Stable Patterns of Gene Expression Regulating Carbohydrate Metabolism Determined by Geographic Ancestry

Background: Individuals of African descent in the United States suffer disproportionately from diseases with a metabolic etiology (obesity, metabolic syndrome, and diabetes), and from the pathological consequences of these disorders (hypertension and cardiovascular disease). Methodology/Principal Findings: Using a combination of genetic/genomic and bioinformatics approaches, we identified a large number of genes that were both differentially expressed between American subjects self-identified to be of either African or European ancestry and that also contained single nucleotide polymorphisms that distinguish distantly related ancestral populations. Several of these genes control the metabolism of simple carbohydrates and are direct targets for the SREBP1, a metabolic transcription factor also differentially expressed between our study populations. Conclusions/Significance: These data support the concept of stable patterns of gene transcription unique to a geographic ancestral lineage. Differences in expression of several carbohydrate metabolism genes suggest both genetic and transcriptional mechanisms contribute to these patterns and may play a role in exacerbating the disproportionate levels o

Tobacco use induces anti-apoptotic, proliferative patterns of gene expression in circulating leukocytes of Caucasian males

Abstract Background Strong epidemiologic evidence correlates tobacco use with a variety of serious adverse health effects, but the biological mechanisms that produce these effects remain elusive. Results We analyzed gene transcription data to identify expression spectra related to tobacco use in circulating leukocytes of 67 Caucasian male subjects. Levels of cotinine, a nicotine metabolite, were used as a surrogate marker for tobacco exposure. Significance Analysis of Microarray and Gene Set Analysis identified 109 genes in 16 gene sets whose transcription levels were differentially regulated by nicotine exposure. We subsequently analyzed this gene set by hyperclustering, a technique that allows the data to be clustered by both expression ratio and gene annotation (e.g. Gene Ontologies). Conclusion Our results demonstrate that tobacco use affects transcription of groups of genes that are involved in proliferation and apoptosis in circulating leukocytes. These transcriptional effects include a repertoire of transcriptional changes likely to increase the incidence of neoplasia through an altered expression of genes associated with transcription and signaling, interferon responses and repression of apoptotic pathways

Ground and low-lying excited states of propadienylidene H2C=C=C: obtained by negative ion photoelectron spectroscopy

A joint experimental-theoretical study has been carried out on electronic states of propadienylidene (H2CCC), using results from negative-ion photoelectron spectroscopy. In addition to the previously characterized X̃1A1 electronic state, spectroscopic features are observed that belong to five additional states: the low-lying ã3B1 and b̃3A2 states, as well as two excited singlets, Ã1A2 and B̃1B1, and a higher-lying triplet, c̃3A1. Term energies (T0, in cm−1) for the excited states obtained from the data are: 10 354±11 (ã3B1); 11 950±30 (b̃3A2); 20 943±11 (c̃3A1); and 13 677±11 (Ã1A2). Strong vibronic coupling affects the Ã1A2 and B̃1B1 states as well as ã3B1 and b̃3A2 and has profound effects on the spectrum. As a result, only a weak, broadened band is observed in the energy region where the origin of the B̃1B1 state is expected. The assignments here are supported by high-level coupled-cluster calculations and spectral simulations based on a vibronic coupling Hamiltonian. A result of astrophysical interest is that the present study supports the idea that a broad absorption band found at 5450 Å by cavity ringdown spectroscopy (and coincident with a diffuse interstellar band) is carried by the B̃1B1 state of H2CCC

Covalency in the 4f Shell of tris-Cyclopentadienyl Ytterbium (YbCp3)-A spectroscopic evaluation

Evidence is presented of significant covalency in the ytterbium 4f shell of tris-cyclopentadienyl ytterbium (YbCp(3)) in its electronic ground state, that can be represented by the superposition of an ionic configuration Yb(III):4f(13)(Cp(3)) and a charge-transfer configuration Yb(II):4f(14)(Cp(3))(-1). The relative weights of these configurations were determined from (i) the difference in their 4f photoionization cross sections, (ii) the accumulation of spin-density centered on the (13)C atoms of the Cp ring, as measured by a pulsed EPR (HYSCORE) experiment, (iii) the reduction in the spin-density in the 4f shell, manifest in the (171)Yb hyperfine interaction, and (iv) the principal values of the g-tensor, obtained from the EPR spectrum of a frozen glass solution at 5.4 K. Each of these methods finds that the spin density attributable to the charge transfer configuration is in the range 12-17%. The presence of configuration interaction (CI) also accounts for the highly anomalous energies, intensities, and vibronic structure in the "f-f" region of the optical spectrum, as well as the strict adherence of the magnetic susceptibility to the Curie law in the range 30-300 K