gebhart/patrepeval huggingface dataset:
Staphylococcus aureus Biofilms Promote Horizontal Transfer of Antibiotic Resistance (2013)

Growth as a biofilm facilitates the emergence of antibiotic resistance by mutation in Staphylococcus aureus. Here we demonstrate that biofilm growth of this species also dramatically increases horizontal transfer of plasmid-borne antibiotic resistance determinants by conjugation/mobilization and that standard laboratory practices to induce conjugation in staphylococci achieve optimal efficiency owing to the presence of a biofilm.
Neuronal Differentiation of C17.2 Neural Stem Cells Induced by a Natural Flavonoid, Baicalin (2011)

Natural medicinal materials are a significant resource for the identification of compounds with specific biological properties. In this study, we employed multipotent C17.2 neural stem cells as a model for screening natural compounds that possess neural differentiation-inducing properties. We show here for the first time that, out of the 67 compounds tested, the flavonoid baicalin is a potent differentiation-inducing agent. Baicalin increased the number of cells bearing extended neurites and the expression levels of a number of neuronal markers. Importantly, baicalin promoted the expression of several key neurogenic transcriptional factors. Moreover, we demonstrated that baicalin enhanced the phosphorylation/activation of Erk1/2. Inhibition of Erk1/2 activation by the MEK inhibitor U0126 attenuated the neuronal differentiation-inducing effect of baicalin. Taken together, our findings suggest that baicalin induces neuronal differentiation of C17.2 neural stem cells and that this is mediated by activation of Erk1/2. Our work lays the foundation for exploring baicalin for the promotion of neural regeneration after injury or disease.
Carbonyl Derivatives of Chloride-Dimethyl Sulfoxide-Ruthenium(II) Complexes: Synthesis, Structural Characterization, and Reactivity of Ru(CO)x(DMSO)4-xCl2 Complexes (x = 1-3) (1995)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbonyl Derivatives of Chloride-Dimethyl Sulfoxide-Ruthenium(II) Complexes: Synthesis, Structural Characterization, and Reactivity of Ru(CO)x(DMSO)4-xCl2 Complexes (x = 1-3)E. Alessio, B. Milani, M. Bolle, G. Mestroni, P. Faleschini, F. Todone, S. Geremia, and M. CalligarisCite this: Inorg. Chem. 1995, 34, 19, 4722–4734Publication Date (Print):September 1, 1995Publication History Published online1 May 2002Published inissue 1 September 1995https://pubs.acs.org/doi/10.1021/ic00123a004https://doi.org/10.1021/ic00123a004research-articleACS PublicationsRequest reuse permissionsArticle Views759Altmetric-Citations59LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (2)»Supporting Information Supporting Information Get e-Alerts
Modification of the hydroxylactone ring of camptothecin: inhibition of mammalian topoisomerase I and biological activity (1989)

Several camptothecin derivatives containing a modified hydroxy lactone ring have been synthesized and evaluated for inhibition of topoisomerase I and cytotoxicity to mammalian cells. Each of the groups of the hydroxy lactone moiety, the carbonyl oxygen, the ring lactone oxygen, and the 20-hydroxy group, were shown to be critical for enzyme inhibition. For example the lactol, lactam, thiolactone, and 20-deoxy derivatives did not stabilize the covalent DNA-topoisomerase I complex. With a few exceptions, those compounds that did not inhibit topoisomerase I were not cytotoxic to mammalian cells. Two cytotoxic derivatives that did not inhibit topoisomerase I were shown to produce non-protein-associated DNA single-strand breaks and are likely to have a different mechanism of action. One of these compounds was tested for antitumor activity and was found to be inactive. The present findings, as well as other reports that the hydroxy lactone ring of camptothecin is critical for antitumor activity in vivo, correlate with the structure-activity relationships at the level of topoisomerase I and support the hypothesis that antitumor activity is related to inhibition of this target enzyme.
Microencapsulation of probiotic bacteria and their survival in frozen fermented dairy desserts (2000)

A procedure was developed to entrap probiotic bacteria (Lactobacillus acidophilus MJLA1 and Bifidobacterium spp. BDBB2) into calcium alginate beads. The effects of sodium lauryl sulfate and Tween 80 on bead sizes and the release of the organisms from the encapsulated beads in the presence of acid and bile were investigated. The external and internal appearances of the bead were observed using scanning electron microscopy. The encapsulated beads were freezedried and incorporated into the mix for making frozen fermented dairy desserts prior to freezing. Two batches of fermented frozen dairy desserts were made with or without encapsulated probiotic bacteria and viable counts of probiotic bacteria were enumerated in fermented frozen dairy desserts at fortnightly intervals for 12 weeks. The mean diameter of the beads without any sodium lauryl sulfate and Tween 80 was 1.17 mm, but the size of the beads decreased as the concentrations of sodium lauryl sulfate and Tween 80 increased. The average diameter of the beads with 1% sodium lauryl sulfate and 0.3% Tween 80 was 0.064 mm. The beads appeared to be ellipsoidal in shape and the microorganisms were located in the matrices formed in the beads. The entrapped bacterial cells were released by shaking in O.1M phosphate buffer for 5 min and in the presence of bile, but not in the presence of acid. In general, the survival of probiotic bacteria in fermented frozen dairy desserts was improved with encapsulation.
Efficient blue LEDs from a partially conjugated Si‐containing PPV copolymer in a double‐layer configuration (1997)

Efficient blue electroluminescent devices based on a novel silicon‐containing poly( P ‐phenylene) derivative are described. It is shown that the turn‐on field and internal quantum efficiency can be improved by using a double‐layer device configuration instead of a single‐layer one and by the addition of a transport layer at the cathodic side. The combined study of electrical and optical properties on one hand and morphological aspects on the other is demonstrated to be a fruitful approach to the improved performance of organic electronics.
Non-linear optimization of biochemical pathways: applications to metabolic engineering and parameter estimation. (1998)

prm@aber.ac.uk
Proton and Cu(ii) binding to tren-based tris-macrocycles. Affinity towards nucleic acids and nuclease activity (2003)

Proton binding by the two tren-based tris-macrocycles L1 and L2, composed, respectively, by three 1,4,7,10-tetrazacyclododecane ([12]aneN4) and three 1-oxa-4,7,10-triazacyclododecane ([12]aneN3O) macrocyclic moieties appended to a “tren” unit (tren = tris(2-aminoethyl)amine), has been analyzed by means of potentiometric and 1H and 13C NMR measurements in aqueous solutions. This study reveals that the ligands form highly charged polyammonium cations at neutral pH, containing six acidic protons equally distributed among the three macrocyclic units. A potentiometric and UV-vis spectrophotometric study shows that both ligands can form stable trinuclear Cu(II) complexes in a wide pH range. In the polynuclear complexes each metal is coordinated to a single macrocyclic unit. While the Cu(II) complexes with L1 do not show any tendency to form hydroxylated complexes, the mono-, di- and trinuclear L2 complexes give stable hydroxo-complexes, present in aqueous solutions from slightly acidic to alkaline pH values. Melting point studies indicate that the new tris-macrocyles and their Cu(II) complexes lead to stronger stabilization of double-stranded nucleic acids than those observed earlier with analogous ditopic macrocyclic ligands, again with preference for RNA-type polymers compared to DNA. The copper complexes promote cleavage of plasmid DNA and of bis-p-nitrophenyl phosphate (BNPP). Particular rate enhancements for BNPP with some complexes are attributed to the simultaneous action of three metal ions and partially to the formation of hydroxo complexes at neutral pH.
Poly‐guanosine motifs costimulate antigen‐reactive CD8 T cells while bacterial CpG‐DNA affect T‐cell activation via antigen‐presenting cell‐derived cytokines (2000)

Pathogen-derived pattern recognition ligands like lipopolysaccharide (LPS) and bacterial cytidine-guanosine (CpG)-DNA not only activate dendritic cells and macrophages but are also mitogenic for B cells. Less clear are the claimed effects of CpG-DNA on T cells, which range from direct activation, costimulation, or indirect transient activation via antigen-presenting cell (APC)-derived interferon type I (IFN type I). Here we demonstrate that CpG-DNA sequence specifically triggers macrophages to produce IFN type I, interleukin (IL)-12, IL-6 and tumour necrosis factor (TNF), but lacks the ability to directly costimulate T cells. Strikingly, poly-guanosine (poly-G) extensions to CpG-containing oligonucleotides (ODN) abolished the macrophage stimulatory potential yet generated T-cell costimulatory activities. In fact, independently of CpG-motifs, poly-G-ODN displayed the ability to costimulate T cells. Costimulation was operative on CD8 T cells but not CD4 T cells. Poly-G-mediated costimulation resulted in IL-2-driven T-cell proliferation and induced cytolytic T cells. Overall the data imply that poly-G motifs costimulate antigen reactive CD8 T cells, while CpG-DNA motifs fail to do so but may affect T-cell activation via APC derived cytokines such as IFN type I.
Characterization of cDNA encoding a human sperm membrane protein related to A4 amyloid protein. (1990)

A rat testis lambda gt11 cDNA library was screened with a monoclonal antibody raised against a human sperm membrane protein designated YWK-II. A clone was found with a cDNA insert composed of 1837 base pairs that contained an open reading frame coding for 191 amino acid residues. The deduced polypeptide contained a segment with high homology to the transmembrane-cytoplasmic domains of the A4 amyloid protein found in brain plaques of Alzheimer disease patients. A sequence of basic amino acid residues, Arg-Lys-Arg, was found instead of Lys-Lys-Lys at the probable membrane-cytoplasmic junction that may be a unique property of sperm membrane proteins.
Emerging features of mRNA decay in bacteria (2000)

The problem of mRNA decay in E. coli has recently seen exciting progress, with the discoveries that key degradation enzymes are associated together in a high molecular weight degradosome and that polyadenylation promotes decay. Recent advances make it clear that mRNA decay in bacteria is far more interesting enzymatically than might have been predicted. In-depth study of specific mRNAs has revealed multiple pathways for degradation. Which pathway a given mRNA follows appears to depend in large part on the location of the initiating endonucleolytic cleavage within the mRNA. During the steps of mRNA decay, stable RNA structures pose formidable barriers to the 3' --> 5' exonucleases. However, polyadenylation is now emerging as a process that plays an important role in maintaining the momentum of exonucleolytic degradation by adding single-stranded extensions to the 3' ends of mRNAs and their decay intermediates, thereby facilitating further exonuclease digestion.
Decoration of ZnO nanowires with Pt nanoparticles and their improved gas sensing and photocatalytic performance (2010)

Pt nanoparticles were introduced on the surface of ZnO nanowires using a chemically driven self-assembly method. Through this controllable method, Pt-nanoparticle-functionalized ZnO nanowires (Pt NPs-ZnO NWs) with uniform particle dispersion, tunable Pt particle sizes, and narrow particle size distribution were obtained. Changes in the morphology of the decorative preparation were observed as the amount of linker reagent and the concentration of Pt nanoparticle solution were altered. The as-prepared Pt NPs-ZnO NWs with optimal morphology showed excellent gas sensing and photocatalytic performance. Tuning of the functionalities of photocatalytic and gas sensors can be obtained by tailoring the morphology of Pt NP-ZnO NW composite materials.
Reactions of 4-(2-hydroxyethylamino)-2-phenyl-5-pyrimidinecarboxylic acid with acetic anhydride. Syntheses of 8,9-dihydro-6.alpha.-methyl-2-phenyl-5H,6aH-oxazolo[2,3-b]pyrimido[4,5-d][1,3]oxazin-5-one and 8,9-dihydro-8,8-dimethyl-2-phenyl-5H-oxazolo[2',3':6,1]pyrido[2,3-d]pyrimidin-5-one (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of 4-(2-hydroxyethylamino)-2-phenyl-5-pyrimidinecarboxylic acid with acetic anhydride. Syntheses of 8,9-dihydro-6.alpha.-methyl-2-phenyl-5H,6aH-oxazolo[2,3-b]pyrimido[4,5-d][1,3]oxazin-5-one and 8,9-dihydro-8,8-dimethyl-2-phenyl-5H-oxazolo[2',3':6,1]pyrido[2,3-d]pyrimidin-5-oneDong Han Kim and Arthur A. SantilliCite this: J. Org. Chem. 1972, 37, 18, 2854–2857Publication Date (Print):September 1, 1972Publication History Published online1 May 2002Published inissue 1 September 1972https://pubs.acs.org/doi/10.1021/jo00983a013https://doi.org/10.1021/jo00983a013research-articleACS PublicationsRequest reuse permissionsArticle Views74Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Platelet-derived Growth Factor Receptor β and Vascular Endothelial Growth Factor Receptor 2 Bind to the β3Integrin through Its Extracellular Domain (2000)

Integrin-mediated cell attachment and growth factor stimulation often act synergistically on cell proliferation, differentiation, migration, and survival. Some of these synergistic effects depend on the physical interaction of integrins with growth factor receptors. Here we examine the nature of the physical interaction between the alpha(v)beta(3) integrin and two receptor tyrosine kinases (RTKs), the platelet-derived growth factor receptor beta (PDGF-Rbeta) and the vascular endothelial growth factor receptor 2 (VEGF-R2, also known as KDR and flk-1). Both of these RTKs associate with the alpha(v)beta(3) integrin but do not associate with beta(1) integrins. Furthermore, growth factor stimulation of these RTKs promotes increased cell proliferation and migration when cells are attached to the alpha(v)beta(3) ligand, vitronectin. We show that alpha(v)beta(3) in which the beta(3) cytoplasmic domain is deleted or replaced with the beta(1) cytoplasmic domain coimmunoprecipitates with PDGF-Rbeta and VEGF-R2. The beta(3) extracellular domain alone was sufficient for the PDGF-Rbeta association whereas the VEGF-R2 association required the presence of the alpha(v) subunit. Activation of the RTKs by their ligands was not required for them to associate with the integrin. Cell migration to PDGF was enhanced in the cells transfected with the chimeric subunit containing the beta(3) extracellular domain but not when that domain came from the beta(1) subunit. These results show that the interactions that lead to the association of the alpha(v)beta(3) integrin with PDGF-Rbeta and VEGF-R2 and enhancement of RTK activity take place outside the cell.
Aspergillus Sinusitis: Clinical Aspects and Treatment Outcomes (1996)

Seventy-two cases of Aspergillus sinusitis were analyzed during a period of 14 years from January 1980 through October 1993. There were 60 cases of primary type and 12 cases of secondary type. The maxillary and ethmoid sinuses were most commonly affected in both primary and secondary types. The sphenoid sinus was commonly involved in secondary type. Fourteen (23%) cases of primary type and 4 (33%) cases of secondary type demonstrated sinus wall destruction on computed tomography or magnetic resonance images. Seventy percent of primary type and all cases of secondary type showed focal or diffuse areas of increased attenuation in the soft tissue mass on computed tomography scans. Sixteen cases assessed by magnetic resonance imaging showed decreased signal intensities on T1-weighted images and markedly reduced signal intensities on T2-weighted images. Fifty-nine (98%) of 60 cases of primary type were noninvasive, and 1 was invasive. In secondary type, 10 (83%) of 12 patients had noninvasive disease. The most common coexisting disease in secondary aspergillosis was diabetes mellitus. Thickened mucosa with necrotic brownish green material, which was the most common finding in both types, was found in 33 patients with primary type and in 5 with secondary type. Surgery was performed in most cases, among which 4 patients received chemotherapy after surgery with amphotericin B with or without flucytosine. All patients were cured without recurrence during a mean follow-up period of 13 months.
Reduction potentials and exchange reactions of thiyl radicals and disulfide anion radicals (1987)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReduction potentials and exchange reactions of thiyl radicals and disulfide anion radicalsParminder S. Surdhar and David A. ArmstrongCite this: J. Phys. Chem. 1987, 91, 26, 6532–6537Publication Date (Print):December 1, 1987Publication History Published online1 May 2002Published inissue 1 December 1987https://pubs.acs.org/doi/10.1021/j100310a022https://doi.org/10.1021/j100310a022research-articleACS PublicationsRequest reuse permissionsArticle Views1327Altmetric-Citations135LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
The Human Tumor Clonogenic Assay as a Model System in Cell Biology (1987)

The human tumor stem cell (clonogenic) assay (HTCA) is a soft agar system designed for growing fresh human tumor specimens in vitro. The assay has been extensively used in studies both of individual patients' response to chemotherapy and for screening new agents. The technical limitations of this assay have been extensively discussed. The use of this test as a model system to study fundamentals of tumor cell growth has not been stressed. The potentials and limitations of this assay for the study of the regulation of tumor growth are presented.
Role of transiently altered sarcolemmal membrane permeability and basic fibroblast growth factor release in the hypertrophic response of adult rat ventricular myocytes to increased mechanical activity in vitro. (1996)

One of the trophic factors that has been implicated in initiating or facilitating growth in response to increased mechanical stress in several tissues and cell types is basic fibroblast growth factor (bFGF; FGF-2). Although mammalian cardiac muscle cells express bFGF, it is not known whether it plays a role in mediating cardiac adaptation to increased load, nor how release of the cytosolic 18-kD isoform of bFGF would be regulated in response to increased mechanical stress. To test the hypothesis that increased mechanical activity induces transient alterations in sarcolemmal permeability that allow cytosolic bFGF to be released and subsequently to act as an autocrine and paracrine growth stimulus, we examined primary isolates of adult rat ventricular myocytes maintained in serum-free, defined medium that were continually paced at 3 Hz for up to 5 d. Paced myocytes, but not nonpaced control cells, exhibited a "hypertrophic" response, which was characterized by increases in the rate of phenylalanine incorporation, total cellular protein content, and cell size. These changes could be mimicked in control cells by exogenous recombinant bFGF and could be blocked in continually paced cells by a specific neutralizing anti-bFGF antibody. In addition, medium conditioned by continually paced myocytes contained significantly more bFGF measured by ELISA and more mitogenic activity for 3T3 cells, activity that could be reduced by a neutralizing anti-bFGF antibody. The hypothesis that transient membrane disruptions sufficient to allow release of cytosolic bFGF occur in paced myocytes was examined by monitoring the rate of uptake into myocytes from the medium of 10-kD dextran linked to fluorescein. Paced myocytes exhibited a significantly higher rate of fluoresceinlabeled dextran uptake. These data are consistent with the hypothesis that nonlethal, transient alterations in sarcolemmal membrane permeability with release of cytosolic bFGF is one mechanism by which increased mechanical activity could lead to a hypertrophic response in cardiac myocytes.
Expression of human O6‐methylguanine‐DNA methyltransferase in chinese hamster ovary cells and restoration of cellular resistance to certain N‐nitroso compounds (1991)

We have constructed a plasmid in which the expression of human O6-methylguanine-DNA methyltransferase (MGMT) cDNA is driven by the Rous sarcoma virus promoter sequence. Transfection of this plasmid into Chinese hamster ovary (CHO) cells results in expression of MGMT and in cellular resistance to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 1-(2-chloroethyl)-1-nitrosourea (CNU), but not to N-nitroso-N-ethylurea. The specific activity of MGMT in transfected CHO cells correlated well with their resistance to MNNG and CNU. Southern analysis showed that the plasmid had been integrated into the CHO cell genome. Western analysis of extracts from transfected CHO cells using an antibody against a peptide corresponding to the carboxyl-terminal end of the human MGMT protein demonstrated a single band with a molecular size of 24-25 kDa; no such band was observed in extracts from wild-type CHO cells. These transfected cells may therefore be used to study the role of MGMT in the repair of alkylating DNA lesions and to determine its importance in carcinogenesis as well as in chemotherapy.