Laser Desorption Ionization Mass Spectrometry Imaging of Drosophila Brain Using Matrix Sublimation versus Modification with Nanoparticles.

Laser desorption ionization mass spectrometry (LDI-MS) is used to image brain lipids in the fruit fly, Drosophila, a common invertebrate model organism in biological and neurological studies. Three different sample preparation methods, including sublimation with two common organic matrixes for matrix-assisted laser desorption ionization (MALDI) and surface-assisted laser desorption ionization (SALDI) using gold nanoparticles, are examined for sample profiling and imaging the fly brain. Recrystallization with trifluoroacetic acid following matrix deposition in MALDI is shown to increase the incorporation of biomolecules with one matrix, resulting in more efficient ionization, but not for the other matrix.

The impact of diagnosis: measuring the psychological response to being diagnosed with serious or potentially lethal cardiac disease in young competitive athletes.

Aim: To determine the psychological impact of athletes diagnosed with cardiac disease.

Methods And Design: Athletes diagnosed with cardiovascular disorders were recruited to complete the Impact of Event Scale (IES), a validated tool measuring responses to a traumatic event. IES scoring =0-88 (<12= normal, 12-32=recommend monitoring, >33=significant stress reaction).

Neuronal Networks on Nanocellulose Scaffolds.

Proliferation, integration, and neurite extension of PC12 cells, a widely used culture model for cholinergic neurons, were studied in nanocellulose scaffolds biosynthesized by Gluconacetobacter xylinus to allow a three-dimensional (3D) extension of neurites better mimicking neuronal networks in tissue. The interaction with control scaffolds was compared with cationized nanocellulose (trimethyl ammonium betahydroxy propyl [TMAHP] cellulose) to investigate the impact of surface charges on the cell interaction mechanisms. Furthermore, coatings with extracellular matrix proteins (collagen, fibronectin, and laminin) were investigated to determine the importance of integrin-mediated cell attachment.

Electrochemical Measurements of Optogenetically Stimulated Quantal Amine Release from Single Nerve Cell Varicosities in Drosophila Larvae.

The nerve terminals found in the body wall of Drosophila melanogaster larvae are readily accessible to experimental manipulation. We used the light-activated ion channel, channelrhodopsin-2, which is expressed by genetic manipulation in Type II varicosities to study octopamine release in Drosophila. We report the development of a method to measure neurotransmitter release from exocytosis events at individual varicosities in the Drosophila larval system by amperometry.

Comparison of pharmaceutical formulations: ATR-FTIR spectroscopic imaging to study drug-carrier interactions.

Attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopic imaging has been used in combination with UV detection to study the release of a model poorly water-soluble drug, indomethacin, when formulated with selected drug carriers. Firstly, formulations of indomethacin and nicotinamide in varying weight ratios were studied since novel tablet dosage forms containing multi-drugs are of industrial interest. The in situ spectroscopic imaging measurements of the dissolving tablets showed that as the loading of indomethacin was increased, the rate of drug release changed from one that expressed first-order drug release to one which showed zero-order drug release.

Glyceollin Effects on MRP2 and BCRP in Caco-2 Cells, and Implications for Metabolic and Transport Interactions.

Glyceollins are phytoalexins produced in soybeans under stressful growth conditions. On the basis of prior evaluations, they show potential to treat multiple diseases, including certain cancers, Type 2 diabetes, and cardiovascular conditions. The aim of the present study was to expand on recent studies designed to initially characterize the intestinal disposition of glyceollins.

Quantitative measurement of transmitters in individual vesicles in the cytoplasm of single cells with nanotip electrodes.

The quantification of vesicular transmitter content is important for studying the mechanisms of neurotransmission and malfunction in disease, and yet it is incredibly difficult to measure the tiny amounts of neurotransmitters in the attoliter volume of a single vesicle, especially in the cell environment. We introduce a novel method, intracellular vesicle electrochemical cytometry. A nanotip conical carbon-fiber microelectrode was used to electrochemically measure the total content of electroactive neurotransmitters in individual nanoscale vesicles in single PC12 cells as these vesicles lysed on the electrode inside the living cell.

Widespread somatic L1 retrotransposition occurs early during gastrointestinal cancer evolution.

Somatic L1 retrotransposition events have been shown to occur in epithelial cancers. Here, we attempted to determine how early somatic L1 insertions occurred during the development of gastrointestinal (GI) cancers. Using L1-targeted resequencing (L1-seq), we studied different stages of four colorectal cancers arising from colonic polyps, seven pancreatic carcinomas, as well as seven gastric cancers.

Effect of Patient Navigation on Breast Cancer Screening Among African American Medicare Beneficiaries: A Randomized Controlled Trial.

Background: There is growing evidence that patient navigation improves breast cancer screening rates; however, there are limited efficacy studies of its effect among African American older adult women.

Objective: To evaluate the effect of patient navigation on screening mammography among African American female Medicare beneficiaries in Baltimore, MD.

Design: The Cancer Prevention and Treatment Demonstration (CPTD), a multi-site study, was a randomized controlled trial conducted from April 2006 through December 2010.

Predictors of Self-Reported Family Health History of Breast Cancer.

The objective of this study was to identify predictors of self-reported family health history of breast cancer in an ethnically diverse population of women participating in a breast cancer screening program. Participants completed a self-administered questionnaire about their demography, health, breast health and family health history of breast cancer. The association between family health history of breast cancer and categorical variables were analyzed using the T test, chi square, and multi-nominal logistic regression.

Combining tumor genome simulation with crowdsourcing to benchmark somatic single-nucleotide-variant detection.

The detection of somatic mutations from cancer genome sequences is key to understanding the genetic basis of disease progression, patient survival and response to therapy. Benchmarking is needed for tool assessment and improvement but is complicated by a lack of gold standards, by extensive resource requirements and by difficulties in sharing personal genomic information. To resolve these issues, we launched the ICGC-TCGA DREAM Somatic Mutation Calling Challenge, a crowdsourced benchmark of somatic mutation detection algorithms.

Analytical Performance of a 15-Gene Prognostic Assay for Early-Stage Non-Small-Cell Lung Carcinoma Using RNA-Stabilized Tissue.

A 15-gene prognostic signature for early-stage, completely resected, non-small-cell lung carcinoma, (which distinguishes between patients with good and poor prognoses) was clinically validated in prior studies. To achieve operational efficiencies, this study was designed to evaluate the assay's performance in RNA-stabilized tissue as an alternative to the fresh-frozen tissue format originally used to develop the assay. The percent concordance between matched tissue formats was 84% (95% Wilson CI, 70%-92%), a level of agreement comparable to the inherent reproducibility of the assay observed within biological replicates of fresh-frozen tissue.

16S and 23S plastid rDNA phylogenies of Prototheca species and their auxanographic phenotypes.

Because algae have become more accepted as sources of human nutrition, phylogenetic analysis can help resolve the taxonomy of taxa that have not been well studied. This can help establish algal evolutionary relationships. Here, we compare Auxenochlorella protothecoides and 23 strains of Prototheca based on their complete 16S and partial 23S plastid rDNA sequences along with nutrient utilization (auxanographic) profiles.

ToF-SIMS imaging of lipids and lipid related compounds in Drosophila brain.

(fruit fly) has a relatively simple nervous system but possesses high order brain functions similar to humans. Therefore, it has been used as a common model system in biological studies, particularly drug addiction. Here, the spatial distribution of biomolecules in the brain of the fly was studied using time-of flight secondary ion mass spectrometry (ToF-SIMS).

Analysis of liposome model systems by time-of-flight secondary ion mass spectrometry.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is an important technique for studying chemical composition of micrometer scale objects due to its high spatial resolution imaging capabilities and chemical specificity. In this work we focus on the application of ToF-SIMS to gain insight into the chemistry of micrometer size liposomes as a potential model for neurotransmitter vesicles. Two models of giant liposomes were analyzed: histamine and aqueous two phase system (ATPS)-containing liposomes.

Evaluating drug delivery with salt formation: Drug disproportionation studied in situ by ATR-FTIR imaging and Raman mapping.

Two different vibrational spectroscopic approaches, ATR-FTIR spectroscopic imaging and Raman mapping, were used to investigate the components within a tablet containing an ionised drug during dissolution experiments. Delivering certain drugs in their salt form is a method that can be used to improve the bioavailability and dissolution of the poorly aqueous soluble materials. However, these ionised species have a propensity to covert back to their thermodynamically favourable free acid or base forms.

Ubiquitous L1 mosaicism in hippocampal neurons.

Somatic LINE-1 (L1) retrotransposition during neurogenesis is a potential source of genotypic variation among neurons. As a neurogenic niche, the hippocampus supports pronounced L1 activity. However, the basal parameters and biological impact of L1-driven mosaicism remain unclear.

Lipid structural effects of oral administration of methylphenidate in Drosophila brain by secondary ion mass spectrometry imaging.

We use time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging to investigate the effects of orally administrated methylphenidate on lipids in the brain of Drosophila melanogaster (fruit fly), a major invertebrate model system in biological study and neuroscience. TOF-SIMS imaging was carried out using a recently designed high energy 40 keV Ar4000(+) gas cluster ion gun which demonstrated improved sensitivity for intact lipids in the fly brain compared to the 40 keV C60(+) primary ion gun. In addition, correlation of TOF-SIMS and SEM imaging on the same fly brain showed that there is specific localization that is related to biological functions of various biomolecules.

Demographic differences in willingness to provide broad and narrow consent for biobank research.

Purpose: This study examined acceptability of two biobank consent models and evaluated the impact of beliefs about privacy and genetic safeguards on acceptance.

Methods: U.S.

Characterizing the catecholamine content of single mammalian vesicles by collision-adsorption events at an electrode.

We present the electrochemical response to single adrenal chromaffin vesicles filled with catecholamine hormones as they are adsorbed and rupture on a 33 μm diameter disk-shaped carbon electrode. The vesicles adsorb onto the electrode surface and sequentially spread out over the electrode surface, trapping their contents against the electrode. These contents are then oxidized, and a current (or amperometric) peak results from each vesicle that bursts.

Identifying the mechanisms of drug release from amorphous solid dispersions using MRI and ATR-FTIR spectroscopic imaging.

The dissolution mechanism of a poorly aqueous soluble drug from amorphous solid dispersions was investigated using a combination of two imaging methods: attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic imaging and magnetic resonance imaging (MRI). The rates of elementary processes such as water penetration, polymer swelling, growth and erosion of gel layer, and the diffusion, release and in some cases precipitation of drug were evaluated by image analysis. The results from the imaging methods were compared with drug release profiles obtained by classical dissolution tests.

Selected recent in vivo studies on chemical measurements in invertebrates.

In vivo measurements of neurotransmitters and related compounds have provided a better understanding of the chemical interactions that are a major part in functioning of brains. In addition, a great deal of technology has been developed to measure chemical species in other areas of living organisms. A key part of this work has been sampling technologies as well as direct measurements in vivo.

Spatial neuroproteomics using imaging mass spectrometry.

The nervous system constitutes arguably the most complicated and least understood cellular network in the human body. This consequently manifests itself in the fact that the molecular bases of neurodegenerative diseases remain unknown. The limited understanding of neurobiological mechanisms relates directly to the lack of appropriate bioanalytical technologies that allow highly resolved, sensitive, specific and comprehensive molecular imaging in complex biological matrices.