NIH electronic cigarette workshop: developing a research agenda.

Background: Electronic cigarettes (e-cigarettes) represent an emerging public health issue. These devices deliver nicotine along with other constituents, including flavorants, via an inhalable aerosol. Their uptake is rapidly increasing in both adults and youths, primarily among current smokers.

2011 investigation of internal contamination with radioactive strontium following rubidium Rb 82 cardiac PET scan.

During routine screening in 2011, US Customs and Border Protection (CBP) identified 2 persons with elevated radioactivity. CBP, in collaboration with Los Alamos National Laboratory, informed the Food and Drug Administration (FDA) that these people could have increased radiation exposure as a result of undergoing cardiac Positron Emission Tomography (PET) scans several months earlier with rubidium Rb 82 chloride injection from CardioGen-82. We conducted a multistate investigation to assess the potential extent and magnitude of radioactive strontium overexposure among patients who had undergone Rb 82 PET scans.

A population model of chaparral vegetation response to frequent wildfires.

The recent increase in wildfire frequency in the Santa Monica Mountains (SMM) may substantially impact plant community structure. Species of Chaparral shrubs represent the dominant vegetation type in the SMM. These species can be divided into three life history types according to their response to wildfires.

Operant self-stimulation of dopamine neurons in the substantia nigra.

We examined the contribution of the nigrostriatal DA system to instrumental learning and behavior using optogenetics in awake, behaving mice. Using Cre-inducible channelrhodopsin-2 (ChR2) in mice expressing Cre recombinase driven by the tyrosine hydroxylase promoter (Th-Cre), we tested whether selective stimulation of DA neurons in the substantia nigra pars compacta (SNC), in the absence of any natural rewards, was sufficient to promote instrumental learning in naive mice. Mice expressing ChR2 in SNC DA neurons readily learned to press a lever to receive laser stimulation, but unlike natural food rewards the lever pressing did not decline with satiation.

Efficacy considerations for U.S. Food and Drug Administration approval of diagnostic radiopharmaceuticals.

The safety and efficacy expectations for U.S. Food and Drug Administration (FDA) approval of diagnostic radiopharmaceuticals (DRs) are described in laws that broadly apply to all prescription drugs and biologic products.

Nephrogenic systemic fibrosis and class labeling of gadolinium-based contrast agents by the Food and Drug Administration.

In 2007, the Food and Drug Administration requested that manufacturers of all approved gadolinium-based contrast agents (GBCAs), drugs widely used in magnetic resonance imaging, use nearly identical text in their product labeling to describe the risk of nephrogenic systemic fibrosis (NSF). Accumulating information about NSF risks led to revision of the labeling text for all of these drugs in 2010. The present report summarizes the basis and purpose of this class-labeling approach and describes some of the related challenges, given the evolutionary nature of the NSF risk evidence.

A fast, effective filtering method for improving clinical pulsed arterial spin labeling MRI.

Purpose: To evaluate the effectiveness of a fully automated postprocessing filter algorithm in pulsed arterial spin labeling (PASL) MRI perfusion images in a large clinical population.

Materials And Methods: A mean and standard deviation-based filter was implemented to remove outliers in the set of perfusion-weighted images (control - label) before being averaged and scaled to quantitative cerebral blood flow (CBF) maps. Filtered and unfiltered CBF maps from 200 randomly selected clinical cases were assessed by four blinded raters to evaluate the effectiveness of the filter.

The effect of daily caffeine use on cerebral blood flow: How much caffeine can we tolerate?

Caffeine is a commonly used neurostimulant that also produces cerebral vasoconstriction by antagonizing adenosine receptors. Chronic caffeine use results in an adaptation of the vascular adenosine receptor system presumably to compensate for the vasoconstrictive effects of caffeine. We investigated the effects of caffeine on cerebral blood flow (CBF) in increasing levels of chronic caffeine use.

Methodological considerations for the quantification of self-reported caffeine use.

Rationale: The field of research regarding the effects of habitual caffeine use is immense and frequently utilizes self-report measures of caffeine use. However, various self-report measures have different methodologies, and the accuracy of these different methods has not been compared.

Materials And Methods: Self-reported caffeine use was estimated from two methods (a retrospective interview of weekly caffeine use and a 7-day prospective diary; n = 79).

The impact of temporal regularization on estimates of the BOLD hemodynamic response function: a comparative analysis.

In fMRI data analysis it has been shown that for a wide range of situations the hemodynamic response function (HRF) can be reasonably characterized as the impulse response function of a linear and time invariant system. An accurate and robust extraction of the HRF is essential to infer quantitative information about the relative timing of the neuronal events in different brain regions. When no assumptions are made about the HRF shape, it is most commonly estimated using time windowed averaging or a least squares estimated general linear model based on either Fourier or delta basis functions.

Hemosuccus Pancreaticus as a Rare Complication of Bariatric Surgery.

Hemosuccus pancreaticus is a rare cause of gastrointestinal bleeding from the duct of Wirsung into the duodenum via the ampulla of Vater. Hemosuccus pancreaticus is difficult to diagnose because the bleeding is usually intermittent, and the clinical findings are often discordant. Patients present with pain, either left upper quadrant or epigastric, and bleeding, which may present as melena, bright red blood per rectum, or even shock, if the hemorrhage is severe.

The roles of two C. elegans HOX co-factor orthologs in cell migration and vulva development.

Anteroposterior cell migration and patterning in C. elegans are governed by multiple, interacting signaling pathways and transcription factors. In this study, we have investigated the role of ceh-20, the C.