bluuebunny/crossref_metadata_2025 huggingface dataset:
Anticipation of conflict monitoring in the anterior cingulate cortex and the prefrontal cortex
Authors: Sohn Myeong-Ho , Albert Mark V. , Jung Kwanjin , Carter Cameron S. , Anderson John R.
Published: June 2007

The anterior cingulate cortex (ACC) has been suggested as a monitoring center that is responsible for online detection of response conflicts. In this view, the conflict signal detected by the ACC is transmitted to other brain regions, such as the dorsal part of the lateral prefrontal cortex (lPFC), to increase the level of cognitive control. In this functional MRI (fMRI) study, we examined the conflict resolution that goes beyond online detection of response conflicts. Participants learned pseudoarithmetic problem-solving tasks that involve stimulus–response mapping rules with high or low conflicts. On half of the trials, participants had a preview of the upcoming operator that allowed advance preparation for the mapping rules. The preview significantly reduced the conflict effects on latency. During the preview, both the ACC and lPFC were activated in anticipation of conflict, and this anticipatory activation was highly predictive of the subsequent latency. These results suggest that the ACC and lPFC are responsible for both anticipatory preparation and online adjustment in response to conflicts. The results also confirm the roles of the lPFC and ACC in managing conflict during problem solving and extend these roles to include responding to anticipation of conflicts that may arise between incompatible stimulus–response mappings maintained in working memory during preparation.
Structural basis for tubulin recognition by cytoplasmic linker protein 170 and its autoinhibition
Authors: Mishima Masaki , Maesaki Ryoko , Kasa Miyuki , Watanabe Takashi , Fukata Masaki , Kaibuchi Kozo , Hakoshima Toshio
Published: June 2007

Cytoplasmic linker protein 170 (CLIP-170) is a prototype of the plus end-tracking proteins that regulate microtubule dynamics, but it is obscure how CLIP-170 recognizes the microtubule plus end and contributes to polymerization rescue. Crystallographic, NMR, and mutation studies of two tandem cytoskeleton-associated protein glycine-rich (CAP-Gly) domains of CLIP-170, CAP-Gly-1 and CAP-Gly-2, revealed positively charged basic grooves of both CAP-Gly domains for tubulin binding, whereas the CAP-Gly-2 domain possesses a more basic groove and directly binds the EExEEY/F motif of the C-terminal acidic-tail ends of α-tubulin. Notably, the p150
Glued
CAP-Gly domain that is furnished with a less positively charged surface only weakly interacts with the α-tubulin acidic tail. Mutation studies showed that this acidic sextette motif is the minimum region for CAP-Gly binding. The C-terminal zinc knuckle domains of CLIP-170 bind the basic groove to inhibit the binding to the acidic tails. These results provide a structural basis for the proposed CLIP-170 copolymerization with tubulin on the microtubule plus end. CLIP-170 strongly binds the acidic tails of EB1 as well as those of α-tubulins, indicating that EB1 localized at the plus end contributes to CLIP-170 recruitment to the plus end. We suggest that CLIP-170 stimulates microtubule polymerization and/or nucleation by neutralizing the negative charges of tubulins with the highly positive charges of the CLIP-170 CAP-Gly domains. Once CLIP-170 binds microtubule, the released zinc knuckle domain may serve to recruit dynein to the plus end by interacting with p150
Glued
and LIS1. Thus, our structures provide the structural basis for the specific dynein loading on the microtubule plus end.
Real-time analysis of uptake and bioactivatable cleavage of luciferin-transporter conjugates in transgenic reporter mice
Authors: Wender Paul A. , Goun Elena A. , Jones Lisa R. , Pillow Thomas H. , Rothbard Jonathan B. , Shinde Rajesh , Contag Christopher H.
Published: June 2007

Many therapeutic leads fail to advance clinically because of bioavailability, selectivity, and formulation problems. Molecular transporters can be used to address these problems. Molecular transporter conjugates of otherwise poorly soluble or poorly bioavailable drugs or probes exhibit excellent solubility in water and biological fluids and at the same time an enhanced ability to enter tissues and cells and with modification to do so selectively. For many conjugates, however, it is necessary to release the drug/probe cargo from the transporter after uptake to achieve activity. Here, we describe an imaging method that provides quantification of transporter conjugate uptake and cargo release in real-time in animal models. This method uses transgenic (luciferase) reporter mice and whole-body imaging, allowing noninvasive quantification of transporter conjugate uptake and probe (luciferin) release in real time. This process effectively emulates drug-conjugate delivery, drug release, and drug turnover by an intracellular target, providing a facile method to evaluate comparative uptake of new transporters and efficacy and selectivity of linker release as required for fundamental studies and therapeutic applications.
Sox9 coordinates a transcriptional network in pancreatic progenitor cells
Authors: Lynn F. C. , Smith S. B. , Wilson M. E. , Yang K. Y. , Nekrep N. , German M. S.
Published: June 2007

During pancreas development, both the exocrine and endocrine lineages differentiate from a common pool of progenitor cells with similarities to mature pancreatic duct cells. A small set of transcription factors, including Tcf2, Onecut1, and Foxa2, has been identified in these pancreatic progenitor cells. The Sry/HMG box transcription factor Sox9 is also expressed in the early pancreatic epithelium and is required for normal pancreatic exocrine and endocrine development in humans. In this study, we found Sox9 in mice specifically expressed with the other progenitor transcription factors in both pancreatic progenitor cells and duct cells in the adult pancreas. Sox9 directly bound to all three genes
in vitro
and in intact cells, and regulated their expression. In turn, both Foxa2 and Tcf2 regulated Sox9 expression, demonstrating feedback circuits between these genes. Furthermore, Sox9 activated the expression of the proendocrine factor Neurogenin3, which also depends on the other members of the progenitor transcription network. These studies indicate that Sox9 plays a dual role in pancreatic progenitor cells: both maintaining a stable transcriptional network and supporting the programs by which these cells differentiate into distinct lineages.
Commensal and pathogenic
Escherichia coli
use a common pilus adherence factor for epithelial cell colonization
Authors: Rendón Marı́a A. , Saldaña Zeus , Erdem Ayşen L. , Monteiro-Neto Valério , Vázquez Alejandra , Kaper James B. , Puente José L. , Girón Jorge A.
Published: June 2007

Enterohemorrhagic
Escherichia coli
(EHEC) O157:H7 is a food-borne pathogen that causes hemorrhagic colitis and the hemolytic uremic syndrome. Colonization of the human gut mucosa and production of potent Shiga toxins are critical virulence traits of EHEC. Although EHEC O157:H7 contains numerous putative pili operons, their role in the colonization of the natural bovine or accidental human hosts remains largely unknown. We have identified in EHEC an adherence factor, herein called
E. coli
common pilus (ECP), composed of a 21-kDa pilin subunit whose amino acid sequence corresponds to the product of the
yagZ
(renamed
ecpA
) gene present in all
E. coli
genomes sequenced to date. ECP production was demonstrated in 121 (71.6%) of a total of 169
ecpA
+
strains representing intestinal and extraintestinal pathogenic as well as normal flora
E. coli
. High-resolution ultrastructural and immunofluorescence studies demonstrated the presence of abundant peritrichous fibrillar structures emanating from the bacterial surface forming physical bridges between bacteria adhering to cultured epithelial cells. Isogenic
ecpA
mutants of EHEC O157:H7 or fecal commensal
E. coli
showed significant reduction in adherence to cultured epithelial cells. Our data suggest that ECP production is a common feature of
E. coli
colonizing the human gut or other host tissues. ECP is a pilus of EHEC O157:H7 with a potential role in host epithelial cell colonization and may represent a mechanism of adherence of both pathogenic and commensal
E. coli
.
Mutational analysis of a viral RNA element that counteracts rapid RNA decay by interaction with the polyadenylate tail
Authors: Conrad Nicholas K. , Shu Mei-Di , Uyhazi Katherine E. , Steitz Joan A.
Published: June 2007

We previously demonstrated that the Kaposi's sarcoma-associated herpesvirus polyadenylated nuclear RNA contains a 79-nt cis-acting element, the ENE, which allows intronless polyadenylated transcripts to accumulate to high nuclear levels by protecting them from rapid degradation. We proposed a model based on the predicted structure of the ENE in which a U-rich internal loop hybridizes with the 3′-polyadenylate (polyA) tail to sequester it from exonucleolytic attack. We have tested this model by mutational analysis of the ENE. Point mutations in the predicted U-rich internal loop and in the flanking stems abolish the ENE's ability to (
i
) interact with the polyA tail, (
ii
) inhibit deadenylation
in vitro
, and (
iii
) stabilize transcripts
in vivo
. In all but one case, compensatory mutations in the flanking stems restore ENE activities, demonstrating the importance of these stems and uncovering a unique role for the loop-proximal G-C base pair in the lower stem. Increasing the U content of the U-rich internal loop surprisingly decreases stability
in vivo
but does not affect deadenylation
in vitro
, comparable to the effects of deleting certain “unstructured” regions of the ENE. Taken together, our data support the formation of the proposed ENE secondary structure
in vivo
and argue that the specific ENE structure inhibits rapid RNA decay in cis by engaging in a limited set of base-pairing interactions with the polyA tail.
Genomic and metabolic adaptations of
Methanobrevibacter smithii
to the human gut
Authors: Samuel Buck S. , Hansen Elizabeth E. , Manchester Jill K. , Coutinho Pedro M. , Henrissat Bernard , Fulton Robert , Latreille Philippe , Kim Kung , Wilson Richard K. , Gordon Jeffrey I.
Published: June 2007

The human gut is home to trillions of microbes, thousands of bacterial phylotypes, as well as hydrogen-consuming methanogenic archaea. Studies in gnotobiotic mice indicate that
Methanobrevibacter smithii
, the dominant archaeon in the human gut ecosystem, affects the specificity and efficiency of bacterial digestion of dietary polysaccharides, thereby influencing host calorie harvest and adiposity. Metagenomic studies of the gut microbial communities of genetically obese mice and their lean littermates have shown that the former contain an enhanced representation of genes involved in polysaccharide degradation, possess more archaea, and exhibit a greater capacity to promote adiposity when transplanted into germ-free recipients. These findings have led to the hypothesis that
M. smithii
may be a therapeutic target for reducing energy harvest in obese humans. To explore this possibility, we have sequenced its 1,853,160-bp genome and compared it to other human gut-associated
M. smithii
strains and other Archaea. We have also examined
M. smithii
's transcriptome and metabolome in gnotobiotic mice that do or do not harbor
Bacteroides thetaiotaomicron
, a prominent saccharolytic bacterial member of our gut microbiota. Our results indicate that
M. smithii
is well equipped to persist in the distal intestine through (
i
) production of surface glycans resembling those found in the gut mucosa, (
ii
) regulated expression of adhesin-like proteins, (
iii
) consumption of a variety of fermentation products produced by saccharolytic bacteria, and (
iv
) effective competition for nitrogenous nutrient pools. These findings provide a framework for designing strategies to change the representation and/or properties of
M. smithii
in the human gut microbiota.
Skeletal Muscle Susceptibility to Clofibrate Induction of Lesions in Rats
Authors: Okada Miyoko , Inoue Yoshimi , Ube Masayuki , Sano Fumiko , Ikeda Itsuko , Sugimoto Jiro , Takagi Shiro
Published: June 2007

Morphological changes induced by clofibrate in type-1 predominant soleus, type-2 predominant tensor fasciae latae, and type-1 and -2 mixed biceps femoris muscles and diaphragm in rats were investigated. Administration of the agent at 500 or 750 mg/kg/day by oral gavage for 14 or 28 days caused lesions in the soleus muscle and diaphragm, bur no changes in the tensor fasciae latae and biceps femoris muscles. In soleus muscle, vacuolation of muscle fibers was observed in all animals treated with clofibrate, and degeneration of muscle fibers and infiltration of leukocytes were noted at 750 mg/kg/day. In diaphragm, vacuolation of muscle fibers was also observed in all animals treated with clofibrate, and these lesions were located in type-1 skeletal muscles densely stained with NADH-TR. The vacuoles seen in soleus muscle and diaphragm were positive for oil red O staining. In addition, increase of lipid droplets and mitochondrial hypertrophy was seen in soleus muscle, ultrastructurally. These data suggest that sensitivity to clofibrate-induced muscle toxicity differs among muscles, with type-1 fibers being susceptible.
Development of a Sensitive and Specific in Situ Hybridization Technique for the Cellular Localization of Antisense Oligodeoxynucleotide Drugs in Tissue Sections
Authors: Goebl Nancy , Berridge Brian , Wroblewski Victor J. , Brown-Augsburger Patricia L.
Published: June 2007

A sensitive method has been developed for the identification and assessment of phosphorothioate oligonucleotide accumulation in dosed animal tissues using an in situ hybridization approach, which is both sequence specific yet adaptable to every antisense oligonucleotide (ASO), which has been tested to date. Hybridization is accomplished using a digoxigenin-tailed oligonucleotide probe complementary to the ASO target sequence on routinely processed paraffin sections which have been pretreated with a mild target retrieval solution. The DIG-labeled probe is amplified first with an anti-DIG:FITC antibody conjugate followed by an anti:FITC Alexa 488 antibody, then visualized using FITC epifluorescence microscopy. Fluorescent labeling of ASO drug in tissue sections by this method confirms that H&E basophilia previously observed in dosed tissues represents largely intact ASO. However, the fluorescent method enables a wider assessment of tissue distribution in a variety of tissue types due to increased sensitivity and lower signal to noise than can be obtained through an examination of H&E stained tissue sections alone.
Altered Protein Expressions in Chronic PCB-153–Induced Human Liver (HepG2) Cells
Authors: Ghosh Somiranjan , De Supriyo , Dutta Sisir K.
Published: June 2007

Polychlorinated biphenyls (PCBs) are a group of persistent and widely distributed environmental pollutants that have various deleterious effects, e.g., neurotoxic, endocrine disruption and reproductive abnormalities, including cancers. Chronic exposure to environmentally hazardous chemicals like PCBs is of great concern to human health. It has been reported earlier that apoptotic proteins change in rats under chronic PCB treatment. It is of importance to determine if chronically exposed human cells develop a different protein expression. In the present study, the authors chronically exposed metabolically competent human liver (HepG2) cells at 50 to 100 μM to examine the role of the well-known environmentally hazardous pollutant non-coplanar 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB-153) to study cell death. After 12 weeks of exposure these cells showed significant changes in apoptotic death in subsequent trypan blue growth assay, fluorescence microscopy, DNA fragmentation, and immunoblotting studies. Interestingly, chronically exposed cells showed marked differences in apoptotic and/or death-related proteins (e.g., Bcl2, Bak, and the pro and active forms of caspase-9, which were up-regulated), in contrast to acutely exposed (i.e., 48-h PCB-153 exposed) cells, which maintained linear growth despite repeated exposures. Similarly, tumor suppressor protein p53, proto-oncogene c- myc, and cell cycle regulator protein p21 were also up-regulated compared to nonchronically exposed HepG2 Cells. The results indicated that PCB-153–induced chronic exposure significantly altered different apoptotic (e.g., Bcl2, Bak, caspase-3) and tumor suppressor (e.g., p21, p53, and c-myc) proteins in the cellular model. These results suggest that chronic exposure to PCB-153 can induce cell survival by altering several apoptotic and tumor suppressor proteins.
Safety Studies Regarding a Standardized Extract of Fermented Wheat Germ
Authors: Heimbach James T. , Sebestyen Gyula , Semjen Gabor , Kennepohl Elke
Published: June 2007

“Avemar pulvis” is a powder consisting of an aqueous extract of fermented wheat germ, with the drying aids maltodextrin and silicon dioxide, standardized to contain approximately 200 μg/g of the natural constituent 2,6-dimethoxy- p-benzoquinone. The results of toxicological and clinical studies of this product demonstrate its safety for its intended use as a dietary supplement ingredient in the United States. Avemar pulvis has been used in Hungary since 1998 and is approved in that country, as well as in the Czech Republic, Bulgaria, and Romania, as a “medical nutriment for cancer patients.” Acute and subacute toxicity studies using rodents orally administered Avemar pulvis showed that dose levels (2000 to 3000 mg/kg body weight [bw]/day) exceeding the normal recommended oral dosage (8.5 g/day or 121 mg/kg bw/day for a 70-kg individual) by up to approximately 25-fold caused no adverse effects. The test substance showed no evidence of mutagenicity or genotoxicity in vitro or in vivo. Clinical studies using Avemar pulvis as a supplement to drug therapy in cancer patients at doses of 8.5 g/day not only showed no evidence of toxicity, but also showed a reduction in the side effects of chemotherapy. Overall, it was concluded that Avemar pulvis would not be expected to cause adverse effects under the conditions of its intended use as an ingredient in dietary supplements.
The Qo site of the mitochondrial complex III is required for the transduction of hypoxic signaling via reactive oxygen species production
Authors: Bell Eric L. , Klimova Tatyana A. , Eisenbart James , Moraes Carlos T. , Murphy Michael P. , Budinger G.R. Scott , Chandel Navdeep S.
Published: June 2007

Mammalian cells increase transcription of genes for adaptation to hypoxia through the stabilization of hypoxia-inducible factor 1α (HIF-1α) protein. How cells transduce hypoxic signals to stabilize the HIF-1α protein remains unresolved. We demonstrate that cells deficient in the complex III subunit cytochrome b, which are respiratory incompetent, increase ROS levels and stabilize the HIF-1α protein during hypoxia. RNA interference of the complex III subunit Rieske iron sulfur protein in the cytochrome b–null cells and treatment of wild-type cells with stigmatellin abolished reactive oxygen species (ROS) generation at the Qo site of complex III. These interventions maintained hydroxylation of HIF-1α protein and prevented stabilization of HIF-1α protein during hypoxia. Antioxidants maintained hydroxylation of HIF-1α protein and prevented stabilization of HIF-1α protein during hypoxia. Exogenous hydrogen peroxide under normoxia prevented hydroxylation of HIF-1α protein and stabilized HIF-1α protein. These results provide genetic and pharmacologic evidence that the Qo site of complex III is required for the transduction of hypoxic signal by releasing ROS to stabilize the HIF-1α protein.
Specific Rab GTPase-activating proteins define the Shiga toxin and epidermal growth factor uptake pathways
Authors: Fuchs Evelyn , Haas Alexander K. , Spooner Robert A. , Yoshimura Shin-ichiro , Lord J. Michael , Barr Francis A.
Published: June 2007

Rab family guanosine triphosphatases (GTPases) together with their regulators define specific pathways of membrane traffic within eukaryotic cells. In this study, we have investigated which Rab GTPase-activating proteins (GAPs) can interfere with the trafficking of Shiga toxin from the cell surface to the Golgi apparatus and studied transport of the epidermal growth factor (EGF) from the cell surface to endosomes. This screen identifies 6 (EVI5, RN-tre/USP6NL, TBC1D10A–C, and TBC1D17) of 39 predicted human Rab GAPs as specific regulators of Shiga toxin but not EGF uptake. We show that Rab43 is the target of RN-tre and is required for Shiga toxin uptake. In contrast, RabGAP-5, a Rab5 GAP, was unique among the GAPs tested and reduced the uptake of EGF but not Shiga toxin. These results suggest that Shiga toxin trafficking to the Golgi is a multistep process controlled by several Rab GAPs and their target Rabs and that this process is discrete from ligand-induced EGF receptor trafficking.
Senataxin, defective in ataxia oculomotor apraxia type 2, is involved in the defense against oxidative DNA damage
Authors: Suraweera Amila , Becherel Olivier J. , Chen Philip , Rundle Natalie , Woods Rick , Nakamura Jun , Gatei Magtouf , Criscuolo Chiara , Filla Alessandro , Chessa Luciana , Fußer Markus , Epe Bernd , Gueven Nuri , Lavin Martin F.
Published: June 2007

Adefective response to DNA damage is observed in several human autosomal recessive ataxias with oculomotor apraxia, including ataxia-telangiectasia. We report that senataxin, defective in ataxia oculomotor apraxia (AOA) type 2, is a nuclear protein involved in the DNA damage response. AOA2 cells are sensitive to H2O2, camptothecin, and mitomycin C, but not to ionizing radiation, and sensitivity was rescued with full-length SETX cDNA. AOA2 cells exhibited constitutive oxidative DNA damage and enhanced chromosomal instability in response to H2O2. Rejoining of H2O2-induced DNA double-strand breaks (DSBs) was significantly reduced in AOA2 cells compared to controls, and there was no evidence for a defect in DNA single-strand break repair. This defect in DSB repair was corrected by full-length SETX cDNA. These results provide evidence that an additional member of the autosomal recessive AOA is also characterized by a defective response to DNA damage, which may contribute to the neurodegeneration seen in this syndrome.
A novel role in cytokinesis reveals a housekeeping function for the unfolded protein response
Authors: Bicknell Alicia A. , Babour Anna , Federovitch Christine M. , Niwa Maho
Published: June 2007

The unfolded protein response (UPR) pathway helps cells cope with endoplasmic reticulum (ER) stress by activating genes that increase the ER's functional capabilities. We have identified a novel role for the UPR pathway in facilitating budding yeast cytokinesis. Although other cell cycle events are unaffected by conditions that disrupt ER function, cytokinesis is sensitive to these conditions. Moreover, efficient cytokinesis requires the UPR pathway even during unstressed growth conditions. UPR-deficient cells are defective in cytokinesis, and cytokinesis mutants activate the UPR. The UPR likely achieves its role in cytokinesis by sensing small changes in ER load and making according changes in ER capacity. We propose that cytokinesis is one of many cellular events that require a subtle increase in ER function and that the UPR pathway has a previously uncharacterized housekeeping role in maintaining ER plasticity during normal cell growth.
Cdc14-regulated midzone assembly controls anaphase B
Authors: Khmelinskii Anton , Lawrence Clare , Roostalu Johanna , Schiebel Elmar
Published: June 2007

Spindle elongation in anaphase of mitosis is a cell cycle–regulated process that requires coordination between polymerization, cross-linking, and sliding of microtubules (MTs). Proteins that assemble at the spindle midzone may be important for this process. In this study, we show that Ase1 and the separase–Slk19 complex drive midzone assembly in yeast. Whereas the conserved MT-bundling protein Ase1 establishes a midzone, separase–Slk19 is required to focus and center midzone components. An important step leading to spindle midzone assembly is the dephosphorylation of Ase1 by the protein phosphatase Cdc14 at the beginning of anaphase. Failure to dephosphorylate Ase1 delocalizes midzone proteins and delays the second, slower phase of anaphase B. In contrast, in cells expressing nonphosphorylated Ase1, anaphase spindle extension is faster, and spindles frequently break. Cdc14 also controls the separase–Slk19 complex indirectly via the Aurora B kinase. Thus, Cdc14 regulates spindle midzone assembly and function directly through Ase1 and indirectly via the separase–Slk19 complex.
C/EBPδ regulates cell cycle and self-renewal of human limbal stem cells
Authors: Barbaro Vanessa , Testa Anna , Di Iorio Enzo , Mavilio Fulvio , Pellegrini Graziella , De Luca Michele
Published: June 2007

Human limbal stem cells produce transit amplifying progenitors that migrate centripetally to regenerate the corneal epithelium. Coexpression of CCAAT enhancer binding protein δ (C/EBPδ), Bmi1, and ΔNp63α identifies mitotically quiescent limbal stem cells, which generate holoclones in culture. Upon corneal injury, a fraction of these cells switches off C/EBPδ and Bmi1, proliferates, and differentiates into mature corneal cells. Forced expression of C/EBPδ inhibits the growth of limbal colonies and increases the cell cycle length of primary limbal cells through the activity of p27Kip1 and p57Kip2. These effects are reversible; do not alter the limbal cell proliferative capacity; and are not due to apoptosis, senescence, or differentiation. C/EBPδ, but not ΔNp63α, indefinitely promotes holoclone self-renewal and prevents clonal evolution, suggesting that self-renewal and proliferation are distinct, albeit related, processes in limbal stem cells. C/EBPδ is recruited to the chromatin of positively (p27Kip1 and p57Kip2) and negatively (p16INK4A and involucrin) regulated gene loci, suggesting a direct role of this transcription factor in determining limbal stem cell identity.
The chemotherapeutic agent DMXAA potently and specifically activates the TBK1–IRF-3 signaling axis
Authors: Roberts Zachary J. , Goutagny Nadege , Perera Pin-Yu , Kato Hiroki , Kumar Himanshu , Kawai Taro , Akira Shizuo , Savan Ram , van Echo David , Fitzgerald Katherine A. , Young Howard A. , Ching Lai-Ming , Vogel Stefanie N.
Published: June 2007

Vascular disrupting agents (VDAs) represent a novel approach to the treatment of cancer, resulting in the collapse of tumor vasculature and tumor death. 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is a VDA currently in advanced phase II clinical trials, yet its precise mechanism of action is unknown despite extensive preclinical and clinical investigations. Our data demonstrate that DMXAA is a novel and specific activator of the TANK-binding kinase 1 (TBK1)–interferon (IFN) regulatory factor 3 (IRF-3) signaling pathway. DMXAA treatment of primary mouse macrophages resulted in robust IRF-3 activation and ∼750-fold increase in IFN-β mRNA, and in contrast to the potent Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS), signaling was independent of mitogen-activated protein kinase (MAPK) activation and elicited minimal nuclear factor κB–dependent gene expression. DMXAA-induced signaling was critically dependent on the IRF-3 kinase, TBK1, and IRF-3 but was myeloid differentiation factor 88–, Toll–interleukin 1 receptor domain–containing adaptor inducing IFN-β–, IFN promoter-stimulator 1–, and inhibitor of κB kinase–independent, thus excluding all known TLRs and cytosolic helicase receptors. DMXAA pretreatment of mouse macrophages induced a state of tolerance to LPS and vice versa. In contrast to LPS stimulation, DMXAA-induced IRF-3 dimerization and IFN-β expression were inhibited by salicylic acid. These findings detail a novel pathway for TBK1-mediated IRF-3 activation and provide new insights into the mechanism of this new class of chemotherapeutic drugs.
CD40 ligand and MHC class II expression are essential for human peripheral B cell tolerance
Authors: Hervé Maxime , Isnardi Isabelle , Ng Yen-shing , Bussel James B. , Ochs Hans D. , Cunningham-Rundles Charlotte , Meffre Eric
Published: June 2007

Hyper-IgM (HIGM) syndromes are primary immunodeficiencies characterized by defects of class switch recombination and somatic hypermutation. HIGM patients who carry mutations in the CD40-ligand (CD40L) gene expressed by CD4+ T cells suffer from recurrent infections and often develop autoimmune disorders. To investigate the impact of CD40L–CD40 interactions on human B cell tolerance, we tested by ELISA the reactivity of recombinant antibodies isolated from single B cells from three CD40L-deficient patients. Antibody characteristics and reactivity from CD40L-deficient new emigrant B cells were similar to those from healthy donors, suggesting that CD40L–CD40 interactions do not regulate central B cell tolerance. In contrast, mature naive B cells from CD40L-deficient patients expressed a high proportion of autoreactive antibodies, including antinuclear antibodies. Thus, CD40L–CD40 interactions are essential for peripheral B cell tolerance. In addition, a patient with the bare lymphocyte syndrome who could not express MHC class II molecules failed to counterselect autoreactive mature naive B cells, suggesting that peripheral B cell tolerance also depends on major histocompatibility complex (MHC) class II–T cell receptor (TCR) interactions. The decreased frequency of MHC class II–restricted CD4+ regulatory T cells in CD40L-deficient patients suggests that these T cells may mediate peripheral B cell tolerance through CD40L–CD40 and MHC class II–TCR interactions.
CD11b facilitates the development of peripheral tolerance by suppressing Th17 differentiation
Authors: Ehirchiou Driss , Xiong Ying , Xu Guangwu , Chen Wanjun , Shi Yufang , Zhang Li
Published: June 2007

Antigen-induced immune suppression, like T cell activation, requires antigen-presenting cells (APCs); however, the role of APCs in mediating these opposing effects is not well understood, especially in vivo. We report that genetic inactivation of CD11b, which is a CD18 subfamily of integrin receptors that is highly expressed on APCs, abolishes orally induced peripheral immune tolerance (oral tolerance) without compromising APC maturation or antigen-specific immune activation. The defective oral tolerance in CD11b−/− mice can be restored by adoptive transfer of wild-type APCs. CD11b deficiency leads to enhanced interleukin (IL) 6 production by APCs, which subsequently promotes preferential differentiation of naive T cells to T helper 17 (Th17) cells, which are a T cell lineage characterized by their production of IL-17. Consequently, antigen feeding and immunization of CD11b−/− mice results in significant production of IL-17 within the draining lymph nodes that interferes with the establishment of oral tolerance. Together, we conclude that CD11b facilitates oral tolerance by suppressing Th17 immune differentiation.
Sodium Flux Ratio in Na/K Pump-Channels Opened by Palytoxin
Authors: Rakowski R.F. , Artigas Pablo , Palma Francisco , Holmgren Miguel , De Weer Paul , Gadsby David C.
Published: June 2007

Palytoxin binds to Na+/K+ pumps in the plasma membrane of animal cells and opens an electrodiffusive cation pathway through the pumps. We investigated properties of the palytoxin-opened channels by recording macroscopic and microscopic currents in cell bodies of neurons from the giant fiber lobe, and by simultaneously measuring net current and 22Na+ efflux in voltage-clamped, internally dialyzed giant axons of the squid Loligo pealei. The conductance of single palytoxin-bound “pump-channels” in outside-out patches was ∼7 pS in symmetrical 500 mM [Na+], comparable to findings in other cells. In these high-[Na+], K+-free solutions, with 5 mM cytoplasmic [ATP], the K0.5 for palytoxin action was ∼70 pM. The pump-channels were ∼40–50 times less permeable to N-methyl-d-glucamine (NMG+) than to Na+. The reversal potential of palytoxin-elicited current under biionic conditions, with the same concentration of a different permeant cation on each side of the membrane, was independent of the concentration of those ions over the range 55–550 mM. In giant axons, the Ussing flux ratio exponent (n') for Na+ movements through palytoxin-bound pump-channels, over a 100–400 mM range of external [Na+] and 0 to −40 mV range of membrane potentials, averaged 1.05 ± 0.02 (n = 28). These findings are consistent with occupancy of palytoxin-bound Na+/K+ pump-channels either by a single Na+ ion or by two Na+ ions as might be anticipated from other work; idiosyncratic constraints are needed if the two Na+ ions occupy a single-file pore, but not if they occupy side-by-side binding sites, as observed in related structures, and if only one of the sites is readily accessible from both sides of the membrane.
Do Japanese Style Acupuncture and Moxibustion Reduce Symptoms of the Common Cold?
Authors: Kawakita Kenji , Shichidou Toshiyuki , Inoue Etsuko , Nabeta Tomoyuki , Kitakoji Hiroshi , Aizawa Shigekatsu , Nishida Atsushi , Yamaguchi Nobuo , Takahashi Norihito , Sumiya Eiji , Okada Kaoru , Umeda Takashi , Yano Tadashi , Tanzawa Shouhachi
Published: June 2007

We summarize the results from a series of investigations of Japanese style acupuncture and moxibustion therapies on symptoms of the common cold that have been conducted (FTLE 1999–03, supported by the Foundation for Training and Licensure Examination in Anma‐ Massage‐ Acupressure, Acupuncture and Moxibustion). We also discuss the various interventions and concerns that we faced during these investigations. The subjects were students and teachers. The pilot study (FTLE1999) of a two arm (real and non‐treatment control) RCT at a Japanese acupuncture school showed that manual acupuncture to a specific needling point at the throat clearly reduced symptoms of the common cold. The first multi‐center (five centers) RCT (FTLE 2000) revealed a significant reduction in cold symptoms, by general linear model analysis (between groups, P = 0.024). To reduce the technical variation, we employed indirect moxibustion to the neck points as a uniform intervention in the next project (FTLE 2001) without statistically significant results. Then we elongated the periods of treatment from 2 to a maximum of 12 weeks (FTLE 2002) with different interventions accompanied by 4 weeks follow‐up. The results were still not statistically significant. As the final project, we tried to develop a new experimental design for individualized intervention by conducting n‐of‐1 trials using elderly subjects in a health care center but without detecting a clear effect. In conclusion, the safety of Japanese acupuncture or moxibustion was sufficiently demonstrated; however, a series of clinical trials could not offer convincing evidence to recommend the use of Japanese style acupuncture or moxibustion for preventing the common cold. Further studies are required as the present trials had several limitations.
Acupuncture Anesthesia and Analgesia for Clinical Acute Pain in Japan
Authors: Taguchi Reina
Published: June 2007

Acupuncture anesthesia has been practiced in China since about 1960. In Japan, Hyodo reported 30 cases of acupuncture anesthesia in 1972. However, from around 1980, the direction of acupuncture investigations turned from anesthesia to analgesia. Acupuncture analgesia is presently considered a way to activate the body′s endogenous analgesic system. Recently, with the rise of acupuncture as one of the most well known CAM therapies, acupuncture or moxibustion treatment has been reported for both acute and chronic pain. Even so, few clinical reports and original articles have been reported in Japan. This review illustrates how acupuncture is being used in Japan for acute pain such as surgical operations, post‐ operative pain (POP), neuropathic pain, pain associated with teeth extractions and after the extraction of impacted wisdom teeth.
Brazilian Propolis: Correlation between Chemical Composition and Antimicrobial Activity
Authors: Salomão Kelly , Pereira Paulo Roberto S. , Campos Leila C. , Borba Cintia M. , Cabello Pedro H. , Marcucci Maria Cristina , de Castro Solange L.
Published: June 2007

The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity against Trypanosoma cruzi, Staphylococcus aureus, Streptococcus pneumoniae, Klebisiella pneumoniae, Candida albicans, Sporothrix schenckii and Paracoccidioides brasiliensis were determined. Based on the predominant botanical origin in the region of samples′ collection, the 10 extracts were separated into three groups: A (B. dracunculifolia + Auraucaria spp), B (B. dracunculifolia) and C (Araucaria spp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, of S. aureus with p‐coumaric acid (PCUM) and 3‐(4‐hydroxy‐3‐(oxo‐butenyl)‐phenylacrylic acid (DHCA1) and of trypomastigotes of T. cruzi with 3,5‐diprenyl‐4‐hydroxycinnamic acid derivative 4 (DHCA4) and 2,2‐dimethyl‐6‐carboxyethenyl‐2H‐1‐benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association of S. aureus with caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), of S. pneumoniae with CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and of T. cruzi also with CAFQ3. For group B, a higher activity against S. pneumoniae was associated DCBEN and for T. cruzi with CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis.
Colletotrichum acutatum Found on Apple Buds in Norway
Authors: Børve Jorunn , Stensvand Arne
Published: June 2007

Healthy appearing buds of five apple cultivars from 2 experimental and 9 commercial orchards were collected and incubated in saturated air at 20°C in early spring (prior to bud break) over three years. Colletotrichum acutatum sporulated on 0 to 7% (mean 1.3%) of the buds from both commercial and experimental orchards. Infected apple buds are suggested as a potential source of inoculum in spring.

Accepted for publication 5 February 2007. Published 22 May 2007.
John Maxwell Cowley. 18 February 1923 — 18 May 2004
Authors: Moodie Alexander , Spence John C.H.
Published: June 2007

Although John Cowley made important contributions across virtually the whole of crystallography, using electrons, X–rays and neutrons, his work in the three areas of short–range order, dynamical electron diffraction, and scanning transmission electron microscopy are of particular significance. In all of these areas his work involved theory and experiment in equal measure, with each reinforcing the other. The outcomes of these activities have now spread across so much of solid-state physics, metallurgy, structural inorganic chemistry and Earth sciences that they have entered the canon, with authors quite frequently no longer feeling the necessity of referring to specific papers on many of the matters of principle first enunciated by John.
Mapping the chromosomal targets of STAT1 by Sequence Tag Analysis of Genomic Enrichment (STAGE)
Authors: Bhinge Akshay A. , Kim Jonghwan , Euskirchen Ghia M. , Snyder Michael , Iyer Vishwanath R.
Published: June 2007

Identifying the genome-wide binding sites of transcription factors is important in deciphering transcriptional regulatory networks. ChIP-chip (Chromatin immunoprecipitation combined with microarrays) has been widely used to map transcription factor binding sites in the human genome. However, whole genome ChIP-chip analysis is still technically challenging in vertebrates. We recently developed STAGE as an unbiased method for identifying transcription factor binding sites in the genome. STAGE is conceptually based on SAGE, except that the input is ChIP-enriched DNA. In this study, we implemented an improved sequencing strategy and analysis methods and applied STAGE to map the genomic binding profile of the transcription factor STAT1 after interferon treatment. STAT1 is mainly responsible for mediating the cellular responses to interferons, such as cell proliferation, apoptosis, immune surveillance, and immune responses. We present novel algorithms for STAGE tag analysis to identify enriched loci with high specificity, as verified by quantitative ChIP. STAGE identified several previously unknown STAT1 target genes, many of which are involved in mediating the response to interferon-γ signaling. STAGE is thus a viable method for identifying the chromosomal targets of transcription factors and generating meaningful biological hypotheses that further our understanding of transcriptional regulatory networks.
Neural coding of reward magnitude in the orbitofrontal cortex of the rat during a five-odor olfactory discrimination task
Authors: van Duuren Esther , Escámez Francisco A. Nieto , Joosten Ruud N.J.M.A. , Visser Rein , Mulder Antonius B. , Pennartz Cyriel M.A.
Published: June 2007

The orbitofrontal cortex (OBFc) has been suggested to code the motivational value of environmental stimuli and to use this information for the flexible guidance of goal-directed behavior. To examine whether information regarding reward prediction is quantitatively represented in the rat OBFc, neural activity was recorded during an olfactory discrimination “go”/“no-go” task in which five different odor stimuli were predictive for various amounts of reward or an aversive reinforcer. Neural correlates related to both actual and expected reward magnitude were observed. Responses related to reward expectation occurred during the execution of the behavioral response toward the reward site and within a waiting period prior to reinforcement delivery. About one-half of these neurons demonstrated differential firing toward the different reward sizes. These data provide new and strong evidence that reward expectancy, regardless of reward magnitude, is coded by neurons of the rat OBFc, and are indicative for representation of quantitative information concerning expected reward. Moreover, neural correlates of reward expectancy appear to be distributed across both motor and nonmotor phases of the task.
A form of perforant path LTP can occur without ERK1/2 phosphorylation or immediate early gene induction
Authors: Steward Oswald , Huang Fen , Guzowski John F.
Published: June 2007

Stimulation paradigms that induce perforant path long-term potentiation (LTP) initiate phosphorylation of ERK1/2 and induce expression of a variety of immediate early genes (IEGs). These events are thought to be critical components of the mechanism for establishing the changes in synaptic efficacy that endure for hours or longer. Here we show that in mice, perforant path LTP can be induced using a standard protocol (repeated trains at 250 Hz), without accompanying increases in immunostaining for p-ERK1/2 or increased in expression of representative IEGs (Arc and c-fos). Signaling pathways capable of inducing ERK phosphorylation and IEG transcription are intact in mice because ERK phosphorylation differs strikingly in awake versus anesthetized mice, and IEG expression is strongly induced by electroconvulsive seizures. In pursuing the reasons for the lack of induction with LTP, we found that in rats, one of the stimulation paradigms used to induce perforant path LTP (trains at 250 Hz) also does not activate MAP kinase or induce IEG expression, despite the fact that the LTP induced by 250 Hz stimulation requires NMDA receptor activation and persists for hours. These findings indicate that there are different forms of perforant path LTP, one of which does not require MAP kinase activation or IEG induction. Moreover, these data demonstrate that different LTP induction paradigms do not have identical molecular consequences, which may account for certain discrepancies between previous studies.
Crystallographic studies of the complexes of antiviral protein griffithsin with glucose and N‐acetylglucosamine
Authors: Ziółkowska Natasza E. , Shenoy Shilpa R. , O'Keefe Barry R. , Wlodawer Alexander
Published: June 2007

Crystal structures of complexes of an antiviral lectin griffithsin (GRFT) with glucose and N‐acetylglucosamine were solved and refined at high resolution. In both complexes, all six monosaccharide‐binding sites of GRFT were occupied and the mode of binding was similar to that of mannose. In our previous attempts to obtain a complex with N‐acetylglucosamine by soaking, only a single site was occupied; thus, cocrystallization was clearly superior despite lower concentration of the ligand. Isothermal titration calorimetric experiments with N‐acetylglucosamine, glucose, and mannose provided enthalpic evidence of distinct binding differences between the three monosaccharides. A comparison of the mode of binding of different monosaccharides is discussed in the context of the antiviral activity of GRFT, based on specific binding to high‐mannose‐containing complex carbohydrates found on viral envelopes.
Controversies in the Treatment of Hypercholesterolemia in the Elderly: Who Should Be Treated and How?
Authors: Miura Dennis S.
Published: June 2007

High levels of low‐density lipoprotein cholesterol may contribute to the development of coronary heart disease in the absence of other risk factors. This paper reviews major cholesterol prevention trials since 1994 concerning possible beneficial results of lowering cholesterol in persons over 65 years of age.
The Frequency of Atrioventricular Block During Adenosine Stress Testing in Young, Middle‐Aged, Young‐Old, and Old‐Old Adults
Authors: Alkoutami Ghassan S. , Reeves William C. , Movahed Assad
Published: June 2007

The frequency of atrioventricular (AV) block was evaluated in 600 consecutive patients of different age groups referred for pharmacologic stress testing. Adenosine was infused at 140 mg/kg/min for a total of 6 minutes in conjunction with radionuclide myocardial perfusion imaging. Seventy‐five patients (12.5%) were young adults (<49 years old), 214 (35.6%) were middle‐aged (50–65 years), 195 (32.6%) were young‐old (66–75 years), and 116 patients (19.3%) were old‐old (over 75 years). The frequencies of first‐degree AV block in young adults, middle‐aged, young‐old, old‐old, and all ages were 14.6%, 9.3%, 14.3%, 17.24%, and 13.16%, respectively. The frequencies of second‐degree AV block were 14.65%, 7.0%, 8.7%, 15.5%, and 10.1%, respectively. The frequencies of third‐degree AV block were 2.66%, 2.33%, 1.0%, 2.58%, and 2.0%, respectively. Comparison of the incidence of the three types of AV block for each age group vs. all patients showed no statistically significant difference (p>0.08). All types of AV block were of short duration, were well tolerated, and did not require discontinuation of the adenosine infusion or specific treatment. This study confirms the safety of adenosine stress testing in all age groups for evaluation of coronary artery disease and risk assessment.
Multifocal Atrial Tachycardia and Ibutilide
Authors: Pierce Walter J. , McGroary KellyAnn
Published: June 2007

Multifocal atrial tachycardia is an electrocardiographic phenomenon seen primarily in the elderly. The hemodynamic consequences of multifocal atrial tachycardia in an elderly woman are presented. Successful treatment with Ibutilide is demonstrated. Treatment with a class III antiarrhythmic agent opposes the frequently accepted mechanism of triggered activity in causing this arrhythmia.