Detecting intraannual dietary variability in wild mountain gorillas by stable isotope analysis of feces

We use stable isotope ratios in feces of wild mountain gorillas (Gorilla beringei) to test the hypothesis that diet shifts within a single year, as measured by dry mass intake, can be recovered. Isotopic separation of staple foods indicates that intraannual changes in the isotopic composition of feces reflect shifts in diet. Fruits are isotopically distinct compared with other staple foods, and peaks in fecal δ¹³C values are interpreted as periods of increased fruit feeding. Bayesian mixing model results demonstrate that, although the timing of these diet shifts match observational data, the modeled increase in proportional fruit feeding does not capture the full shift. Variation in the isotopic and nutritional composition of gorilla foods is largely independent, highlighting the difficulty for estimating nutritional intake with stable isotopes. Our results demonstrate the potential value of fecal sampling for quantifying short-term, intraindividual dietary variability in primates and other animals with high temporal resolution even when the diet is composed of C₃ plants.     

Kidney dysfunction and deterioration of ejection fraction pose independent risk factors for mortality in implantable cardioverter-defibrillator recipients for primary prevention

Background:

A growing number of patients with advanced heart failure fulfill a primary‐prevention indication for an implantable cardioverter‐defibrillator (ICD). This study seeks to identify new predictors of overall mortality in a Sudden Cardiac Death in Heart Failure Trial (SCD‐HeFT)‐like collective to enhance risk stratification.

Hypothesis:

An impaired renal function and severely depressed left ventricular ejection fraction pose relevant risk factors for mortality in primary prevention ICD recipients.

Methods:

Ninety‐four consecutive ICD patients with New York Heart Association class II–III heart failure and depressed left ventricular function (left ventricular ejection fraction [LVEF] ≤35%) with no history of malignant ventricular arrhythmias were followed for 34 ± 20 months.

Results:

During this period, 30 patients died (32%). Deceased patients revealed a significantly worse renal function before ICD implantation (1.55 ± 0.7 mg/dL vs 1.1 ± 0.4 mg/dL; P = 0.007), suffered more often from coronary artery disease (53 vs 29; P = 0.006), and were older (69.5 ± 8 y vs 67 ± 12 y; P = 0.0002) than surviving patients. Furthermore, increased serum creatinine at baseline (2 mg/dL vs 1 mg/dL; odds ratio [OR]: 3.96, 95% confidence interval [CI]: 1.2–13.04, P = 0.02), presence of coronary artery disease (OR: 8.6, 95% CI: 1.1–65, P = 0.036), and low LVEF (OR per 5% baseline LVEF deterioration: 1.4, 95% CI: 1–1.8, P = 0.034) represented strong and independent predictors for overall mortality.

Conclusions:

Impaired renal function, the presence of coronary artery disease, and reduced LVEF before implantation represent independent predictors for mortality in a cohort of patients with advanced systolic heart failure. These conditions still bear a high mortality risk, even if ICD implantation effectively prevents sudden arrhythmic death. Indeed, in patients suffering from several of the identified “high‐risk” comorbidities, primary‐prevention ICD implantation might have a limited survival benefit. The possible adverse effects of these comorbidities should be openly discussed with the potential ICD recipient and his or her close relatives. Clin. Cardiol. 2012 doi: 10.1002/clc.22018 The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Childhood polybrominated diphenyl ether (PBDE) exposure and executive function in children in the HOME Study

Prenatal exposure to polybrominated diphenyl ethers (PBDEs) have been reported to impair executive function in children, but little is known whether childhood PBDE exposures play a role. Using the Health Outcomes and Measures of the Environment (HOME) Study, a prospective birth cohort in the greater Cincinnati area, we investigated the association between repeated measures of PBDEs during childhood and executive function at 8 years in 208 children and whether effect modification by child sex was present. We used child serum collected at 1, 2, 3, 5, and 8 years to measure PBDEs. The Behavior Rating Inventory of Executive Function was completed by parents to assess executive function at 8 years. We used multiple informant models to examine childhood PBDEs during several exposure windows. Null associations were observed between early childhood PBDEs and executive function. However, we observed significant adverse associations between a 10-fold increase in concurrent concentrations of BDE-28 (β = 4.6, 95% CI 0.5, 8.7) and BDE-153 (β = 4.8, 95% CI 0.8, 8.8) with behavioral regulation. In addition, PBDEs at 8 years were significantly associated with poorer emotional and impulse control. No associations were noted between childhood PBDEs and metacognition or global executive function. However, child sex significantly modified the associations, with significantly poorer executive function among males with higher concurrent BDE-153, and null associations in females. Our study findings suggest that concurrent PBDE exposures during childhood may be associated with poorer executive function, specifically behavior regulation. Males may also be more sensitive to adverse associations of concurrent PBDEs on executive function.     

Mechanistic analysis of metabolomics patterns in rat plasma during administration of direct thyroid hormone synthesis inhibitors or compounds increasing thyroid hormone clearance

For identification of toxicological modes of action (MoAs) a database (MetaMap^®Tox) was established containing plasma metabolome consisting of approximately 300 endogenous metabolites. Each five male and female Wistar rats per groups were treated with >500 reference compounds over a period of 28 days. More than 120 specific toxicity patterns of common metabolite changes associated with unique MoAs were established.     

Comparing Active and Passive Varicella Surveillance in Philadelphia, 2005–2010: Recommendations for the Transition to Nationwide Passive Varicella Disease Surveillance

Objective

The Philadelphia Department of Public Health (PDPH) conducts active surveillance for varicella in West Philadelphia. For its approximately 300 active surveillance sites, PDPH mandates biweekly reports of varicella (including zero cases) and performs intensive case investigations. Elsewhere in Philadelphia, surveillance sites passively report varicella cases, and abbreviated investigations are conducted. We used active varicella surveillance program data to inform the transition to nationwide passive varicella surveillance.

Methods

We compared classification of reported cases, varicella disease incidence, and reporting completeness for active and passive surveillance areas for 2005–2010. We assessed reporting completeness using capture-recapture analysis of 2- to 18-year-old cases reported by schools/daycare centers and health-care providers.

Results

From 2005 to 2010, PDPH received 3,280 passive and 969 active surveillance varicella case reports. Most passive surveillance reports were classified as probable cases (18% confirmed, 56% probable, and 26% excluded), whereas nearly all of the active surveillance reports were either confirmed or excluded (36% confirmed, 11% probable, and 53% excluded). Overall incidence rates calculated using confirmed/probable cases were similar in the active and passive surveillance areas. Detection of laboratory-confirmed, breakthrough, and moderate-to-severe cases was equivalent for both surveillance areas.

Conclusions

Although active surveillance for varicella results in better classified cases, passive surveillance provides comparable data for monitoring disease trends in breakthrough and moderate-to-severe varicella. To further improve passive surveillance in the two-dose-varicella vaccine era, jurisdictions should consider conducting periodic enhanced surveillance, encouraging laboratory testing, and collecting additional varicella-specific variables for passive surveillance.To monitor the impact of the varicella vaccination program, the Centers for Disease Control and Prevention, in collaboration with the Philadelphia Department of Public Health (PDPH) and Los Angeles County Department of Health Services, conducted varicella surveillance through the Varicella Active Surveillance Project (VASP) from 1996–2011.¹ This new program was essential, because when varicella vaccine was recommended for use in the United States in 1996, varicella was not nationally notifiable; varicella had been removed from the list of notifiable conditions in 1981 because reporting the then-common disease was not feasible in many states.² VASP has supplied vital information for programmatic decision-making, including the 2007 recommendation for a second dose of varicella vaccine.³With the success of the varicella vaccination program in reducing the incidence of disease, relatively small active surveillance areas cannot accurately monitor further declines in varicella incidence, changes in age distribution, and disease severity. Therefore, more widespread passive surveillance is required. In 2003, varicella was again added to the national notifiable diseases list, and the Council of State and Territorial Epidemiologists (CSTE) recommended that all states implement case-based surveillance by 2005.^4–6 To mitigate the burden of varicella surveillance, CSTE recommended that states begin by focusing on the collection of three varicella-specific variables: age at disease onset, number of lesions (as a proxy for disease severity), and vaccination status, adding variables, including rash characteristics, varicella-related complications, and diagnostic laboratory data, when feasible.² As of 2010, 38 states were conducting case-based passive surveillance, but the completeness of information collected is unknown.⁷In this article, we briefly summarize the characteristics of active and passive surveillance in Philadelphia, Pennsylvania, and compare active and passive varicella surveillance data for 2005–2010 as the basis for recommendations to optimize the quality of national passive surveillance. Specifically, we compared (1) the proportions of confirmed, probable, and excluded cases among overall reports; (2) the proportions of cases reported by type of reporting site; (3) the overall reported incidence of varicella; (4) the completeness of reporting assessed by capture-recapture methodology; and (5) the extent of laboratory testing and findings from testing. Our results suggest that optimizing passive surveillance in the U.S. will require efforts to improve the identification and exclusion of non-varicella cases through periodic enhanced surveillance, laboratory testing, or more thorough investigation of rash characteristics.