Uncertainties in effective dose estimates of adult CT head scans: the effect of head size.

Purpose: This study is an extension of a previous study where the uncertainties in effective dose estimates from adult CT head scans were calculated using four CT effective dose estimation methods, three of which were computer programs (CT-EXPO, CTDOSIMETRY, and IMPACTDOSE) and one that involved the dose length product (DLP). However, that study did not include the uncertainty contribution due to variations in head sizes.

Methods: The uncertainties due to head size variations were estimated by first using the computer program data to calculate doses to small and large heads.

Emerging infectious disease agents and their potential threat to transfusion safety.

Background: Emerging infections have been identified as a continuing threat to human health. Many such infections are known to be transmissible by blood transfusion, while others have properties indicating this potential. There has been no comprehensive review of such infectious agents and their threat to transfusion recipient safety to date.

Global measures of quality- and patient safety-related childbirth outcomes: should we monitor adverse or ideal rates?

Objective: The objective of the study was to propose a new measure of ideal childbirth outcome, based on the proportion of women delivering without maternal or newborn childbirth morbidity.

Study Design: Using the 2002 California discharge dataset, we calculated rates of childbirth complications among women with singleton, term deliveries, stratified by pregnancy risk status, method of delivery, and parity. An ideal delivery (ID) was defined as a delivery without any complications.

Reduction of sample evaporation in small volume microplate luminescence assays.

Luminescence detection has great potential for use in small volume assays for high-throughput applications. However, the need for automated injection of detection reagents dictates an open well format, making small volume luminescence assays very susceptible to sample evaporation effects. Here we describe a technique for reducing evaporation of small sample volumes that uses layering of silicone oil on solution surfaces but still allows the use of automated injection.

Efficiency and specificity of microRNA-primed nucleotide analog incorporation by various DNA polymerases.

MicroRNAs (miRNAs) as endogenous regulators of gene expression have spurred a surge of interest for their quantification and expression analysis. High-sensitivity and high-specificity miRNA detection techniques, such as real-time polymerase chain reaction and recently introduced bioluminescent miRNA detection, require systematic study of DNA polymerases for use with miRNAs. In this study, a variety of DNA polymerases were studied to assess their capabilities of using miRNA as a primer and incorporating 2'-deoxyadenosine-5'-O-(1-thiotriphosphate) as a dATP alternative during DNA strand extension.

Adaptive memory: fitness relevance and the hunter-gatherer mind.

Recent studies suggest that human memory systems are "tuned" to remember information that is processed in terms of its fitness value. When people are asked to rate the relevance of words to a survival scenario, performance on subsequent surprise memory tests exceeds that obtained after most other known encoding techniques. The present experiments explored this effect using survival scenarios designed to mimic the division of labor thought to characterize early hunter-gatherer societies.

Measurement of trace explosive residues in a surrogate operational environment: implications for tactical use of chemical sensing in C-IED operations.

A campaign to measure the amount of trace explosive residues in an operational military environment was conducted on May 27-31, 2007, at the National Training Center at Fort Irwin, CA, USA. The objectives of this campaign were to develop the methods needed to collect and analyze samples from tactical military settings, to use the data obtained to determine what the trace explosive signatures suggest about the potential capabilities of chemical-based means to detect IEDs, and, finally, to present a framework whereby a sound understanding of the signature science can be used to guide development of new sensing technologies and sensor concepts of operation. Through our use of combined background and threat signature data, we have performed statistical analyses to estimate upper limits of notional sensor performance that is limited only by the spatial correlation of the signature chemicals to the threats of interest.

Prolonged second stage of labor and postpartum hemorrhage.

Objective: To examine the relationship between prolonged second stage and postpartum hemorrhage (PPH).

Methods: We conducted a retrospective case-control study of all cases of PPH which occurred at four Southern California hospitals in 2003. Cases were identified by ICD-9 codes and confirmed by chart reviews, and non-cases were randomly selected as controls.

Novel web-based tools combining chemistry informatics, biology and social networks for drug discovery.

A convergence of different commercial and publicly accessible chemical informatics, databases and social networking tools is positioned to change the way that research collaborations are initiated, maintained and expanded, particularly in the realm of neglected diseases. A community-based platform that combines traditional drug discovery informatics with Web2.0 features in secure groups is believed to be the key to facilitating richer, instantaneous collaborations involving sensitive drug discovery data and intellectual property.

Identifying women most likely to benefit from prevention strategies for postpartum hemorrhage.

Objective: To identify women who are most likely to benefit from primary prevention strategies for postpartum hemorrhage (PPH).

Study Design: In a retrospective patient cohort, we applied recursive partitioning algorithms to identify the most discriminant risk factors and their interactions, and calculated the 'number needed to treat' to prevent a single case of PPH (estimated blood loss >1000 ml).

Result: By delivery category, the highest risk groups with 'number needed to treat' ranging from 4 to 7 were: (1) vaginal delivery (PPH=0.

Management of familial hypertriglyceridemia during pregnancy with plasma exchange.

Hypertriglyceridemia-induced pancreatitis is a serious complication of familial dyslipidemias. Hormonal influences during pregnancy can compromise otherwise controlled lipid levels in women with familial hypertriglyceridemia and predispose to pancreatitis leading to increased morbidity in both mother and fetus. We report the successful use of therapeutic plasma exchange (TPE) in the management of hypertriglyceridemia during pregnancy resulting in avoidance of pancreatitis and delivery of a healthy term infant.

The Health Assessment Questionnaire Disability Index is a valid measure of physical function in gout.

Objective: There are no disability instruments that have specifically been validated for gout. The aim of this study was to determine the construct validity of the Health Assessment Questionnaire Disability Index (HAQ-DI) in gout and the internal validity using Rasch analysis.

Methods: An observational cohort study of two groups of clinic patients with gout (n=20, n=53), in which clinical and functional measures were correlated with HAQ-DI scores.

On the uncertainties in effective dose estimates of adult CT head scans.

Estimates of the effective dose to adult patients from computed tomography (CT) head scanning can be calculated using a number of different methods. These estimates can be used for a variety of purposes, such as improving scanning protocols, comparing different CT imaging centers, and weighing the benefits of the scan against the risk of radiation-induced cancer. The question arises: What is the uncertainty in these effective dose estimates? This study calculates the uncertainty of effective dose estimates produced by three computer programs (CT-EXPO, CTDosimetry, and ImpactDose) and one method that makes use of dose-length product (DLP) values.

A novel mechanism of G protein-coupled receptor functional selectivity. Muscarinic partial agonist McN-A-343 as a bitopic orthosteric/allosteric ligand.

Many G protein-coupled receptors (GPCRs) possess allosteric binding sites distinct from the orthosteric site utilized by their cognate ligands, but most GPCR allosteric modulators reported to date lack signaling efficacy in their own right. McN-A-343 (4-(N-(3-chlorophenyl)carbamoyloxy)-2-butynyltrimethylammonium chloride) is a functionally selective muscarinic acetylcholine receptor (mAChR) partial agonist that can also interact allosterically at the M(2) mAChR. We hypothesized that this molecule simultaneously utilizes both an allosteric and the orthosteric site on the M(2) mAChR to mediate these effects.

Mechanisms of bone erosion in gout: a quantitative analysis using plain radiography and computed tomography.

Objective: The underlying basis of bone erosion in gout remains speculative. The aim of this study was to understand the mechanisms of bone erosion in gout using non-invasive imaging techniques.

Methods: Paired plain radiographs and computed tomography (CT) scans of 798 individual hand and wrist joints from 20 patients with gout were analysed.

Clinical predictors of necrotizing enterocolitis in premature infants.

Background: Necrotizing enterocolitis (NEC) has emerged as the most common neonatal gastrointestinal emergency, is the most common cause of death in neonates undergoing surgery, and accounts for yearly additional hospital charges in excess of $6.5 million. Prematurity is the only common variable identified in case-controlled studies exploring this disease.

Health care costs associated with changing clinics and "walk-in" deliveries: evidence supporting a regionalized health information network.

Objective: The objective of the study was to describe the prevalence of changing clinics and "walk-in" deliveries and estimate associated health care costs.

Study Design: This was a retrospective review at an urban teaching hospital over a 6 month period. Principal outcome measures were availability of laboratory data at delivery and the number, type, and costs of duplicated tests for patients receiving various amounts of prenatal care (PNC) at our site.

Vaginal birth after cesarean: clinical risk factors associated with adverse outcome.

Objective: The objective of the study was to identify vaginal birth after cesarean (VBAC) success rates and maternal and neonatal complication rates for selected antenatal conditions.

Study Design: This was a population-based cohort study using administrative discharge data for women delivering in California hospitals during 2002.

Results: Among 41,450 women, 29.

USPSTF recommendations for STI screening.

Since 2000, the U.S. Preventive Services Task Force (USPSTF) has issued eight clinical recommendation statements on screening for sexually transmitted infections.

Perceptions of wood in rivers and challenges for stream restoration in the United States.

This article reports a study of the public perception of large wood in rivers and streams in the United States. Large wood is an element of freshwater aquatic ecosystems that has attracted much scientific interest in recent years because of its value in biological and geomorphological processes. At the heart of the issue is the nature of the relationship between scientific recognition of the ecological and geomorphological benefits of wood in rivers, management practices utilizing wood for river remediation progress, and public perceptions of in-channel wood.

Sucrose octasulfate regulates fibroblast growth factor-2 binding, transport, and activity: potential for regulation of tumor growth.

The antithrombotic activity of heparin has largely been credited with the success found in some cancer treatment by heparin. There are, however, many potent growth factors involved in tumor and blood vessel growth that bind to heparin with high affinity and their regulation by heparin may play a role in heparin's efficacy. We therefore chose to study the activity of a heparin analog, sucrose octasulfate (SOS), which has been similarly shown to interact with heparin-binding growth factors.

Growth with high planktonic biomass in Shewanella oneidensis fuel cells.

Shewanella oneidensis MR-1 grew for over 50 days in microbial fuel cells, incompletely oxidizing lactate to acetate with high recovery of the electrons derived from this reaction as electricity. Electricity was produced with lactate or hydrogen and current was comparable to that of electricigens which completely oxidize organic substrates. However, unlike fuel cells with previously described electricigens, in which cells are primarily attached to the anode, at least as many of the S.

Tophaceous joint disease strongly predicts hand function in patients with gout.

Objectives: The functional impact of gout is poorly understood. The aim of this study was to determine predictors of hand function in gout.

Methods: Twenty unselected patients with gout were recruited from rheumatology clinics.

Allosteric modulation of muscarinic acetylcholine receptors.

Muscarinic acetylcholine receptors (mAChRs) are prototypical Family A G protein coupled-receptors. The five mAChR subtypes are widespread throughout the periphery and the central nervous system and, accordingly, are widely involved in a variety of both physiological and pathophysiological processes. There currently remains an unmet need for better therapeutic agents that can selectively target a given mAChR subtype to the relative exclusion of others.