1,343 research outputs found
A unit on national government
Thesis (Ed.M.)--Boston UniversityThis paper deals with the problem of subdividing an over-sized unit in ninth-grade civics on the topic, national government, into three shorter units. Then the paper takes up, more extensively, the organization and presentation of the last of the three units according to the principles and procedures set down in Fundanentals of Secondary-School Teaching and the course in the Unit Method at Boston University under the direction of Professor Roy O. Billett
Autoradiographic Characterization and Localization of Quisqualate Binding Sites in Rat Brain Using the Antagonist [ 3 H]6-Cyano-7-Nitroquinoxaline-2,3-Dione: Comparison with ( R,S )-[ 3 H]Α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Binding Sites
Using quantitative autoradiography, we have investigated the binding sites for the potent competitive non- N -methyl-D-aspartate (non-NMDA) glutamate receptor antagonist [ 3 H]6-cyano-7-nitro-quinoxaline-2,3-dione ([ 3 H]-CNQX) in rat brain sections. [ 3 H]CNQX binding was regionally distributed, with the highest levels of binding present in hippocampus in the stratum radiatum of CA1, stratum lucidum of CA3, and molecular layer of dentate gyrus. Scatchard analysis of [ 3 H]CNQX binding in the cerebellar molecular layer revealed an apparent single binding site with a K D = 67 ± 9.0 n M and B max = 3.56 ± 0.34 pmol/mg protein. In displacement studies, quisqualate, L-glutamate, and kainate also appeared to bind to a single class of sites. However, ( R,S )- Α -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) displacement of [ 3 H]CNQX binding revealed two binding sites in the cerebellar molecular layer. Binding of [ 3 H]AMPA to quisqualate receptors in the presence of potassium thiocyanate produced curvilinear Scatchard plots. The curves could be resolved into two binding sites with K D1 = 9.0 ± 3.5 n M , B max = 0.15 ± 0.05 pmol/mg protein, K D2 = 278 ± 50 n M , and B max = 1.54 ± 0.20 pmol/mg protein. The heterogeneous anatomical distribution of [ 3 H]CNQX binding sites correlated to the binding of L-[ 3 H]glutamate to quisqualate receptors and to sites labeled with [ 3 H]AMPA. These results suggest that the non-NMDA glutamate receptor antagonist [ 3 H]CNQX binds with equal affinity to two states of quisqualate receptors which have different affinities for the agonist [ 3 H]AMPA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65634/1/j.1471-4159.1990.tb01925.x.pd
L008 Défaut de différenciation veino-lymphatique embyonnaire par modulation de l’ARN interférence
L’ARN interférence, mécanisme de régulation de l’expression des gènes, est médiée par les siARNs et les microARNs, ARN non-codants de 20 à 22 nucléotides affectant la régulation post-transcriptionnelle d’ARNm cibles avec lesquels ils s’apparient.La RNase DICER est une enzyme centrale de la biosynthèse des siARNs et microARNs. Les souris dont le gène dicer est invalidé ont un phénotype complexe, et meurent très tôt pendant le développement, notamment à cause d’un défaut d’angiogenèse.Afin d’étudier l’ARN interférence au cours de l’angiogenèse embryonnaire, des souris dont le gène dicer est floxé (mutant conditionnel) sont croisées avec des souris exprimant la recombinase Cre, de manière constitutive, sous le contrôle du promoteur du gène tie2, dirigeant ainsi son expression dans les cellules endothéliales (CE) et les cellules hématopiétiques.Nos résultats montrent que l’invalidation de dicer sous le contrôle du promoteur du gène tie2 entraine une mortalité embryonnaire suite à un œdème et des hémorragies au treizième jour du développement (E13,5). L’analyse histologique montre des vaisseaux lymphatiques remplis de sang, suggérant une mauvaise séparation du réseau sanguin et lymphatique. Cette hypothèse est étudiée par marquage des vaisseaux lymphatiques (LYVE-1) et des vaisseaux sanguins (PECAM) sur embryon entier et peaux isolées à différents stades précédant la mort.Ces embryons présentent également un problème de développement du foie, probablement dû à l’activité du promoteur tie2 dans les lignées hématopoiétiques. La mise en culture de ces foies fœtaux à E13,5 révèle une atteinte des précurseurs hématopoétiques.L’étude de ces précurseurs à des stades plus précoces (E8,5) est en cours au laboratoire.Nos résultats démontrent donc un rôle important de l’ARN interférence dans le contrôle épigénétique de l’angiogenèse et de la lymphangiogenèse embryonnaire mais également dans le développement de l’hématopoièse, suggérant son implication dans la différenciation veino-lymphangiogenèse, dont les mécanismes moléculaires seront discutés
The lady vanishes: what's missing from the stem cell debate
Most opponents of somatic cell nuclear transfer and embryonic stem cell technologies base their arguments on the twin assertions that the embryo is either a human being or a potential human being, and that it is wrong to destroy a human being or potential human being in order to produce stem cell lines. Proponents’ justifications of stem cell research are more varied, but not enough to escape the charge of obsession with the status of the embryo. What unites the two warring sides in ‘the stem cell wars’ is that women are equally invisible to both: ‘the lady vanishes’. Yet the only legitimate property in the body is that which women possess in their reproductive tissue and the products of their reproductive labour. By drawing on the accepted characterisation in law of property as a bundle of rights, and on a Hegelian model of contract as mutual recognition, we can lessen the impact of the tendency to regard women and their eggs as merely receptacles and women’s reproductive labour as unimportant
Increased function of pronociceptive TRPV1 at the level of the joint in a rat model of osteoarthritis pain
Objectives Blockade of transient receptor potential vanilloid 1 (TRPV1) with systemic antagonists attenuates osteoarthritis (OA) pain behaviour in rat models, but on-target-mediated hyperthermia has halted clinical trials. The present study investigated the potential for targeting TRPV1 receptors within the OA joint in order to produce analgesia.
Methods The presence of TRPV1 receptors in human synovium was detected using western blotting and immunohistochemistry. In a rat model of OA, joint levels of an endogenous ligand for TRPV1, 12- ydroxyeicosatetraenoic acid (12-HETE), were quantified using liquid chromatography-tandem mass spectrometry (LCMS/MS). Effects of peripheral administration of the TRPV1 receptor antagonist JNJ-17203212 on afferent fibre activity, pain behaviour and core body temperature were investigated. Effects of a spinal administration of JNJ-17203212 on dorsal horn neuronal responses were studied.
Results We demonstrate increased TRPV1 immunoreactivity in human OA synovium, confirming the diseased joint as a potential therapeutic target for TRPV1-mediated analgesia. In a model of OA pain, we report increased joint levels of 12-HETE, and the sensitisation of joint afferent neurones to mechanical
stimulation of the knee. Local administration of JNJ- 17203212 reversed this sensitisation of joint afferents
and inhibited pain behaviour (weight-bearing asymmetry), to a comparable extent as systemic JNJ-
17203212, in this model of OA pain, but did not alter core body temperature. There was no evidence for
increased TRPV1 function in the spinal cord in this model of OA pain.
Conclusions Our data provide a clinical and mechanistic rationale for the future investigation of the therapeutic benefits of intra-articular administration of TRPV1 antagonists for the treatment of OA pain
Nomenclature for renal replacement therapy and blood purification techniques in critically ill patients: practical applications
This article reports the conclusions of the second part of a consensus expert conference on the nomenclature of renal replacement therapy (RRT) techniques currently utilized to manage acute kidney injury and other organ dysfunction syndromes in critically ill patients. A multidisciplinary approach was taken to achieve harmonization of definitions, components, techniques, and operations of the extracorporeal therapies. The article describes the RRT techniques in detail with the relevant technology, procedures, and phases of treatment and key aspects of volume management/fluid balance in critically ill patients. In addition, the article describes recent developments in other extracorporeal therapies, including therapeutic plasma exchange, multiple organ support therapy, liver support, lung support, and blood purification in sepsis. This is a consensus report on nomenclature harmonization in extracorporeal blood purification therapies, such as hemofiltration, plasma exchange, multiple organ support therapies, and blood purification in sepsis
Ethyl 4-{1-[(2,4-dinitrophenyl)hydrazono]ethyl}-5-(2-naphthylmethoxymethyl)isoxazole-3-carboxylate
The title compound, C26H23N5O8, was prepared and its structure investigated to further develop a working hypothesis for the essential binding pharmacophore for ligands of the System Xc- transporter [Patel et al. (2004 ▶). Neuropharmacology, 46, 273–284]. The hydrazone group displays an E geometry and the isoxazole double bond and C=N group of the hydrazone are in an s-cis relationship. The secondary amino NH group forms an intramolecular N—H⋯O hydrogen bond to a ring nitro group. There is a dihedral angle of 44.27 (5)° between the isoxazole plane and the hydrazone group plane
Septic AKI in ICU patients. diagnosis, pathophysiology, and treatment type, dosing, and timing: a comprehensive review of recent and future developments
Evidence is accumulating showing that septic acute kidney injury (AKI) is different from non-septic AKI. Specifically, a large body of research points to apoptotic processes underlying septic AKI. Unravelling the complex and intertwined apoptotic and immuno-inflammatory pathways at the cellular level will undoubtedly create new and exciting perspectives for the future development (e.g., caspase inhibition) or refinement (specific vasopressor use) of therapeutic strategies. Shock complicating sepsis may cause more AKI but also will render treatment of this condition in an hemodynamically unstable patient more difficult. Expert opinion, along with the aggregated results of two recent large randomized trials, favors continuous renal replacement therapy (CRRT) as preferential treatment for septic AKI (hemodynamically unstable). It is suggested that this approach might decrease the need for subsequent chronic dialysis. Large-scale introduction of citrate as an anticoagulant most likely will change CRRT management in intensive care units (ICU), because it not only significantly increases filter lifespan but also better preserves filter porosity. A possible role of citrate in reducing mortality and morbidity, mainly in surgical ICU patients, remains to be proven. Also, citrate administration in the predilution mode appears to be safe and exempt of relevant side effects, yet still requires rigorous monitoring. Current consensus exists about using a CRRT dose of 25 ml/kg/h in non-septic AKI. However, because patients should not be undertreated, this implies that doses as high as 30 to 35 ml/kg/h must be prescribed to account for eventual treatment interruptions. Awaiting results from large, ongoing trials, 35 ml/kg/h should remain the standard dose in septic AKI, particularly when shock is present. To date, exact timing of CRRT is not well defined. A widely accepted composite definition of timing is needed before an appropriate study challenging this major issue can be launched
The pore structure and gating mechanism of K2P channels
K2P potassium channels are important regulators of cellular excitability. This study reveals that in contrast to most other K+ channels the primary gating mechanism in the K2P channel TREK-1 does not involve opening and closure of the cytoplasmic bundle crossing, but takes place close to or within the selectivity filter
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