bluuebunny/crossref_metadata_2025_split huggingface dataset:
Entry of Pseudorabies Virus: an Immunogold-Labeling Study
Authors: Granzow Harald , Klupp Barbara G. , Mettenleiter Thomas C. 
Published: February 2005

ABSTRACT
Herpesviruses infect cells by fusion of the viral envelope with cellular membranes, primarily the plasma membrane. During this process structural components of the mature virion are lost from the invading nucleocapsid, which then travels along microtubules to the nuclear pore. We examined the penetration process by immunoelectron microscopy and analyzed which of the major tegument proteins remained associated with the incoming capsid. We show that the UL36, UL37, and US3 proteins were present at intracytoplasmic capsids after penetration, whereas the UL11, UL47, UL48, and UL49 tegument proteins were lost. Thus, the three capsid-associated tegument proteins are prime candidates for viral proteins that interact with cellular motor proteins for transport of nucleocapsids to the nucleus.
The Coiled-Coil Domain of the Adenovirus Type 5 Protein IX Is Dispensable for Capsid Incorporation and Thermostability
Authors: Vellinga Jort , van den Wollenberg Diana J. M. , van der Heijdt Stephanie , Rabelink Martijn J. W. E. , Hoeben Rob C. 
Published: February 2005

ABSTRACT
The 14.4-kDa hexon-associated protein IX (pIX) acts as a cement in the capsids of primate adenoviruses and confers a thermostable phenotype. Here we show that deletion of amino acids 100 to 114 of adenovirus type 5 pIX, which eliminates the conserved coiled-coil domain, impairs its capacity to self-associate. However, pIXΔ100-114 is efficiently incorporated into the viral capsid, and the resulting virions are thermostable. Deletion of the central alanine-rich domain, as in pIXΔ60-72, does not impair self-association, incorporation into the capsid, or the thermostable phenotype. These data demonstrate, first, that the self-association of pIX is dispensable for its incorporation into the capsid and generation of the thermostability phenotype and, second, that the increased thermostability results from pIX monomers binding to different hexon capsomers rather than capsid stabilization by pIX multimers.
Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8 RTA Reactivates Murine Gammaherpesvirus 68 from Latency
Authors: Rickabaugh Tammy M. , Brown Helen J. , Wu Ting-Ting , Song Moon Jung , Hwang Seungmin , Deng Hongyu , Mitsouras Katherine , Sun Ren 
Published: February 2005

ABSTRACT
Murine gammaherpesvirus 68 (MHV-68), Kaposi's sarcoma-associated herpesvirus (HHV-8), and Epstein-Barr virus (EBV) are all members of the gammaherpesvirus family, characterized by their ability to establish latency in lymphocytes. The RTA protein, conserved in all gammaherpesviruses, is known to play a critical role in reactivation from latency. Here we report that HHV-8 RTA, not EBV RTA, was able to induce MHV-68 lytic viral proteins and DNA replication and processing and produce viable MHV-68 virions from latently infected cells at levels similar to those for MHV-68 RTA. HHV-8 RTA was also able to activate two MHV-68 lytic promoters, whereas EBV RTA was not. In order to define the domains of RTA responsible for their functional differences in viral promoter activation and initiation of the MHV-68 lytic cycle, chimeric RTA proteins were constructed by exchanging the N-terminal and C-terminal domains of the RTA proteins. Our data suggest that the species specificity of MHV-68 RTA resides in the N-terminal DNA binding domain.
REGULATION OF LYMPHOID DEVELOPMENT, DIFFERENTIATION, AND FUNCTION BY THE NOTCH PATHWAY
Authors: Maillard Ivan , Fang Terry , Pear Warren S. 
Published: February 2005

▪ Abstract  The Notch pathway is gaining increasing recognition as a key regulator of developmental choices, differentiation, and function throughout the hematolymphoid system. Notch controls the generation of hematopoietic stem cells during embryonic development and may affect their subsequent homeostasis. Commitment to the T cell lineage and subsequent stages of early thymopoiesis is critically regulated by Notch. Recent data indicate that Notch can also direct the differentiation and activity of peripheral T and B cells. Thus, the full spectrum of Notch effects is just beginning to be understood. In this review, we discuss this explosion of knowledge as well as current controversies and challenges in the field.
Effect of P-Selectin on Phosphatidylserine Exposure and Surface-Dependent Thrombin Generation on Monocytes
Authors: del Conde Ian , Nabi Faisal , Tonda Raúl , Thiagarajan Perumal , López José A. , Kleiman Neal S. 
Published: February 2005

Objective—Stimulation of monocytes with P-selectin induces the synthesis of an array of mediators of inflammation, as well as the expression of tissue factor (TF), the main initiator of coagulation. Because the membrane-bound reactions of coagulation are profoundly influenced by the presence of phosphatidylserine on the membranes of cells, factors that increase its expression may have an impact on coagulation.Methods and Results—Using flow cytometry, we studied the effect of P-selectin on phosphatidylserine expression in blood monocytes and in the monocytic cells, THP-1. Soluble P-selectin at biologically relevant concentrations (0.31 to 2.5 μg/mL) induced a time-dependent increase in phosphatidylserine expression, an effect that could be inhibited with an anti–PSGL-1 blocking antibody, and by genistein, a tyrosine kinase inhibitor. Binding of activated platelets to THP-1 cells also resulted in a significant increase in phosphatidylserine expression that was dependent on PSGL-1. Consistent with the role of phosphatidylserine on surface-dependent reactions of coagulation, treatment of monocytic cells with soluble P-selectin led to increased thrombin generation. We excluded P-selectin induced apoptosis of monocyte as a mechanism for the increased phosphatidylserine exposure.Conclusion—In summary, we show that P-selectin, either soluble or in its membrane-bound form, induces phosphatidylserine exposure in monocytes through a mechanism dependent on PSGL-1.
Platelet activation in cystic fibrosis
Authors: O'Sullivan Brian P. , Linden Matthew D. , Frelinger Andrew L. , Barnard Marc R. , Spencer-Manzon Michele , Morris James E. , Salem Raneem O. , Laposata Michael , Michelson Alan D. 
Published: February 2005

AbstractCystic fibrosis (CF) is caused by a mutation of the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). We examined platelet function in CF patients because lung inflammation is part of this disease and platelets contribute to inflammation. CF patients had increased circulating leukocyte-platelet aggregates and increased platelet responsiveness to agonists compared with healthy controls. CF plasma caused activation of normal and CF platelets; however, activation was greater in CF platelets. Furthermore, washed CF platelets also showed increased reactivity to agonists. CF platelet hyperreactivity was incompletely inhibited by prostaglandin E1 (PGE1). As demonstrated by Western blotting and reverse-transcriptase-polymerase chain reaction (RT-PCR), there was neither CFTR nor CFTR-specific mRNA in normal platelets. There were abnormalities in the fatty acid composition of membrane fractions of CF platelets. In summary, CF patients have an increase in circulating activated platelets and platelet reactivity, as determined by monocyte-platelet aggregation, neutrophil-platelet aggregation, and platelet surface P-selectin. This increased platelet activation in CF is the result of both a plasma factor(s) and an intrinsic platelet mechanism via cyclic adenosine monophosphate (cAMP)/adenylate cyclase, but not via platelet CFTR. Our findings may account, at least in part, for the beneficial effects of ibuprofen in CF. (Blood. 2005;105:4635-4641)
Stress-induced activation of the p53 tumor suppressor in leukemia cells and normal lymphocytes requires mitochondrial activity and reactive oxygen species
Authors: Karawajew Leonid , Rhein Peter , Czerwony Grit , Ludwig Wolf-Dieter 
Published: February 2005

AbstractThe p53 system is highly stress sensitive and integrates diverse intracellular signals in a complex and poorly defined manner. We report on the high dependence of stress-induced p53 activation on mitochondrial activity. Down-regulation of mitochondrial transmembrane potential (MTMP) by inhibitors of electron transport (rotenone, thenoyltrifluoroacetone (TTFA)) and adenosine triphosphate (ATP) synthesis (oligomycin) prevented stress-induced p53 protein accumulation and abrogated p53-dependent apoptosis in a wild-type p53 leukemia cell line MOLT-3, in primary leukemia cells and in normal T lymphocytes. Using genome-wide gene expression analysis, stress-induced up-regulation of the p53 transcriptional targets and their specific inhibition by oligomycin has been demonstrated. Oligomycin did not impair p53-independent apoptosis and caused only a slight reduction of intracellular ATP levels. Reactive oxygen species (ROS) localized to mitochondria decreased in the presence of oligomycin, and stress-induced p53 activation showed strong ROS sensitivity both in leukemic and normal cells. These observations identify mitochondrial activity, described by MTMP and ROS levels, as a critical intracellular determinant of the p53 stress sensitivity and suggest potential implications of this linkage in the mechanisms of chemoresistance of acute leukemia cells. (Blood. 2005;105:4767-4775)
Constitutive homing of mast cell progenitors to the intestine depends on autologous expression of the chemokine receptor CXCR2
Authors: Abonia J. Pablo , Austen K. Frank , Rollins Barrett J. , Joshi Sunil K. , Flavell Richard A. , Kuziel William A. , Koni Pandelakis A. , Gurish Michael F. 
Published: February 2005

AbstractHoming of mast cell progenitors (MCps) to the mouse small intestine involves the interaction of α4β7 integrin with mucosal addressin cellular adhesion molecule-1 (MAdCAM-1). We now demonstrate the dependence of this process on CXC chemokine receptor 2 (CXCR2) and vascular cell adhesion molecule-1 (VCAM-1) using null strains and mice sublethally irradiated and bone marrow (BM) reconstituted (SIBR) with wild-type or null BM or with wild-type BM followed by administration of blocking antibody. The intestinal MCp concentration in CXCR2-/- mice was reduced by 67%, but was unaltered in CC chemokine receptor 2-/- (CCR2-/-), CCR3-/-, or CCR5-/- mice. SIBR mice given CXCR2-/- BM had an intestinal MCp concentration that was 76% less than that in BALB/c BM reconstituted mice. Antibody blockade of VCAM-1 or of CXCR2 in SIBR mice reduced intestinal MCp reconstitution, and mice lacking endothelial VCAM-1 also had a marked reduction relative to wild-type mice. Finally, the half-life of intestinal MCps in wild-type mice was less than one week on the basis of a more than 50% reduction by administration of anti-α4β7 integrin or anti-CXCR2. Thus, the establishment and maintenance of MCps in the small intestine is a dynamic process that requires expression of the α4β7 integrin and the α-chemokine receptor CXCR2.
Thrombin-catalyzed activation of factor VIII with His substituted for Arg372 at the P1 site
Authors: Nogami Keiji , Zhou Qian , Wakabayashi Hironao , Fay Philip J. 
Published: February 2005

AbstractThrombin-catalyzed proteolysis at Arg372 of factor VIII is essential for procofactor activation. However, hemophilia A patients with the missense mutation Arg372 to His possess a mild to moderate phenotype yet show no detectable cleavage at this bond. To evaluate this discrepancy, we prepared and stably expressed a recombinant, B-domainless factor VIII mutant (R372H) that possessed approximately 1% the specific activity of wild type. Cleavage at R372H by thrombin occurred with an approximately 80-fold decreased rate compared with wild type. N-terminal sequence analysis of the derived A2 subunit confirmed that cleavage occurred at the His372-Ser373 bond. Factor VIII R372H was activated slowly, attained lower activity levels, and exhibited an apparent reduced inactivation rate compared with factor VIII wild type. These observations were attributed to a reduced cleavage rate at His372. Factor Xa generation assays showed similar Michaelis-Menten constant (Km, apparent) values for thrombin-catalyzed activation for either factor VIII form, but suggested an approximately 70-fold reduced maximum velocity (Vmax) for factor VIII R372H. However, prolonged reaction with thrombin yielded similar activity and stability values for the mutant and wild-type factor VIIIa forms. These results indicate a markedly reduced rate of cleavage following substitution at the P1Arg, and this property likely reflects the severity of the hemophilia A phenotype.
Lnk inhibits erythropoiesis and Epo-dependent JAK2 activation and downstream signaling pathways
Authors: Tong Wei , Zhang Jing , Lodish Harvey F. 
Published: February 2005

AbstractErythropoietin (Epo), along with its receptor EpoR, is the principal regulator of red cell development. Upon Epo addition, the EpoR signaling through the Janus kinase 2 (JAK2) activates multiple pathways including Stat5, phosphoinositide-3 kinase (PI-3K)/Akt, and p42/44 mitogen-activated protein kinase (MAPK). The adaptor protein Lnk is implicated in cytokine receptor signaling. Here, we showed that Lnk-deficient mice have elevated numbers of erythroid progenitors, and that splenic erythroid colony-forming unit (CFU-e) progenitors are hypersensitive to Epo. Lnk-/- mice also exhibit superior recovery after erythropoietic stress. In addition, Lnk deficiency resulted in enhanced Epo-induced signaling pathways in splenic erythroid progenitors. Conversely, Lnk overexpression inhibits Epo-induced cell growth in 32D/EpoR cells. In primary culture of fetal liver cells, Lnk overexpression inhibits Epo-dependent erythroblast differentiation and induces apoptosis. Lnk blocks 3 major signaling pathways, Stat5, Akt, and MAPK, induced by Epo in primary erythroblasts. In addition, the Lnk Src homology 2 (SH2) domain is essential for its inhibitory function, whereas the conserved tyrosine near the C-terminus and the pleckstrin homology (PH) domain of Lnk are not critical. Furthermore, wild-type Lnk, but not the Lnk SH2 mutant, becomes tyrosine-phosphorylated following Epo administration and inhibits EpoR phosphorylation and JAK2 activation. Hence, Lnk, through its SH2 domain, negatively modulates EpoR signaling by attenuating JAK2 activation, and regulates Epo-mediated erythropoiesis. (Blood. 2005; 105:4604-4612)
Stress-echocardiography in idiopathic dilated cardiomyopathy: instructions for use
Authors: Neskovic Aleksandar N , Otasevic Petar 
Published: February 2005

Abstract
A number of studies have suggested that stress-echocardiography may be used for prognostic stratification in patients with idiopathic dilated cardiomyopathy. There is no consensus on which protocol or which measurements of left ventricular contractile reserve to use. The most frequently used protocol is low-dose dobutamine stress-echocardiography, and most commonly used measures of left ventricular systolic performance are ejection fraction, wall motion score index and cardiac power output.
Stress-echocardiography has been shown to predict improvement in cardiac function in patients with recently diagnosed dilated cardiomyopathy, as well as to predict which patients will benefit from the treatment with beta-blockers. Most importantly, stress-echocardiography can identify patients with worse prognosis in terms of cardiac death and need for transplantation. Additionally, contractile reserve is closely correlated with maximal oxygen consumption and can even be used for further stratification in patients with maximal oxygen consumption between 10 and 14 ml/kg/min.
Future studies are needed for head-to-head comparison of various protocols in an attempt to make standardization in the assessment of patients with dilated cardiomyopathy.
Chromatography paper strip sampling of enteric adenoviruses type 40 and 41 positive stool specimens
Authors: Zlateva Kalina T , Maes Piet , Rahman Mustafizur , Van Ranst Marc 
Published: February 2005

Abstract
Background
The enteric subgroup F adenoviruses type 40 (Ad40) and 41 (Ad41) are the second most important cause of acute infantile gastroenteritis after rotaviruses. Repeated community outbreaks have been associated with antigenic changes among the Ad40 and Ad41 strains due to host immune pressure. Therefore large field epidemiological surveys and studies on the genetic variations in different isolates of Ad40 and Ad41 are important for disease control programs, the design of efficient diagnostic kits and vaccines against subgroup F adenoviruses. A novel method using sodium dodecyl sulphate SDS/EDTA-pretreated chromatography paper strips was evaluated for the collection, storage and shipping of Ad40/41 contaminated stool samples.

Results
This study shows that adenoviral DNA can be successfully detected in the filter strips by PCR after four months storage at -20°C, 4°C, room temperature (20–25°C) and 37°C. Furthermore no adenoviral infectivity was observed upon contact with the SDS/EDTA-pretreated strips.

Conclusions
Collecting, storing and transporting adenovirus type 40 and 41 positive stool samples on SDS/EDTA-pretreated chromatography filter strips is a convenient, biosafe and cost effective method for studying new genome variants and monitoring spread of enteric adenovirus strains during outbreaks.
Estrogen Target Gene Regulation and Coactivator Expression in Rat Uterus after Developmental Exposure to the Ultraviolet Filter 4-Methylbenzylidene Camphor
Authors: Durrer Stefan , Maerkel Kirsten , Schlumpf Margret , Lichtensteiger Walter 
Published: February 2005

Abstract
Because the estrogen receptor (ER) ligand type influences transactivation, it is important to obtain information on molecular actions of nonclassical ER agonists. UV filters from cosmetics represent new classes of endocrine active chemicals, including the preferential ERβ ligands 4-methylbenzylidene camphor (4-MBC) and 3-benzylidene camphor. We studied estrogen target gene expression in uterus of Long Evans rats after developmental exposure to 4-MBC (0.7, 7, 24, and 47 mg/kg·d) administered in feed to the parent generation before mating, during pregnancy and lactation, and to the offspring until adulthood. 4-MBC altered steady-state levels of mRNAs encoding for ERα, ERβ, progesterone receptor (PR), IGF-I, androgen receptor, determined by real-time RT-PCR in uterus of 12-wk-old offspring. Western-blot analyses of the same tissue homogenates indicated changes in ERα and PR but not ERβ proteins. To assess sensitivity to estradiol (E2), offspring were ovariectomized on d 70, injected with E2 (10 or 50 μg/kg sc) on d 84, and killed 6 h later. Acute up-regulation of PR and IGF-I and down-regulation of ERα and androgen receptor by E2 were dose-dependently reduced in 4-MBC-exposed rats. The reduced response to E2 was accompanied by reduced coactivator SRC-1 mRNA and protein levels. Our data indicate that developmental exposure to 4-MBC affects the regulation of estrogen target genes and the expression of nuclear receptor coregulators in uterus at mRNA and protein levels.
Gα12/Gα13 Subunits of Heterotrimeric G Proteins Mediate Parathyroid Hormone Activation of Phospholipase D in UMR-106 Osteoblastic Cells
Authors: Singh A. T. K. , Gilchrist A. , Voyno-Yasenetskaya T. , Radeff-Huang J. M. , Stern P. H. 
Published: February 2005

AbstractPTH, a major regulator of bone remodeling and a therapeutically effective bone anabolic agent, stimulates several signaling pathways in osteoblastic cells. Our recent studies have revealed that PTH activates phospholipase D (PLD) -mediated phospholipid hydrolysis through a RhoA-dependent mechanism in osteoblastic cells, raising the question of the upstream link to the PTH receptor. In the current study, we investigated the role of heterotrimeric G proteins in mediating PTH-stimulated PLD activity in UMR-106 osteoblastic cells. Transfection with antagonist minigenes coding for small peptide antagonists to Gα12 and Gα13 subunits of heterotrimeric G proteins prevented PTH-stimulated activation of PLD, whereas an antagonist minigene to Gαs failed to produce this effect. Effects of pharmacological inhibitors (protein kinase inhibitor, Clostridium botulinum exoenzyme C3) were consistent with a role of Rho small G proteins, but not of cAMP, in the effect of PTH on PLD. Expression of constitutively active Gα12 and Gα13 activated PLD, an effect that was inhibited by dominant-negative RhoA. The results identify Gα12 and Gα13 as upstream transducers of PTH effects on PLD, mediated through RhoA in osteoblastic cells.
Choice of Lard, But Not Total Lard Calories, Damps Adrenocorticotropin Responses to Restraint
Authors: la Fleur Susanne E. , Houshyar Hani , Roy Monica , Dallman Mary F. 
Published: February 2005

Abstract
Although rats given the choice of eating high-density calories as concentrated sucrose solutions or lard exhibit reduced responsivity in the hypothalamo-pituitary-adrenal axis, rats fed high-fat diets have normal or augmented responses to stressors. To resolve this apparent discrepancy, we compared in adult male rats the effects of 7-d feeding with lard + chow (choice) to feeding a 50% lard-chow mixture (no-choice) and to chow only. Rats with choice composed diets with 50–60% total calories from lard. Rats were exposed to 30 min of restraint on d 7. In the choice group, there was a robust inhibition of ACTH and corticosterone responses to restraint compared with chow or no-choice groups. Total caloric intake was less with choice than no-choice. Fat depot weights and body weight gain were similar in the high-fat groups. Leptin concentrations were equal but insulin was higher in the choice group. We conclude the following: 1) choice of eating high-density calories strongly damps hypothalamo-pituitary-adrenal responses to stress; without choice, high-density diet is ineffective; and 2) insulin may signal metabolic well-being, and may act through hypothalamic sites to reduce caloric intake but through forebrain sites to damp stress responses.
Organic Syntheses Utilizing Titanium Carbene Complexes
Authors: Takeda Takeshi 
Published: February 2005

Abstract
Synthetic reactions utilizing titanium carbene complexes prepared by the desulfurizative titanation of thioacetals and related organosulfur compounds with the titanocene(II) species [Cp2Ti{P(OEt)3}2] are described. The Wittig type olefination of carbonyl compounds including carboxylic acid derivatives with the titanium carbene complexes affords a variety of olefinic compounds. The reaction is successfully applied to the intramolecular carbonyl olefination of carboxylic acid derivatives, giving various carbo- and hetero-cycles. The organotitanium species generated by the treatment of gem-dihalides and certain alkyl halides with the titanocene(II) species are also useful for the transformation of carbonyl compounds into highly substituted olefins or into olefins bearing a bulky substituent.
The alkylidenetitanocenes generated from thioacetals react with olefins in both inter- and intramolecular fashions to give olefin metathesis products. The ring-closing olefin metathesis of the carbene complexes formed from thioacetals having a terminal olefin provides a variety of unsaturated heterocyclic compounds. On the other hand, cyclopropanation proceeds when terminal olefins are treated with alkenyl- and alkynyl-carbene complexes. Cyclopropanes are also obtained by treatment of gem-dihalides having a terminal carbon–carbon double bond.
The carbene complexes are also highly reactive toward triple bonds. Their reactions with nitriles afford the acylation products after hydrolysis of intermediary titanium vinylimido complexes. The reactions of the carbene complexes with internal alkynes via the formation of titanacyclobutene intermediates afford conjugated dienes with high stereoselectivity, whereas metathesis polymerization proceeds to give trans-polyacetylene when the carbene complexes are treated with excess acetylene. The carbene complexes also react with t-alkyl halides and group 14 metal hydrides.