Coronary angiography is a better predictor of mortality than noninvasive testing in patients evaluated for renal transplantation

Objectives : The goal of this study was to compare whether coronary angiography or noninvasive imaging more accurately identifies coronary artery disease (CAD) and predicts mortality in patients with end‐stage renal disease (ESRD) under evaluation for transplantation. Background : CAD is a leading cause of mortality in patients with ESRD. The optimal method for identifying CAD in ESRD patients evaluated for transplantation remains controversial with a paucity of prognostic data currently available comparing noninvasive methods to coronary angiography. Methods : The study cohort consisted of 57 patients undergoing both coronary angiography and stress perfusion imaging. Severe CAD was defined by angiography as ≥70% stenosis, and by noninvasive testing as ischemia in ≥1 zone. Follow‐up for all cause mortality was 3.3 years. Results : On noninvasive imaging, 63% had ischemia. On angiography, 40% had at least one vessel with severe stenoses. Abnormal perfusion was observed in 56% of patients without severe disease angiographically. Noninvasive imaging had poor specificity (24%) and poor positive predictive value (43%) for identifying severe disease. Angiography but not noninvasive imaging predicted survival; 3 year survival was 50% and 73% for patients with and without severe CAD by angiography (p<0.05). Conclusions : False positive scintigrams limited noninvasive imaging in patients with ESRD. Angiography was a better predictor of mortality compared with noninvasive testing. © 2010 Wiley‐Liss, Inc.     

Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is one of the most diverse autoimmune diseases as it may affect any organ in the body and display a broad spectrum of clinical and immunological manifestations. Epidemiological studies have identified marked differences in the prevalence and course of SLE between genders, and across different ages, races and geographic locations. Methodological differences between studies may account for some of the disparity seen. Additionally, some insights into possible environmental risk factors for SLE have also been provided. As this condition is relatively uncommon, multifactorial, and largely influenced by genetic predisposition, it is inherently difficult to confirm or exclude infectious or environmental contributors to its etiology. Movement of people between communities and defining specific exposures can also be problematic. Despite these limitations, ongoing observation of SLE cohorts in multiple countries and settings, along with large international cooperative efforts in recent years, have helped clarify the risks of SLE in various groups and have defined marked differences in the worldwide occurrence of the disease.     

Bone marrow reticulin and collagen content in patients with adult chronic immune thrombocytopenic purpura: a Danish nationwide study

We quantified and differentiated reticulin and collagen content in bone marrow specimens from chronic immune thrombocytopenic (ITP) patients and examined the correlation between some clinical characteristics and the fibrosis grading. Through the Danish National Patient Registry, we identified 378 patients with chronic ITP from 1997 until 2007. Of these, 253 (67%) had undergone at least one bone marrow biopsy, and we retrieved the bone marrow specimens from 187 (74%). We graded the bone marrow content of reticulin and collagen according to the Thiele scale (Grade 0–3). We also retrieved information on patients' clinical characteristics. We examined the prevalence of bone marrow fibrosis grading >0 by patients' age (≤75 years and >75 years), sex, platelet count at baseline (<30 × 10⁹/L, and ≥30 × 10⁹/L), splenomegaly, hepatomegaly, and medications. In total 75 chronic ITP patients (40%) had a bone marrow grading >0. Of these, 72 (39%) had Grade 1 reticulin fibers present. Only three patients (<2%) had collagen fibers present: two had Grade 2 and one had Grade 3. The prevalence of bone marrow grading >0 was lower in patients aged >75 years than ≤75 years (prevalence ratio = 0.64, 95% CI: 0.36–1.15) and lower in men than women (prevalence ratio = 0.70, 95% CI: 0.45–1.09), while a baseline platelet count ≥30 × 10⁹/L was associated with a higher prevalence of grading >0 (prevalence ratio = 1.24, 95% CI: 0.81–1.86). Thus, bone marrow reticulin and collagen content in chronic ITP patients may be associated with some clinical characteristics. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.     

Variation in Estimates of Limited Health Literacy by Assessment Instruments and Non-Response Bias

Objectives

This paper compares estimates of poor health literacy using two widely used assessment tools and assesses the effect of non-response on these estimates.

Study Design and Setting

A total of 4,868 veterans receiving care at four VA medical facilities between 2004 and 2005 were stratified by age and facility and randomly selected for recruitment. Interviewers collected demographic information and conducted assessments of health literacy (both REALM and S-TOFHLA) from 1,796 participants. Prevalence estimates for each assessment were computed. Non-respondents received a brief proxy questionnaire with demographic and self-report literacy questions to assess non-response bias. Available administrative data for non-participants were also used to assess non-response bias.

Results

Among the 1,796 patients assessed using the S-TOFHLA, 8% had inadequate and 7% had marginal skills. For the REALM, 4% were categorized with 6th grade skills and 17% with 7–8th grade skills. Adjusting for non-response bias increased the S-TOFHLA prevalence estimates for inadequate and marginal skills to 9.3% and 11.8%, respectively, and the REALM estimates for ≤6th and 7–8th grade skills to 5.4% and 33.8%, respectively.

Conclusions

Estimates of poor health literacy varied by the assessment used, especially after adjusting for non-response bias. Researchers and clinicians should consider the possible limitations of each assessment when considering the most suitable tool for their purposes.KEY WORDS: health literacy, veterans, prevalence, measurement, non-response bias, REALM, S-TOFHLA     

Transitory Activation of AMPK at Reperfusion Protects the Ischaemic-Reperfused Rat Myocardium Against Infarction

Purpose  

AMPK plays a crucial role in the regulation of the energy metabolism of the heart. During ischaemia, AMPK activation is a known adaptative prosurvival mechanism that helps to maintain the energy levels of the myocardium. However, it still remains unclear if activation of AMPK during reperfusion is beneficial for the heart. Two known AMPK activators (metformin and AICAR) were used to verify the hypothesis that a transitory activation of AMPK at reperfusion may exert cardioprotection, as reflected in a reduction in myocardial infarct size.     

Consideration of dosimetry in evaluation of ToxCast™ data

The US Environmental Protection Agency (US EPA) Toxcast? program has the stated goal of predicting hazard, characterizing toxicity pathways and prioritizing the toxicity testing of environmental chemicals through the use of in vitro high‐throughput screening (HTS) assays. This analysis integrates data from biomonitoring and from in vivo toxicity and pharmacokinetic studies to examine the physiological relevance of the tested and responding in vitro concentrations for five case study chemicals: triclosan, 2,4‐dichlorophenoxyacetic acid, perfluorooctanoic acid, monobutyl phthalate and mono‐2(ethylhexyl)phthalate. This analysis also examines the ToxCast? phase 1 data set for approximately 50 chemicals belonging to four ‘common mechanism groups’ which have been the subject of cumulative risk assessments by the US EPA for both the pattern of key responses and the relative potencies of included chemicals compared with the in vivo relative potencies. Responding concentrations in vitro were generally in the range of serum or plasma concentrations associated with no‐observed to lowest‐observed effect levels for the case study chemicals, while available biomonitoring data demonstrating actual exposures were generally lower. ToxCast? assay endpoints related to acetylcholinesterase (AChE) inhibition had low sensitivity for detecting organophosphate pesticides but good sensitivity for detecting N‐methyl carbamates. However, in vitro relative potencies did not correlate with in vivo potency. Both qualitative and quantitative predictive power is probably affected by the lack of comprehensive metabolic activity in most current in vitro systems explored in the ToxCast? program, and this remains a fundamental challenge for high‐throughput toxicity screening efforts. Copyright © 2011 John Wiley & Sons, Ltd.     

Biomonitoring equivalents for DDT/DDE

Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite in a biological medium (blood, urine, or other medium) that is consistent with an existing health-based exposure guideline such as a reference dose (RfD) or tolerable daily intake (TDI). BE values can be used as a screening tool for the evaluation of population-based biomonitoring data in the context of existing risk assessments. This study reviews available health based risk assessments and exposure guidance values for DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, CAS #50-29-3) and related metabolites and degradation products DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane, CAS #72-55-90) and DDD (1,1-dichloro-2,2-bis(p-chloro-phenyl)ethane) based on both non-cancer and cancer risk assessments from the Food and Agriculture Organization/World Health Organization (FAO/WHO), the United States Environmental Protection Agency (US EPA), and other organizations. Laboratory data on distribution and toxicokinetics of DDT and metabolites and estimates of human elimination half-lives were used to estimate BE values (lipid-adjusted blood, serum, or plasma concentrations) corresponding to the various non-cancer exposure guidance values and cancer risk-specific doses. The BE values based on non-cancer risk assessments range from 5000 to 40,000ng/g lipid for the sum of DDT, DDE, and DDD. The BE values corresponding to a 1E-05 cancer risk level for DDT and DDE based on the US EPA assessment are 300 and 500ng/g lipid, respectively. Sources of uncertainty relating to both the basis for the BE values and their use in evaluation of biomonitoring data are discussed. The BE values derived here can be used as a screening tools for evaluation of population biomonitoring data for DDT and related compounds in the context of the existing risk assessment and can assist in prioritization of the potential need for additional risk assessment efforts for DDT relative to other chemicals.     

Production of monodisperse epigallocatechin gallate (EGCG) microparticles by spray drying for high antioxidant activity retention

Epigallocatechin gallate (EGCG) originated from green tea is well-known for its pharmaceutical potential and antiproliferating effect on carcinoma cells. For drug delivery, EGCG in a micro-/nanoparticle form is desirable for their optimized chemopreventive effect. In this study, first time reports that EGCG microparticles produced by low temperature spray drying can maintain high antioxidant activity. A monodisperse droplet generation system was used to realize the production of EGCG microparticles. EGCG microparticles were obtained with narrow size distribution and diameter of 30.24 ± 1.88 μM and 43.39 ± 0.69 μM for pure EGCG and lactose-added EGCG, respectively. The EC50 value (the amount of EGCG necessary to scavenge 50% of free radical in the medium) of spray dried pure EGCG particles obtained from different temperature is in the range of 3.029-3.075 μM compared to untreated EGCG with EC50 value of 3.028 μM. Varying the drying temperatures from 70°C and 130°C showed little detrimental effect on EGCG antioxidant activity. NMR spectrum demonstrated the EGCG did not undergo chemical structural change after spray drying. The major protective mechanism was considered to be: (1) the use of low temperature and (2) the heat loss from water evaporation that kept the particle temperature at low level. With further drier optimization, this monodisperse spray drying technique can be used as an efficient and economic approach to produce EGCG micro-/nanoparticles.