RESUMO
We show that homogeneous superconductors with broken spin/isospin symmetry lower their energy via a transition to a novel superconducting state where the Fermi surfaces are deformed to a quasiellipsoidal form at zero total momentum of Cooper pairs. In this state, the gain in the condensation energy of the pairs dominates over the loss in the kinetic energy caused by the lowest order (quadrupole) deformation of Fermi surfaces from the spherically symmetric form. The phase transition from the spherically symmetric state to the superconducting state with broken rotational symmetry is first order.
RESUMO
The authors present the case history of a child with neuroblastoma and early infiltration of the orbit accompanied by bilateral blindness. The typical clinical signs developed later. The thickening of the periosteum infiltrated by the tumor in the lateral wall of the orbit was demonstrated by computerized tomography. This may be regarded as an early sign of infiltration of the orbit by the neuroblastoma. In the case reported here a severe inflammatory reaction developed in the left orbit and anterior segment during massive chemotherapy and melted the cornea.
Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Cegueira/patologia , Neuroblastoma/secundário , Neoplasias Orbitárias/secundário , Pré-Escolar , Feminino , Humanos , Neuroblastoma/patologia , Órbita/patologia , Neoplasias Orbitárias/patologia , Tomografia Computadorizada por Raios XRESUMO
Interleukin 2 is thought to be active as a monomeric protein. As the nonessential Cys-140 of murine interleukin 2 (mIL2) is located in the hydrophobic interface of the amphiphilic F domain it was successfully used to stabilize hydrophobic amino acid contacts between two mIL2 cores yielding biologically active cystine-bonded dimeric mIL2. (3H) thymidine incorporation assays with intermolecular cystine-bonded or monomeric mIL2 revealed almost identical median effective concentrations (EC50) and high-affinity dissociation constants (Kdh), respectively. Comparative binding and internalization assays suggest that one cystine-bonded dimeric or two monomeric mIL2 molecules bind to the high-affinity receptor complex. Furthermore, DSS concentration-dependent crosslinking studies using monomeric mIL2 revealed four membrane-derived protein-complexes with apparent molecular weights of about 70 kDa, 85 kDa, 95 kDa and 100 kDa, respectively, showing that both mIL2 receptor chains may be crosslinked to a monomeric or dimeric ligand molecule, respectively. We therefore propose that dimerization of murine interleukin 2 occurring either in solution at concentrations above the low-affinity dissociation constant or at the low-affinity receptor is important for regulation of high-affinity complex formation and signal transduction.
Assuntos
Cistina/metabolismo , Interleucina-2/metabolismo , Receptores de Interleucina-2/metabolismo , Sequência de Aminoácidos , Animais , Divisão Celular , Linhagem Celular , Reagentes de Ligações Cruzadas/farmacologia , Interleucina-2/química , Cinética , Ligantes , Camundongos , Dados de Sequência Molecular , Succinimidas/farmacologiaRESUMO
In the course of extensive operations there are disturbances of the turnover-rate because of the activation of the clotting-system. These may equally be demonstrated by simple reproducible and quick global tests as by methods which are expensive and reserved only to special laboratories. By consequent low dosis-heparin-medication hypercoagulability-conditions and reactive hemorrhage complications are prevented and the hemostasis situation is significantly improved. No disturbance of the hemostasis by antithrombin-3-effect of the heparin-application in this dosage can be proved. The results of the examination including quality control and interpretation can be obtained in 30 minutes.
Assuntos
Coagulação Intravascular Disseminada/prevenção & controle , Heparina/administração & dosagem , Testes de Coagulação Sanguínea , Hemostasia , Humanos , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/prevenção & controle , Cuidados Pré-OperatóriosRESUMO
Homodimeric murine interleukin 3 (mIL-3) agonists were generated by intermolecular cystine-bonding. Steady-state binding assays and association kinetics performed at 4 degrees C using these agonists revealed specific binding to both the high- and low-affinity receptor. DSS-mediated crosslinking studies performed at 4 degrees C with agonist concentrations compatible with high-affinity receptor complex formation allowed to detect protein complexes of the alpha chain, the beta chain(s) and the high-affinity receptor complex migrating with apparent molecular weights of 90 kDa, 140 kDa, and above 180 kDa, respectively. In contrast, monomeric mIL-3 was crosslinked to the alpha chain receptor only unless high concentrations were used. Binding studies performed at 4 degrees C revealed a positive cooperative interaction of monomeric mIL-3 with the low-affinity receptor. Proliferation studies and association kinetics performed at 37 degrees C showed that under physiological conditions these agonists were at least 2- to 3-fold more potent than monomeric mIL-3. We therefore propose that dimerization of mIL-3 may be involved in high-affinity receptor complex formation.