Deconstructing a Disease: RAR, Its Fusion Partners, and Their Roles in the Pathogenesis of Acute Promyelocytic Leukemia

CD30(+) anaplastic large cell lymphoma: a review of its histopathologic, genetic, and clinical features.

Modern aspects of the Jahn-Teller effect theory and applications to molecular problems.

Detection of Anaplastic Lymphoma Kinase (ALK) and Nucleolar Protein Nucleophosmin (NPM)-ALK Proteins in Normal and Neoplastic Cells With the Monoclonal Antibody ALK1

The Menin Tumor Suppressor Protein Is an Essential Oncogenic Cofactor for MLL-Associated Leukemogenesis

The ${\mathit{T}}_{1\mathit{u}}$\ensuremath{\bigotimes}${\mathit{h}}_{\mathit{g}}$ Jahn-Teller system is studied analytically on an icosahedral cluster model. This system is a model for the effects of vibronic coupling in the ${\mathrm{C}}_{60}$ molecule. Vibronic coupling is very important in this system because both the electronic and vibrational states are of high symmetry. The method employed is to apply a unitary transformation to the Hamiltonian for the system in order to obtain expressions for the states associated with minima in the potential-energy surface. Quadratic coupling terms are included in the Hamiltonian in order to obtain distinct minima located at either pentagonal (${\mathit{D}}_{5\mathit{h}}$) or trigonal (${\mathit{D}}_{3\mathit{h}}$) positions in Q space. These states are good eigenstates of the system as a whole in very strong coupling. For finite couplings, projection operator techniques are then used to obtain explicit expressions for the vibronic ground and inversion states from these basis states for both the pentagonal and trigonal cases. Expressions for the corresponding energies are then derived as a function of the coupling constants. These results are necessary in order to be able to calculate further properties of the system, such as Jahn-Teller reduction factors, which are in turn necessary to explain experimental data on these systems.

Analysis of the T1u

In all linear Jahn-Teller (JT) systems studied to date, the ground state, after allowing for the vibronic interaction, has always been of the same symmetry as the original electronic state. Furthermore, the ground state remains the same symmetry for all coupling strengths. We now report results for the {ital H}{circle_times}{ital h} JT system (as occur in various states of the C{sub 60} molecule) where this is not the case. There are two possible types of JT effects in this system, depending upon whether {ital D}{sub 3{ital d}} or {ital D}{sub 5{ital d}} extrema are absolute minima. For the case of {ital D}{sub 3{ital d}} minima, we find that for couplings above a certain value the ground state is an {ital A}-type singlet, rather than the expected {ital H}-type quintet. {copyright} {ital 1996 The American Physical Society.}

H⊗ h: A Jahn-Teller Coupling That Really Does Reduce the Degeneracy of the Ground State

We show that the precise orientation of a C-60 molecule which terminates the tip of a scanning probe microscope can be determined with atomic precision from submolecular contrast images of the fullerene cage. A comparison of experimental scanning tunneling microscopy data with images simulated using computationally inexpensive Huckel theory provides a robust method of identifying molecular rotation and tilt at the end of the probe microscope tip. Noncontact atomic force microscopy resolves the atoms of the C-60 cage closest to the surface for a range of molecular orientations at tip-sample separations where the molecule-substrate interaction potential is weakly attractive. Measurements of the C-60-C-60 pair potential acquired using a fullerene-terminated tip are in excellent agreement with theoretical predictions based on a pairwise summation of the van der Waals interactions between C atoms in each cage, i.e., the Girifalco potential [L. Girifalco, J. Phys. Chem. 95, 5370 (1991)].

Precise Orientation of a Single C 60 Molecule on the Tip of a Scanning Probe Microscope

The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) in the regulatory regions of the apolipoprotein E (APOE) gene modify the well-established epsilon4-associated risk for Alzheimer's disease (AD). Sequencing of the APOE gene regulatory regions revealed four previously reported promoter SNPs and one novel SNP in the previously described macrophage enhancer (ME.1). In addition, we also studied the two classic allelic missense SNPs that define epsilon2/epsilon3/epsilon4 status in a case-control association study. Analysis of pair-wise linkage disequilibrium (LD) of the five regulatory region SNPs with classic APOE SNPs revealed a previously unreported 7 kb LD block covering the entire APOE gene, part of the promoter and 3' enhancer region. We report here that in a case-control association study (N=719) of the seven SNPs, the genotype at codon 112 captures all the information required to assess disease risk. To explore correlations with quantitative traits, 169 patients were studied in whom rates of cognitive decline were available. In addition to the epsilon4 allele, two regulatory region SNPs were associated with the rate of cognitive decline in AD patients. This study highlights the effect of APOE gene variation on risk of AD and rate of cognitive decline and demonstrates that a single SNP, which confers epsilon4 status, captures all of the risk of developing AD but two SNPs in the regulatory region may affect the rate of cognitive decline in AD patients.

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Regulatory region single nucleotide polymorphisms of the apolipoprotein E gene and the rate of cognitive decline in Alzheimer's disease

The T(X)(e+t2) Jahn-Teller system is studied in the strong-coupling approximation on a cluster model by transformation methods. An energy-minimisation procedure is used to show that the system will be localised in potential energy minima having either tetragonal, trigonal or orthorhombic symmetry depending upon the strengths of the e and t2 coupling constants. Detailed results are given for the orthorhombic case to underline the physical processes involved in the Jahn-Teller effect and provide a detailed mathematical framework for the calculation of other properties of the system (e.g. first- and second-order reduction factors, random-strain effects).

Janette L. Dunn

Papers

Analysis of the T1u

H⊗ h: A Jahn-Teller Coupling That Really Does Reduce the Degeneracy of the Ground State

Precise Orientation of a Single C 60 Molecule on the Tip of a Scanning Probe Microscope

Regulatory region single nucleotide polymorphisms of the apolipoprotein E gene and the rate of cognitive decline in Alzheimer's disease

An analysis of the T⊗(e+t2) Jahn-Teller system with strong coupling