gebhart/patrepeval huggingface dataset:
Immobilized anti-CD3 antibody activates T cell clones to induce the production of interstitial collagenase, but not tissue inhibitor of metalloproteinases, in monocytic THP-1 cells and dermal fibroblasts. (1995)

In this study we have investigated whether direct cell to cell contact between activated paraformaldehyde-fixed T cell clones obtained from synovial tissue of patients with osteoarthritis (OA) or rheumatoid arthritis and target monocytic cells or dermal fibroblasts influenced the balance between interstitial collagenase and its specific inhibitor tissue inhibitor of metalloproteinases (TIMP) produced by the latter cell types. PHA/PMA-activated fixed T cell clones or their membranes strongly induced the production of collagenase both in monocytic THP-1 cells and in dermal fibroblasts. In contrast, only low levels of TIMP were induced in THP-1 cells and no change of TIMP expression was observed in fibroblasts as a result of stimulation with PHA/PMA-activated T cells or T cell membranes. Anti-CD3-activated T cell clones stimulated the production of collagenase both in THP-1 cells and fibroblasts, whereas TIMP levels were not influenced. Collagenase production in THP-1 cells induced by anti-CD3-activated T cell clones was 1) dependent on the dose of anti-CD3 used to stimulate the T cells, 2) initiated only when CD3 was cross-linked, and 3) inhibited when cyclosporin A was included during T cell activation. Our data collectively indicate that activated T cells in contact with monocytic cells or fibroblasts may alter the balance between interstitial collagenase and its specific inhibitor TIMP. This selective induction of a mediator profile representative of matrix breakdown as a result of target cell interaction with activated T cells may be an important factor in the local process of tissue destruction that characterizes osteoarthritis and rheumatoid arthritis.
Kinetics and thermodynamics of triple-helix formation: effects of ionic strength and mismatched (1992)

Thermodynamic and kinetic parameters for the triplex-forming reactions between a homopurine-homopyrimidine 22-base-pair duplex (sequence of the purine strand: 5'd[AAAGGAGGAGAAGAAGAAAAAA]3') and the four 22-dN third strands (22 dN: 5'd[TTTCCTCCTCTNCTTCTTTTTT]3', where N = A, C, T, or G) were determined from thermal denaturation and renaturation UV absorbance profiles. Cooling and heating curves were not superimposable and thus allowed us to determine the rate constants of association (k(on)) and dissociation (k(off)) as a function of temperature, assuming a two-state model analogous to that developed for duplex-forming reactions. Experiments were performed in 10 mM cacodylate buffer (pH 6.8) in the presence of NaCl concentrations ranging from 20 to 300 mM. Within experimental accuracy, the main results are the following: (i) The rate constants k(on) and k(off) result in linear Arrhenius plots, consistent with the prediction of two-state association and dissociation (ii) k(on) is independent of the nature of the base N located in the center of the third strand. (iii) k(on) strongly decreases when the NaCl concentration is decreased. (iv) The activation energy, E(on), is always negative and becomes more negative when the NaCl concentration is decreased. (v) k(off) is independent of NaCl concentration but depends on the base N, with its magnitude following the order C greater than G greater than A much greater than T. (vi) The activation energy, E(off), is independent of the base N. All these results are discussed in the light of a nucleation-zipping model similar to that developed for the duplex-coil transitions [Craig, M. E., Crothers, D. M., & Doty, P. (1971) J. Mol. Biol. 62, 383-401; Pörschke, D., Eigen, M. (1971) J. Mol. Biol. 62, 361-381].
Emerging Technologies for Making Glycan-Defined Glycoproteins (2011)

Protein glycosylation is a common and complex posttranslational modification of proteins, which expands functional diversity while boosting structural heterogeneity. Glycoproteins, the end products of such a modification, are typically produced as mixtures of glycoforms possessing the same polypeptide backbone but differing in the site of glycosylation and/or in the structures of pendant glycans, from which single glycoforms are difficult to isolate. The urgent need for glycan-defined glycoproteins in both detailed structure-function relationship studies and therapeutic applications has stimulated an extensive interest in developing various methods for manipulating protein glycosylation. This review highlights emerging technologies that hold great promise in making a variety of glycan-defined glycoproteins, with a particular emphasis in the following three areas: specific glycoengineering of host biosynthetic pathways, in vitro chemoenzymatic glycosylation remodeling, and chemoselective and site-specific glycosylation of proteins.
PEG-SS-PPS:  Reduction-Sensitive Disulfide Block Copolymer Vesicles for Intracellular Drug Delivery (2007)

Under appropriate conditions, block copolymeric macroamphiphiles will self-assemble in water to form vesicles, referred to as polymersomes. We report here polymersomes that can protect biomolecules in the extracellular environment, are taken up by endocytosis, and then suddenly burst within the early endosome, releasing their contents prior to exposure to the harsh conditions encountered after lysosomal fusion. Specifically, block copolymers of the hydrophile poly(ethylene glycol) (PEG) and the hydrophobe poly(propylene sulfide) (PPS) were synthesized with an intervening disulfide, PEG17-SS-PPS30. Polymersomes formed from this block copolymer were demonstrated to disrupt in the presence of intracellular concentrations of cysteine. In cellular experiments, uptake, disruption, and release were observed within 10 min of exposure to cells, well within the time frame of the early endosome of endolysosomal processing. This system may be useful in cytoplasmic delivery of biomolecular drugs such as peptides, proteins, oligonucleotides, and DNA.
IMMUNOSUPPRESSION BY ANTI-CD4 TREATMENT IN VIVO CELLULAR AND HUMORAL RESPONSES TO ALLOANTIGENS (1989)

Antibody-mediated elimination of CD4+ lymphocytes in vivo has been successfully used to suppress the humoral response to foreign antigens and to induce long-term tolerance. However, secondary humoral responses, as well as secondary cytolytic responses specific for viral antigens, could not be prevented, providing evidence for functional heterogeneity within the helper cell compartment. Data presented here support the notion that helper cell requirements for cellular responses to alloantigens are unique and do not involve CD4+ T lymphocytes. While the administration of anti-CD4 mcAb failed to suppress allospecific CTL responses, the formation of alloantibodies was initially inhibited in parallel to the deficiency in CD4+ helper cells. After regeneration of CD4+ T cells, the animals regained the ability to produce specific IgG alloantibodies. The dichotomy of helper pathways in humoral and cellular alloreactive responses challenges the concept of a single CD4+ helper cell population. Insights into the functional heterogeneity of helper cells for primary, secondary, and allospecific responses might open new avenues for selective manipulation of helper subpopulations.
High prevalence and persistence of sleep apnoea in patients referred for acute left ventricular failure and medically treated over 2 months (1999)

We have demonstrated a high prevalence of sleep apnoea, which persisted after 2 months of medical treatment, in patients referred for acute left ventricular failure. Central sleep apnoea can be considered a marker of the severity of congestive heart failure.
The Light Chain of Factor VIII Comprises a Binding Site for Low Density Lipoprotein Receptor-related Protein (1999)

In the present study, the interaction between the endocytic receptor low density lipoprotein receptor-related protein (LRP) and coagulation factor VIII (FVIII) was investigated. Using purified components, FVIII was found to bind to LRP in a reversible and dose-dependent manner (K(d) approximately 60 nM). The interaction appeared to be specific because the LRP antagonist receptor-associated protein readily inhibited binding of FVIII to LRP (IC(50) approximately 1 nM). In addition, a 12-fold molar excess of the physiological carrier of FVIII, i.e. von Willebrand factor (vWF), reduced the binding of FVIII to LRP by over 90%. Cellular degradation of (125)I-labeled FVIII by LRP-expressing cells ( approximately 8 fmol/10(5) cells after a 4.5-h incubation) was reduced by approximately 70% in the presence of receptor-associated protein. LRP-directed antibodies inhibited degradation to a similar extent, indicating that LRP indeed contributes to binding and transport of FVIII to the intracellular degradation pathway. Degradation of FVIII was completely inhibited by vWF. Because vWF binding by FVIII involves its light chain, LRP binding to this subunit was studied. In ligand blotting experiments, binding of FVIII light chain to LRP could be visualized. More detailed analysis revealed that FVIII light chain interacts with LRP with moderate affinity (k(on) approximately 5 x 10(4) M(-1) s(-1); k(off) approximately 2.5 x 10(-3) s(-1); K(d) approximately 50 nM). Furthermore, experiments using recombinant FVIII C2 domain showed that this domain contributes to the interaction with LRP. In contrast, no association of FVIII heavy chain to LRP could be detected under the same experimental conditions. Collectively, our data demonstrate that in vitro LRP is able to bind FVIII at the cell surface and to mediate its transport to the intracellular degradation pathway. FVIII-LRP interaction involves the FVIII light chain, and FVIII-vWF complex formation plays a regulatory role in LRP binding. Our findings may explain the beneficial effect of vWF on the in vivo survival of FVIII.
Contribution of VanY D,D-carboxypeptidase to glycopeptide resistance in Enterococcus faecalis by hydrolysis of peptidoglycan precursors (1994)

The vanR, vanS, vanH, vanA, and vanX genes of enterococcal transposon Tn1546 were introduced into the chromosome of Enterococcus faecalis JH2-2. Complementation of this portion of the van gene cluster by a plasmid encoding VanY D,D-carboxypeptidase led to a fourfold increase in the vancomycin MIC (from 16 to 64 micrograms/ml). Multicopy plasmids pAT80 (vanR vanS vanH vanA vanX) and pAT382 (vanR vanS vanH vanA vanX vanY) conferred similar levels of vancomycin resistance to JH2-2. The addition of D-alanine (100 mM) to the culture medium restored the vancomycin susceptibility of E. faecalis JH2-2/pAT80. The pentapeptide UDP-MurNAc-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala partially replaced pentadepsipeptide UDP-MurNAc-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Lac when the strain was grown in the presence of D-alanine. In contrast, resistance mediated by pAT382 was almost unaffected by the addition of the amino acid. Expression of the vanY gene of pAT382 resulted in the formation of the tetrapeptide UDP-MurNAc-L-Ala-gamma-D-Glu-L-Lys-D-Ala, indicating that a portion of the cytoplasmic precursors had been hydrolyzed. These results show that VanY contributes to glycopeptide resistance in conditions in which pentapeptide is present in the cytoplasm above a threshold concentration. However, the contribution of the enzyme to high-level resistance mediated by Tn1546 appears to be moderate, probably because hydrolysis of D-alanyl-D-alanine by VanX efficiently prevents synthesis of the pentapeptide.
Representing moving images with layers (1994)

We describe a system for representing moving images with sets of overlapping layers. Each layer contains an intensity map that defines the additive values of each pixel, along with an alpha map that serves as a mask indicating the transparency. The layers are ordered in depth and they occlude each other in accord with the rules of compositing. Velocity maps define how the layers are to be warped over time. The layered representation is more flexible than standard image transforms and can capture many important properties of natural image sequences. We describe some methods for decomposing image sequences into layers using motion analysis, and we discuss how the representation may be used for image coding and other applications.
EQUIPMENT IN SCANDINAVIAN COUNTRIES (1995)

Several Scandinavian countries have been experimenting with new and highly promising techniques and systems which have lead to substantial savings in de-icing chemicals without sacrificing the level of roadway service during the winter. Some of these techniques required the development and utilization of equipment such as brine making plants, spreaders for applying liquid salt and prewetted salt, and snow and slush plows. The equipment is summarized in this report.
Minimum-time control characteristics of flexible structures (1996)

The time-optimal control for rest-to-rest maneuvers of flexible structures is considered. We formulate the general time-optimal control problem for single-axis flexible structures, and analytical results are given for the number of control switches for the one-bending-mode case, with and without damping. When there is no damping, it is shown that the time-optimal control generally has three switches and is an odd function of time about the second switch except in certain isolated cases where there is only one switch. With damping, it is shown that there is always more than one switch. A numerical method is presented for solving the time-optimal control for general linear systems, and solutions are presented for flexible structures with several flexible modes, revealing interesting trends of the time-optimal control switch times as the maneuver sizes and the frequencies and damping ratios of the flexible modes are varied.
Highly Improved Copper-Mediated Michael Addition of Ethyl Bromodifluoroacetate in the Presence of Protic Additive (2012)

Copper-mediated Michael addition of ethyl bromodi­fluoroacetate to Michael acceptors is accompanied by the formation of a substantial amount of byproducts. Elucidation of their structure hinted the cause of their formation, from which we discovered a highly improved and robust protocol by treatment with protic additives such as H<sub>2</sub>O and AcOH. This modification led to significant increase of yield with concomitant decreased use of reagent.
Pentachlorophenyl esters of N-carbobenzoxy-L-amino acids (1967)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPentachlorophenyl esters of N-carbobenzoxy-L-amino acidsJoseph Kovacs, Mario Q. Ceprini, Carol A. Dupraz, and G. N. SchmitCite this: J. Org. Chem. 1967, 32, 11, 3696–3698Publication Date (Print):November 1, 1967Publication History Published online1 May 2002Published inissue 1 November 1967https://doi.org/10.1021/jo01286a098RIGHTS & PERMISSIONSArticle Views75Altmetric-Citations46LEARN 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 InReddit PDF (347 KB) Get e-Alerts Get e-Alerts
Activation of cell surface glucose transporters measured by photoaffinity labeling of insulin-sensitive 3T3-L1 adipocytes. (1992)

Several studies have demonstrated that the intrinsic catalytic activity of cell surface glucose transporters is highly regulated in 3T3-L1 adipocytes expressing GLUT1 (erythrocyte/brain) and GLUT4 (adipocyte/skeletal muscle) glucose transporter isoforms. For example, inhibition of protein synthesis in these cells by anisomycin or cycloheximide leads to marked increases in hexose transport without a change in the levels of cell surface glucose transporter proteins (Clancy, B. M., Harrison, S. A., Buxton, J. M., and Czech, M. P. (1991) J. Biol. Chem. 266, 10122-10130). In the present work the exofacial hexose binding sites on GLUT1 and GLUT4 in anisomycin-treated 3T3-L1 adipocytes were labeled with the cell-impermeant photoaffinity reagent [2-3H]2-N-[4-(1-azitrifluoroethyl)benzoyl]-1,3-bis- (D-mannos-4-yloxy)-2-propylamine [( 2-3H] ATB-BMPA) to determine which isoform is activated by protein synthetic blockade. As expected, a 15-fold increase in 2-deoxyglucose uptake in response to insulin was associated with 1.7- and 2.6-fold elevations in plasma membrane GLUT1 and GLUT4 protein levels, respectively. Anisomycin treatment of cultured adipocytes for 5 h produced an 8-fold stimulation of hexose transport but no increase in the content of glucose transporters in the plasma membrane fraction as measured by protein immunoblot analysis. Cell surface GLUT1 levels were also shown to be unaffected on 3T3-L1 adipocytes in response to anisomycin using an independent method, the binding of an antiexofacial GLUT1 antibody to intact cells. In contrast, anisomycin fully mimicked the action of insulin to stimulate (about 4-fold) the radiolabeling of GLUT1 transporters specifically immunoprecipitated from intact 3T3-L1 adipocytes irradiated after incubation with [2-3H] ATB-BMPA. Photolabeling of GLUT4 under these conditions was also significantly enhanced (1.8-fold) by anisomycin treatment, but this effect was only 15% of that caused by insulin. These results suggest that: 1) the photoaffinity reagent [2-3H]ATB-BMPA labels those cell surface glucose transporters present in a catalytically active state rather than total cell surface transporters as assumed previously and 2) inhibition of protein synthesis in 3T3-L1 adipocytes stimulates sugar transport primarily by enhancing the intrinsic catalytic activity of cell surface GLUT1, and to a lesser extent, GLUT4 proteins.
Hyperbaric oxygen stimulates vasculogenic stem cell growth and differentiation in vivo (2008)

We hypothesized that oxidative stress from hyperbaric oxygen (HBO(2), 2.8 ATA for 90 min daily) exerts a trophic effect on vasculogenic stem cells. In a mouse model, circulating stem/progenitor cell (SPC) recruitment and differentiation in subcutaneous Matrigel were stimulated by HBO(2) and by a physiological oxidative stressor, lactate. In combination, HBO(2) and lactate had additive effects. Vascular channels lined by CD34(+) SPCs were identified. HBO(2) and lactate accelerated channel development, cell differentiation based on surface marker expression, and cell cycle entry. CD34(+) SPCs exhibited increases in thioredoxin-1 (Trx1), Trx reductase, hypoxia-inducible factors (HIF)-1, -2, and -3, phosphorylated mitogen-activated protein kinases, vascular endothelial growth factor, and stromal cell-derived factor-1. Cell recruitment to Matrigel and protein synthesis responses were abrogated by N-acetyl cysteine, dithioerythritol, oxamate, apocynin, U-0126, neutralizing anti-vascular endothelial growth factor, or anti-stromal cell-derived factor-1 antibodies, and small inhibitory RNA to Trx reductase, lactate dehydrogenase, gp91(phox), HIF-1 or -2, and in mice conditionally null for HIF-1 in myeloid cells. By causing an oxidative stress, HBO(2) activates a physiological redox-active autocrine loop in SPCs that stimulates vasculogenesis. Thioredoxin system activation leads to elevations in HIF-1 and -2, followed by synthesis of HIF-dependent growth factors. HIF-3 has a negative impact on SPCs.
ChemInform Abstract: KINETICS AND MECHANISM OF THE REDUCTION OF IODINE BY IRON(II) IN THE PRESENCE OF SODIUM FLUORIDE (1978)

Abstract Die durch F′‐Ionen katalysierte Reduktion von Iod durch Fe(II) ist d′ erster Ordnung sowohl in bezug auf [I2] als auch auf [Fe′ ].
Minimisation de la somme des retards pour les problèmes d'ordonnancement à une machine (1989)

Dans cet article, nous démontrons un théorème qui présente une condition suffisante d'optimalité locale pour le problème d'ordonnancement du type n/1/ri/\sumTi. Cette condition nous permet de définir un nouveau sous-ensemble dominant de solutions pour ce problème qui est NP-difficile. Nous utilisons les résultats obtenus pour construire un algorithme approché polynômial et donnons une majoration de l'erreur commise par cet algorithme dans le pire des cas.
Rapid DNA fingerprinting of pathogens by flow cytometry (2000)

DNA fragment sizing by flow cytometry is a fast and reliable technique that can be applied to the discrimination among species and strains of human pathogens. Unlike some polymerase chain reaction (PCR)-based methods, sequence information about the bacterial strains is not required, allowing the detection of unknown, newly emerged, or unanticipated strains.
Effects of Mutations in Residues near the Active Site of Human Immunodeficiency Virus Type 1 Integrase on Specific Enzyme-Substrate Interactions (1998)

The phylogenetically conserved catalytic core domain of human immunodeficiency virus type 1 (HIV-1) integrase contains elements necessary for specific recognition of viral and target DNA features. In order to identify specific amino acids that determine substrate specificity, we mutagenized phylogenetically conserved residues that were located in close proximity to the active-site residues in the crystal structure of the isolated catalytic core domain of HIV-1 integrase. Residues composing the phylogenetically conserved DD(35)E active-site motif were also mutagenized. Purified mutant proteins were evaluated for their ability to recognize the phylogenetically conserved CA/TG base pairs near the viral DNA ends and the unpaired dinucleotide at the 5' end of the viral DNA, using disintegration substrates. Our findings suggest that specificity for the conserved A/T base pair depends on the active-site residue E152. The phenotype of IN(Q148L) suggested that Q148 may be involved in interactions with the 5' dinucleotide of the viral DNA end. The activities of some of the proteins with mutations in residues in close proximity to the active-site aspartic and glutamic acids were salt sensitive, suggesting that these mutations disrupted interactions with DNA.
Left prefrontal glucose hypometabolism in the depressed state: a confirmation (1990)

The resting-state cerebral metabolic rates for glucose of 10 severely depressed patients (seven bipolar and three unipolar) were compared, before and after treatment with tricyclic antidepressants, to those of 10 control subjects of similar age by means of positron emission tomography and the fluorodeoxyglucose method. Significant left-right prefrontal asymmetry was present in the patients before but not after successful treatment, suggesting that medication can reduce this asymmetry. Also, significant hypofrontality and whole-cortex hypometabolism were found in the patients in the depressed state and persisted in the treated state, despite clinical improvement, suggesting that these abnormalities are not state dependent.