A framework for One Health research.

The need for multidisciplinary research to address today's complex health and environmental challenges has never been greater. The One Health (OH) approach to research ensures that human, animal, and environmental health questions are evaluated in an integrated and holistic manner to provide a more comprehensive understanding of the problem and potential solutions than would be possible with siloed approaches. However, the OH approach is complex, and there is limited guidance available for investigators regarding the practical design and implementation of OH research. In this paper we provide a framework to guide researchers through conceptualizing and planning an OH study. We discuss key steps in designing an OH study, including conceptualization of hypotheses and study aims, identification of collaborators for a multi-disciplinary research team, study design options, data sources and collection methods, and analytical methods. We illustrate these concepts through the presentation of a case study of health impacts associated with land application of biosolids. Finally, we discuss opportunities for applying an OH approach to identify solutions to current global health issues, and the need for cross-disciplinary funding sources to foster an OH approach to research.

Fueling the public health workforce pipeline through student surge capacity response teams.

In January 2003, the University of North Carolina Center for Public Health Preparedness established Team Epi-Aid to match graduate student volunteers with state and local health departments to assist with outbreaks and other applied public health projects. This study assessed whether Team Epi-Aid participation by full-time graduate students impacted post-graduation employment, particularly by influencing students to work in governmental public health upon graduation. In September 2010, 223 program alumni were contacted for an online survey and 10 selected for follow-up interviews. Eighty-three Team Epi-Aid alumni answered the survey (response rate = 37 %). Forty-one (49 %) reported participating in at least one activity, with 12/41 (29 %) indicating participation in Team Epi-Aid influenced their job choice following graduation. In 6 months prior to enrolling at UNC, 30 (36 %) reported employment in public health, with 16/30 (53 %) employed in governmental public health. In 6 months following graduation, 34 (41 %) reported employment in public health, with 27 (80 %) employed in governmental public health. Eight alumni completed telephone interviews (response rate = 80 %). Five credited Team Epi-Aid with influencing their post-graduation career. Experience in applied public health through a group such as Team Epi-Aid may influence job choice for public health graduates.

Does monitoring newborn weight discourage breast feeding?

BACKGROUND: A policy of regular neonatal weight monitoring was introduced to a geographically defined population in 2000. This was combined with targeted breast feeding support for infants reaching specified intervention thresholds. AIMS: To look for evidence of compromise in breast feeding rates as a result of this policy change. METHODS: Breast feeding rates at 10 days and 6 weeks were compared for this intervention population and two local non-intervention groups for the years 1999 and 2001. The data were analysed using Poisson regression analysis and the Z-test. RESULTS: There was a 3.1% (95% CI 0.8% to 5.5%) rise in the deprivation corrected breast feeding rate at 6 weeks for the intervention population compared to an increase of 0.8% (95% CI -0.8% to 2.3%) for the combined control groups. Multivariate analysis showed that breast feeding rates were adversely influenced by deprivation, but were not significantly influenced by the intervention. CONCLUSION: No evidence was found to support claims that regular monitoring of newborn weight adversely affects breast feeding rates.

Neonatal weight loss in breast and formula fed infants.

OBJECTIVE: To define the range of neonatal weight loss in a population relative to feeding method. DESIGN: Prospective observational cohort study. SETTING: Maternity service providing geographically defined, community based newborn follow up. PARTICIPANTS: 971 consecutive term newborns of birth weight > or = 2500 g during the first 2-3 weeks of life; 34 excluded (inadequate data). 937 included: 45% breast fed, 42% formula fed, 13% breast and formula fed. OUTCOME MEASURES: Maximum weight loss and timing, age on regaining birth weight. RESULTS: Median weight loss: formula fed 3.5%, breast fed 6.6%. Upper centiles for maximum weight loss differ considerably (95th centiles: breast fed = 11.8%, formula fed = 8.4%; 97.5th centiles: breast fed = 12.8%, formula fed = 9.5%). Median time of maximum weight loss: 2.7 days for breast fed and formula fed. Recovery of birth weight: breast fed median 8.3 days, 95th centile 18.7 days, 97.5th centile 21.0 days; formula fed median 6.5 days, 95th centile 14.5 days, 97.5th centile 16.7 days. The time taken to regain birth weight correlates with both the degree and timing of initial weight loss for all groups. CONCLUSIONS: Early neonatal weight loss is defined allowing identification of infants who merit closer assessment and support.

Endothelin-1 levels in infants with pulmonary hypertension receiving extracorporeal membrane oxygenation.

We studied the possibility of an etiological role for endothelin-1 (ET-1) in the development of persistent pulmonary hypertension of the newborn (PPHN). Ten infants with severe PPHN requiring extracorporeal membrane oxygenation (ECMO) were studied. Pre and post pulmonary blood samples were obtained on commencing ECMO and on recovery. The samples were analyzed by radio-immunoassay. The infants with PPHN requiring ECMO had a significantly higher mean ET-1 concentration (21.1 pmol/l, S. D. 3.59) than a group of healthy controls (16.6 pmol/l, S. D. 4.44); however 8 of our 10 infants had individual ET-1 levels within our reference range for healthy newborns. Pre and post pulmonary ET-1 levels did not differ significantly and there was no evidence of a decline in ET-1 levels with resolution of PPHN. Pulmonary overproduction of ET-1 does not appear to be the cause of PPHN, although the endothelin system may still play a role in the pathophysiology of PPHN, probably mediated through changes in receptor expression.

An unusual hernia: congenital pericardial effusion associated with liver herniation into the pericardial sac.

To our knowledge there have been only two previous cases of diaphragmatic hernia into the pericardium diagnosed antenatally. We describe our pre- and post-natal radiological findings in such a case, although the final diagnosis eluded us until after delivery.

Interventionalists' guide to the patient's experience of lower extremity arterial occlusive disease.

This article is intended as a guide for all who propose to intervene in patients with symptomatic lower extremity arterial occlusive disease. It reviews the natural history of and therapies for intermittent claudication. The results of a survey of claudicants are summarized; this survey gathered data on claudicants' general health, comorbid conditions, symptoms of claudication, and functional abilities. Respondents predicted a 20% improvement in their ability to perform instrumental activities of daily living (eg, walking several blocks, climbing one flight of stairs, performing household tasks) if lower extremity symptoms were relieved. This level of improvement is consistent with that reported in the literature following revascularization. The conclusion is that patients with claudication have modest goals with respect to improvement following vascular intervention. More data should be collected on the functional outcomes of vascular intervention so that patients can make better informed choices regarding treatment of symptomatic lower extremity arterial occlusive disease.

Neonatal endothelin-1 concentrations in term infants.

Endothelin-1 concentrations were studied in 30 term infants during the first week of life using a radioimmunoassay kit. A neonatal reference range was established (7.5-25.7 pmol/l). No significant relation with age, sex, gestation, or birth weight was found.

Simultaneous measurement of preductal and postductal oxygen saturation by pulse oximetry in hyaline membrane disease.

Preductal and postductal oxygen saturation were compared in 20 ventilated preterm infants with hyaline membrane disease to establish the frequency of right to left shunting and to assess the accuracy of postductus arteriosus blood gas sampling. One hundred and thirty eight comparisons were made and the frequency of right to left shunting was 17% (95% confidence interval 12 to 25%). Shunting episodes with possible preductal hyperoxia occurred far less commonly on a maximum of 5% of occasions. The findings in infants under 1000 g and of 24-28 weeks' gestation were not significantly different from larger or more mature infants. Shunting occurred significantly more frequently in very ill infants who subsequently died as a result of respiratory disease.

Randomised trial of continuous nasogastric, bolus nasogastric, and transpyloric feeding in infants of birth weight under 1400 g.

Forty three infants under 1400 g were fed by a bolus nasogastric, continuous nasogastric, or transpyloric route. There were more complications with transpyloric feeding and no identifiable benefits in the growth rate, oral energy input, or chosen biochemical indices of nutrition. Bolus or continuous nasogastric feeds rather than transpyloric are better routine methods in infants of low birth weight.

Pertussis outbreaks in groups claiming religious exemptions to vaccinations.

Four recent outbreaks of pertussis in Massachusetts illustrate some features that contribute to the increased incidence of the disease. The outbreaks involved unimmunized groups of children with philosophical or religious exemptions from school or day-care immunization requirements and children and adults who were reluctant to undergo antibiotic prophylaxis or therapy. Parents and physicians should be aware that failure to immunize and to cooperate in follow-up preventive measures can have public health and potential medicolegal repercussions.

Protein C activity in severely ill newborns with congenital heart disease.

Levels of protein C functional activity were studied in twenty-nine full-term infants with symptomatic congenital heart disease, who presented in the neonatal period. Protein C levels on admission ranged from < 10% to 61% (mean 37.7% S. D. 14.1%). Eight of the twenty-nine babies had protein C levels between 1.5 and > 3.0 S. D. below the normal neonatal mean with no parental evidence of familial deficiency. Of these infants with low protein C two developed thrombotic complications and four had evidence of coagulation factor consumption. Critically ill infants were over-represented in the group with low protein C. Severely ill newborn infants with protein C at or below the lower limit of the normal neonatal range may be at increased risk of either a consumptive coagulopathy or major thrombosis.

Cell cycle kinetics of rat hepatocytes in early putative preneoplastic lesions in hepatocarcinogenesis.

This set of experiments is the first of a series designed to explore facets of cell proliferation of hepatocytes during the carcinogenic process induced in liver by chemical carcinogens. A rat model for hepatocarcinogenesis, the resistant hepatocyte model, was used. A major advantage of this model is the unusual degree of synchrony in the early steps. Carcinogenesis was initiated by the administration of a necrogenic dose of diethylnitrosamine. Resistant hepatocytes so induced were stimulated rapidly to proliferate by partial hepatectomy in the presence of a brief exposure to dietary 2-acetylaminofluorene sufficient to inhibit the proliferation of the majority of hepatocytes, the nonresistant population. Cell cycle parameters were measured in the early carcinogen-altered resistant hepatocyte populations and in regenerating hepatocytes. Growth fraction and doubling time were experimentally determined in the altered hepatocytes. The mean cell cycle length of the resistant cells was 38.6 hr, somewhat longer than that of regenerating hepatocytes, which was 33.6 hr. Most of the increase was due to a prolonged S phase which was 13.6 hr in the altered cell population as compared to 7.0 hr in hepatocytes in regenerating control liver. The hepatocytes in normal regenerating liver had a mean duration of 21.6 hr for G1 as compared to 20.4 hr for the altered hepatocytes and a G2 of 3.4 hr as compared to 3.0 hr for carcinogen-altered hepatocyte. M was assumed to be 1.6 hr in both populations. The growth fraction in the altered cell population was determined to be a minimum of 0.83, and the doubling time was about 45 hr. Thus, the resistant hepatocytes which represent an early putative preneoplastic population show, in general, a prolongation of the cell cycle, mostly due to a prolonged S phase.

Fecundability, coital frequency and the viability of Ova.

Summary An extension of Barrett and Marshall's model expressing fecundability as a function of coital pattern is proposed. In particular, this extension includes the probability that the ovum remains alive. The extended model has been applied to Barrett and Marshall's data, a series of cycles for which basal body temperature curves and the date of coitus have been recorded. It was thus possible to estimate the daily probabilities of fertilization and, under certain assumptions, the proportion of lost ova. This proportion was estimated to be above 50 per cent, and increases with age. The increase of fecundability with frequency of intercourse is more moderate than that predicted by Barrett and Marshall's model.