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Publication
Journal: Virology
December/5/1994
Abstract
The receptor specificity of 56 H2 and H3 influenza virus isolates from various animal species has been determined to test the relevance of receptor specificity to the ecology of influenza virus. The results show that the receptor specificity of both H2 and H3 isolates evaluated for sialic acid linkage specificity and inhibition of hemagglutination by horse serum correlates with the species of origin, as postulated earlier for H3 strains based on a limited survey of five human, three avian, and one equine strain. Elucidation of the amino acid sequence of several human H2 receptor variants and analysis of known sequences of H2 and H3 isolates revealed that receptor specificity varies in association with an amino acid change at residues 228 in addition to the change at residue 226 previously documented to affect receptor specificity of H3 but not H1 isolates. Residues 226 and 228 are leucine and serine in human isolates, which preferentially bind sialic acid alpha 2,6-galactose beta 1,4-N-acetyl glucosamine (SA alpha 2,6Gal), and glutamine and glycine in avian and equine isolates, which exhibit specificity for sialic acid alpha-2,3-galactose beta-1,3-N-acetyl galactosamine (SA alpha 2,3Gal). The results demonstrate that the correlation of receptor specificity and species of origin is maintained across both H2 and H3 influenza virus serotypes and provide compelling evidence that influenza virus hosts exert selective pressure to maintain the receptor specificity characteristics of strains isolated from that species.
Publication
Journal: Virology
August/25/1983
Abstract
The binding of influenza virus to erythrocytes and host cells is mediated by the interaction of the viral hemagglutinin (H) with cell surface receptors containing sialic acid (SA). The specificity of this interaction for 19 human and animal influenza isolates was examined using human erythrocytes enzymatically modified to contain cell surface sialyloligosaccharides with the sequence SA alpha 2,6Gal beta 1,4GlcNAc; SA alpha 2,3Gal beta 1,4(3)GlcNAc; SA alpha 2,3Gal beta 1,3GalNAc; or SA alpha 2,6GalNAc. Although none of the viruses agglutinated cells containing the SA alpha 2,6GalNAc linkage, differential agglutination of cells containing the other three sequences revealed at least three distinct receptor binding types. Several virus isolates exhibited marked receptor specificity, binding only to cells containing the SA alpha 2,6Gal or the SA alpha 2,3Gal linkage, while others bound equally well to cells containing either linkage. Moreover, some viruses could distinguish between two oligosaccharide receptor determinants containing the terminal SA alpha 2,3Gal linkage when present in the SA alpha 2,3Gal beta 1,4(3)GlcNAc sequence or the SA alpha 2,3Gal beta 1,3GalNAc sequence binding cells containing only the former. The observed receptor specificities were not significantly influenced by the viral neuraminidases as shown by the use of the potent neuraminidase inhibitor 2-deoxy-2,3-dehydro-N-acetylneuraminic acid. Receptor specificity appeared, to some extent, to be dependent on the species from which the virus was isolated. In particular, human isolates of the H3 serotype all agglutinated cells containing the SA alpha 2,6Gal linkage, but not cells bearing the SA alpha 2,3Gal beta 1,3GalNAc sequence. In contrast, antigenically similar (H3) isolates from avian and equine species preferentially bound erythrocytes containing the SA alpha 2,3Gal linkage. This is of particular interest in view of the identification of the avian virus H3 hemagglutinin as the progenitor of the H3 hemagglutinin present on the current human Hong Kong viruses.
Publication
Journal: Plant Physiology
April/19/2006
Abstract
Salicylic acid (SA) has been proposed to antagonize jasmonic acid (JA) biosynthesis and signaling. We report, however, that in salicylate hydroxylase-expressing tobacco (Nicotiana tabacum) plants, where SA levels were reduced, JA levels were not elevated during a hypersensitive response elicited by Pseudomonas syringae pv phaseolicola. The effects of cotreatment with various concentrations of SA and JA were assessed in tobacco and Arabidopsis (Arabidopsis thaliana). These suggested that there was a transient synergistic enhancement in the expression of genes associated with either JA (PDF1.2 [defensin] and Thi1.2 [thionin]) or SA (PR1 [PR1a-beta-glucuronidase in tobacco]) signaling when both signals were applied at low (typically 10-100 microm) concentrations. Antagonism was observed at more prolonged treatment times or at higher concentrations. Similar results were also observed when adding the JA precursor, alpha-linolenic acid with SA. Synergic effects on gene expression and plant stress were NPR1- and COI1-dependent, SA- and JA-signaling components, respectively. Electrolyte leakage and Evans blue staining indicated that application of higher concentrations of SA + JA induced plant stress or death and elicited the generation of apoplastic reactive oxygen species. This was indicated by enhancement of hydrogen peroxide-responsive AoPR10-beta-glucuronidase expression, suppression of plant stress/death using catalase, and direct hydrogen peroxide measurements. Our data suggests that the outcomes of JA-SA interactions could be tailored to pathogen/pest attack by the relative concentration of each hormone.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
December/9/2001
Abstract
Plants possess multiple resistance mechanisms that guard against pathogen attack. Among these are inducible systems such as systemic acquired resistance (SAR). SAR is activated by pathogen exposure and leads to an increase in salicylic acid (SA), high-level expression of SAR-related genes, and resistance to a spectrum of pathogens. To identify components of the signal transduction pathways regulating SAR, a mutant screen was developed that uses 2,6-dichloroisonicotinic acid as an activator of SAR gene expression and pathogen resistance, followed by assays for resistance to the fungal pathogen Peronospora parasitica. Mutants from this screen were subsequently examined to assess their defense responses. We describe here a recessive mutation that causes a phenotype of insensitivity to chemical and biological inducers of SAR genes and resistance. These data indicate the existence of a common signaling pathway that couples these diverse stimuli to induction of SAR genes and resistance. Because of its non-inducible immunity phenotype, we call this mutant nim1. Although nim1 plants fail to respond to SA, they retain the ability to accumulate wild-type levels of SA, a probable endogenous signal for SAR. Further, the ability of nim1 plants to support growth of normally incompatible races of a fungal pathogen indicates a role for this pathway in expression of genetically determined resistance, consistent with earlier findings for transgenic plants engineered to break down SA. These results suggest that the wild-type NIM1 gene product functions in a pathway regulating acquired resistance, at a position downstream of SA accumulation and upstream of SAR gene induction and expression of resistance.
Publication
Journal: Science
April/16/2009
Abstract
Plants possess inducible systemic defense responses when locally infected by pathogens. Bacterial infection results in the increased accumulation of the mobile metabolite azelaic acid, a nine-carbon dicarboxylic acid, in the vascular sap of Arabidopsis that confers local and systemic resistance against the pathogen Pseudomonas syringae. Azelaic acid primes plants to accumulate salicylic acid (SA), a known defense signal, upon infection. Mutation of the AZELAIC ACID INDUCED 1 (AZI1) gene, which is induced by azelaic acid, results in the specific loss of systemic immunity triggered by pathogen or azelaic acid and of the priming of SA induction in plants. Furthermore, the predicted secreted protein AZI1 is also important for generating vascular sap that confers disease resistance. Thus, azelaic acid and AZI1 are components of plant systemic immunity involved in priming defenses.
Publication
Journal: Journal of Abnormal Child Psychology
August/6/1998
Abstract
This study examined the utility of modifying the Social Anxiety Scale for Children-Revised (SASC-R) for use with adolescents, and examined associations between adolescents' social anxiety (SA) and their peer relations, friendships, and social functioning. Boys (n = 101) and girls (n = 149) in the 10th through 12th grades completed the Social Anxiety Scale for Adolescents (SAS-A) and measures of social support, perceived competence, and number and quality of their best friendships. Factor analysis of the SAS-A confirmed a three-factor structure: Fear of Negative Evaluation, Social Avoidance and Distress in General, and Social Avoidance Specific to New Situations or Unfamiliar Peers. Girls reported more SA than boys, and SA was more strongly linked to girls' social functioning than boys'. Specifically, adolescents with higher levels of SA reported poorer social functioning (less support from classmates, less social acceptance), and girls with higher levels of SA reported fewer friendships, and less intimacy, companionship, and support in their close friendships. These findings extend work on the SASC-R to adolescents, and suggest the importance of SA for understanding the social functioning and close friendships of adolescents, especially girls.
Publication
Journal: Plant Cell
May/28/1997
Abstract
The phenylpropanoid-derived natural product salicylic acid (SA) plays a key role in disease resistance. However, SA administered in the absence of a pathogen is a paradoxically weak inductive signal, often requiring concentrations of 0.5 to 5 mM to induce acquired resistance or related defense mechanisms or to precondition signal systems. In contrast, endogenous SA accumulates to concentrations of < 70 microM at the site of attempted infection. Here, we show that although 10 to 100 microM SA had negligible effects when administered to soybean cell suspensions in the absence of a pathogen, physiological concentrations of SA markedly enhanced the induction of defense gene transcripts, H2O2 accumulation, and hypersensitive cell death by an avirulent strain of Pseudomonas syringae pv glycinea, with optimal effects being at approximately 50 microM. SA also synergistically enhanced H2O2 accumulation in response to the protein phosphatase type 2A inhibitor cantharidin in the absence of a pathogen. The synergistic effect of SA was potent, rapid, and insensitive to the protein synthesis inhibitor cycloheximide, and we conclude that SA stimulates an agonist-dependent gain control operating at an early step in the signal pathway for induction of the hypersensitive response. This fine control mechanism differs from previously described time-dependent, inductive coarse control mechanisms for SA action in the absence of a pathogen. Induction of H2O2 accumulation and hypersensitive cell death by avirulent P. s. glycinea was blocked by the phenylpropanoid synthesis inhibitor alpha-aminooxy-beta-phenylpropionic acid, and these responses could be rescued by exogenous SA. Because the agonist-dependent gain control operates at physiological levels of SA, we propose that rapid fine control signal amplification makes an important contribution to SA function in the induction of disease resistance mechanisms.
Publication
Journal: Cytometry Part A
March/31/2010
Abstract
The in vivo progenitor of culture-expanded mesenchymal-like adipose-derived stem cells (ADSC) remains elusive, owing in part to the complex organization of stromal cells surrounding the small vessels, and the rapidity with which adipose stromal vascular cells adopt a mesenchymal phenotype in vitro. Immunohistostaining of intact adipose tissue was used to identify three markers (CD31, CD34, and CD146), which together unambiguously discriminate histologically distinct inner and outer rings of vessel-associated stromal cells, as well as capillary and small vessel endothelial cells. These markers were used in multiparameter flow cytometry in conjunction with stem/progenitor markers (CD90 and CD117) to further characterize stromal vascular fraction (SVF) subpopulations. Two mesenchymal and two endothelial populations were isolated by high speed flow cytometric sorting, expanded in short term culture, and tested for adipogenesis. The inner layer of stromal cells in contact with small vessel endothelium (pericytes) was CD146+/alpha-SMA+/CD90+/-/CD34-/CD31-; the outer adventitial stromal ring (designated supra adventitial-adipose stromal cells, SA-ASC) was CD146-/alpha-SMA-/CD90+/CD34+/CD31-. Capillary endothelial cells were CD31+/CD34+/CD90+ (endothelial progenitor), whereas small vessel endothelium was CD31+/CD34-/CD90- (endothelial mature). Flow cytometry confirmed these expression patterns and revealed a CD146+/CD90+/CD34+/CD31- pericyte subset that may be transitional between pericytes and SA-ASC. Pericytes had the most potent adipogenic potential, followed by the more numerous SA-ASC. Endothelial populations had significantly reduced adipogenic potential compared with unsorted expanded SVF cells. In adipose tissue, perivascular stromal cells are organized in two discrete layers, the innermost consisting of CD146+/CD34- pericytes, and the outermost of CD146-/CD34+ SA-ASC, both of which have adipogenic potential in culture. A CD146+/CD34+ subset detected by flow cytometry at low frequency suggests a population transitional between pericytes and SA-ASC.
Publication
Journal: Molecular Plant-Microbe Interactions
February/25/1997
Abstract
Salicylic acid (SA) plays an important signaling role in the resistance of many plants to pathogen invasion. Increases in endogenous SA levels have been associated with the hypersensitive response as well as systemic acquired resistance (SAR). SA also induces the expression of a subset of the pathogenesis-related (PR) genes. However, relatively little is known about the events occurring subsequent to SA accumulation during a resistance response. In order to identify mutations in components of the SA signal transduction pathway, we have developed a genetic screen in Arabidopsis thaliana that utilizes the Agrobacterium tumefaciens tms2 gene as a counter-selectable marker. SA-inducible expression of the tms2 gene from the tobacco PR-1a promoter confers sensitivity to alpha-naphthalene acetamide (alpha-NAM), resulting in inhibition of root growth in germinating transgenic Arabidopsis seedlings. Mutants in which root growth is insensitive to alpha-NAM have been selected from this PR-1a:tms2 transgenic line with the expectation that a subset will lack a regulatory component downstream of SA. The sail mutant so identified expressed neither the PR-1a:tms2 transgene nor the endogenous Arabidopsis PR-1, PR-2, and PR-5 genes in response to SA. These genes also were not induced in sai1 by 2,6-dichloroisonicotinic acid (INA) or benzothiadiazole (BTH), two chemical inducers of SAR. As expected of a mutation acting downstream of SA, sai1 plants accumulate SA and its glucoside in response to infection with an avirulent pathogen and are more susceptible to this avirulent pathogen than the wild-type parent. sai1 is allelic to npr1, a previously identified SA-noninducible mutation. The recessive nature of the noninducible sai1 mutation suggests that the wild-type SAI1 gene acts as a positive regulator in the SA signal transduction pathway.
Publication
Journal: Plant Journal
July/28/2003
Abstract
The signal transduction network controlling plant responses to pathogens includes pathways requiring the signal molecules salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). The network topology was explored using global expression phenotyping of wild-type and signaling-defective mutant plants, including eds3, eds4, eds5, eds8, pad1, pad2, pad4, NahG, npr1, sid2, ein2, and coi1. Hierarchical clustering was used to define groups of mutations with similar effects on gene expression and groups of similarly regulated genes. Mutations affecting SA signaling formed two groups: one comprised of eds4, eds5, sid2, and npr1-3 affecting only SA signaling; and the other comprised of pad2, eds3, npr1-1, pad4, and NahG affecting SA signaling as well as another unknown process. Major differences between the expression patterns in NahG and the SA biosynthetic mutant sid2 suggest that NahG has pleiotropic effects beyond elimination of SA. A third group of mutants comprised of eds8, pad1, ein2, and coi1 affected ethylene and jasmonate signaling. Expression patterns of some genes revealed mutual inhibition between SA- and JA-dependent signaling, while other genes required JA and ET signaling as well as the unknown signaling process for full expression. Global expression phenotype similarities among mutants suggested, and experiments confirmed, that EDS3 affects SA signaling while EDS8 and PAD1 affect JA signaling. This work allowed modeling of network topology, definition of co-regulated genes, and placement of previously uncharacterized regulatory genes in the network.
Publication
Journal: Virus Research
November/14/1993
Abstract
The complement of sialyloligosaccharides present on the surface of human tracheal epithelium has been implicated as an important factor in the selection of hemagglutinin receptor specificity of human influenza A virus. Human strains of influenza A virus preferentially recognize host cell receptors bearing SA alpha 2,6Gal sequences, a sequence which is found on the surface of ciliated tracheal epithelium. A fluorescently-labelled H3 human virus strain bound avidly to the apical surface of human tracheal epithelium, while a fluorescently-labelled receptor variant strain, which preferentially binds SA alpha 2,3Gal sequences, showed little binding to the epithelial surface and localized primarily to intracellular mucin droplets. Extracts of human bronchial mucin, which is known to contain sialic acid primarily in the SA alpha 2,3Gal linkage, was a potent inhibitor of the binding of the receptor variant strain to trachea sections, while the binding of the parent strain was unaffected by the presence of mucin. Human bronchial mucin also inhibited the binding of the receptor variant strains, but not the parent virus strains, to human erythrocytes derivatized to contain SA alpha 2,6Gal sequences. These results suggest that a combination of selection pressures present in the respiratory tract environment have resulted in the evolution of a hemagglutinin receptor specificity in human influenza A virus strains which optimizes recognition of, binding to and infection of host cells.
Publication
Journal: Pharmacological Reviews
November/25/1996
Abstract
In this article, the actions, mechanisms and applications of various ions and drugs that interact with MG channels have been discussed. At present, no compound has been found that displays the high specificity and affinity exhibited by tetrodotoxin or alpha-bungarotoxin that proved so useful in the functional and structural characterization of the voltage-gated Na+ channel and the acetylcholine receptor channel, respectively. Nevertheless, three different classes of compounds have been discovered since Paintal's review that clearly block MG channels. These compounds, represented by amiloride, gentamicin and gadolinium, act mainly on the SA cation channel, which appears to be shared by many nonsensory and some mechanosensory cells. Each class of compound can be distinguished by the voltage and concentration dependence of the block and most likely involves different mechanisms of blocking action. In general, the MG channel blocker pharmacology indicates a variety of "receptor sites" on MG channels. The recognition and acceptance of such receptors should provide added impetus for continued screening for more potent drugs, venoms and toxins. In the case of activators, little is understood of the mechanisms by which the various amphipathic and amphiphilic compounds stimulate MG channels, although different bilayer and protein mechanisms have been evoked. Even less is understood of the role the new class of MG K+ channel and their modulation by fatty acids plays in physiological and perhaps pathological processes. However, given that K+ channels in general tend to reduce the excitability of nerve and muscle, plausible roles include fatty acid regulation of vascular tone and control of neuronal network excitability. In both cases, more detailed understanding is required regarding the physiological stimuli that modulate these channels through their fatty acid receptors. It may turn out that recognition and/or development of cell-type specific agents that activate such MG channels will possess high therapeutic potential. In any case, the observation that MG channels can be chemically blocked and/or activated by a wide range of compounds requires revision of the long-standing conclusion of Paintal that mechanotransduction is a process that has a low susceptibility to chemical influence.
Publication
Journal: Nature Medicine
December/6/2011
Abstract
Epileptic seizures are a common and poorly understood comorbidity for individuals with primary brain tumors. To investigate peritumoral seizure etiology, we implanted human-derived glioma cells into severe combined immunodeficient mice. Within 14-18 d, glioma-bearing mice developed spontaneous and recurring abnormal electroencephalogram events consistent with progressive epileptic activity. Acute brain slices from these mice showed marked glutamate release from the tumor mediated by the system x(c)(-) cystine-glutamate transporter (encoded by Slc7aal and optical recordings showed glutamatergic epileptiform hyperexcitability that spread into adjacent brain tissue. We inhibited glutamate release from the tumor and the ensuing hyperexcitability by sulfasalazine (SAS), a US Food and Drug Administration-approved drug that blocks system x(c)(-). We found that acute administration of SAS at concentrations equivalent to those used to treat Crohn's disease in humans reduced epileptic event frequency in tumor-bearing mice compared with untreated controls. SAS should be considered as an adjuvant treatment to ameliorate peritumoral seizures associated with glioma in humans.
Publication
Journal: Journal of Biological Chemistry
January/30/2002
Abstract
Type 1 diabetes mellitus results from an autoimmune destruction of pancreatic beta-cells. Cytokines, such as interleukin-1 beta and interferon-gamma, are putative mediators of immune-induced beta-cell death and, under in vitro conditions, cause beta-cell apoptosis. We have recently shown that interleukin-1 beta + interferon-gamma modifies the expression of >200 genes in beta-cells. Several of these genes are putative targets for the transcription factor nuclear factor-kappa B (NF-kappa B), and in subsequent experiments we showed that NF-kappa B activation is mostly pro-apoptotic in beta-cells. To identify cytokine-induced and NF-kappa B-regulated genes in primary rat beta-cells, we presently combined two experimental approaches: 1) blocking of NF-kappa B activation in cytokine-exposed beta-cells by a recombinant adenovirus (AdI kappa B((SA)2)) containing an inhibitor of NF-kappa B alpha (I kappa Bac) super-repressor (S32A/S36A) and 2) study of gene expression by microarray analysis. We identified 66 cytokine-modified and NF-kappa B-regulated genes in beta-cells. Cytokine-induced NF-kappa B activation decreased Pdx-1 and increased c-Myc expression. This, together with NF-kappa B-dependent inhibition of Glut-2, pro-hormone convertase-1, and Isl-1 expression, probably contributes to the loss of differentiated beta-cell functions. NF-kappa B also regulates several genes encoding for chemokines and cytokines in beta-cells. The present data suggest that NF-kappa B is a key "switch regulator" of transcription factors and gene networks controlling cytokine-induced beta-cell dysfunction and death.
Publication
Journal: The Lancet
July/19/2010
Abstract
BACKGROUND
Expanded access to combination antiretroviral therapy (ART) in resource-poor settings is dependent on task shifting from doctors to other health-care providers. We compared outcomes of nurse versus doctor management of ART care for HIV-infected patients.
METHODS
This randomised non-inferiority trial was undertaken at two South African primary-care clinics. HIV-positive individuals with a CD4 cell count of less than 350 cells per microL or WHO stage 3 or 4 disease were randomly assigned to nurse-monitored or doctor-monitored ART care. Patients were randomly assigned by stratified permuted block randomisation, and neither the patients nor those analysing the data were masked to assignment. The primary objective was a composite endpoint of treatment-limiting events, incorporating mortality, viral failure, treatment-limiting toxic effects, and adherence to visit schedule. Analysis was by intention to treat. Non-inferiority of the nurse versus doctor group for cumulative treatment failure was prespecified as an upper 95% CI for the hazard ratio that was less than 1.40. This study is registered with ClinicalTrials.gov, number NCT00255840.
RESULTS
408 patients were assigned to doctor-monitored ART care and 404 to nurse-monitored ART care; all participants were analysed. 371 (46%) patients reached an endpoint of treatment failure: 192 (48%) in the nurse group and 179 (44%) in the doctor group. The hazard ratio for composite failure was 1.09 (95% CI 0.89-1.33), which was within the limits for non-inferiority. After a median follow-up of 120 weeks (IQR 60-144), deaths (ten vs 11), virological failures (44 vs 39), toxicity failures (68 vs 66), and programme losses (70 vs 63) were similar in nurse and doctor groups, respectively.
CONCLUSIONS
Nurse-monitored ART is non-inferior to doctor-monitored therapy. Findings from this study lend support to task shifting to appropriately trained nurses for monitoring of ART.
BACKGROUND
National Institutes of Health; United States Agency for International Development; National Institute of Allergy and Infectious Diseases.
Publication
Journal: Virology
November/27/1989
Abstract
It has been previously reported that several human H1 influenza viruses isolated prior to 1956, in contrast to human H3 isolates which are quite specific for SA alpha 2,6Gal sequences, apparently recognize both SA alpha 2,3Gal and SA alpha 2,6Gal sequences (Rogers, G.N., and Paulson, J.C., Virology 127, 361-373, 1983). In this report human H1 isolates representative of two epidemic periods, from 1934 to 1957 and from 1977 to 1986, and H1 influenza isolated from pigs, ducks, and turkeys were compared for their ability to utilize sialyloligosaccharide structures containing terminal SA alpha 2,3Gal or SA alpha 2,6Gal sequences as receptor determinants. Five of the eight human isolates from the first epidemic period recognize both SA alpha 2,3Gal and SA alpha 2,6Gal linkages, in agreement with our previous results. Of the remaining three strains, all isolated towards the end of the first epidemic, two appear to prefer SA alpha 2,6Gal sequences while the third preferentially binds SA alpha 2,3Gal sequences. In contrast to the early isolates, 11 of 13 human strains isolated during the second epidemic period preferentially bind SA alpha 2,6Gal containing oligosaccharides. On the basis of changes in receptor binding associated with continued passage in the laboratory for some of these later strains, it seems likely that human H1 isolates preferentially bind SA alpha 2,6Gal sequences in nature, and that acquisition of SA alpha 2,3Gal-binding is associated with laboratory passage. Influenza H1 viruses isolated from pigs were predominantly SA alpha 2,6Gal-specific while those isolated from ducks were primarily SA alpha 2,3Gal-specific. Thus, as has been previously reported for H3 influenza isolates, receptor specificity for influenza H1 viruses appears to be influenced by the species from which they were isolated, human isolates binding preferentially to SA alpha 2,6Gal-containing oligosaccharides while those isolated from ducks prefer SA alpha 2,3Gal-containing oligosaccharides. However, unlike the SA alpha 2,6Gal-specific H3 isolates, binding to cell surface receptors by the H1 influenza viruses is not sensitive to inhibition by horse serum glycoproteins, regardless of their receptor specificity. These results suggest that, while the H1 and H3 hemagglutinins appear to be subject to similar host-derived selective pressures, there appear to be certain fundamental differences in the detailed molecular interaction of the two hemagglutinins with their sialyloligosaccharide receptor determinants.
Publication
Journal: American Heart Journal
June/15/2003
Abstract
BACKGROUND
Endothelial injury plays a critical role in coronary artery disease (CAD), but the assessment of this injury has been problematical. Recently, it has been shown in vitro that endothelial cells (ECs) release endothelial microparticles (EMPs) on activation or apoptosis and that an assay of EMPs can provide useful information on EC status in patients with thrombotic disorders. This study is aimed at assessing possible correlations between EMPs, which are markers of endothelial injury, and clinical subgroups of patients with CAD.
METHODS
A prospective, case-controlled study was conducted on 84 patients with CAD and 42 control subjects to investigate EMP profiles. Included were 64 patients with acute coronary syndromes ([ACS], 38 with myocardial infarction [MI] and 26 with unstable angina [UA]) and 20 patients with stable angina (SA). EMPs in platelet-poor plasma were measured flow cytometrically with combinations of fluorescent antibodies (anti-CD31, -51, -42), allowing distinction of EMPs from platelet microparticles (PMPs). Clinical subgroups of patients were correlated with EMP and PMP levels in blood.
RESULTS
Two species of EMPs (CD31+ and CD51+) were evaluated. Both were significantly higher in patients with CAD than in control subjects. CD31+ EMP was higher in ACS than SA. Among patients with first MI, CD31+ EMP was higher in patients with MI than in patients with UA and was significantly higher than in patients with recurring MI. CD51+ EMP did not discriminate ACS from SA. A simultaneous assay of PMP showed correlation between EMPs and PMPs. However, PMPs did not discriminate patients with SA from control subjects.
CONCLUSIONS
EMP assay appears promising for assessing EC injury in CAD.
Publication
Journal: Science
January/5/2004
Abstract
The Toll-dependent defense against Gram-positive bacterial infections in Drosophila is mediated through the peptidoglycan recognition protein SA (PGRP-SA). A mutation termed osiris disrupts the Gram-negative binding protein 1 (GNBP1) gene and leads to compromised survival of mutant flies after Gram-positive infections, but not after fungal or Gram-negative bacterial challenge. Our results demonstrate that GNBP1 and PGRP-SA can jointly activate the Toll pathway. The potential for a combination of distinct proteins to mediate detection of infectious nonself in the fly will refine the concept of pattern recognition in insects.
Publication
Journal: Journal of Cell Biology
December/29/1991
Abstract
Recently we developed an isolation procedure for the cell-to-cell adherens junctions (AJ; cadherin-based junctions) from rat liver (Tsukita, Sh. and Sa. Tsukita. 1989. J. Cell Biol. 108:31-41). In this study, using the isolated AJ, we have obtained two mAbs specific to the 220-kD undercoat-constitutive protein. Immunofluorescence and immunoelectron microscopy with these mAbs showed that this 220-kD protein was highly concentrated at the undercoat of cell-to-cell AJ in various types of tissues and that this protein was located in the immediate vicinity of the plasma membrane in the undercoat of AJ. In the cells lacking typical cell-to-cell AJ, such as fibroblasts, the 220-kD protein was immunofluorescently shown to be coconcentrated with cadherin molecules at cell-cell adhesion sites. These localization analyses appeared to indicate the possible direct or indirect association of the 220-kD protein with cadherin molecules. Furthermore, it was revealed that the 220-kD protein and alpha-spectrin were coimmunoprecipitated with the above mAbs in both the isolated AJ and the brain. The affinity-purified 220-kD protein molecule looked like a spherical particle, and its binding site on the spectrin molecule was shown to be in the position approximately 10-20 nm from the midpoint of spectrin tetramer by low-angle rotary-shadowing electron microscopy. Taking all these results together with biochemical and immunological comparisons, we are persuaded to speculate that the 220-kD protein is a novel member of the ankyrin family. However, the possibility cannot be excluded that the 220-kD protein is an isoform of beta-spectrin. The possible roles of this 220-kD protein in the association of cadherin molecules with the spectrin-based membrane skeletons at the cadherin-based cell-cell adhesion sites are discussed.
Publication
Journal: PLoS ONE
August/24/2014
Abstract
OBJECTIVE
This study was designed to investigate the revised and short version of the smartphone addiction scale and the proof of its validity in adolescents. In addition, it suggested cutting off the values by gender in order to determine smartphone addiction and elaborate the characteristics of smartphone usage in adolescents.
METHODS
A set of questionnaires were provided to a total of 540 selected participants from April to May of 2013. The participants consisted of 343 boys and 197 girls, and their average age was 14.5 years old. The content validity was performed on a selection of shortened items, while an internal-consistency test was conducted for the verification of its reliability. The concurrent validity was confirmed using SAS, SAPS and KS-scale. Receiver operating characteristics analysis was conducted to suggest cut-off.
RESULTS
The 10 final questions were selected using content validity. The internal consistency and concurrent validity of SAS were verified with a Cronbach's alpha of 0.911. The SAS-SV was significantly correlated with the SAS, SAPS and KS-scale. The SAS-SV scores of gender (p<.001) and self-evaluation of smartphone addiction (p<.001) showed significant difference. The ROC analysis results showed an area under a curve (AUC) value of 0.963(0.888-1.000), a cut-off value of 31, sensitivity value of 0.867 and specificity value of 0.893 in boys while an AUC value of 0.947(0.887-1.000), a cut-off value of 33, sensitivity value of 0.875, and a specificity value of 0.886 in girls.
CONCLUSIONS
The SAS-SV showed good reliability and validity for the assessment of smartphone addiction. The smartphone addiction scale short version, which was developed and validated in this study, could be used efficiently for the evaluation of smartphone addiction in community and research areas.
Publication
Journal: PLoS ONE
August/22/2013
Abstract
OBJECTIVE
The aim of this study was to develop a self-diagnostic scale that could distinguish smartphone addicts based on the Korean self-diagnostic program for Internet addiction (K-scale) and the smartphone's own features. In addition, the reliability and validity of the smartphone addiction scale (SAS) was demonstrated.
METHODS
A total of 197 participants were selected from Nov. 2011 to Jan. 2012 to accomplish a set of questionnaires, including SAS, K-scale, modified Kimberly Young Internet addiction test (Y-scale), visual analogue scale (VAS), and substance dependence and abuse diagnosis of DSM-IV. There were 64 males and 133 females, with ages ranging from 18 to 53 years (M = 26.06; SD = 5.96). Factor analysis, internal-consistency test, t-test, ANOVA, and correlation analysis were conducted to verify the reliability and validity of SAS.
RESULTS
Based on the factor analysis results, the subscale "disturbance of reality testing" was removed, and six factors were left. The internal consistency and concurrent validity of SAS were verified (Cronbach's alpha = 0.967). SAS and its subscales were significantly correlated with K-scale and Y-scale. The VAS of each factor also showed a significant correlation with each subscale. In addition, differences were found in the job (p<0.05), education (p<0.05), and self-reported smartphone addiction scores (p<0.001) in SAS.
CONCLUSIONS
This study developed the first scale of the smartphone addiction aspect of the diagnostic manual. This scale was proven to be relatively reliable and valid.
Publication
Journal: Circulation Research
May/27/2002
Abstract
We directly examined the role of the Ca(v)1.3 (alpha(1D)) Ca(2+) channel in the sinoatrial (SA) node by using Ca(v)1.3 Ca(2+) channel-deficient mice. A previous report has shown that the null mutant (Ca(v)1.3(-/-)) mice have sinus bradycardia with a prolonged PR interval. In the present study, we show that spontaneous action potentials recorded from the SA nodes show a significant decrease in the beating frequency and rate of diastolic depolarization in Ca(v)1.3(-/-) mice compared with their heterozygous (Ca(v)1.3(+/-)) or wild-type (WT, Ca(v)1.3(+/+)) littermates, suggesting that the deficit is intrinsic to the SA node. Whole-cell L-type Ca(2+) currents (I(Ca,L)s) recorded in single isolated SA node cells from Ca(v)1.3(-/-) mice show a significant depolarization shift in the activation threshold. The voltage-dependent activation of Ca(v)1.2 (alpha(1C)) versus Ca(v)1.3 Ca(2+) channel subunits was directly compared by using a heterologous expression system without beta coexpression. Similar to the I(Ca,L) recorded in the SA node of Ca(v)1.3(-/-) mutant mice, the Ca(v)1.2 Ca(2+) channel shows a depolarization shift in the voltage-dependent activation compared with that in the Ca(v)1.3 Ca(2+) channel. In summary, using gene-targeted deletion of the Ca(v)1.3 Ca(2+) channel, we were able to establish a role for Ca(v)1.3 Ca(2+) channels in the generation of the spontaneous action potential in SA node cells.
Publication
Journal: Journal of Virology
April/10/1997
Abstract
Human influenza viruses are more efficiently isolated by inoculating patient samples into the amniotic rather than the allantoic cavity of embryonated chicken eggs. This type of cultivation selects virus variants with mutations around the hemagglutinin (HA) receptor binding site. To understand the molecular basis of these phenomena, we investigated the abundances of sialic acid (<em>SA</em>) linked to galactose (Gal) by the <em>alpha</em>-2,3 linkage (<em>SA</em> <em>alpha</em>2,3Gal) and <em>SA</em> <em>alpha</em>2,6Gal in egg amniotic and allantoic cells and in Madin-Darby canine kidney (MDCK) cells. Using <em>SA</em>-Gal linkage-specific lectins (Maackia amurensis agglutinin specific for <em>SA</em> <em>alpha</em>2,6Gal and Sambucus nigra agglutinin specific for <em>SA</em> <em>alpha</em>2,3Gal), we found <em>SA</em> <em>alpha</em>2,3Gal in both allantoic and amniotic cells and <em>SA</em> <em>alpha</em>2,6Gal in only the amniotic cells. MDCK cells contained both linkages. To investigate how this difference in abundances of <em>SA</em> <em>alpha</em>2,3Gal and <em>SA</em> <em>alpha</em>2,6Gal in allantoic and amniotic cells affects the appearance of host cell variants in eggs, we determined the receptor specificities and HA amino acid sequences of two different patient viruses which were isolated and passaged in the amnion or in the allantois and which were compared with MDCK cell-grown viruses. We found that the viruses maintained high <em>SA</em> <em>alpha</em>2,6Gal specificities when grown in MDCK cells or following up to two amniotic passages; however, further passages in either the amnion or allantois resulted in the acquisition of, or a complete shift to, <em>SA</em> <em>alpha</em>2,3Gal specificity, depending on the virus strain. This change in receptor specificity was accompanied by the appearance of variants in the population with Leu-to-Gln mutations at position 226 in their HA. These findings suggest that lack of <em>SA</em> <em>alpha</em>2,6Gal linkages in the allantois of chicken eggs is a selective pressure for the appearance of host cell variants with altered receptor specificities and amino acid changes at position 226.
Publication
Journal: The Lancet
March/9/1997
Abstract
BACKGROUND
In patients with heart failure, beta-blocker therapy improves left-ventricular function after 3-6 months of treatment, but effects of such treatment on symptoms and exercise performance are inconsistent, and the longer-term effects on death and other serious clinical events remain uncertain. We have investigated these issues in a double-blind, placebo-controlled, randomised trial of the beta-adrenergic blocker carvedilol (which also has alpha 1-blocking properties).
METHODS
415 patients with chronic stable heart failure were randomly assigned treatment with carvedilol (207) or matching placebo (208). At baseline, 6 months, and 12 months, we measured left-ventricular ejection fraction, left-ventricular dimensions, treadmill exercise duration, 6 min walk distance, New York Heart Association (NYHA) class, and specific activity scale (SAS) score. Double-blind follow-up continued for an average of 19 months, during which all deaths, hospital admissions, and episodes of worsening heart failure were documented.
RESULTS
After 12 months, left-ventricular ejection fraction had increased by 5.3% (2p < 0.0001) and end-diastolic and end-systolic dimensions had decreased by 1.7 mm (2p = 0.06) and 3.2 mm (2p = 0.001), respectively, in the carvedilol group compared with the placebo group. During the same period that were no clear changes in treadmill exercise duration, 6 min walk distance, NYHA class, or SAS score. After 19 months, the frequency of episodes of worsening heart failure was similar in the carvedilol and placebo groups (82 vs 75; relative risk 1.12 [95% Cl 0.82-1.53]) but the rate of death or hospital admission was lower in the carvedilol group than in the placebo group (104 vs 131; relative risk 0.74 [0.57-0.95]).
CONCLUSIONS
The beneficial effects of carvedilol on left-ventricular function and size were maintained for at least a year after the start of treatment, but carvedilol had no effect on exercise performance, symptoms, or episodes of worsening heart failure. There was an overall reduction in events resulting in death or hospital admission, and a year of treatment with carvedilol resulted in the avoidance of one such serious event among every 12-13 (SE 5) of these patients with chronic stable heart failure.
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