Increases in heroin overdose deaths - 28 States, 2010 to 2012.

Nationally, death rates from prescription opioid pain reliever (OPR) overdoses quadrupled during 1999-2010, whereas rates from heroin overdoses increased by <50%. Individual states and cities have reported substantial increases in deaths from heroin overdose since 2010. CDC analyzed recent mortality data from 28 states to determine the scope of the heroin overdose death increase and to determine whether increases were associated with changes in OPR overdose death rates since 2010. This report summarizes the results of that analysis, which found that, from 2010 to 2012, the death rate from heroin overdose for the 28 states increased from 1.0 to 2.1 per 100,000, whereas the death rate from OPR overdose declined from 6.0 per 100,000 in 2010 to 5.6 per 100,000 in 2012. Heroin overdose death rates increased significantly for both sexes, all age groups, all census regions, and all racial/ethnic groups other than American Indians/Alaska Natives. OPR overdose mortality declined significantly among males, persons aged <45 years, persons in the South, and non-Hispanic whites. Five states had increases in the OPR death rate, seven states had decreases, and 16 states had no change. Of the 18 states with statistically reliable heroin overdose death rates (i.e., rates based on at least 20 deaths), 15 states reported increases. Decreases in OPR death rates were not associated with increases in heroin death rates. The findings indicate a need for intensified prevention efforts aimed at reducing overdose deaths from all types of opioids while recognizing the demographic differences between the heroin and OPR-using populations. Efforts to prevent expansion of the number of OPR users who might use heroin when it is available should continue.

Exploring the nicotinic acetylcholine receptor-associated proteome with iTRAQ and transgenic mice.

Neuronal nicotinic acetylcholine receptors (nAChRs) containing α4 and ß2 subunits are the principal receptors in the mammalian central nervous system that bind nicotine with high affinity. These nAChRs are involved in nicotine dependence, mood disorders, neurodegeneration and neuroprotection. However, our understanding of the interactions between α4ß2-containing (α4ß2(∗)) nAChRs and other proteins remains limited. In this study, we identified proteins that interact with α4ß2(∗) nAChRs in a genedose dependent pattern by immunopurifying ß2(∗) nAChRs from mice that differ in α4 and ß2 subunit expression and performing proteomic analysis using isobaric tags for relative and absolute quantitation (iTRAQ). Reduced expression of either the α4 or the ß2 subunit results in a correlated decline in the expression of a number of putative interacting proteins. We identified 208 proteins co-immunoprecipitated with these nAChRs. Furthermore, stratified linear regression analysis indicated that levels of 17 proteins was correlated significantly with expression of α4ß2 nAChRs, including proteins involved in cytoskeletal rearrangement and calcium signaling. These findings represent the first application of quantitative proteomics to produce a ß2(∗) nAChR interactome and describe a novel technique used to discover potential targets for pharmacological manipulation of α4ß2 nAChRs and their downstream signaling mechanisms.

Identification of kalirin-7 as a potential post-synaptic density signaling hub.

Kalirin-7 (Kal7), a multifunctional Rho GDP/GTP exchange factor (GEF) for Rac1 and RhoG, is embedded in the postsynaptic density at excitatory synapses, where it participates in the formation and maintenance of dendritic spines. Kal7 has been implicated in long-term potentiation, fear memories, and addiction-like behaviors. Using liquid chromatography and tandem mass spectroscopy, we identified sites phosphorylated by six PSD-localized kinases implicated in synaptic plasticity and behavior, sites phosphorylated when myc-Kal7 was expressed in non-neuronal cells and sites phosphorylated in mouse brain Kal7. A site in the Sec14p domain phosphorylated by calcium/calmodulin dependent protein kinase II, protein kinase A and protein kinase C, was phosphorylated in mouse brain but not in non-neuronal cells. Phosphorylation in the spectrin-like repeat region was more extensive in mouse brain than in non-neuronal cells, with a total of 20 sites identified. Sites in the pleckstrin homology domain and in the linker region connecting the GEF domain to the PDZ binding motif were heavily phosphorylated in both non-neuronal cells and in mouse brain and affected GEF activity. We postulate that the kinase convergence and divergence observed in Kal7 identify it as a key player in integration of the multiple inputs that regulate synaptic structure and function.

MALDI-MS data analysis for disease biomarker discovery.

In this chapter, we address the issue of matrix-assisted laser desorption/ionization mass spectrometry (MS) data analysis for disease biomarker discovery. We first give a general framework of MS data analysis, then focus on several key steps. After that, we show some application examples using an ovarian sera cancer dataset. Finally, we discuss the limitations of current approaches and possible future research directions.

Detecting and aligning peaks in mass spectrometry data with applications to MALDI.

In this paper, we address the peak detection and alignment problem in the analysis of mass spectrometry data. To deal with the peak redundancy problem existing in the MALDI data acquired in the reflectron mode, we propose to use the amplitude modulation technique in peak detection. The alignment of two peak sets is formulated as a non-rigid registration problem and is solved using a robust point matching (RPM) approach. To align multiple peak sets, we first use a super set method to find a common peak set among all peak sets as a standard and then align all peak sets to the standard using the robust point matching approach in a sequential manner (i.e. We align only one peak set to the standard each time, thus reducing the multiple peak set alignment problem to a simpler two peak set alignment problem). Experimental results from a study of ovarian cancer data set show that the quantitative cross-correlation coefficients among technical replicates are increased after peak alignment. Additional comparisons also demonstrate that our method has a similar performance as the hierarchical clustering method, although the implementations of these methods are different.

Proteomics in mixtures: Study results of ABRF-PRG02.

The trend in proteomics is to work with increasingly complex protein mixtures, limiting the protein separation steps prior to analysis. This is due in part to the difficulties encountered with detecting low abundance proteins, protein losses during SDS PAGE, and the limited separation capability of even 2D PAGE where a single protein spot may still contain multiple proteins. Hence, the ABRF-PRG02 sample was designed to study a simple protein mixture of five proteins at the approximately 2 pmol and approximately 200 fmol levels. The sample, after a tryptic digestion, was sent out by the Proteomics Research Group of the ABRF to interested member labs. A total of 41 labs participated in this study, with each participant using some type of mass spectrometric analysis. Laboratories that used microLC-NSI (microLC with nanospray ionization) with MS/MS analysis had a higher percent accuracy than labs using MALDI-MS (matrix assisted laser desorption ionization mass spectrometry).