS
Authors: Yang Lung-Jieh
Published: October 2010

A theoretical model of gas permeation in polydimethylsiloxane (PDMS) is conducted for two prior works involving MEMS sensors and actuators. The issue for modeling a sensor is about using PDMS slabs to replace Pyrex glass as the packaging substrate for bulk-micromachined pressure sensors. The leakage pressure due to gas permeation in PDMS reveals the time-varying behavior of exponential decay. The issue for modeling an actuator is the flow rate in a PDMS-based gas permeation pump. The nonlinear dependence of the flow rate with the diffusion area can be explained by this model. The prediction of this theoretical result is therefore in qualitative agreement with two previous experimental data sets by a conventional curve-fitting technique.
Determining Weight and Moisture Properties of Sound and Fusarium‐Damaged Single Wheat Kernels by Near‐Infrared Spectroscopy
Authors: Peiris K. H. S. , Dowell F. E.
Published: October 2010

Single kernel moisture content (MC) is important in the measurement of other quality traits in single kernels because many traits are expressed on a dry weight basis. MC also affects viability, storage quality, and price. Also, if near‐infrared (NIR) spectroscopy is used to measure grain traits, the influence of water must be accounted for because water is a strong absorber throughout the NIR region. The feasibility of measurement of MC, fresh weight, dry weight, and water mass of single wheat kernels with or without Fusarium damage was investigated using two wheat cultivars with three visually selected classes of kernels with Fusarium damage and a range of MC. Calibration models were developed either from all kernel classes or from only undamaged kernels of one cultivar that were then validated using all spectra of the other cultivar. A calibration model developed for MC when using all kernels from the wheat cultivar Jagalene had a coefficient of determination (R2) of 0.77 and standard error of cross validation (SECV) of 1.03%. This model predicted the MC of the wheat cultivar 2137 with R2 of 0.81 and a standard error of prediction (SEP) of 1.02% and RPD of 2.2. Calibration models developed using all kernels from both cultivars predicted MC, fresh weight, dry weight, or water mass in kernels better than models that used only undamaged kernels from both cultivars. Single kernel water mass was more accurately estimated using the actual fresh weight of kernels and MC predicted by calibrations that used all kernels or undamaged kernels. The necessity for evaluating and expressing constituent levels in single kernels on a mass/kernel basis rather than a percentage basis was elaborated. The need to overcome the effects of kernel size and water mass on single kernel spectra before using in calibration model development was also highlighted.
Comparative Analysis of the Capacity of Tombusvirus P22 and P19 Proteins to Function as Avirulence Determinants in Nicotiana species
Authors: Angel Carlos A. , Hsieh Yi-Cheng , Schoelz James E.
Published: October 2010

We have used an agroinfiltration assay for a comparative study of the roles of tombusvirus P22 and P19 proteins in elicitation of hypersensitive response (HR)-like necrosis and the role of P19 in silencing suppression in Nicotiana species. The advantage of agroinfiltration rather than expression in plant virus vectors is that putative viral avirulence proteins can be evaluated in isolation, eliminating the possibility of synergistic effects with other viral proteins. We found that tombusvirus P22 and P19 proteins elicited HR-like necrosis in certain Nicotiana species but, also, that Nicotiana species could recognize subtle differences in sequence between these proteins. Furthermore, Nicotiana species that responded with systemic necrosis to virion inoculations responded to agroinfiltration of tombusvirus P19 with a very weak and delayed necrosis, indicating that the rapid HR-like necrosis was associated with putative resistance genes and a plant defense response that limited the spread of the virus. Tombusvirus P19 proteins also appeared to differ in their effectiveness as silencing suppressors; in our assay, the P19 proteins of Cymbidium ringspot virus and Tomato bushy stunt virus were stronger silencing suppressors than Cucumber necrosis virus P20. Finally, we show that agroinfiltration can be used to track the presence of putative plant resistance genes in Nicotiana species that target either tombusvirus P19 or P22.
Response to Environmental Stresses, Cell-wall Integrity, and Virulence Are Orchestrated Through the Calcineurin Pathway in Ustilago hordei
Authors: Cervantes-Chávez José Antonio , Ali Shawkat , Bakkeren Guus
Published: October 2010

In eukaryotes, several biological processes are regulated through calcium signaling. Calcineurin is a calcium-calmodulin-regulated serine/threonine phosphatase consisting of catalytic subunit A and regulatory subunit B. Phosphatase activity resides in the catalytic subunit, which activates by dephosphorylation downstream components such as transcription factor Crz1. The importance of this pathway to respond to environmental stress has been explored in several fungal pathogens. The basidiomycete Ustilago hordei causes covered smut of barley. We addressed the role of the Ca2+-calcineurin activated pathway by deleting UhCna1 and UhCnb1. These genes were not essential in U. hordei but the corresponding mutants displayed a variety of phenotypes when applying environmental stress such as sensitivity to pH, temperature, H2O2, mono- and divalent cations; and to genotoxic, acid, or oxidative stresses. Cell-wall integrity was compromised and mutants displayed altered cell morphologies. Mating was delayed but not abolished, and combined sensitivities likely explained a severely reduced virulence toward barley plants. Expression analyses revealed that response to salt stress involved the induction of membrane ATPase genes UhEna1 and UhEna2, which were regulated through the calcineurin pathway. Upregulation of UhFKS1, a 1,3-β-d-glucan synthase gene, correlated with the increased amount of 1,3-β-d-glucan in the calcineurin mutants grown under salt stress.
Identification of AtoxigenicAspergillus flavusIsolates to Reduce Aflatoxin Contamination of Maize in Kenya
Authors: Probst C. , Bandyopadhyay R. , Price L. E. , Cotty P. J.
Published: October 2010

Aspergillus flavus has two morphotypes, the S strain and the L strain, that differ in aflatoxin-producing ability and other characteristics. Fungal communities on maize dominated by the S strain of A. flavus have repeatedly been associated with acute aflatoxin poisonings in Kenya, where management tools to reduce aflatoxin levels in maize are needed urgently. A. flavus isolates (n = 290) originating from maize produced in Kenya and belonging to the L strain morphotype were tested for aflatoxin-producing potential. A total of 96 atoxigenic isolates was identified from four provinces sampled. The 96 atoxigenic isolates were placed into 53 vegetative compatibility groups (VCGs) through complementation of nitrate non-utilizing mutants. Isolates from each of 11 VCGs were obtained from more than one maize sample, isolates from 10 of the VCGs were detected in multiple districts, and isolates of four VCGs were found in multiple provinces. Atoxigenic isolates were tested for potential to reduce aflatoxin concentrations in viable maize kernels that were co-inoculated with highly toxigenic S strain isolates. The 12 most effective isolates reduced aflatoxin levels by >80%. Reductions in aflatoxin levels caused by the most effective Kenyan isolates were comparable with those achieved with a United States isolate (NRRL-21882) used commercially for aflatoxin management. This study identified atoxigenic isolates of A. flavus with potential value for biological control within highly toxic Aspergillus communities associated with maize production in Kenya. These atoxigenic isolates have potential value in mitigating aflatoxin outbreaks in Kenya, and should be evaluated under field conditions.
OPA1 links human mitochondrial genome maintenance to mtDNA replication and distribution
Authors: Elachouri Ghizlane , Vidoni Sara , Zanna Claudia , Pattyn Alexandre , Boukhaddaoui Hassan , Gaget Karen , Yu-Wai-Man Patrick , Gasparre Giuseppe , Sarzi Emmanuelle , Delettre Cécile , Olichon Aurélien , Loiseau Dominique , Reynier Pascal , Chinnery Patrick F. , Rotig Agnès , Carelli Valerio , Hamel Christian P. , Rugolo Michela , Lenaers Guy
Published: October 2010

Eukaryotic cells harbor a small multiploid mitochondrial genome, organized in nucleoids spread within the mitochondrial network. Maintenance and distribution of mitochondrial DNA (mtDNA) are essential for energy metabolism, mitochondrial lineage in primordial germ cells, and to prevent mtDNA instability, which leads to many debilitating human diseases. Mounting evidence suggests that the actors of the mitochondrial network dynamics, among which is the intramitochondrial dynamin OPA1, might be involved in these processes. Here, using siRNAs specific to OPA1 alternate spliced exons, we evidenced that silencing of the OPA1 variants including exon 4b leads to mtDNA depletion, secondary to inhibition of mtDNA replication, and to marked alteration of mtDNA distribution in nucleoid and nucleoid distribution throughout the mitochondrial network. We demonstrate that a small hydrophobic 10-kDa peptide generated by cleavage of the OPA1-exon4b isoform is responsible for this process and show that this peptide is embedded in the inner membrane and colocalizes and coimmunoprecipitates with nucleoid components. We propose a novel synthetic model in which a peptide, including two trans-membrane domains derived from the N terminus of the OPA1-exon4b isoform in vertebrates or from its ortholog in lower eukaryotes, might contribute to nucleoid attachment to the inner mitochondrial membrane and promotes mtDNA replication and distribution. Thus, this study places OPA1 as a direct actor in the maintenance of mitochondrial genome integrity.
pex5Mutants That Differentially Disrupt PTS1 and PTS2 Peroxisomal Matrix Protein Import in Arabidopsis
Authors: Khan Bibi Rafeiza , Zolman Bethany K.
Published: October 2010

PEX5 and PEX7 are receptors required for the import of peroxisome-bound proteins containing one of two peroxisomal targeting signals (PTS1 or PTS2). To better understand the role of PEX5 in plant peroxisomal import, we characterized the Arabidopsis (Arabidopsis thaliana) pex5-10 mutant, which has a T-DNA insertion in exon 5 of the PEX5 gene. Sequencing results revealed that exon 5, along with the T-DNA, is removed in this mutant, resulting in a truncated pex5 protein. The pex5-10 mutant has germination defects and is completely dependent on exogenous Suc for early seedling establishment, based on poor utilization of seed-storage fatty acids. This mutant also has delayed development and reduced fertility, although adult pex5-10 plants appear normal. Peroxisomal metabolism of indole-3-butyric acid, propionate, and isobutyrate also is disrupted. The pex5-10 mutant has reduced import of both PTS1 and PTS2 proteins, and enzymatic processes that occur in peroxisomes are disrupted. To specifically study the import and importance of PTS1 proteins, we made a truncated PEX5 construct lacking the PTS1-binding region (PEX5454). Transformation of this construct into pex5-10 resulted in the rescue of PTS2 import, thereby creating a line with PTS1-specific import defects. The pex5-10 (PEX5454) plants still had developmental defects, although restoring PTS2 import resulted in a less severe mutant phenotype. Comparison of pex5-10 and pex5-10 (PEX5454) phenotypes can separate the import mechanisms for enzymes acting in different peroxisomal processes, including indole-3-butyric acid/2,4-dichlorophenoxybutyric acid oxidation, isobutyrate and propionate metabolism, and photorespiration.
Osmoregulation in Lilium Pollen Grains Occurs via Modulation of the Plasma Membrane H+ ATPase Activity by 14-3-3 Proteins
Authors: Pertl Heidi , Pöckl Magdalena , Blaschke Christian , Obermeyer Gerhard
Published: October 2010

To allow successful germination and growth of a pollen tube, mature and dehydrated pollen grains (PGs) take up water and have to adjust their turgor pressure according to the water potential of the surrounding stigma surface. The turgor pressure of PGs of lily (Lilium longiflorum) was measured with a modified pressure probe for simultaneous recordings of turgor pressure and membrane potential to investigate the relation between water and electrogenic ion transport in osmoregulation. Upon hyperosmolar shock, the turgor pressure decreased, and the plasma membrane (PM) hyperpolarizes in parallel, whereas depolarization of the PM was observed with hypoosmolar treatment. An acidification and alkalinization of the external medium was monitored after hyper- and hypoosmotic treatments, respectively, and pH changes were blocked by vanadate, indicating a putative role of the PM H+ ATPase. Indeed, an increase in PM-associated 14-3-3 proteins and an increase in PM H+ ATPase activity were detected in PGs challenged by hyperosmolar medium. We therefore suggest that in PGs the PM H+ ATPase via modulation of its activity by 14-3-3 proteins is involved in the regulation of turgor pressure.
Natural Variation in Arabidopsis Leads to the Identification of REME1, a Pentatricopeptide Repeat-DYW Protein Controlling the Editing of Mitochondrial Transcripts
Authors: Bentolila Stéphane , Knight Walter , Hanson Maureen
Published: October 2010

In vascular plants, organelle RNAs are edited by C-to-U base modification. Hundreds of mitochondrial C residues are targeted for editing in flowering plants. In this study, we exploited naturally occurring variation in editing extent to identify Required for Efficiency of Mitochondrial Editing1 (REME1), an Arabidopsis (Arabidopsis thaliana) pentatricopeptide repeat protein-encoding gene belonging to the DYW subclass that promotes editing of at least two C residues on different mitochondrial transcripts. Positional cloning identified REME1 unambiguously as the gene controlling editing of nad2-558. Virus-induced gene silencing of REME1 confirmed its role in editing of nad2-558 and allowed us to identify orfX-552 as a second C whose editing is positively controlled by REME1. An unexpected outcome of REME1 silencing was the finding of a number of mitochondrial C targets whose editing extent exhibits a significant and reproducible increase in silenced tissues. That increase was shown to be partly due to the virus inoculation and partly to REME1-specific silencing. Analysis of an insertional T-DNA mutant within the REME1 coding sequence confirmed the findings of the virus-induced gene silencing experiments: decrease in editing extent of nad2-558 and orfX-552 and increase in editing extent of two sites, matR-1771 and rpl5-92. Transgenic complementation of the low-edited accession (Landsberg erecta) restored the editing of nad2-558 and orfX-552 to high-edited accession (Columbia)-type levels or to even higher levels than Columbia. There was no effect of the transgene on editing extent of matR-1771 and rpl5-92. The strategy and tools used in this report can be applied to identify additional genes that affect editing extent in plant mitochondria.
Tumor–stroma interactions reduce the efficacy of adenoviral therapy through the HGF‐MET pathway
Authors: Yasui Takaharu , Ohuchida Kenoki , Zhao Ming , Onimaru Manabu , Egami Takuya , Fujita Hayato , Ohtsuka Takao , Mizumoto Kazuhiro , Tanaka Masao
Published: October 2010

Many preclinical studies have shown the potential of adenovirus‐based cancer gene therapy. However, successful translation of these promising results into the clinic has not yet been achieved. Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant desmoplastic stroma, and tumor–stromal cell interactions play a critical role in tumor progression. Therefore, we hypothesized that tumor–stroma interactions reduce the efficacy of adenoviral therapy. We investigated the effect of fibroblasts on adenovirus‐based gene therapy using SUIT‐2 and PANC‐1 pancreatic cancer cells cultured with or without fibroblast‐conditioned culture supernatant then infected with Ad‐LacZ. After 48 h, the cells were stained for β‐galactosidase. The results showed that the number of β‐galactosidase‐positive cells was significantly reduced after culture with fibroblast‐conditioned supernatant (P < 0.05). Because the hepatocyte growth factor (HGF)/MET pathway plays an important role in tumor–stroma interactions we next investigated the involvement of this pathway in tumor–stroma interactions leading to the decreased efficacy of adenoviral therapy. SUIT‐2 cells were cultured with or without SU11274 (a MET inhibitor) and/or fibroblast‐conditioned culture supernatant, then infected with Ad‐GFP. After 48 h, GFP‐positive cells were counted. The number of GFP‐positive cells in cultures containing fibroblast‐conditioned supernatant plus SU11274 was significantly greater than in cultures without SU11274. In conclusion, our results suggest that stromal cells in PDAC reduce the efficacy of adenoviral therapy through a mechanism involving the HGF/MET pathway. Control of such tumor–stroma interactions may lead to improvements in adenoviral gene therapy for PDAC. (Cancer Sci 2011; 102: 484–491)
Phylogenetic analysis of the latitude‐niche breadth hypothesis in the butterfly subfamily Nymphalinae
Authors: SLOVE JESSICA , JANZ NIKLAS
Published: October 2010

1. One possible explanation for the latitudinal gradient in species richness often demonstrated is a related gradient in niche breadth, which may allow for denser species packing in the more stable environments at low latitudes.

2. The evidence for such a gradient is, however, ambiguous, and the results have varied as much as the methods. Several studies have considered the non‐independence of species, but few have performed explicit phylogenetic analyses.

3. In the present study, we tested for a correlation between diet breadth and latitude of distribution in Nymphalinae butterflies using generalised estimating equations (GEE) and accounting for phylogenetic independence.

4. Using a simple model with only latitude of distribution as a predictor variable revealed a significant positive relationship with diet breadth. Previous studies, however, have shown that diet breadth is also correlated with butterfly range size, and in turn, that range size may be correlated with latitude of distribution. Including geographical range size in the model also turned out to have a profound effect on the results – to the extent that the relationship between latitude of distribution and diet breadth was effectively reversed.

5. We conclude that, at least for this group of butterflies, there is no evidence for a positive correlation between latitude of species distribution and diet breadth when controlling for range size, and that the effect may actually even be reversed.
Saccharomyces cerevisiae Ssd1p promotes CLN2 expression by binding to the 5′‐untranslated region of CLN2 mRNA
Authors: Ohyama Yoshifumi , Kasahara Koji , Kokubo Tetsuro
Published: October 2010

In Saccharomyces cerevisiae, TFIID, which is composed of TATA‐binding protein (TBP) and a set of TBP‐associated factors (TAFs), mediates the transcription of most class II genes. Previous studies have shown that CLN2 expression was significantly reduced by taf1–ts2, but not by taf1‐N568Δ, although both mutations display similar temperature‐sensitive growth phenotypes and transcriptional defects in other genes. Here, we show that the reduced expression of CLN2 is not because of differences in taf1 alleles in the previous experiments but because of allelic differences at the SSD1 locus in the host strains. Specifically, ssd1‐d reduces CLN2 expression when combined with taf1. Ssd1p expressed from SSD1‐V, but not from ssd1‐d, stabilizes a subpopulation of CLN2 mRNA in wild‐type and taf1‐N568Δ strains and facilitates the continuous transcription of CLN2 after heat shock in the taf1‐N568Δ strain. Reporter assays show that both activities appear to depend on the 5′‐untranslated region of CLN2 mRNA and that Ssd1p binds to this region via its amino‐ and carboxy‐terminal domains. Based on these observations, we propose a model for the action of Ssd1p and discuss its biologic role.
Caenorhabditis elegans UBX cofactors for CDC‐48/p97 control spermatogenesis
Authors: Sasagawa Yohei , Yamanaka Kunitoshi , Saito‐Sasagawa Yuko , Ogura Teru
Published: October 2010

UBX (ubiquitin regulatory X) domain–containing proteins act as cofactors for CDC‐48/p97. CDC‐48/p97 is essential for various cellular processes including retro‐translocation in endoplasmic reticulum–associated degradation, homotypic membrane fusion, nuclear envelope assembly, degradation of ubiquitylated proteins, and cell cycle progression. CDC‐48/p97‐dependent processes are determined by differential binding of cofactors including UBX proteins, but the cellular functions of UBX proteins have not yet been elucidated, especially in multicellular organisms. Therefore, we investigated the functions of UBX family members using Caenorhabditis elegans, which expresses six UBX proteins, UBXN‐1 to UBXN‐6. All six UBXN proteins directly interacted with CDC‐48.1 and CDC‐48.2, and simultaneous knockdown of the expression of three genes, ubxn‐1, ubxn‐2 and ubxn‐3, induced embryonic lethal and sterile phenotypes, but knockdown of either one or two did not. The sterile worms had a feminized germ‐line phenotype, producing oocytes but no sperm. UBXN‐1, UBXN‐2 and UBXN‐3 colocalized with CDC‐48 in spermatocytes but not mature sperm. TRA‐1A, which is a key factor in the sex determination pathway and inhibits spermatogenesis, accumulated in worms in which UBXN‐1, UBXN‐2 and UBXN‐3 had been simultaneously knocked down. Taken together, these results suggest that UBXN‐1, UBXN‐2 and UBXN‐3 are redundant cofactors for CDC‐48/p97 and control spermatogenesis via the degradation of TRA‐1A.
Fidelity to clinical guidelines using a care pathway in the treatment of first episode psychosis
Authors: Petrakis Melissa , Hamilton Bridget , Penno Steve , Selvendra Ajit , Laxton Simon , Doidge Graeme , Svenson Megan , Castle David
Published: October 2010

Objective  To evaluate the implementation of clinical practice guidelines in the initial stages of treatment of first episode psychosis, through use of a care pathway within one area mental health service.

Methods  A fidelity audit was undertaken using data from local Early Psychosis Care Pathway documents, completed for the cohort of clients with early psychosis seen in the first 2 years of an integrated early psychosis programme model, at St Vincent's Mental Health Service, Melbourne, Australia.

Results  The utilisation of a care pathway greatly supported both the documentation of clinical process and fidelity to clinical guidelines in early psychosis treatment. Excellent adherence (over 80%) was achieved for therapeutic alliance with the client, conducting a comprehensive bio‐psychosocial assessment, medical investigations, reduction of client trauma and increased orientation to the service and the mental health systems of care, and for contact with family. Good adherence (over 70%) was achieved for client re‐integration to the community and promotion of carer well‐being; the service plans to focus on these areas in future service improvement initiatives, along with a focus on physical health assessment and enhancing primary care liaison.

Conclusions  The process of formally operationalizing and implementing clinical guidelines utilizing a care pathway within an area mental health service has proved to be an effective way to ensure fidelity with standard agency practices and protocols. The integrated approach, supported by quality assurance initiatives, provides an excellent goodness‐of‐fit within an established area mental health service.
Taking the PACIC back to basics: the structure of the Patient Assessment of Chronic Illness Care
Authors: Spicer John , Budge Claire , Carryer Jenny
Published: October 2010

Rationale, aims and objectives  The Patient Assessment of Chronic Illness Care (PACIC) is a widely used 20‐item measure consisting of five subscales. Published factor analyses of PACIC scores have produced conflicting results on the measure's factorial validity, and therefore some confusion as to the utility of its subscales. We aim to reduce this confusion by reviewing the evidence on the PACIC's factorial validity, exploring the statistical issues it raises, and considering more broadly what such analyses can reveal about the validity of the PACIC.

Methods  To achieve these aims we review six published studies on the PACIC's factorial validity, present confirmatory factor analyses of our own PACIC data from 251 chronic care patients, and assess the PACIC with respect to its status as a reflective or a formative measure.

Results  Our statistical analyses support the view that a 5‐factor model does not fit the structure of the PACIC, and highlight a variety of technical issues that confront researchers who wish to factor analyse the measure. However, we argue that, as the PACIC is more accurately seen as a formative measure, such analyses do not provide information that should be used to assess the PACIC's validity.

Conclusions  We conclude that, while it is important to continue examining the reliability and validity of the PACIC in a variety of ways, traditional analyses of its factorial validity (and internal consistency) are inappropriate. Meanwhile, use of the subscales is defensible as long as they continue to meet other types of reliability and validity requirements.
Psychometric properties of a scale to measure investment in the sick role: the Illness Cognitions Scale
Authors: Berk Michael , Berk Lesley , Dodd Seetal , Jacka Felice N. , Fitzgerald Paul B. , de Castella Anthony R. , Filia Sacha , Filia Kate , Kulkarni Jayashri , Jackson Henry J. , Stafford Lesley
Published: October 2010

Rationale, aims and objectives A person's beliefs about their illness may contribute to recovery and prognosis. Some degree of acceptance of illness and its impact is necessary to integrate the presence of a chronic disorder into one's lifestyle and adhere to necessary components of illness management; however, some individuals can become ‘stuck’ and have difficulty adjusting out of the sick role. Inventories exist to measure illness cognitions, attitudes and behaviours as they relate to hypochondria and psychosomatic illness, but there is no extant measure of sick role inertia. We describe the psychometric properties of a new scale, the Illness Cognitions Scale (ICS), a metric of investment in the sick role.

Methods The ICS was administered to 97 individuals with bipolar or schizoaffective disorder, and the psychometric properties of the scale measured. Dimensionality was assessed using Principal Components Analysis with Oblimin rotation.

Results The scale has a strong internal consistency, with a Cronbach's alpha of 0.858. Results of a factor analysis suggested the presence of one main factor, with three other smaller, related sub‐factors, capturing aspects of maladaptive illness beliefs.

Conclusion The ICS is a 17‐item, internally validated scale measuring difficulty adjusting out of the sick role. The scale predominantly measures a single construct. Further research on external validity of the ICS is required as well as determination of the clinical significance and patient acceptability of the scale.
Genetic evidence for male‐biased dispersal in the Siberian jay (Perisoreus infaustus) based on autosomal and Z‐chromosomal markers
Authors: LI M.‐H. , MERILÄ J.
Published: October 2010

Sex‐bias in natal dispersal patterns can have important genetic and evolutionary consequences; however, reliable information about sex‐biased dispersal can be difficult to obtain with observational methods. We analysed the sex‐specific patterns of genetic differentiation among three Siberian jay (Perisoreus infaustus) populations, using 11 autosomal and six Z‐chromosomal microsatellite markers. Irrespective of marker‐type and indices used (viz. FST, average pairwise relatedness and effective number of immigrants), all analyses provided strong evidence for male‐biased dispersal. Population structuring at autosomal loci (FST = 0.046, P < 0.05) exceeded that at Z‐chromosomal loci (FST = 0.033, P < 0.05), and levels of introgression were inferred to be significantly higher for Z‐chromosomal when compared to autosomal loci. Of the three populations studied, levels of genetic variability were the lowest in the southernmost fringe population, despite the fact that it harboured a group of divergent Z‐chromosomal haplotypes that were not found in the other two populations. In general, the results provide strong genetic evidence for male‐biased dispersal in Siberian jays, where observational data have previously suggested male philopatry. The results also highlight the utility of Z‐chromosomal markers for gaining insights into the genetic diversity and structuring of populations.
Intestinal immune response of Silurus glanis and Barbus barbus naturally infected with Pomphorhynchus laevis (Acanthocephala)
Authors: DEZFULI B. S. , CASTALDELLI G. , BO T. , LORENZONI M. , GIARI L.
Published: October 2010

Immunopathological and ultrastructural studies were conducted on the intestine of barbel Barbus barbus and sheatfish Silurus glanis that were naturally infected with the acanthocephalan Pomphorhynchus laevis. Enteric helminths often cause inflammation of the digestive tract, inducing the recruitment of different types of immune cells at the site of infection. The results of our study clearly demonstrated that mast cells (MC) were the dominant immune cells which occur at the site of inflammation in both hosts. MC were associated with fibroblasts and were found in close proximity to, and inside, the capillaries of the intestine, thus, migration of mast cells via the bloodstream was suggested. Significant degranulation of MC was present. Immunohistochemical staining revealed met‐enkephalin and serotonin (5‐HT) in intestinal MC of both uninfected and infected barbel and the absence of the antimicrobial peptides piscidin 3 and piscidin 4 in both species. Data are discussed with respect to host immune response to an intestinal helminth and compared with other host‐parasite systems.
Frequent down‐regulation of hABH2 in gastric cancer and its involvement in growth of cancer cells
Authors: Gao Wei , Li Leijia , Xu Ping , Fang Jingyuan , Xiao Shudong , Chen Shengliang
Published: October 2010

Background and Aim:  Methyl or 1, N6‐ethenoadenine base lesions are frequent and highly‐mutagenic or ‐carcinogenic events in mammalian DNA. Human AlkB homologue‐2 (hABH2), a homologue of the Escherichia coli AlkB protein, has been found to be the principal dioxygenase for the repair of these lesions. Mounting evidence indicates that impaired DNA repair contributes to gastric cancer induction and progression. Whether hABH2 is involved in this malignancy is unknown. The present study was aimed to investigate the expression profile of hABH2 in gastric cancer and the effect of hABH2 on cancer cell growth.

Methods:  The expression of hABH2 in 35 pair‐matched gastric neoplastic and adjacent non‐neoplastic tissues, and in five gastric cancer cell lines, was examined by real‐time polymerase chain reaction (PCR), immunohistochemistry, or Western blot. The cell growth was determined using cell‐counting kit‐8 assay. The apoptosis or cell‐cycle analysis was determined using flow cytometry.

Results:  The hABH2 expression was downregulated in 68% (24/35) of primary gastric cancers, as determined by real‐time PCR; the hABH2 expression was also substantially decreased in gastric cancer cell lines. Immunohistochemical or Western blot analysis further confirmed the downregulation of hABH2 expression in gastric cancers. The overexpression of hABH2 significantly inhibited the proliferation of gastric cancer cells, and induced G1 arrest of the cell cycle, while hABH2 knockdown promoted cell growth and cell‐cycle progression of gastric cancer cells.

Conclusions:  These results suggest that hABH2 is downregulated in a subset of gastric cancers, and might be involved in the molecular mechanism of gastric cancer through inhibiting the proliferation of gastric cancer cells.
Ovarian cyst torsion coexisting with acute pyelonephritis in an eight‐year‐old premenarchal girl
Authors: Kim Rahyeon , Kim Youngjae , Roh Jaesook
Published: October 2010

We report the case of a premenarchal eight‐year‐old girl with an adnexal torsion accompanied by acute pyelonephritis with vague, non‐specific symptoms. In young girls, symptoms may be vague, with patients complaining of non‐specific gastro‐intestinal problems. Combination with other complications such as pyelonephritis makes the diagnosis of adnexal torsion even more difficult as in the present case. To preserve future reproductive function, early surgical intervention is required. Although the impact on menarchal development of oophorectomy or partial removal of ovarian tissue before menarche remains to be evaluated, timely recognition and treatment of adnexal torsion clearly increases the possibility of retaining the ovary. Therefore, to decrease the time between the onset of symptoms and the identification of patients at risk, sonography should be considered as a first imaging modality for evaluating children with any degree of abdominal pain accompanied by non‐specific symptoms.
A simplified table improves the recognition of paediatric hypertension
Authors: Mitchell Charlene K , Theriot Judith A , Sayat Jonathan G , Muchant Dianne G , Franco Sofia M
Published: October 2010

Aim:  Unrecognised and untreated hypertension can lead to significant morbidity and mortality over time. In a 2003 chart review, we found that our providers only recognised 15% of hypertensive blood pressure (BP). Our objective was to determine whether a simplified BP table improves the recognition of elevated BP in children.

Methods:  We developed a simplified BP table for children 3–18 years and posted it in provider work areas beginning August 2006. We reviewed a retrospective sample of well visits for children aged 3–18 years, with equal numbers by sex and year of age, presenting at a university‐based paediatric clinic between January and August 2007. Visit notes for all children with elevated BP values ≥90th percentile were reviewed to identify whether the provider recognised that the BP was elevated.

Results:  In 493 well visits, 85 (17.2%) children had pre‐hypertensive (90th to <95th percentile) and 100 (20.3%) had hypertensive (≥95th percentile) BP values. Providers recognised elevations in 34 (40%) pre‐hypertensive and 77 (77%) hypertensive measurements. Recognition was significantly more common for those in the hypertensive than the pre‐hypertensive range (χ2 = 24.9, degrees of freedom = 1, P < 0.001). Compared with our 2003 data, recognition of hypertensive BP values was significantly greater (77% vs. 15%) (t = 14.479, degrees of freedom = 98, P < 0.001) after introduction of the simplified BP table.

Conclusions:  Use of a simplified BP table can lead to significantly improved recognition of elevated BP in children.
Maternal psychosocial factors around delivery on development of 2‐year‐old children: A prospective cohort study
Authors: Chuang Chao‐Hua , Liao Hua‐Fang , Hsieh Wu‐Shiun , Jeng Suh‐Fang , Su Yi‐Ning , Chen Pau‐Chung
Published: October 2010

Aim:  To explore whether maternal psychosocial factors around delivery are related to development of 2‐year‐old children.

Methods:  Pregnant women going to the hospital for delivery were recruited, and their children were observed at 24 months. A total of 186 mother–child dyads completed the measurement. Self‐report data of maternal psychosocial factors around delivery were selected from the Taiwanese version of the short‐form 36. The Comprehensive Developmental Inventory for Infants and Toddlers was completed by interviewers and the main care givers for the child at 2 years old.

Results:  Using the multiple linear regression analysis and adjusting for potential confounders, maternal vitality around delivery was found to have a significantly positive relationship with the whole Comprehensive Developmental Inventory for Infants and Toddlers (P = 0.005) and self‐help development (P = 0.001), but work stress had a significantly negative relationship with motor development (seldom, P = 0.050; always, P = 0.048).

Conclusions:  Maternal vitality around delivery was beneficial to a child's self‐help development, while work stress seemed to be an adverse effect on child's motor development in later life. It is important to improve the psychosocial health of pregnant women.