gebhart/patrepeval huggingface dataset:
Xyloglucan endotransglycosylase, a new wall-loosening enzyme activity from plants (1992)

1. Cell-free extracts of all plants tested contained a novel enzyme activity (xyloglucan endotransglycosylase, XET) able to transfer a high-Mr portion from a donor xyloglucan to a suitable acceptor such as a xyloglucan-derived nonasaccharide (Glc4Xyl3GalFuc; XG9). 2. A simple assay for the enzyme, using [3H]XG9 and based on the ability of the [3H]polysaccharide product to bind to filter paper, is described. 3. The enzyme was highly specific for xyloglucan as the glycosyl donor, and showed negligible transglycosylation of other polysaccharides, including CM-cellulose. 4. The Km for XG9 was 50 microM; certain other 3H-labelled xyloglucan oligosaccharides also acted as acceptors, and certain non-radioactive xyloglucan oligosaccharides competed with [3H]XG9 as acceptor; the minimum acceptor structure was deduced to be: [formula: see text] 5. The pH optimum was approx. 5.5 and the enzyme was less than half as active at pH 7.0. The enzyme was slightly activated by Ca2+, Mg2+, Mn2+, spermidine, ascorbate and 2-mercaptoethanol, and inhibited by Ag+, Hg2+, Zn2+ and La3+. 6. XET activity was essentially completely extracted by aqueous solutions of low ionic strength; Triton X-100, Ca2+, La3+, and Li+ did not enhance extraction. Negligible activity was left in the unextractable (cell-wall-rich) residue. 7. The enzyme differed from the major cellulases (EC 3.2.1.4) of pea in: (a) susceptibility to inhibition by cello-oligosaccharides, (b) polysaccharide substrate specificity, (c) inducibility by auxin, (d) requirement for salt in the extraction buffer and (e) activation by 2-mercaptoethanol. XET is therefore concluded to be a new enzyme activity (xyloglucan: xyloglucan xyloglucanotransferase; EC 2.4.1.-). 8. XET was detected in extracts of the growing portions of dicotyledons, monocotyledons (graminaceous and liliaceous) and bryophytes. 9. The activity was positively correlated with growth rate in different zones of the pea stem. 10. We propose that XET is responsible for cutting and rejoining intermicrofibrillar xyloglucan chains and that it thus causes the wall-loosening required for plant cell expansion.
Spin-orbit torque switching without external field with a ferromagnetic exchange-biased coupling layer (2015)

Magnetization reversal of a perpendicular ferromagnetic free layer by spin-orbit torque (SOT) is an attractive alternative to spin-transfer torque (STT) switching in magnetic random-access memory (MRAM) where the write process involves passing a high current across an ultrathin tunnel barrier. A small symmetry-breaking bias field is usually needed for deterministic SOT switching but it is impractical to generate the field externally for spintronic applications. Here, we demonstrate robust zero-field SOT switching of a perpendicular Co90Fe10 (CoFe) free layer where the symmetry is broken by magnetic coupling to a second in-plane exchange-biased CoFe layer via a nonmagnetic Ru spacer. The preferred magnetic state of the free layer is determined by the current polarity and the nature of the interlayer exchange coupling (IEC). Our strategy offers a scalable solution to realize bias-field-free SOT switching that can lead to a generation of SOT-based devices, that combine high storage density and endurance with potentially low power consumption.
Human Papillomavirus Type 16 E2 Protein Has No Effect on Transcription from Episomal Viral DNA (2003)

The human papillomavirus (HPV) E2 protein plays an important role in viral DNA replication. Many studies with high-risk HPVs have demonstrated that the E2 protein can also repress transcription of the E6 and E7 oncogenes. This conclusion, based on experiments carried out with cervical cancer cells bearing integrated HPV genomes, is currently assumed to be applicable to the normal HPV life cycle, in which the viral genomes are episomal. Here, we have tested experimentally whether this assumption is correct. We made use of a pair of isogenic cell lines, W12 and S12. W12 cells contain episomal HPV16 genomes, whereas S12 cells, which are derived from the W12 line, contain HPV DNA as integrated copies. When we expressed E2 in S12 cells, we observed strong repression of E6 and E7 transcription. In contrast, no effect of E2 on the transcription of these genes was detected in W12 cells. While integration of the viral genome into the host DNA contributes to the difference between W12 and S12 cells, integration by itself is not sufficient to explain this difference. Instead, the chromatin structure in the region of the E6 and E7 promoter (p97), which we show to be very different in these two cell lines, is likely to be the cause of the different responsiveness of p97 to the E2 protein. Experiments with the histone deacetylase inhibitor trichostatin A (TSA) indicated that the episomal HPV16 DNA is in a relatively inaccessible state prior to TSA treatment. Our results, together with those of others, suggest that any effect of the E2 protein on the expression of the E6 and E7 genes during the normal viral life cycle is of secondary importance compared to the function of E2 in replication.
Calcitonin gene–related peptide does not excite or sensitize meningeal nociceptors: Implications for the pathophysiology of migraine (2005)

Migraine is among the most common types of pain, but its mechanisms are poorly understood. A growing body of evidence points to a critical role of calcitonin gene-related peptide (CGRP) in the pathophysiology of migraine headache. During migraine, CGRP is thought to be released from peripheral endings of perivascular meningeal nociceptors primary and to promote vasodilatation. A current hypothesis suggests that peripheral CGRP and its related meningeal vasodilatation results in activation and sensitization, leading to the generation of migraine headache. However, direct evidence supporting this idea is lacking. Here, using electrophysiological, extracellular, single-unit recording combined with laser-Doppler flowmetry measurements of dural blood flow (DBF), we examined whether CGRP and meningeal vasodilatation promote activation or sensitization of meningeal nociceptors. Changes in (DBF), ongoing discharge, and responsiveness to mechanical stimulation of the dura were studied after either topical administration or intravenous infusion of rat alpha-CGRP in anesthetized rats. Both topical and systemic administration of CGRP caused a significant increase in dural blood flow; however, neither method of CGRP administration resulted in activation or sensitization of meningeal nociceptors. The results of this study suggest that CGRP effects in the meninges, including meningeal vasodilatation, are not sufficient to activate or sensitize meningeal nociceptors.
Are antibasal ganglia antibodies important, and clinically useful? (2007)

In the last decade there has been controversy over the existence and clinical significance of autoantibodies that react with the basal ganglia, referred to as antibasal ganglia antibodies (ABGAs) (some investigators have referred to them as anti-neuronal antibodies). The spectrum of disorders associated with ABGAs has recently been widened to include several neuropsychiatric syndromes; in common is their association with recent streptococcal infection, which suggests that these syndromes are due to an aberrant immune response triggered by streptococcal infection. Like other emerging diseases it will take time to establish causation, if any, and for these disorders to be accepted as real disease entities. Because they may turn out to have a considerable clinical impact, they clearly need to be better understood, as does ABGA testing in clinical practice.

ABGAs are autoantibodies that cross-react with human brain tissue, with the highest binding specificity against extracts from the caudate and putamen.1 They were originally detected using immunofluorescence microscopy (fig 1) in patients with Sydenham’s chorea,2 the prototypical post-streptococcal disease of the central nervous system (CNS). ABGAs can also be detected by Western blotting of an antigen preparation of human or rodent basal ganglia, or using enzyme-linked immunosorbent assays (ELISA).1 The sensitivity and specificity of the ELISA when using a crude antigen preparation is inferior to Western blotting.1 The performance of the ELISA may be improved in the future with the use of recombinant autoantigens.3



 Figure 1 
Immuofluorescence microscopy and Western blot of ABGAs. (A) Normal control diluted 1/50 tested against human basal ganglia with no specific staining (magnification ×200). (B) Sample from a patient with Sydenham’s chorea diluted 1/50 and tested against human basal ganglia tissue; IgG staining of axons (arrows) (magnification ×200). (C) Western blots showing serial dilution of strongly positive ABGAs in patients with post-streptococcal movement disorder. …
Optimization of a Reusable, DNA Pseudoknot-Based Electrochemical Sensor for Sequence-Specific DNA Detection in Blood Serum (2008)

We describe in detail a new electrochemical DNA (E-DNA) sensing platform based on target-induced conformation changes in an electrode-bound DNA pseudoknot. The pseudoknot, a DNA structure containing two stem-loops in which the first stem's loop forms part of the second stem, is modified with a methylene blue redox tag at its 3' terminus and covalently attached to a gold electrode via the 5' terminus. In the absence of a target, the structure of the pseudoknot probe minimizes collisions between the redox tag and the electrode, thus reducing faradaic current. Target binding disrupts the pseudoknot structure, liberating a flexible, single-stranded element that can strike the electrode and efficiently transfer electrons. In this article we report further characterization and optimization of this new E-DNA architecture. We find that optimal signaling is obtained at an intermediate probe density ( approximately 1.8 x 10(13) molecules/cm(2) apparent density), which presumably represents a balance between steric and electrostatic blocking at high probe densities and increased background currents arising from transfer from the pseudoknot probe at lower densities. We also find that optimal 3' stem length, which appears to be 7 base pairs, represents a balance between pseudoknot structural stability and target affinity. Finally, a 3' loop comprised of poly(A) exhibits better mismatch discrimination than the equivalent poly(T) loop, but at the cost of decreased gain. Optimization over this parameter space significantly improves the signaling of the pseudoknot-based E-DNA architecture, leading to the ability to sensitively and specifically detect DNA targets even when challenged in complex, multicomponent samples such as blood serum.
Sub-Microsecond Decay Time Phosphors for Pressure Sensitive Paint Applications (2001)

The purpose of the effort described here is to identify and characterize thermally sensitive phosphors of potential use to pressure-sensitive paint (PSP) applications. Some PSPs show a pronounced dependence on both temperature and pressure. Pressure dependence of a phosphor is negligible. Thus a phosphor can
The anti-gene strategy: control of gene expression by triplex-forming-oligonucleotides. (1991)

Oligonucleotides are being developed to selectively inhibit gene expression at the translational level (antisense oligonucleotides) and at the transcriptional level (anti-gene oligonucleotides). This review deals with the anti-gene strategy whereby an oligonucleotide binds to the major groove of double helical DNA where it forms a local triple helix. The molecular mechanisms for DNA recognition by triple helix formation are discussed together with some of the rules presently available to design the sequence and orientation of the triple helix forming oligonucleotide. Triplex stability can be enhanced by covalent attachment of an intercalating agent to the terminal nucleotide of the oligonucleotide. The intercalating agent can be used to induce irreversible reactions in the target sequence: double strand cleavage by a phenanthroline-Cu chelate in the presence of a reducing agent, photo-induced cleavage by ellipticine derivatives, photo-induced cross-linking of the two DNA strands by psoralen... Triple helix-forming oligonucleotides can be used to control gene expression at the transcriptional level. Inhibition of binding of transcription activating factors by triplex formation modulates the level of transcription of the target gene. Binding of a triplex-forming oligonucleotide immediately downstream of the RNA polymerase binding site can inhibit transcription initiation as shown with the E. coli beta-lactamase gene. Studies with cells in culture show that triple helix formation may occur in the intracellular environment and consequently leads to transcription inhibition. This inhibitory effect can be made irreversible by using, e.g., psoralen-substituted oligonucleotides. Oligonucleotides synthesized with the alpha-anomers of nucleotide units are resistant to nucleases and still form triple helices with double-stranded DNA. Oligo-[alpha]-deoxynucleotides can be derived by stabilizing (intercalating) agents or reactive groups (cleaving reagents, cross-linkers ...). The results presently available provide a rational basis for the development of new tools for cellular biology and of new therapeutical approaches to selectively control gene expression at the transcriptional level.
Novel compounds inhibit estrogen formation and action. (1992)

Estrogens are well known to play a predominant role in human breast cancer. The current endocrine therapy of breast cancer consists in administering an antiestrogen which blocks the action of estrogens at the receptor level. However, the currently available antiestrogens possess mixed estrogenic and antiestrogenic activity, thus limiting their potential therapeutic efficacy. The present data show that a series of new estrogen derivatives demonstrate not only pure antiestrogenic activity in the sensitive in vivo mouse uterus assay, but simultaneously exert potent inhibitory effects on 17 beta-hydroxysteroid dehydrogenase activity, the enzyme responsible for the formation of 17 beta-estradiol from estrone, the last step in estrogen formation. Such compounds having a dual site of inhibitory action, namely on estrogen formation and on the estrogen receptor, could well lead to an improved endocrine therapy of breast and other estrogen-sensitive cancers as well as other nonmalignant estrogen-sensitive diseases.
Pulmonary Edema: Atypical Anaphylactoid Reaction to Intravenous Iron Dextran (1997)

Two cases of atypical anaphylactoid reactions to intravenous iron dextran in hemodialysis patients are described. Anaphylactic reactions to iron dextran in dialysis patients are not uncommon. Pulmonary edema is not generally seen in anaphylaxis. Our patients both developed significant pulmonary edema following intravenous infusion of iron dextran, which responded promptly to treatment of anaphylaxis. Potential mechanisms are discussed.
Secular Increases in Relative Weight and Adiposity Among Children Over Two Decades: The Bogalusa Heart Study (1997)

The increasing prevalence of obesity in early life indicates a need for primary prevention. Additional study is needed to determine whether these trends are continuing to accelerate and to examine possible explanations, such as diet and physical activity, for these changes.
Qué es la Tanatología (2006)

Durante nuestra vida vamos teniendo diversas muertes, algunas pequenas, otras no tanto. Sin embargo cada una de estas perdidas nos dan la oportunidad de vivir y crecer como seres humanos, como hijos, hermanos, esposos, amigos, padres. Para poder recorrer cada uno de esos caminos la Tanatologia ayuda a encontrar ese sentido al proceso de la muerte
Polyamines as Targets for Therapeutic Intervention (1995)

Polyamines are ubiquitous cell components essential for normal growth. Compounds interfering with polyamine biosynthesis or function have considerable potential for use as therapeutic agents. Inhibitors of ornithine decarboxylase have been shown to be valuable for the treatment of diseases caused by parasitic protozoa, most notably African sleeping sickness. They may also be useful chemopreventive and antineoplastic agents. Inhibitors of S-adenosylmethionine decarboxylase also have potential as treatments of these diseases. Protocols minimizing uptake of exogenous polyamines via the polyamine-transport system will probably be needed for the full potential of the inhibitors to be realized. Polyamine analogues, notably those with ethyl or benzyl groups on the terminal nitrogen atoms, have potent antiproliferative activity and are promising agents for the treatment of cancer. These analogues are transported by the polyamine-transport system, and their therapeutic effects are less likely to be blocked by the availability of the exogenous polyamines.
Differential responses of invariant V alpha 24J alpha Q T cells and MHC class II-restricted CD4+ T cells to dexamethasone. (1999)

NK T cells are a T cell subset in the human that express an invariant alpha-chain (V alpha 24invt T cells). Because of the well-described immunomodulation by glucocorticoids on activation-induced cell death (AICD), the effects of dexamethasone and anti-CD3 stimulation on V alpha 24invt T cell clones and CD4+ T cell clones were investigated. Dexamethasone significantly enhanced anti-CD3-mediated proliferation of V alpha 24invt T cells, whereas CD4+ T cells were inhibited. Addition of neutralizing IL-2 Ab partially abrogated dexamethasone-induced potentiation of V alpha 24invt T cell proliferation, indicating a role for autocrine IL-2 production in corticosteroid-mediated proliferative augmentation. Dexamethasone treatment of anti-CD3-stimulated V alpha 24invt T cells did not synergize with anti-Fas blockade in enhancing proliferation or preventing AICD. The V alpha 24invt T cell response to dexamethasone was dependent on the TCR signal strength. In the presence of dexamethasone, lower doses of anti-CD3 inhibited proliferation of V alpha 24invt T cells and CD4+ T cells; at higher doses of anti-CD3, which caused inhibition of CD4+ T cells, the V alpha 24invt T cell clones proliferated and were rescued from AICD. These results demonstrate significant differences in TCR signal strength required between V alpha 24invt T cells and CD4+ cells, and suggest important immunomodulatory consequences for endogenous and exogenous corticosteroids in immune responses.
Inhibition of human lymphocyte natural cytotoxicity and antibody-dependent cell-mediated cytotoxicity by K-76 COONa, a reagent that blocks complement activity. (1984)

K-76 COONa is a 440 m.w. fungal product that can inhibit complement activity of C5 and Factor I. K-76 COONa abrogated both human natural killer (NK) cell activity and antibody-dependent cell-mediated cytotoxicity (ADCC) (ID50 approximately 1.5 mM). To be effective, K-76 COONa had to be present during the assay, because pretreatment of lymphocytes with highly inhibitory concentrations of K-76 COONa did not inhibit cytolysis. The monocarboxylic K-76 derivative was more inhibitory to NK than the dicarboxylic derivative. This relative efficacy is similar to that observed for inhibition of complement lysis. K-76 COONa inhibited NK when added before NK conjugate formation, but had little effect when added after conjugate formation. The compound also inhibited the formation of conjugates by NK and K cells. Therefore, this reagent selectively affected events that occurred between the initial effector-target cell interactions and the formation of stable conjugates. It had little influence on the post-binding "lethal hit" stage of cytolysis. These data imply a) that if any molecules similar to C5 are activated during the "lethal hit" stage of cytolysis, then they are inaccessible to K-76 COONa , and b) that C3bi-like molecules may be involved in lymphocyte binding.
Relaxin binding in the rat heart atrium. (1992)

Relaxin is a member of the insulin family of polypeptides that is best known as a reproductive hormone. In an effort to elucidate the mechanism of action of relaxin we previously localized the specific binding sites of a 32P-labeled relaxin in the rat uterus and brain. These studies suggested that, in addition to its classical role in pregnancy, relaxin might have other physiological functions. In the present paper we describe the specific and high-affinity binding of relaxin to the cardiac atrium of both male and female rats. The relaxin binding could not be displaced by peptides belonging to the same family [insulin, insulin-like growth factor I (IGF-I)] or by peptides that were identified in the atrium or were known to have cardiovascular functions (atrial natriuretic peptide, angiotensin II). The dissociation constant for relaxin in the atrium was estimated to be 1.4 nM, which was similar to that found in the uterus (1.3 nM) and the brain (1.4 nM). In view of the close association of relaxin with reproduction, an experiment was also performed to compare the relaxin binding in the uterus and heart after gonadectomy and sex steroid treatment. It was found that the relaxin binding in the rat uterus was diminished by 53% overall following ovariectomy but was restored to 90% of normal levels when treated with estrogen (but not with testosterone). In contrast, the relaxin binding in the rat heart was not affected by castration or sex steroid treatment. We conclude that specific and high-affinity relaxin receptors exist in the atrium of both the male and female rat heart and that these are regulated differently than the relaxin receptors in the uterus.
Data compression and local metrics for nearest neighbor classification (1999)

A local distance measure for the nearest neighbor classification rule is shown to achieve high compression rates and high accuracy on real data sets. In the approach proposed here, first, a set of prototypes is extracted during training and, then, a feedback learning algorithm is used to optimize the metric. Even if the prototypes are randomly selected, the proposed metric outperforms, both in compression rate and accuracy, common editing procedures like ICA, RNN, and PNN. Finally, when accuracy is the major concern, we show how compression can be traded for accuracy by exploiting voting techniques. That indicates how voting can be successfully integrated with instance-based approaches, overcoming previous negative results.
Luminescent passive-oxidized silicon quantum dots as biological staining labels and their cytotoxicity effects at high concentration (2008)

Semiconductor quantum dots (QDs) hold some advantages over conventional organic fluorescent dyes.Due to these advantages, they are becoming increasingly popular in the field of bioimaging.However, recent work suggests that cadmium based QDs affect cellular activity.As a substitute for cadmium based QDs, we have developed photoluminescent stable silicon quantum dots (Si-QDs) with a passive-oxidation technique.Si-QDs (size: 6.5 1.5 nm) emit green light, and they have been used as biological labels for living cell imaging.In order to determine the minimum concentration for cytotoxicity, we investigated the response of HeLa cells.We have shown that the toxicity of Si-QDs was not observed at 112 g ml -1 and that Si-QDs were less toxic than CdSe-QDs at high concentration in mitochondrial assays and with lactate dehydrogenase (LDH) assays.Especially under UV exposure, Si-QDs were more than ten times safer than CdSe-QDs.We suggest that one mechanism for the cytotoxicity is that Si-QDs can generate oxygen radicals and these radicals are associated with membrane damages.This work has demonstrated the suitability of Si-QDs for bioimaging in lower concentration, and their cytotoxicity and one toxicity mechanism at high concentration.