From eDNA to decisions using a multi-method approach to restoration planning in streams.

Reintroduction efforts are increasingly used to mitigate biodiversity losses, but are frequently challenged by inadequate planning and uncertainty. High quality information about population status and threats can be used to prioritize reintroduction and restoration efforts and can transform ad hoc approaches into opportunities for improving conservation outcomes at a landscape scale. We conducted comprehensive environmental DNA (eDNA) and visual encounter surveys to determine the distribution of native and non-native aquatic species in two high-priority watersheds to address key uncertainties-such as the distribution of threats and the status of existing populations-inherent in restoration planning. We then used these occurrence data to develop a menu of potential conservation actions and a decision framework to benefit an endangered vertebrate (foothill yellow-legged frog, Rana boylii) in dynamic stream systems. Our framework combines the strengths of multiple methods, allowing managers and conservation scientists to incorporate conservation science and site-specific knowledge into the planning process to increase the likelihood of achieving conservation goals.

Seasonal dynamics and potential drivers of ranavirus epidemics in wood frog populations.

Epidemics in wildlife populations often display a striking seasonality. Ranaviruses can cause rapid, synchronous mass mortality events in populations of wood frog (Rana sylvatica) larvae in the summer. While there are several possible explanations for this pattern-from seasonal introductions of the virus to environmental stressors to windows of susceptibility to mortality from infection during development-most studies have focused on single factors in laboratory settings. We characterized the time course of ranavirus epidemics in eight ephemeral ponds in Connecticut, USA, measuring the prevalence and intensity of infections in wood frog larvae and Ranavirus DNA in water samples using environmental DNA methods. We found little evidence that the timing of pathogen introduction affected the timing of epidemics (rising prevalence) or the resulting die-offs. Instead, we observed a pulse in transmission asynchronous with die-offs; prevalence reached high levels (≥ 50%) up to 6 weeks before mortality was observed, suggesting that die-offs may be uncoupled from this pulse in transmission. Rather, mortality occurred when larvae reached later stages of development (hind limb formation) and coinciding water temperatures rose (≥ 15 °C), both of which independently increase pathogenicity (i.e., probability of host mortality) of infections in laboratory experiments. In summary, the strong seasonality of die-offs appears to be driven by development- and/or temperature-dependent changes in pathogenicity rather than occurring chronologically with pathogen introduction, after a pulse in transmission, or when susceptible host densities are greatest. Furthermore, our study illustrates the potential for eDNA methods to provide valuable insight in aquatic host-pathogen systems.

A method for estimating population sex ratio for sage-grouse using noninvasive genetic samples.

Population sex ratio is an important metric for wildlife management and conservation, but estimates can be difficult to obtain, particularly for sexually monomorphic species or for species that differ in detection probability between the sexes. Noninvasive genetic sampling (NGS) using polymerase chain reaction (PCR) has become a common method for identifying sex from sources such as hair, feathers or faeces, and is a potential source for estimating sex ratio. If, however, PCR success is sex-biased, naively using NGS could lead to a biased sex ratio estimator. We measured PCR success rates and error rates for amplifying the W and Z chromosomes from greater sage-grouse (Centrocercus urophasianus) faecal samples, examined how success and error rates for sex identification changed in response to faecal sample exposure time, and used simulation models to evaluate precision and bias of three sex assignment criteria for estimating population sex ratio with variable sample sizes and levels of PCR replication. We found PCR success rates were higher for females than males and that choice of sex assignment criteria influenced the bias and precision of corresponding sex ratio estimates. Our simulations demonstrate the importance of considering the interplay between the sex bias of PCR success, number of genotyping replicates, sample size, true population sex ratio and accuracy of assignment rules for designing future studies. Our results suggest that using faecal DNA for estimating the sex ratio of sage-grouse populations has great potential and, with minor adaptations and similar marker evaluations, should be applicable to numerous species.

A school-based health education program can improve cholesterol values for middle school students.

BACKGROUND: This prospective study aimed to measure the impact of a school-based multidisciplinary education program on risk factors for atherosclerosis in sixth-grade students. METHODS: A prospective study was performed in which patients served as their own controls. Healthy sixth-grade students from three middle schools in a city of approximately 100,000 were exposed to an educational program promoting healthful habits through behavioral and environmental change. Risk factors including body mass index (BMI), systolic and diastolic blood pressure (SBP and DBP), cholesterol panel, and random blood glucose were measured before program initiation, then 5 months afterward. RESULTS: Of 711 sixth-graders at three middle schools, 287 (47% boys; mean age, 11.5 +/- 0.37 years) consented to participate in the study. The mean total cholesterol value decreased from 169 +/- 26 to 154 +/- 26 mg/dl (p < 0.0001). The low-density lipoprotein (LDL) cholesterol value decreased from 86 +/- 25 to 84 +/- 23 mg/dl (p = 0.01), and the high-density lipoprotein (HDL) cholesterol value decreased from 56 +/- 13 to 50 +/- 13 mg/dl (p < 0.0001). The random glucose value decreased from 96 +/- 13 to 93 +/- 15 mm/dl (p = 0.01). The mean SBP did not change, showing 109 +/- 12.5 mmHg before the program and 108 +/- 11.5 mmHg afterward. The DBP decreased from 63.6 +/- 8.6 to 62.3 +/- 7.8 mmHg (p = 0.01). CONCLUSIONS: The Project Healthy Schools program is feasible and appears to be effective. The results showed significant improvement in risk factors for early atherosclerosis among sixth-grade students including total cholesterol, LDL cholesterol, random glucose levels, and diastolic blood pressure. Further study with a larger group and a longer follow-up period would be valuable.

The lateral tunnel Fontan procedure for hypoplastic left heart syndrome: results of 100 consecutive patients.

The Fontan procedure for hypoplastic left heart syndrome (HLHS) is well established. Multiple surgical techniques including extracardiac conduits and autologous tissue connections have been developed. We reviewed the results of 100 consecutive patients undergoing the lateral tunnel modification of the Fontan procedure at the University of Michigan. A cross-sectional retrospective study was performed for 100 consecutive patients identified in the University of Michigan Congenital Heart Surgery database with the diagnosis of HLHS. All patients had undergone a lateral tunnel Fontan procedure between June 2000 and August 2004. The medical record was reviewed to assess patient, procedural, and morphologic determinants of outcome. Hospital survival was 97% and intermediate-term survival was 96% with a median follow-up time of 34 months. Preoperative mean pulmonary artery pressure, right ventricular end diastolic pressure, aortic cross-clamp time, and tricuspid valve regurgitation were not associated with late right ventricular function or survival. Three patients required takedown of the lateral tunnel Fontan in the early postoperative period. A positive association was found between protein-losing enteropathy and prolonged (>2 weeks) postoperative pleural drainage (p = 0.035). No patient required cardiac transplantation or late intervention on the Fontan pathway. At the time of follow-up, 100% of patients were New York Heart Association class I or II and 90% were in normal sinus rhythm. The lateral tunnel Fontan procedure for HLHS can be performed with acceptable early and intermediate-term risk. There was a low prevalence of late rhythm disturbances and other complications. Protein-losing enteropathy and prolonged pleural drainage were associated.

Putting the "landscape" in landscape genetics.

Landscape genetics has emerged as a new research area that integrates population genetics, landscape ecology and spatial statistics. Researchers in this field can combine the high resolution of genetic markers with spatial data and a variety of statistical methods to evaluate the role that landscape variables play in shaping genetic diversity and population structure. While interest in this research area is growing rapidly, our ability to fully utilize landscape data, test explicit hypotheses and truly integrate these diverse disciplines has lagged behind. Part of the current challenge in the development of the field of landscape genetics is bridging the communication and knowledge gap between these highly specific and technical disciplines. The goal of this review is to help bridge this gap by exposing geneticists to terminology, sampling methods and analysis techniques widely used in landscape ecology and spatial statistics but rarely addressed in the genetics literature. We offer a definition for the term "landscape genetics", provide an overview of the landscape genetics literature, give guidelines for appropriate sampling design and useful analysis techniques, and discuss future directions in the field. We hope, this review will stimulate increased dialog and enhance interdisciplinary collaborations advancing this exciting new field.

The Ross/Konno procedure in neonates and infants: intermediate-term survival and autograft function.

BACKGROUND: The Ross procedure has been increasingly applied to neonates and infants. Addition of a modified Konno-type enlargement of the aortic annulus allows the application of this procedure to neonates and infants with significant annular hypoplasia. The potential for growth and the proven durability make the autograft an ideal aortic valve replacement. METHODS: Between March 1993 and December 2000, 10 patients under 1 year of age underwent a Ross/Konno procedure at our institution (range, 2 to 349 days; median 16). All patients had severe to critical aortic stenosis. All patients required aortic annulus enlargement for size mismatch between the aortic and pulmonary valves. RESULTS: There were no deaths at a median follow-up of 48 months (range, 1 to 74 months). All patients had none to mild aortic stenosis on Doppler echocardiography. Eight patients had a 0 to 1+ aortic insufficiency, 1 patient had a 2+ aortic insufficiency, and 1 patient had a 3+ aortic insufficiency. Aortic annular dilatation was not observed. Aortic sinus dilatation occurred initially (mean change in z-value: 0 to 12 months, +2.1) and then stabilized (mean change in z-value: 12 to > 36 months, +0.6). No patient required additional procedures for aortic valve disease. Two patients required three pulmonary allograft replacements. CONCLUSIONS: The Ross procedure with a modified Konno-type enlargement of the aortic annulus is an excellent approach to aortic valve disease in the neonate and infant. The procedure can be accomplished with low morbidity and mortality, and low rates of reoperation. The pulmonary autograft demonstrates durability without developing aortic stenosis, aortic insufficiency, or progressive dilatation. Enlargement of the aortic annulus parallels somatic growth.

A method for preventive cardiology in children.

There are clear indications for prevention of atherosclerotic disease to begin in childhood. Optimal primary prevention will utilize a public health strategy. For children with elevated risk for atherosclerotic disease a clinically based prevention program is helpful. The indications for and an approach to the pediatric preventive cardiology clinic are reviewed.

Postoperative hemodynamics after Norwood palliation for hypoplastic left heart syndrome.

Hemodynamics after Norwood palliation for hypoplastic left heart syndrome (HLHS) have been incompletely characterized, although emphasis has been placed on the role that an excess pulmonary-to-systemic blood flow ratio (Qp/Qs) may play in causing hemodynamic instability. Studies suggest that maximal oxygen delivery occurs at a Qp/Qs < 1. However, it remains unclear to what extent cardiac output can increase with increasing pulmonary perfusion. One approach is to use the oxygen excess factor omega, an index of systemic oxygen delivery, and compare omega with measured Qp/Qs. We measured Qp/Qs and omega in neonates after Norwood palliation for HLHS, and determined how they were related. In addition, we determined the temporal course of surrogate indexes of systemic perfusion in the early postoperative period. Arteriovenous oxygen saturation difference, blood lactate, and omega were recorded on admission and every 3 to 12 hours for 2 days in 18 consecutive infants with HLHS or variant after Norwood palliation. Three infants required extracorporeal membrane oxygenation (ECMO) 6 to 9 hours after admission. These infants had higher Qp/Qs, blood lactate, arteriovenous oxygen saturation difference, and lower omega than non-ECMO patients. In non-ECMO patients between admission and 6 hours, omega decreased significantly despite no appreciable change in Qp/Qs. We conclude that: (1) Oxygen delivery is significantly decreased at 6 postoperative hours unrelated to Qp/Qs. This modest decline in oxygen delivery is insufficient to compromise tissue oxygenation. (2) Patients requiring ECMO have significant derangements in oxygen delivery.

Neurodevelopmental outcome of patients after the fontan operation: A comparison between children with hypoplastic left heart syndrome and other functional single ventricle lesions.

OBJECTIVE: To compare neurodevelopmental outcome (NDO) in patients with hypoplastic left heart syndrome (HLHS), other functional single ventricle lesions, and the standard population and to investigate predictors of NDO in the population of children with functional single ventricle (FSV). STUDY DESIGN: A time- and age-defined cohort of patients with the Fontan circulation was recruited to participate in neurodevelopmental testing, behavioral evaluation, and imaging of the central nervous system. The Wechsler Intelligence test was the primary measure of NDO. Analysis included comparison of patients with HLHS with other patients with functional single ventricles. Other potential clinical predictors of NDO were investigated. RESULTS: The mean Full Scale Wechsler Intelligence score was 101.4+/-5.4. For the HLHS subgroup the mean Full Scale Wechsler score was 93.8+/-7.3, and for the non-HLHS subgroup it was 107.0+/-7.0. Although the HLHS group had significantly lower scores than the non-HLHS subgroup, neither subgroup scored significantly different from the standard population on the Wechsler Scales. Socioeconomic status, circulatory arrest, and perioperative seizures also were predictive of neurodevelopmental outcome. CONCLUSION: Neurodevelopmental and behavioral outcome in patients who have undergone the Fontan procedure including patients with HLHS is good in the preschool and early school years, with Wechsler Intelligence scores generally in the normal range.

Evaluation of a noninvasive index of global ventricular function to predict rejection after pediatric cardiac transplantation.

A Doppler myocardial performance index, defined as the sum of the isovolumetric contraction and relaxation time divided by the ejection time (ICT + IRT/ET), reflects global cardiac function, and when applied to the left ventricle, may serve as a predictor of moderate rejection in pediatric cardiac transplant patients.

Serial blood lactate measurements predict early outcome after neonatal repair or palliation for complex congenital heart disease.

OBJECTIVES: Neonates with congenital heart disease may appear hemodynamically stable after operation and then suddenly experience catastrophic decompensation. An improved means of predicting which infants will suddenly die in the early postoperative period may lead to lifesaving interventions. Studies indicate that blood lactate level is proportional to tissue oxygen debt, but information linking lactate levels with outcome in infants after operation is limited. We sought to determine whether a change in lactate level over time was predictive of a poor outcome defined as death within the first 72 hours or the need for extracorporeal membrane oxygenation. METHODS: To test this hypothesis, we studied prospectively 46 infants who were less than 1 month old and were undergoing complex cardiac surgical palliation or repair. Postoperative arterial oxygen saturation, bicarbonate, and lactate levels were recorded on admission to the intensive care unit and every 3 to 12 hours for the first 3 days. RESULTS: Thirty-seven patients had a good outcome, and 9 patients had a poor outcome. Mean initial lactate level was significantly greater in patients with a poor outcome (9.4 +/- 3.8 mmol/L) than in patients with a good outcome (5.6 +/- 2.1 mmol/L; P =.03). However, an elevated initial lactate level of more than 6 mmol/L had a low positive predictive value (38%) for poor outcome. In contrast, a change in lactate level of 0.75 mmol/L per hour or more was associated with a poor outcome (P <.0001) and predicted a poor outcome with an 89% sensitivity value, a 100% specificity value, and a 100% positive predictive value. CONCLUSIONS: Serial blood lactate level measurements may be an accurate predictor of death or the requirement for extracorporeal membrane oxygenator support for patients who undergo complex neonatal cardiac surgery.

Facial animation in children with Möbius syndrome after segmental gracilis muscle transplant.

Möbius syndrome is a complex congenital anomaly involving multiple cranial nerves, including the abducens (VI) and facial (II) nerves, and often associated with limb anomalies. Muscle transplantation has been used to address the lack of facial animation, lack of lower lip support, and speech difficulties these patients experience. The purpose of this study was to investigate the results of bilateral, segmental gracilis muscle transplantation to the face using the facial vessels for revascularization and the motor nerve to the masseter for reinnervation. The outcome of the two-stage procedure was assessed in 10 consecutive children with Möbius syndrome by direct interview, speech assessment, and oral commissure movement. Preoperative data were collected from direct questioning, viewing of preoperative videotapes, notes from prior medical evaluations, and rehabilitation medicine and speech pathology assessments. All of the patients developed reinnervation and muscle movement. The children who described self-esteem to be an issue preoperatively reported a significant posttransplant improvement. The muscle transplants produced a smile with an average commissure excursion of 1.37 cm. The frequency and severity of drooling and drinking difficulties decreased postoperatively in the seven symptomatic children. Speech difficulties improved in all children. Specifically, of the six children with bilabial incompetence, three received complete correction and three had significant improvement. Despite the length and complexity of these procedures, complications were minimal. Muscle transplantation had positive effects in all problematic areas, with a high degree of patient satisfaction and improvement in drooling, drinking, speech, and facial animation. The surgical technique is described in detail and the advantages over regional muscle transfers are outlined. Segmental gracilis muscle transplantation innervated by the motor nerve to the masseter is an effective method of treating patients with Möbius syndrome.

Primary repair of aortic arch obstruction with ventricular septal defect in preterm and low birth weight infants.

OBJECTIVE: Previous reports have suggested that prematurity and low birth weight are risk factors for definitive surgical intervention in congenital cardiac malformations. The following data review our experience with primary repair of the complex malformation of aortic arch obstruction with ventricular septal defect (VSD) in this patient population. METHODS: Since 1988, 21 consecutive preterm (

Early results of the fontan procedure in one hundred consecutive patients with hypoplastic left heart syndrome.

OBJECTIVES: The purpose of this study was to review a large, single institutional experience with the Fontan procedure for patients with hypoplastic left heart syndrome. METHODS: One hundred consecutive patients with "classic" hypoplastic left heart syndrome underwent Fontan palliation between February 1992 and April 1998. Patient demographic, morphologic, and procedural variables were examined and analyzed. In particular, two different surgical techniques were used: technique I (February 1992 to December 1995) employed cardiopulmonary bypass and moderate systemic hypothermia, and technique II (December 1995 to April 1998), profound hypothermia and circulatory arrest. A retrospective review of medical records was performed and variables were examined and analyzed. RESULTS: Hospital survival for the entire cohort was 89% (95% CI 83%-95%). The technique of operation, cardiopulmonary bypass time, and aortic crossclamp time were each strongly associated with survival. Survival for patients treated by technique I was 79% (95% CI 68-91%; n = 48) and for those treated by technique II, 98% (95% CI 94%-100%; n = 52). Cardiopulmonary bypass and crossclamp times were also highly correlated with time to extubation and length of intensive care unit stay. Preoperative pulmonary artery pressure was correlated with survival; preoperative oxygen saturation, right atrial pressure, pulmonary vascular resistance, pulmonary artery size, extent of aortopulmonary artery collaterals, and echocardiographic estimates of ventricular function and tricuspid regurgitation were not correlated with survival. CONCLUSIONS: Our recent experience with Fontan palliation for patients with hypoplastic left heart syndrome suggests that it is attended by low perioperative mortality. The precise operative technique used appears to be an important determinant of outcome, with the duration of cardiopulmonary bypass and crossclamping being particularly significant.

Biventricular repair for aortic atresia or hypoplasia and ventricular septal defect.

OBJECTIVE: Aortic valve atresia or hypoplasia can present with a ventricular septal defect and a normal mitral valve and left ventricle. These patients may be suitable for biventricular repair, although the optimal initial management strategy remains unknown. METHODS: From January 1991 through March 1999, 20 patients with aortic atresia or hypoplasia and ventricular septal defect underwent operation with the intent to achieve biventricular repair. Aortic atresia was present in 7 patients, and aortic valve hypoplasia was present in 13 patients. Among those patients with aortic hypoplasia, Z-scores of the aortic valve anulus ranged from -8.8 to -2.7. Associated anomalies included interrupted aortic arch (n = 12 patients), coarctation (n = 6 patients), aortopulmonary window (n = 1 patient), and heterotaxia (n = 1 patient). Nine patients were staged with an initial Norwood procedure followed by biventricular repair in 8 patients. One patient awaits biventricular repair after a Norwood procedure. The conditions of 11 patients were corrected with a single procedure. RESULTS: Among the 9 patients who underwent staged repair, there were no deaths after the Norwood procedure and 1 death after biventricular repair. For the 11 patients who underwent a primary biventricular repair, there was 1 early death and 2 late deaths from noncardiac causes. Follow-up ranged from 1 to 85 months (mean, 28 months). Actuarial survival for the entire group was 78% +/- 10% at 5 years and was not significantly different between staged repair (89%) and primary biventricular repair (73%). CONCLUSIONS: Both primary and staged biventricular repair for patients with aortic atresia or hypoplasia and ventricular septal defect may be performed with good late survival. Refinements in technique of conduit insertion and arch reconstruction have resulted in primary biventricular repair becoming our preferred approach.

Hemi-Fontan procedure for hypoplastic left heart syndrome: outcome and suitability for Fontan.

BACKGROUND: Following the Norwood procedure for hypoplastic left heart syndrome (HLHS), pulmonary artery distortion and hypoplasia are common and may negatively impact late outcome. The hemi-Fontan procedure (HFP) augments the central pulmonary arteries and establishes a connection between the right atrial/superior vena cava junction and the pulmonary arteries, while excluding the inferior vena cava. METHODS: The hospital records of all 114 patients undergoing a HFP for HLHS between August 1993 and April 1998 were reviewed to assess patient, procedural, and morphologic determinations of outcome. The results of cardiac catheterization, Doppler/echocardiography, 12 lead electrocardiograms, hospital and subsequent course, as well as suitability and outcome for the Fontan procedure were analyzed. RESULTS: Mean age was 5.4 months (range 1.5 to 15 months). Right ventricular function was normal in 95 patients, moderately depressed in 14, and severely depressed in five. Tricuspid regurgitation was absent or mild in 91 patients, moderate in 13, and severe in 10. Concomitant procedures included left superior vena cava to pulmonary artery anastomosis (12), tricuspid valve repair (10), pulmonary artery stent placement (3), coarctation repair (2), and aortic pseudoaneurysm repair (1). Hospital survival was 112/114, 98% (95% confidence interval [CI]: 95% to 100%). There were two late deaths, one noncardiac. Sinus rhythm is present in 105 patients (92%, 95% CI: 87% to 97%). To date, 79 of these patients have undergone the Fontan procedure with 74 survivors (94%, 95% CI: 89% to 99%). CONCLUSIONS: The HFP may be performed with excellent results for HLHS. It effectively augments the central pulmonary arteries while preserving sinus rhythm in the majority. In addition, the HFP facilitates the subsequent Fontan procedure and has significantly improved the overall outcome.

The dimensions of the triangle of Koch in children.

We measured the dimensions of Koch's triangle in children with normal intracardiac anatomy to determine the relation between the size of the triangle of Koch and patient age, weight, height, and body surface area. We found that the dimensions of Koch's triangle varies significantly and directly with patient age and body habitus in this pediatric population.