The dose window for radiation-induced protective adaptive responses.

Adaptive responses to low doses of low LET radiation occur in all organisms thus far examined, from single cell lower eukaryotes to mammals. These responses reduce the deleterious consequences of DNA damaging events, including radiation-induced or spontaneous cancer and non-cancer diseases in mice. The adaptive response in mammalian cells and mammals operates within a certain window that can be defined by upper and lower dose thresholds, typically between about 1 and 100 mGy for a single low dose rate exposure.

Carotid atherosclerosis progression in familial hypercholesterolemia patients: a pooled analysis of the ASAP, ENHANCE, RADIANCE 1, and CAPTIVATE studies.

Background: Until recently, patients with heterozygous familial hypercholesterolemia (HeFH) were considered the best subjects for the assessment of changes in carotid intima-media thickness (cIMT) in randomized intervention trials. Our aims were to investigate whether contemporary statin-treated HeFH patients still show accelerated cIMT increase and to assess the impact of statin treatment, before and after random assignment, on atherosclerosis progression.

Methods And Results: We retrospectively evaluated cIMT change, and prior statin treatment and postbaseline LDL-C change as predictors of cIMT change, in 1513 HeFH patients who were randomly assigned to the statin arms of the early ASAP and more recent RADIANCE 1, CAPTIVATE, and ENHANCE studies.

Neurite outgrowth at the biomimetic interface.

Understanding the cues that guide axons and how we can optimize these cues to achieve directed neuronal growth is imperative for neural tissue engineering. Cells in the local environment influence neurons with a rich combination of cues. This study deconstructs the complex mixture of guidance cues by working at the biomimetic interface--isolating the topographical information presented by cells and determining its capacity to guide neurons.

Topography, cell response, and nerve regeneration.

In the body, cells encounter a complex milieu of signals, including topographical cues, in the form of the physical features of their surrounding environment. Imposed topography can affect cells on surfaces by promoting adhesion, spreading, alignment, morphological changes, and changes in gene expression. Neural response to topography is complex, and it depends on the dimensions and shapes of physical features.

Molecular structures of crossover and noncrossover intermediates during gap repair in yeast: implications for recombination.

The molecular structures of crossover (CO) and noncrossover (NCO) intermediates were determined by sequencing the products formed when a gapped plasmid was repaired using a diverged chromosomal template. Analyses were done in the absence of mismatch repair (MMR) to allow efficient detection of strand-transfer intermediates, and the results reveal striking differences in the extents and locations of heteroduplex DNA (hDNA) in NCO versus CO products. These data indicate that most NCOs are produced by synthesis-dependent strand annealing rather than by a canonical double-strand break repair pathway and that resolution of Holliday junctions formed as part of the latter pathway is highly constrained to generate CO products.

Sickle cell trait, hemoglobin C trait, and invasive pneumococcal disease.

Background: The cause of historically higher rates of invasive pneumococcal disease among blacks than whites has remained unknown. We tested the hypothesis that sickle cell trait or hemoglobin C trait is an independent risk factor for invasive pneumococcal disease.

Method: Eligible children were born in Tennessee (1996-2003), had a newborn screen, enrolled in TennCare aged <1 year, and resided in a Tennessee county with laboratory-confirmed, pneumococcal surveillance.

Adherence to disease-modifying antirheumatic drugs and the effects of exposure misclassification on the risk of hospital admission.

Objective: To describe the effect of different exposure classification strategies for disease-modifying antirheumatic drugs (DMARDs) on drug-outcome associations.

Methods: We studied the association between DMARD initiation and all-cause hospitalizations in patients with rheumatoid arthritis (RA), 1995-2005. Initiators of DMARDs and oral glucocorticoids were followed for < or =180 days.

Cancer and non-cancer risks in normal and cancer-prone Trp53 heterozygous mice exposed to high-dose radiation.

This report tests the hypotheses that cancer proneness elevates risk from a high radiation exposure and that the risk response to high doses is qualitatively similar to that from low doses. Groups of about 170 female mice heterozygous for Trp53 (Trp53(+/-)) and their normal female littermates (Trp53(+/+)) were exposed at 7-8 weeks of age to (60)Co gamma-radiation doses of 0, 1, 2, 3 or 4 Gy at a high dose rate (0.5 Gy/min) or 4 Gy at a low dose rate (0.

Initiation of rheumatoid arthritis treatments and the risk of serious infections.

Objective: In clinical trials of RA patients on traditional DMARDs, the addition of TNF-alpha antagonists increased infections compared with addition of placebo. Our objective was to compare serious infections following initiation of different RA regimens. Prior comparative studies of DMARD initiation have yielded conflicting results.

Design of the DEFINE trial: determining the EFficacy and tolerability of CETP INhibition with AnacEtrapib.

Background: Residual cardiovascular (CV) risk often remains high despite statin therapy to lower low-density lipoprotein cholesterol (LDL-C). New therapies to raise high-density lipoprotein cholesterol (HDL-C) are currently being investigated. Anacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor that raises HDL-C and reduces LDL-C when administered alone or with a statin.

An algorithm to identify incident myocardial infarction using Medicaid data.

Purpose: Studies of non-steroidal anti-inflammatory drugs (NSAIDs) and cardiovascular events using administrative data require identification of incident acute myocardial infarctions (AMIs) and information on whether confounders differ by NSAID status.

Methods: We identified patients with a first AMI hospitalization from Tennessee Medicaid files as those with primary ICD-9 discharge diagnosis 410.x and hospitalization stay of > 2 calendar days.

Effects of sources of variability on sample sizes required for RCTs, applied to trials of lipid-altering therapies on carotid artery intima-media thickness.

Objective: Studies measuring progression of carotid artery intima-media thickness (cIMT) have been used to estimate the effect of lipid-modifying therapies cardiovascular event risk. The likelihood that future cIMT clinical trials will detect a true treatment effect is estimated by leveraging results from prior studies. The present analyses assess the impact of between- and within-study variability based on currently published data from prior clinical studies on the likelihood that ongoing or future cIMT trials will detect the true treatment effect of lipid-modifying therapies.

Non-aspirin NSAIDs, cyclooxygenase-2 inhibitors and risk for cardiovascular events-stroke, acute myocardial infarction, and death from coronary heart disease.

Purpose: To determine if certain non-steroidal anti-inflammatory drugs (NSAIDs) are associated with increased risk of cardiovascular events: acute myocardial infarction (AMI), stroke, and death from coronary heart disease (CHD).

Methods: We conducted a retrospective cohort study of Tennessee Medicaid enrollees aged 35-94 years between 1 January 1999 and 31 December 2005. Eligible persons were non-institutionalized, had continuous enrollment, and had no serious illness prior to cohort entry.

Flushing profile of extended-release niacin/laropiprant versus gradually titrated niacin extended-release in patients with dyslipidemia with and without ischemic cardiovascular disease.

Niacin has beneficial effects on a patient's lipid and lipoprotein profiles and cardiovascular risk, particularly at doses >2 g/day, but is underused due to flushing. Laropiprant (LRPT), a selective prostaglandin D(2) receptor-1 antagonist, decreases flushing associated with extended-release niacin (ERN). We compared flushing with ERN/LRPT dosed by a simplified 1-g --> 2-g regimen versus gradually titrated niacin extended-release (N-ER; given as NIASPAN, trademark of Kos Life Sciences LLC).

Increased skin carcinogenesis in caspase-activated DNase knockout mice.

Caspase-activated DNase (CAD), also called DNA fragmentation factor (DFF), is the enzyme responsible for DNA fragmentation during apoptosis, a hallmark of programmed cell death. CAD/DFF has been shown to suppress radiation-induced carcinogenesis by preventing genomic instability in cells. In this study, we have investigated the role of CAD in chemical carcinogenesis using CAD-null mice and two-stage model of skin carcinogenesis.

Fluoroquinolone resistance in Mycobacterium tuberculosis: the effect of duration and timing of fluoroquinolone exposure.

Rationale: Fluoroquinolones are the most commonly prescribed antibiotic class in the United States. They have the potential to become first-line antituberculosis therapy, but the effect of fluoroquinolone use on fluoroquinolone resistance in Mycobacterium tuberculosis is not well characterized.

Objectives: To determine the prevalence of and risk factors for fluoroquinolone-resistant tuberculosis in a large United States population.

The severity-dependent relationship of infant bronchiolitis on the risk and morbidity of early childhood asthma.

Background: Infants hospitalized for bronchiolitis have a high rate of early childhood asthma. It is not known whether bronchiolitis severity correlates with the risk of early childhood asthma or with asthma-specific morbidity.

Objectives: We sought to determine whether a dose-response relationship exists between severity of infant bronchiolitis and both the odds of early childhood asthma and asthma-specific morbidity.

Trajectories emerging from discrete versus continuous processing models in phonological competitor tasks: a commentary on Spivey, Grosjean, and Knoblich (2005).

M. J. Spivey, M.

Blood pressure-lowering effects of extended-release niacin alone and extended-release niacin/laropiprant combination: a post hoc analysis of a 24-week, placebo-controlled trial in dyslipidemic patients.

Background: Dyslipidemia and high blood pressure are both major cardiovascular disease risk factors. Niacin is an effective lipid-altering agent that has been reported to reduce the risk of cardiovascular disease. However, the more widespread use of niacin is limited, mainly due to the occurrence of flushing.

Efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy and coadministered with atorvastatin in dyslipidemic patients.

Background: High-density lipoprotein cholesterol (HDL-C) levels are inversely associated with cardiovascular risk. Cholesteryl ester transfer protein inhibition is one strategy for increasing HDL-C. This study evaluated the lipid-altering efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy or coadministered with atorvastatin in patients with dyslipidemia.

Season of infant bronchiolitis and estimates of subsequent risk and burden of early childhood asthma.

There is a population-based increased risk of early childhood asthma following infant bronchiolitis occurring during rhinovirus-predominant months compared to asthma following infant bronchiolitis during RSV-predominant months.

Lipid-modifying efficacy and tolerability of extended-release niacin/laropiprant in patients with primary hypercholesterolaemia or mixed dyslipidaemia.

Background: Improving lipids beyond low-density lipoprotein cholesterol (LDL-C) lowering with statin monotherapy may further reduce cardiovascular risk. Niacin has complementary lipid-modifying efficacy to statins and cardiovascular benefit, but is underutilised because of flushing, mediated primarily by prostaglandin D(2) (PGD(2)). Laropiprant (LRPT), a PGD(2) receptor (DP1) antagonist that reduces niacin-induced flushing has been combined with extended-release niacin (ERN) into a fixed-dose tablet.

A lower dose threshold for the in vivo protective adaptive response to radiation. Tumorigenesis in chronically exposed normal and Trp53 heterozygous C57BL/6 mice.

Low doses of ionizing radiation to cells and animals may induce adaptive responses that reduce the risk of cancer. However, there are upper dose thresholds above which these protective adaptive responses do not occur. We have now tested the hypothesis that there are similar lower dose thresholds that must be exceeded to induce protective effects in vivo.