bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure of the bacteriophage T4 long tail fiber receptor-binding tip
Authors: Bartual Sergio G. , Otero José M. , Garcia-Doval Carmela , Llamas-Saiz Antonio L. , Kahn Richard , Fox Gavin C. , van Raaij Mark J.
Published: November 2010

Bacteriophages are the most numerous organisms in the biosphere. In spite of their biological significance and the spectrum of potential applications, little high-resolution structural detail is available on their receptor-binding fibers. Here we present the crystal structure of the receptor-binding tip of the bacteriophage T4 long tail fiber, which is highly homologous to the tip of the bacteriophage lambda side tail fibers. This structure reveals an unusual elongated six-stranded antiparallel beta-strand needle domain containing seven iron ions coordinated by histidine residues arranged colinearly along the core of the biological unit. At the end of the tip, the three chains intertwine forming a broader head domain, which contains the putative receptor interaction site. The structure reveals a previously unknown beta-structured fibrous fold, provides insights into the remarkable stability of the fiber, and suggests a framework for mutations to expand or modulate receptor-binding specificity.
Ivermectin disrupts the function of the excretory-secretory apparatus in microfilariae of
Brugia malayi
Authors: Moreno Yovany , Nabhan Joseph F. , Solomon Jonathan , Mackenzie Charles D. , Geary Timothy G.
Published: November 2010

Ivermectin (IVM) is a broad-spectrum anthelmintic used in filariasis control programs. By binding to nematode glutamate-gated chloride channels (GluCls), IVM disrupts neurotransmission processes regulated by GluCl activity. IVM treatment of filarial infections is characterized by an initial dramatic drop in the levels of circulating microfilariae, followed by long-term suppression of their production, but the drug has little direct effect on microfilariae in culture at pharmacologically relevant concentrations. We localized
Brugia malayi
GluCl expression solely in a muscle structure that surrounds the microfilarial excretory-secretory (ES) vesicle, which suggests that protein release from the ES vesicle is regulated by GluCl activity. Consistent with this hypothesis, exposure to IVM in vitro decreased the amount of protein released from microfilariae. To better understand the scope of IVM effects on protein release by the parasite, three different expression patterns were identified from immunolocalization assays on a representative group of five microfilarial ES products. Patterns of expression suggest that the ES apparatus is the main source of regulated ES product release from microfilariae, as it is the only compartment that appears to be under neuromuscular control. Our results show that IVM treatment of microfilariae results in a marked reduction of protein release from the ES apparatus. Under in vivo conditions, the rapid microfilarial clearance induced by IVM treatment is proposed to result from suppression of the ability of the parasite to secrete proteins that enable evasion of the host immune system.
Relation of Phanerozoic stable isotope excursions to climate, bacterial metabolism, and major extinctions
Authors: Stanley Steven M.
Published: November 2010

Conspicuous global stable carbon isotope excursions that are recorded in marine sedimentary rocks of Phanerozoic age and were associated with major extinctions have generally paralleled global stable oxygen isotope excursions. All of these phenomena are therefore likely to share a common origin through global climate change. Exceptional patterns for carbon isotope excursions resulted from massive carbon burial during warm intervals of widespread marine anoxic conditions. The many carbon isotope excursions that parallel those for oxygen isotopes can to a large degree be accounted for by the Q10 pattern of respiration for bacteria: As temperature changed along continental margins, where ∼90% of marine carbon burial occurs today, rates of remineralization of isotopically light carbon must have changed exponentially. This would have reduced organic carbon burial during global warming and increased it during global cooling. Also contributing to the
δ
13
C excursions have been release and uptake of methane by clathrates, the positive correlation between temperature and degree of fractionation of carbon isotopes by phytoplankton at temperatures below ∼15°, and increased phytoplankton productivity during “icehouse” conditions. The Q10 pattern for bacteria and climate-related changes in clathrate volume represent positive feedbacks for climate change.
Autocrine TGF-β and stromal cell-derived factor-1 (SDF-1) signaling drives the evolution of tumor-promoting mammary stromal myofibroblasts
Authors: Kojima Yasushi , Acar Ahmet , Eaton Elinor Ng , Mellody Kieran T. , Scheel Christina , Ben-Porath Ittai , Onder Tamer T. , Wang Zhigang C. , Richardson Andrea L. , Weinberg Robert A. , Orimo Akira
Published: November 2010

Much interest is currently focused on the emerging role of tumor-stroma interactions essential for supporting tumor progression. Carcinoma-associated fibroblasts (CAFs), frequently present in the stroma of human breast carcinomas, include a large number of myofibroblasts, a hallmark of activated fibroblasts. These fibroblasts have an ability to substantially promote tumorigenesis. However, the precise cellular origins of CAFs and the molecular mechanisms by which these cells evolve into tumor-promoting myofibroblasts remain unclear. Using a coimplantation breast tumor xenograft model, we show that resident human mammary fibroblasts progressively convert into CAF myofibroblasts during the course of tumor progression. These cells increasingly acquire two autocrine signaling loops, mediated by TGF-β and SDF-1 cytokines, which both act in autostimulatory and cross-communicating fashions. These autocrine-signaling loops initiate and maintain the differentiation of fibroblasts into myofibroblasts and the concurrent tumor-promoting phenotype. Collectively, these findings indicate that the establishment of the self-sustaining TGF-β and SDF-1 autocrine signaling gives rise to tumor-promoting CAF myofibroblasts during tumor progression. This autocrine-signaling mechanism may prove to be an attractive therapeutic target to block the evolution of tumor-promoting CAFs.
Transposable element insertions have strongly affected human evolution
Authors: Britten Roy J.
Published: November 2010

Comparison of a full collection of the transposable element (TE) sequences of vertebrates with genome sequences shows that the human genome makes 655 perfect full-length matches. The cause is that the human genome contains many active TEs that have caused TE inserts in relatively recent times. These TE inserts in the human genome are several types of young Alus (AluYa5, AluYb8, AluYc1, etc.). Work in many laboratories has shown that such inserts have many effects including changes in gene expression, increases in recombination, and unequal crossover. The time of these very effective changes in the human lineage genome extends back about 4 million years according to these data and very likely much earlier. Rapid human lineage-specific evolution, including brain size is known to have also occurred in the last few million years. Alu insertions likely underlie rapid human lineage evolution. They are known to have many effects. Examples are listed in which TE sequences have influenced human-specific genes. The proposed model is that the many TE insertions created many potentially effective changes and those selected were responsible for a part of the striking human lineage evolution. The combination of the results of these events that were selected during human lineage evolution was apparently effective in producing a successful and rapidly evolving species.
Aryl hydrocarbon receptor negatively regulates dendritic cell immunogenicity via a kynurenine-dependent mechanism
Authors: Nguyen Nam Trung , Kimura Akihiro , Nakahama Taisuke , Chinen Ichino , Masuda Kazuya , Nohara Keiko , Fujii-Kuriyama Yoshiaki , Kishimoto Tadamitsu
Published: November 2010

Although an immunoregulatory role of aryl hydrocarbon receptor (Ahr) has been demonstrated in T cells and macrophages, little is known about its function in dendritic cells (DC). Here, we show that lipopolysaccharide (LPS) and CpG stimulate Ahr expression in bone marrow-derived dendritic cells (BMDC). Furthermore, we found that Ahr is required to induce indoleamine 2,3-dioxygenase (IDO) expression, an immunosuppressive enzyme that catabolizes tryptophan into kynurenine (Kyn) and other metabolites in DC. In the presence of LPS or CpG, Ahr-deficient (Ahr
−/−
) mature BMDC induced immune responses characterized by reduced Kyn and IL-10 production compared with results observed with tolerogenic mature WT BMDC. In a coculture system with LPS- or CpG-stimulated BMDC and naive T cells, Ahr
−/−
BMDC inhibited naive T-cell differentiation into regulatory T (Treg) cells, which likely facilitated Th17 cell development and promoted naive T-cell proliferation. Addition of synthetic L-Kyn to the coculture system skewed the differentiation of naive T cells to Treg cells rather than Th17 cells. Taken together, our results demonstrate a previously unknown negatively regulatory role for Ahr in DC-mediated immunogenesis in the presence of LPS or CpG, which, in turn, alters the Kyn-dependent generation of Treg cells and Th17 cells from naive T cells.
MyD88 signaling in nonhematopoietic cells protects mice against induced colitis by regulating specific EGF receptor ligands
Authors: Brandl Katharina , Sun Lei , Neppl Christina , Siggs Owen M. , Le Gall Sylvain M. , Tomisato Wataru , Li Xiaohong , Du Xin , Maennel Daniela N. , Blobel Carl P. , Beutler Bruce
Published: November 2010

Toll-like receptors (TLRs) trigger intestinal inflammation when the epithelial barrier is breached by physical trauma or pathogenic microbes. Although it has been shown that TLR-mediated signals are ultimately protective in models of acute intestinal inflammation [such as dextran sulfate sodium (DSS)-induced colitis], it is less clear which cells mediate protection. Here we demonstrate that TLR signaling in the nonhematopoietic compartment confers protection in acute DSS-induced colitis. Epithelial cells of MyD88/Trif-deficient mice express diminished levels of the epidermal growth factor receptor (EGFR) ligands amphiregulin (AREG) and epiregulin (EREG), and systemic lipopolysaccharide administration induces their expression in the colon.
N
-ethyl-
N
-nitrosourea (ENU)-induced mutations in
Adam17
(which is required for AREG and EREG processing) and in
Egfr
both produce a strong DSS colitis phenotype, and the
Adam17
mutation exerts its deleterious effect in the nonhematopoietic compartment. The effect of abrogation of TLR signaling is mitigated by systemic administration of AREG. A TLR→MyD88→AREG/EREG→EGFR signaling pathway is represented in nonhematopoietic cells of the intestinal tract, responds to microbial stimuli once barriers are breached, and mediates protection against DSS-induced colitis.
Real-time analysis of T cell receptors in naive cells in vitro and in vivo reveals flexibility in synapse and signaling dynamics
Authors: Friedman Rachel S. , Beemiller Peter , Sorensen Caitlin M. , Jacobelli Jordan , Krummel Matthew F.
Published: November 2010

The real-time dynamics of the T cell receptor (TCR) reflect antigen detection and T cell signaling, providing valuable insight into the evolving events of the immune response. Despite considerable advances in studying TCR dynamics in simplified systems in vitro, live imaging of subcellular signaling complexes expressed at physiological densities in intact tissues has been challenging. In this study, we generated a transgenic mouse with a TCR fused to green fluorescent protein to provide insight into the early signaling events of the immune response. To enable imaging of TCR dynamics in naive T cells in the lymph node, we enhanced signal detection of the fluorescent TCR fusion protein and used volumetric masking with a second fluorophore to mark the T cells expressing the fluorescent TCR. These in vivo analyses and parallel experiments in vitro show minimal and transient incorporation of TCRs into a stable central supramolecular activating cluster (cSMAC) structure but strong evidence for rapid, antigen-dependent TCR internalization that was not contingent on T cell motility arrest or cSMAC formation. Short-lived antigen-independent TCR clustering was also occasionally observed. These in vivo observations demonstrate that varied TCR trafficking and cell arrest dynamics occur during early T cell activation.
A BAFF-R mutation associated with non-Hodgkin lymphoma alters TRAF recruitment and reveals new insights into BAFF-R signaling
Authors: Hildebrand Joanne M. , Luo Zhenghua , Manske Michelle K. , Price-Troska Tammy , Ziesmer Steven C. , Lin Wai , Hostager Bruce S. , Slager Susan L. , Witzig Thomas E. , Ansell Stephen M. , Cerhan James R. , Bishop Gail A. , Novak Anne J.
Published: November 2010

The cytokine B cell activating factor (BAFF) and its receptor, BAFF receptor (BAFF-R), modulate signaling cascades critical for B cell development and survival. We identified a novel mutation in TNFRSF13C, the gene encoding human BAFF-R, that is present in both tumor and germline tissue from a subset of patients with non-Hodgkin lymphoma. This mutation encodes a His159Tyr substitution in the cytoplasmic tail of BAFF-R adjacent to the TRAF3 binding motif. Signaling through this mutant BAFF-R results in increased NF-κB1 and NF-κB2 activity and increased immunoglobulin production compared with the wild-type (WT) BAFF-R. This correlates with increased TRAF2, TRAF3, and TRAF6 recruitment to His159Tyr BAFF-R. In addition, we document a requirement for TRAF6 in WT BAFF-R signaling. Together, these data identify a novel lymphoma-associated mutation in human BAFF-R that results in NF-κB activation and reveals TRAF6 as a necessary component of normal BAFF-R signaling.
On the existence of open and bi-continuing codes
Authors: Jung Uijin
Published: November 2010

Given an irreducible sofic shift

X
X

, we show that an irreducible shift of finite type

Y
Y

of lower entropy is a factor of

X
X

if and only if it is a factor of

X
X

by an open bi-continuing code. If these equivalent conditions hold and

Y
Y

is mixing, then any code from a proper subshift of

X
X

to

Y
Y

can be extended to an open bi-continuing code on

X
X

. These results are still valid when

X
X

is assumed to be only an almost specified shift, i.e., a subshift satisfying an irreducible version of the specification property.
Multi-dimensional Morse Index Theorems and a symplectic view of elliptic boundary value problems
Authors: Deng Jian , Jones Christopher
Published: November 2010

Morse Index Theorems for elliptic boundary value problems in multi-dimensions are proved under various boundary conditions. The theorems work for star-shaped domains and are based on a new idea of measuring the “oscillation” of the trace of the set of solutions on a shrinking boundary. The oscillation is measured by formulating a Maslov index in an appropriate Sobolev space of functions on this boundary. A fundamental difference between the cases of Dirichlet and Neumann boundary conditions is exposed through a monotonicity that holds only in the former case.
Generalized log sine integrals and the Mordell-Tornheim zeta values
Authors: Onodera Kazuhiro
Published: November 2010

We introduce certain integrals of a product of the Bernoulli polynomials and logarithms of Milnor’s multiple sine functions. It is shown that all the integrals are expressed by the Mordell-Tornheim zeta values at positive integers and that the converse is also true. Moreover, we apply the theory of the integral to obtain various new results for the Mordell-Tornheim zeta values.
A trichotomy of countable, stable, unsuperstable theories
Authors: Laskowski Michael , Shelah S.
Published: November 2010

Every countable, strictly stable theory either has the Dimensional Order Property (DOP), is deep, or admits an ‘abelian group witness to unsuperstability’. To obtain this and other results, we develop the notion of a ‘regular ideal’ of formulas and study types that are minimal with respect to such an ideal.
Refinements of the Littlewood-Richardson rule
Authors: Haglund J. , Luoto K. , Mason S. , van Willigenburg S.
Published: November 2010

In the prequel to this paper, we showed how results of Mason involving a new combinatorial formula for polynomials that are now known as Demazure atoms (characters of quotients of Demazure modules, called standard bases by Lascoux and Schützenberger) could be used to define a new basis for the ring of quasisymmetric functions we call “Quasisymmetric Schur functions” (QS functions for short). In this paper we develop the combinatorics of these polynomials further, by showing that the product of a Schur function and a Demazure atom has a positive expansion in terms of Demazure atoms. We use these techniques, together with the fact that both a QS function and a Demazure character have explicit expressions as a positive sum of atoms, to obtain the expansion of a product of a Schur function with a QS function (Demazure character) as a positive sum of QS functions (Demazure characters). Our formula for the coefficients in the expansion of a product of a Demazure character and a Schur function into Demazure characters is similar to known results and includes in particular the famous Littlewood-Richardson rule for the expansion of a product of Schur functions in terms of the Schur basis.
Predictors and prognostic impact of recurrent myocardial infarction in patients with left ventricular dysfunction, heart failure, or both following a first myocardial infarction
Authors: Thune Jens Jakob , Signorovitch James E. , Kober Lars , McMurray John J.V. , Swedberg Karl , Rouleau Jean , Maggioni Aldo , Velazquez Eric , Califf Robert , Pfeffer Marc A. , Solomon Scott D.
Published: October 2010

Aims

Recurrent myocardial infarction (MI) is common after a first MI and is associated with increased morbidity and mortality. Predictors and prognosis of a recurrent MI with contemporary management are not well known.

Methods and results

We assessed the predictors and prognostic impact of a first recurrent MI in 10 599 patients with left ventricular dysfunction, heart failure, or both following a first MI from the Valsartan in Acute Myocardial Infarction Trial (VALIANT) cohort. During a median follow‐up of 27.4 months, 861 patients (9.6%) had a recurrent MI. The median time to recurrence was 136 days (quartiles 35–361 days), with a declining rate of recurrent MI within the first 3 months. The strongest predictors of recurrent MI were reduced estimated glomerular filtration rate, unstable angina, diabetes, and age. Mortality was markedly elevated (20.5%) within the first 7 days of a recurrent MI. Patients who survived 7 days after a recurrent MI continued to be at increased risk of death compared with patients without a recurrent MI and the risk of death remained elevated more than two‐fold a year after the recurrent MI (adjusted hazards ratio 2.4, 95% confidence interval 1.7–3.2). One‐year mortality for the entire VALIANT cohort was 10.3%, whereas 38.3% of the patients were dead 1 year after recurrent MI. Early reinfarctions (within 1 month) was associated with significantly higher 30‐day mortality than later reinfarctions.

Conclusion

Even in the context of contemporary treatment, a recurrent MI confers a significantly increased risk of death in patients following a high‐risk first MI. Strategies aimed at reducing recurrent MI will thus likely prolong survival in post‐MI survivors.
The Pseudomonas Secondary Metabolite 2,4-Diacetylphloroglucinol Is a Signal Inducing Rhizoplane Expression of Azospirillum Genes Involved in Plant-Growth Promotion
Authors: Combes-Meynet Emeline , Pothier Joël F. , Moënne-Loccoz Yvan , Prigent-Combaret Claire
Published: November 2010

During evolution, plants have become associated with guilds of plant-growth-promoting rhizobacteria (PGPR), which raises the possibility that individual PGPR populations may have developed mechanisms to cointeract with one another on plant roots. We hypothesize that this has resulted in signaling phenomena between different types of PGPR colonizing the same roots. Here, the objective was to determine whether the Pseudomonas secondary metabolite 2,4-diacetylphloroglucinol (DAPG) can act as a signal on Azospirillum PGPR and enhance the phytostimulation effects of the latter. On roots, the DAPG-producing Pseudomonas fluorescens F113 strain but not its phl-negative mutant enhanced the phytostimulatory effect of Azospirillum brasilense Sp245-Rif on wheat. Accordingly, DAPG enhanced Sp245-Rif traits involved in root colonization (cell motility, biofilm formation, and poly-β-hydroxybutyrate production) and phytostimulation (auxin production). A differential fluorescence induction promoter-trapping approach based on flow cytometry was then used to identify Sp245-Rif genes upregulated by DAPG. DAPG enhanced expression of a wide range of Sp245-Rif genes, including genes involved in phytostimulation. Four of them (i.e., ppdC, flgE, nirK, and nifX-nifB) tended to be upregulated on roots in the presence of P. fluorescens F113 compared with its phl-negative mutant. Our results indicate that DAPG can act as a signal by which some beneficial pseudomonads may stimulate plant-beneficial activities of Azospirillum PGPR.
Root Infections May Challenge Management of Invasive Phytophthora spp. in U.K. Woodlands
Authors: Fichtner E. J. , Rizzo D. M. , Kirk S. A. , Webber J. F.
Published: November 2010

Because sporulation of Phytophthora ramorum and P. kernoviae on Rhododendron ponticum, an invasive plant, serves as primary inoculum for trunk infections on trees, R. ponticum clearance from pathogen-infested woodlands is pivotal to inoculum management. The efficacy of clearance for long-term disease management is unknown, in part due to lack of knowledge of pathogen persistence in roots and emerging seedlings. The main objectives of this work were to (i) investigate whether both pathogens infect R. ponticum roots, (ii) determine the potential for residual inoculum of P. kernoviae to infect R. ponticum seedlings in cleared woodlands, and (iii) assess potential for R. ponticum roots to support survival and transmission of P. kernoviae. Roots of R. ponticum were collected from both unmanaged and cleared woodlands and assessed for pathogen recovery. Both P. ramorum and P. kernoviae were recovered from asymptomatic roots of R. ponticum in unmanaged woodlands, and P. kernoviae was recovered from asymptomatic roots from seedlings in cleared woodland. Oospore production of P. kernoviae was observed in naturally infected R. ponticum foliage and in inoculated roots. Roots also supported P. kernoviae sporangia production. The results of this study suggest that post-clearance management of R. ponticum regrowth is necessary for long-term inoculum management in invaded woodlands.
Selection of Biocontrol Agents of Pink Rot Based on Efficacy and Growth Kinetics Index Rankings
Authors: Adiyaman Tugba , Schisler David A. , Slininger Patricia J. , Sloan Jennifer M. , Jackson Mark A. , Rooney Alejandro P.
Published: November 2010

The microbiota of 84 different agricultural soils were transferred to separate samples of a γ irradiation-sterilized field soil enriched with potato periderm, and the resulting soils were assayed for biological suppressiveness to Phytophthora erythroseptica and their effect on zoospore production. The 13 most suppressive soil samples, which reduced zoospore production by 14 to 93% and disease severity on tubers by 6 to 21%, were used to isolate 279 organisms. Fourteen strains that reduce pink rot infections in preliminary tests were selected for further study. Six bacterial strains that reduced the severity of disease (P ≤ 0.05, Fischer's protected least significant difference) in subsequent tests were identified as Bacillus simplex (three strains), Pantoea agglomerans, Pseudomonas koreensis, and P. lini. Relative performance indices (RPIs) for biocontrol efficacy and for each of four kinetic parameters, including total colony-forming units (CFUmax), biomass production values (DWmax), cell production after 8 h (OD8), and time of recovery from oxygen depletion (DT) were calculated for each strain. Overall RPIEff,Kin values for each strain then were calculated using strain RPI values for both efficacy (RPIEff) and kinetics (RPIKin). Strains with the highest RPIEff,Kin possess the best biocontrol efficacy of the strains tested and liquid culture growth characteristics that suggest commercial development potential.
Identification of Sources of Resistance toXanthomonas campestrispv.campestrisinBrassica napusCrops
Authors: Lema M. , Soengas P. , Velasco P. , Francisco M. , Cartea M. E.
Published: November 2010

Black rot, caused by Xanthomonas campestris pv. campestris, is one of the most important diseases affecting Brassica crops worldwide. Nine races have been differentiated in X. campestris pv. campestris, with races 1 and 4 being the most virulent and widespread. The objective of this work was to identify sources of resistance to races 1 and 4 of X. campestris pv. campestris in different Brassica napus crops, mainly in the underexplored pabularia group. Seventy-six accessions belonging to four B. napus groups were screened for resistance to two X. campestris pv. campestris races (1 and 4). The strain of race 1 used in this study was more virulent on the tested materials than the strain of race 4. No race-specific resistance was found to race 1. Most cultivars were susceptible except Russian kale, from the pabularia group, which showed some resistant plants and some other accessions with some partially resistant plants. High levels of race-specific resistance to race 4 were found in the pabularia group, and great variability within accessions was identified. Three improved cultivars (Ragged Jack kale, Friese Gele, and Valle del Oro) and four landraces (Russian kale, MBG-BRS0037, MBG-BRS0041, and MBG-BRS0131) showed plants with some degree of resistance to both races, which may indicate that race-nonspecific resistance is involved. These accessions could be directly used in breeding programs, either as improved cultivars or as donors of race-specific resistance to other Brassica cultivars.
Colletotrichum simmondsii Causing Anthracnose on Safflower in the Czech Republic
Authors: Víchová J. , Vejražka K. , Cholastová T. , Pokorný R. , Hrudová E.
Published: November 2010

Safflower (Carthamus tinctorius L.) is an oil crop that is suitable for dry growing conditions in the Czech Republic. Most of the Czech production is used as bird feed. Typical anthracnose symptoms were observed at one safflower field in the Moravia Region of the Czech Republic during the 2005 growing season. Since then, the disease has become widespread with 100% yield losses observed in several locations in 2009. Symptoms consisted of circular spots on leaves and stem blight characterized by dark-colored stem lesions bearing salmon-colored conidia masses in acervuli. A fungus was isolated from symptomatic safflower plants (cv. Sabina) on potato dextrose agar and incubated at 25°C as described by Kwon et al. (3). The color of fungal colonies changed from white to gray with age with salmon-orange pigmentation on the reverse side of plates. Similar observations had been reported by Jelev et al. (1). Conidia were colorless, fusiform, and measured 10 to 17 μm (mean 13.59) × 4 to 8 μm (mean 5.98). Morphology suggested a Colletotrichum sp. To fulfill Koch' postulates, safflower plants at the BBCH 12 growth stage (second leaf fully expanded) were spray inoculated with a conidia suspension (1 × 105 conidia/ml). Growth chamber conditions were temperature 20 ± 1°C, relative humidity 70 ± 5%, with a 16-h photoperiod. Control plants were treated with sterile distilled water. Typical anthracnose symptoms were observed 1 week after inoculation. Control plants were symptomless. The pathogen was reisolated from infected stems and leaves. PCR with primers CaInt2 and ITS4 was used to confirm the identification of a Colletotrichum sp. Reaction products obtained with these primers were approximately 500 bp long. The ribosomal DNA internal transcribed spacer region containing ITS1, 5.8S, and ITS2 of the isolate from safflower was sequenced and identified with the BLASTn program. The sequence matches with 100% similarity to the sequence of the Glomerella acutata teleomorph of Colletotrichum acutatum (GenBank Accession No. AB548282) and 100% similarity to C. simmondsii (GenBank Accession No. GU183359). C. acutatum and C. simmondsii can be distinguished from each other by pigment color (4), with the safflower isolate matching the description of C. simmondsii. Kim et al. (2) recorded C. acutatum on safflower fields in the Euiseong area of Korea in 1997. To our knowledge, this is the first report of C. simmondsii causing safflower anthracnose in the Czech Republic.

References: (1) Z. J. Jelev et al. Plant Dis. 92:172, 2008. (2) W. G. Kim et al. Plant Pathol. J. 15:62, 1999. (3) J. H. Kwon et al. Plant Pathol. J. 15:172, 1999. (4) R. G. Shivas and Y. P. Tan. Fungal Divers. 39:111, 2009.
First Report of Damping-Off Caused by Rhizoctonia solani AG-4 on Pink Ipê (Tabebuia impetiginosa) in Italy
Authors: Polizzi G. , Aiello D. , Vitale A. , Guarnaccia V. , Panebianco A. , Cirvilleri G.
Published: November 2010

Pink ipê or pink lapacho (Tabebuia impetiginosa Martius ex DC., family Bignoniaceae) is one of the most attractive blooming trees in the world. In Europe, pink ipê is widely used as an ornamental tree in landscaped gardens and public areas. In August 2010, a widespread damping-off was observed in a stock of approximately 100,000 potted 2-month-old seedlings in a nursery in eastern Sicily (Italy). The seedlings were being watered with overhead irrigation. More than 5% of the seedlings showed disease symptoms. Initial symptoms were black lesions at the seedling crown that expanded rapidly to girdle the stem. On infected seedlings, leaves turned black and gradually died. Black extended stem lesions were followed by death of the entire seedling in a few days. A fungus with mycelial and morphological characteristics of Rhizoctonia solani Kühn was consistently isolated from crown and stem lesions when plated on potato dextrose agar (PDA) amended with streptomycin sulfate at 100 μg/ml. Fungal colonies were initially white, turned brown with age, and produced irregularly shaped, brown sclerotia. Mycelium was branched at right angles with a septum near the branch and a slight constriction at the branch base. Hyphal cells removed from cultures grown at 25°C on 2% water agar were determined to be multinucleate when stained with 1% safranin O and 3% KOH solution (1) and examined at ×400. Anastomosis groups were determined by pairing isolates with tester strains AG-1 IA, AG-2-2-1, AG-2-2IIIB, AG-2-2IV, AG-3, AG-4, AG-5, AG-6, and AG-11 on 2% water agar in petri plates (4). Anastomosis was observed only with tester isolates of AG-4, giving both C2 and C3 reactions (2). Pathogenicity tests were performed on container-grown, healthy, 3-month-old seedlings. Forty seedlings of T. impetiginosa were inoculated near the base of the stem with two 1-cm2 PDA plugs from 5-day-old mycelial cultures. The same number of plants only inoculated with PDA plugs served as controls. Plants were incubated in a growth chamber and maintained at 25°C and 95% relative humidity on a 12-h fluorescent light/dark regimen. Crown and stem lesions identical to those observed in the nursery appeared 5 days after inoculation and all plants died within 25 days. No disease was observed on control plants. R. solani AG-4 was reisolated from symptomatic tissues and identified as previously described. R. solani AG-4 was previously detected in the same nursery on Chamaerops humilis (3). To our knowledge, this is the first report of R. solani causing damping-off on T. impetiginosa.

References: (1) R. J. Bandoni. Mycologia 71:873, 1979. (2) D. E. Carling. Page 37 in: Grouping in Rhizoctonia solani by Hyphal Anastomosis Reactions. Kluwer Academic Publishers, the Netherlands, 1996. (3) G. Polizzi et al. Plant Dis. 94:125, 2010. (4) C. C. Tu and J. W. Kimbrough. Mycologia 65:941, 1973.
Impact of Consumer-Driven Changes to Crop Production Practices on Lettuce Drop Caused bySclerotinia sclerotiorumandS. minor
Authors: Wu B. M. , Koike S. T. , Subbarao K. V.
Published: November 2010

Increasing demands for value-added salad products have triggered revolutionary changes in the production practices of vegetable salad crops in recent years. One of the pivotal changes is the adaptation of 2-m-wide beds for increased vegetable biomass per unit area. The move away from the traditional 1-m-wide raised beds in cool-season vegetable production and the associated irrigation practices potentially can have a major influence on diseases affecting cool-season vegetables. To assess the potential impacts of this shift on lettuce drop caused by Sclerotinia minor and S. sclerotiorum, the two bed widths and different irrigation frequencies within each were compared in two separate field experiments over four lettuce crops in 2 years. Treatments included 1- and 2-m bed widths with twice-weekly, weekly and biweekly drip irrigation serving as subplot treatments that were begun immediately following thinning. Incidence of lettuce drop was evaluated weekly thereafter until maturity. For S. sclerotiorum, 36 half-liter soil samples were also collected once each season and assayed for the number of sclerotia, and apothecia were counted weekly in a 10-m2area for each plot. Regardless of the species, the effects of bed width and irrigation frequency were both significant. Twice-weekly irrigation and 2-m bed width resulted in higher lettuce drop incidence than other treatments. For S. sclerotiorum, twice-weekly irrigation and 2-m bed width also significantly increased the number of apothecia per unit area and the accumulation of soilborne sclerotia over multiple cropping seasons. Results demonstrated that the 2-m bed width combined with the practiced frequency of irrigations can result in higher lettuce drop caused by S. minor and increased incidence of airborne infection by S. sclerotiorum in the Salinas Valley where, historically, it has not been a serious threat. Increased incidence of S. sclerotiorum infection in commercial lettuce fields in the Salinas Valley between 2001 and 2006 validates these experimental results. These relatively new crop production practices can alter the balance of the two Sclerotinia spp. that has long existed in California.
Increased Anxiety‐Like Behavior and Ethanol Self‐Administration in Dependent Rats: Reversal via Corticotropin‐Releasing Factor‐2 Receptor Activation
Authors: Valdez Glenn R. , Sabino Valentina , Koob George F.
Published: November 2010

Background: Corticotropin‐releasing factor (CRF) has been hypothesized to be one of the main regulators of the stress response observed during alcohol withdrawal. The CRF receptor subtypes seem to have a differential role in the regulation of stress‐related behavior. Given the behavioral characterization of these receptors, the objective of the following experiments was to characterize the role of CRF2 receptors in the interaction between alcohol and stress by examining the effects of CRF2 receptor activation in the behavioral stress response and ethanol self‐administration during early ethanol withdrawal in dependent rats.

Methods: Male Wistar rats were made dependent on ethanol via chronic exposure to an ethanol containing liquid diet. Behavior in the elevated plus maze and ethanol self‐administration were measured at 2 hr after removal of the diet. The role of the CRF2 receptor in the regulation of these behaviors during the early stages of withdrawal was examined via central injection of the highly selective CRF2 receptor agonist urocortin 3.

Results: Rats showed decreased exploration of the open arms of the elevated plus maze, an indication of a heightened behavioral stress response, after chronic ethanol exposure. This effect was attenuated by central injection of urocortin 3. In addition, urocortin 3 injections reversed the increase in ethanol self‐administration observed during early withdrawal in dependent rats.

Conclusions: Reversal of the increased stress‐related behavior in the elevated plus maze observed after injections of urocortin 3 indicates that the decreased responding for ethanol also seen after urocortin 3 administration is likely due to a diminished anxiety‐like state. These data suggest that activation of the CRF2 receptor may provide a novel target in the attenuation of the stress response characteristic of the early stages of ethanol withdrawal.
Heightened Ethanol Intake in Infant and Adolescent Rats After Nursing Experiences With an Ethanol‐Intoxicated Dam
Authors: Pepino Marta Yanina , Abate Paula , Spear Norman E. , Molina Juan Carlos
Published: November 2010

Background: Preweanling rats detect ethanol (175 mg/100 ml) in maternal milk when the dam is moderately intoxicated. Repeated experiences with the intoxicated dam facilitate subsequent recognition of ethanol's chemosensory attributes and promote ethanol‐related memories with a negative hedonic content. This memory has been attributed to the infant's acquired association between ethanol's chemosensory attributes and its disruptive effects on maternal care. In this study, infant and adolescent ethanol intake patterns were analyzed as a function of prior interactions, during early infancy, with their intoxicated dams.

Methods: During postpartum days 3, 5, 7, 9, 11, and 13, breast‐feeding dams received an intragastric administration of either 2.5 g/kg of ethanol or water. Pups whose dams had been given one of these two maternal treatments were tested on postnatal day 15 for ingestion of 0% (water), 2.5, 5.0, or 10% v/v ethanol solution. During adolescence, remaining animals from these litters were first adapted to ingest water from drinking tubes and then were given simultaneous access to tap water and a given ethanol solution. The first day, a 3% v/v ethanol solution was used. This solution was increased by 1% ethanol each following day until the solution was 6% v/v ethanol.

Results: Maternal drug treatment did not affect the body weights of dams, infants, or adolescents. Water intake during infancy and adolescence also was unaffected by prior maternal treatment. However, infants that had previously interacted with ethanol‐intoxicated dams exhibited heightened ethanol intake scores (grams per kilogram and percentage body weight gains), especially when tested with 5 or 10% v/v ethanol solutions. Similarly, adolescent males (but not females) that had interacted with an intoxicated dam during infancy also had higher ethanol consumption levels than those that had interacted with a nonintoxicated dam.

Conclusions: Contrary to what might be expected in animals that acquire an aversive memory for ethanol's chemosensory cues as a function of prior interactions with an intoxicated mother, these results indicate that such interactions promote a long‐lasting increase in ethanol intake. These results suggest that rats reared by intoxicated dams become sensitive to the negative reinforcing properties of ethanol.
Differential Effects of Chronic Ethanol Administration and Withdrawal on γ‐Aminobutyric Acid Type A and NMDA Receptor Subunit Proteins in Male and Female Rat Brain
Authors: Devaud Leslie L. , Alele Paul
Published: November 2010

Background:Investigations have shown that chronic ethanol exposure results in selective alterations in levels of γ‐aminobutyric acid (GABA)Aand NMDA receptor subunits. We previously reported significant sex differences in these chronic ethanol‐induced adaptations. Because we have more recently found important sex differences in timing for the development of and recovery from ethanol dependence, we wanted to ascertain whether there were associations between overt expression of withdrawal and neuroadaptations at the level of GABAAand NMDA receptors.

Methods:Western blot analysis was used to assay protein levels for several GABAAand NMDA receptor subunits in rat cerebral cortex and hippocampus by using subunit‐selective antibodies. Rats were fed 6% ethanol in a liquid diet with pair‐fed controls. Feeding, harvesting of tissue, and Western blot experiments were all conducted while maintaining the paired design. Tissue was harvested after 3 days of ethanol exposure, 9 days of ethanol exposure, or 3 days of ethanol withdrawal after 14 days of liquid diet administration.

Results:We again found sex‐, subunit‐, and brain region–selective effects of ethanol administration and withdrawal for GABAAand NMDA receptors. There was a strong association between increased GABAAreceptor α4subunit levels and previously determined withdrawal‐induced changes in seizure susceptibility, highlighted by the sex differences in ethanol exposure length required to cause withdrawal signs. In addition, results obtained after 9 days of ethanol administration were in general agreement with previous findings after 14 days of ethanol administration.

Conclusions:These data further support the suggestion that alterations in subunit assembly of GABAAand NMDA receptors may have some mechanistic role in neuroadaptations underlying ethanol dependence and withdrawal. Furthermore, significant sex differences in these adaptations suggest that multiple types of adaptations may be elicited, depending on innate differences in the actions/effects of ethanol.
Prenatal Alcohol Exposure Causes Long‐Term Serotonin Neuron Deficit in Mice
Authors: Sari Youssef , Zhou Feng C.
Published: November 2010

Background: Previous work from this laboratory showed that prenatal alcohol exposure at approximately 100 mg/dl from embryonic day (E)7 to early midgestation reduced the number and retarded the migration of serotonin (5‐HT) neurons in the raphe nuclei in C57BL/6 mice. In this study, we report that the deficit of 5‐HT neurons found in midgestation persisted on E18 and into young adulthood.

Methods: Pregnant dams were treated from E7 to E18 in three groups—(1) the alcohol group, fed with liquid diet with 25% ethanol‐derived calories; (2) the isocaloric pair‐fed group; and (3) the chow group for analysis of concentrations of active caspase‐3—to study apoptosis at E18 in the brainstem and the number of 5‐HT neurons at E18 and postnatal day 45. The concentrations of active caspase‐3 were determined by using a colorimetric assay, and the 5‐HT neurons were determined by immunocytochemistry.

Results: Prenatal alcohol exposure increased the concentration of active caspase‐3 in the brainstem and caused reductions in brain weight by 20% and in the total number of 5‐HT–immunostaining neurons in the dorsal and median raphe nuclei by 20% at E18 as compared with those of the pair‐fed and chow controls. Continuous observation from prenatal to postnatal stages showed that the reduction of 5‐HT–immunostaining neurons in the dorsal and median raphe nuclei persisted in the young adult stage.

Conclusions: Upon prenatal alcohol exposure, an increased concentration of active caspase‐3 and a decreased number of 5‐HT–immunostaining neurons in the brainstem were observed at E18. The decreased number of 5‐HT neurons persisted to the young adult stage of postnatal day 45. This suggests that ethanol has a long‐lasting effect on 5‐HT deficit. A fetal alcohol exposure–rendered lasting deficit of 5‐HT and other transmitter systems may underlie the neuropsychiatric deficits in fetal alcohol spectrum disorder.
Prolonged Exposure to Intermittent Alcohol Vapors Decreases the ACTH as Well as Hypothalamic Nitric Oxide and Cytokine Responses to Endotoxemia
Authors: Seo Dong O. , Lee Soon , Rivier Catherine
Published: November 2010

Background: Prolonged exposure to alcohol blunts the response of the hypothalamic‐pituitary‐adrenal (HPA) axis to various stressors, including the systemic injection of a lipopolysaccharide (LPS). We previously showed that decreased synthesis of the hypothalamic peptides corticotropin‐releasing factor (CRF) and vasopressin (VP) played a central role in this phenomenon. However, the mechanisms that lead to decreased hypothalamic neuronal activity have not been identified. In the present work, we tested the hypothesis that alcohol decreased signals that are elicited by LPS and that stimulate hypothalamic CRF and VP synthesis, namely nitric oxide (NO) and the proinflammatory cytokines tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6).

Methods: Adult male rats were exposed to intermittent (5 hr/day) alcohol vapors for 5 days. Control animals were kept in comparable chambers but not exposed to the vapors. On day 6, the animals received an injection of LPS through permanent indwelling intravenous cannulae. The dependent variables were plasma ACTH levels measured by IRMA (immunoradiometric assay); pituitary and hypothalamic TNF‐α and IL‐6 mRNA levels measured by RNase protection assay; basal activity of neuronal NO synthase measured by conversion of [14C]arginine to [14C]citrulline, the constitutive enzyme that synthesizes NO and modulates the influence of this gas on LPS‐induced HPA axis activity; and basal and LPS‐induced levels of citrulline (an index of NO formation) in the hypothalamus, measured by immunocytochemistry.

Results: After injection with LPS, rats that were pretreated with alcohol exhibited a significantly (p < 0.01) decreased release of ACTH, compared with controls. There was no difference in basal NO synthase activity or hypothalamic citrulline levels. In contrast, LPS‐induced hypothalamic citrulline levels were significantly (p < 0.01) lower in alcohol‐exposed rats, as were pituitary TNF‐α and IL‐6 transcripts. In the hypothalamus, the TNF‐α but not IL‐6 response to LPS was also reduced.

Conclusions: These results indicate that prolonged exposure to alcohol decreases the ACTH, hypothalamic NO and TNF‐α, and pituitary TNF‐α and IL‐6 responses to LPS. This suggests that altered NO and proinflammatory cytokine levels in the brain may modulate the inhibitory influence exerted by alcohol on the HPA axis response to endotoxemia.
Brief Alcohol Interventions With Mandated or Adjudicated College Students
Authors: Barnett Nancy P. , Tevyaw Tracy O'Leary , Fromme Kim , Borsari Brian , Carey Kate B. , Corbin William R. , Colby Suzanne M. , Monti Peter M.
Published: November 2010

This article summarizes the proceedings of a symposium presented at the 2003 RSA Meeting in Ft. Lauderdale, Florida, organized and chaired by Nancy Barnett. The purpose of the symposium was to present information and efficacy data about approaches to brief intervention with students who get into trouble on their campuses for alcohol and as a result are required to attend alcohol education or counseling. Presentations were (1) Differences Between Mandated College Students and Their Peers on Alcohol Use and Readiness to Change, by Tracy O'Leary Tevyaw; (2) An Effective Alcohol Prevention Program for Mandated College Students, by Kim Fromme; (3) Two Brief Alcohol Interventions for a Referred College Population, by Kate Carey; and (4) Brief Motivational Intervention With College Students Following Medical Treatment or Discipline for Alcohol, by Nancy Barnett. The data presented in this symposium indicated that students who are evaluated or disciplined for alcohol use are on average heavy drinkers who drink more heavily than their closest peers. Brief intervention approaches described by the speakers included group classroom sessions, individual motivational intervention, individual alcohol education, and computerized alcohol education. Reductions in consumption and problems were noted across the various intervention groups. Brief motivational intervention as a general approach with mandated students shows promise in that it reduced alcohol problems in a group of mandated students who were screened for being at risk (in the Borsari and Carey study) and increased the likelihood that students would attend further counseling (in the Barnett study).