Estimating US dairy clinical disease costs with a stochastic simulation model.

A farm-level stochastic model was used to estimate costs of 7 common clinical diseases in the United States: mastitis, lameness, metritis, retained placenta, left-displaced abomasum, ketosis, and hypocalcemia. The total disease costs were divided into 7 categories: veterinary and treatment, producer labor, milk loss, discarded milk, culling cost, extended days open, and on-farm death. A Monte Carlo simulation with 5,000 iterations was applied to the model to account for inherent system variation. Four types of market prices (milk, feed, slaughter, and replacement cow) and 3 herd-performance factors (rolling herd average, product of heat detection rate and conception rate, and age at first calving) were modeled stochastically. Sensitivity analyses were conducted to study the relationship between total disease costs and selected stochastic factors. In general, the disease costs in multiparous cows were greater than in primiparous cows. Left-displaced abomasum had the greatest estimated total costs in all parities ($432.48 in primiparous cows and $639.51 in multiparous cows). Cost category contributions varied for different diseases and parities. Milk production loss and treatment cost were the 2 greatest cost categories. The effect of market prices were consistent in all diseases and parities; higher milk and replacement prices increased total costs, whereas greater feed and slaughter prices decreased disease costs.

Characteristics of potential adopters of wild horses and their willingness-to-pay for wild horses.

An overabundance of wild horses and burros on federal lands can lead to suboptimal welfare when there are insufficient forage and water resources. Placing some of these animals in private homes has been identified as a key part of the solution. A nationwide online survey completed by 2,247 current and former horse owners is used to assess the feasibility of accommodating this strategy. The survey tool addressed basic horse ownership and demographic information, previous experience with wild horses, and hypothetical wild horse adoption scenarios. Results suggest that most respondents are receptive to the idea of adopting a wild horse, with previous adopters and younger potential adopters showing greater willingness-to-pay. By reducing existing barriers to adoption, which includes educating the horse-owning public on adoption requirements, expanding the training of wild horses, and targeting certain age groups of potential adopters, our study suggests that it may be possible to increase the annual number of adoptions over current levels. With appropriate and informed strategies, enhanced welfare of privately adopted and on-range animals can be achieved.

A survey of general road transportation: How and why horses are transported in the U.S.

Horses are regularly transported in the United States (U.S.); however, how, and why horses travel by road has not been explored. Consequently, an online nationwide survey was conducted to understand 1) the most common reasons for travel; 2) the types of journeys undertaken when being transported by road in the U.S. and 3) the general management practices when transporting for 3 h or less. Responses were collected from 1294 participants with at least one response from every state in the continental U.S. The most common survey taker was a female (93.9 %), adult amateur (81.2 %), horse owner (64.6 %) who rode recreationally (33.1 %) and transported their own horse (79.4 %). The most common reasons for travel were for trail or leisure riding (34.2 %) followed by showing and competition (25.3 %); however, this varied by discipline. The most common trip duration was less than one hour (46.8 %), with only 12.4 % of the most common trip durations being 4 h or more. The most common specific horse transported by road for 3 h or less was an adult (age 5-15; 59.0 %), Quarter Horse (21.2 %), used for pleasure or trail riding (44.3 %). The biggest concern when transporting was injury to the horse (26.7 %), whilst the biggest factor when planning to travel was the weather (24.1 %). These results provide insight into why horses are being transported by road in the U.S. and that it is more common to transport horses for shorter durations.

Horse Owner Preferences for Equine Insurance Policies.

Equine life and health insurance policies provide coverage for veterinary expenses or the loss of use (or life) of a horse, making horse health care accessible to more owners. Utilizing a best-worst scaling choice experiment targeted to horse owners, the rate of insurance adoption is explored, along with factors influencing insurance decisions and willingness-to-pay for policy attributes. Results indicate owners with lower-valued horses prefer insurance policies which cover medical expenses and routine care, whereas owners with higher-valued horses are willing to pay higher premiums to insure the market value of a horse but are not willing to pay extra for programs covering routine care.

Altruism is associated with an increased neural response to agency.

Although the neural mechanisms underlying altruism remain unknown, empathy and its component abilities, such as the perception of the actions and intentions of others, have been proposed as key contributors. Tasks requiring the perception of agency activate the posterior superior temporal cortex (pSTC), particularly in the right hemisphere. Here, we demonstrate that differential activation of the human pSTC during action perception versus action performance predicts self-reported altruism.

Neural signatures of economic preferences for risk and ambiguity.

People often prefer the known over the unknown, sometimes sacrificing potential rewards for the sake of surety. Overcoming impulsive preferences for certainty in order to exploit uncertain but potentially lucrative options may require specialized neural mechanisms. Here, we demonstrate by functional magnetic resonance imaging (fMRI) that individuals' preferences for risk (uncertainty with known probabilities) and ambiguity (uncertainty with unknown probabilities) predict brain activation associated with decision making. Activation within the lateral prefrontal cortex was predicted by ambiguity preference and was also negatively correlated with an independent clinical measure of behavioral impulsiveness, suggesting that this region implements contextual analysis and inhibits impulsive responses. In contrast, activation of the posterior parietal cortex was predicted by risk preference. Together, this novel double dissociation indicates that decision making under ambiguity does not represent a special, more complex case of risky decision making; instead, these two forms of uncertainty are supported by distinct mechanisms.

Evaluation of phone-based genetic counselling in African American women using culturally tailored visual aids.

Genetic counselling (GC) services for inherited breast and ovarian cancer (HBOC) are underutilized by African American (AA) women. We sought to evaluate factors associated with knowledge gain in a sample of AA women diagnosed with early-onset breast cancer, in whom GC for HBOC was provided, using a culturally targeted genetic counselling aid (GCA). Through a cancer registry-based study, phone-based GC for HBOC was offered to AA women with breast cancer < or =50. A questionnaire to assess knowledge about HBOC was completed prior to GC. All women were provided a GCA about HBOC developed by the investigative team for use during the GC session. Following GC, a personalized summary letter was mailed to all study participants and the same knowledge questionnaire was completed. A total of 37 study participants completed the pre- and post-GC knowledge questionnaires with significant gains in knowledge following the GC process (p < 0.0001). Statistically significant factors associated with knowledge gain included earlier stage of diagnosis of breast cancer and education level. Our results indicate that phone-based GC supplemented by a culturally targeted visual aid is an effective means of improving knowledge about HBOC in young AA women with invasive breast cancer.

Ontogeny of dextromethorphan O- and N-demethylation in the first year of life.

The exponential increase in the number of drugs used to treat infant and childhood illnesses necessitates an understanding of the ontogeny of drug biotransformation for the development of safe and effective therapies. Healthy infants received an oral dose (0.3 mg/kg) of dextromethorphan (DM) at 0.5, 1, 2, 4, 6, and 12 months of age. DM and its major metabolites were measured in urine. CYP2D6 genotype was determined by polymerase chain reaction-restriction fragment length polymorphism. Genotyping data indicated a strong correlation between CYP2D6 genotype and DM O-demethylation (beta=-0.638; 95% CI: -0.745, -0.532; P<0.001). CYP2D6 activity was detectable and concordant with genotype by 2 weeks of age, showed no relationship with gestational age, and did not change with post natal age up to 1 year. In contrast, DM N-demethylation developed significantly more slowly over the first year of life. Genotype and the temporal acquisition of drug biotransformation are critical determinants of a drug response in infants.

Characteristics of Adopted Thoroughbred Racehorses in Second Careers.

The unwanted horse issue continues to be a major concern in the U.S. equine industry. Nonprofit organizations dedicated to rescuing, retraining, and rehoming unwanted horses are critical in minimizing this problem. This study utilized data collected nationwide from organizations that provide these services for thoroughbreds retired from racing to identify individual horse characteristics that influenced length of stay at the adoption facility as well as characteristics that increased the probability that an adopted horse would be returned to the facility. The results suggested that horses with fewer activity limitations were rehomed more quickly (p <  .01), as were gray horses (relative to bays, p <  .03) and stallions (relative to geldings, p <  .04). Older horses took longer to rehome (p <  .05). Interestingly, the results also suggested that gray horses were more likely to be returned to the facility postadoption (p <  .02). Results from this study could benefit thoroughbreds retired from racing, nonprofit organizations, end consumers, and the thoroughbred racing industry.

An ultrasonographic scoring method for transabdominal monitoring of ascarid burdens in foals.

REASONS FOR PERFORMING STUDY: Parascaris spp. infections can lead to life-threatening small intestinal impactions in foals. Currently available diagnostic techniques cannot estimate the magnitude of an ascarid burden, and hence identify foals potentially at risk of developing impactions. OBJECTIVES: To describe and evaluate an ultrasonographic transabdominal scoring technique for monitoring of ascarid burdens in foals and to perform a cost-benefit analysis of the application of this technique. STUDY DESIGN: A transabdominal ultrasonographic technique was validated against ascarid worm counts from 10 foals aged 162-294 days. In a treatment trial, 15 foals were randomly allocated to 3 treatment groups: ivermectin, oxibendazole and no treatment. Blinded ultrasound examinations were performed daily for 5 consecutive days following treatment. Foals were examined ultrasonographically twice by the same investigator, and by different investigators for intra- and interobserver agreement evaluation. Cost-benefit analyses identified threshold values for the probability of ascarid impactions above which the screening method becomes cost-effective. METHODS: The ultrasound technique used 3 locations along the ventral midline. An ascarid scoring system was established that assessed the magnitude of ascarid burden ranging from 1-4. The method was validated against worm burdens of 10 worms and above with calculation of diagnostic specificity, sensitivity, and predictive values. Treatment trial data were evaluated statistically using mixed model analysis. Kappa values were generated for intra- and interobserver agreement. RESULTS: Two consecutive examinations were found to detect worm burdens >10 ascarids reliably. Ascarid scores declined in response to both anthelmintic treatments, although differences were not statistically significant. Kappa values indicated fair to moderate intra- and interobserver agreements. The majority of cost-benefit analyses indicated that ultrasound examinations are cost effective when the probability of ascarid impactions is above a range of 0.0001-0.0082 (i.e. 1 in 10,000 to 8 in 1000 foals). CONCLUSIONS: The ultrasonographic screening techniques can be a useful tool for monitoring ascarid burdens in foals.

Attitudes towards implementation of surveillance-based parasite control on Kentucky Thoroughbred farms - Current strategies, awareness and willingness-to-pay.

REASONS FOR PERFORMING STUDY: Traditionally, equine parasite control has relied heavily on frequent routine anthelmintic treatments applied at regular intervals all year round. However, current recommendations aim to employ a more surveillance-based approach and it remains unknown to what extent these recommendations are being implemented on US horse farms. OBJECTIVES: To describe equine parasite control on Kentucky Thoroughbred farms and evaluate respondents' willingness to pay for various attributes of surveillance-based parasite control strategies. STUDY DESIGN: Questionnaire survey performed among the membership of the Kentucky Thoroughbred Farm Managers' Club. METHODS: The survey collected demographic data and information about current parasite control strategies. Further, respondents were asked to choose between hypothetical parasite control strategies described with a combination of different attributes: costs, time and effort needed, hypothetical disease-risk levels and hypothetical risks of anthelmintic resistance. Data were analysed with multivariable logistic analysis. RESULTS: About 26% responded to the survey (n = 112). Most respondents were concerned about anthelmintic resistance and incorporated veterinary advice in defining their deworming programme. However, almost 70% were following a traditional rotational deworming programme with little or no faecal surveillance. Respondents were willing to pay a premium for a product for which there is no known anthelmintic resistance and provided the highest possible decrease in health risks. The number of young horses on the farm, utilisation of veterinarian advice in developing a deworming programme, expressed concern about drug resistance in parasites and having documented drug resistance on the farm all associated significantly with the type of parasite control programme used. CONCLUSIONS: Traditional approaches for equine parasite control are still widely used in the Kentucky Thoroughbred industry. The data suggest that respondents were only willing to make these changes if they could be given assurance that the surveillance-based approach would prevent anthelmintic resistance and decrease health risks significantly for the horses.

Occlusion of the innominate, common carotid, and subclavian arteries: long-term results of surgical treatment.

During the 23-year period from January 1959 to February 1982, 142 patients (78 men and 64 women) underwent arterial reconstructive operations for obstruction of the brachiocephalic arteries. A single vessel was involved in 75% and multiple vessels were involved in 25% of the cases. Distal involvement of internal carotid and vertebral arteries was present in 58 (41%) patients. Transthoracic operation was performed in 43 (31%) and extrathoracic operation was performed in 99 (69%) patients. One hundred and thirty-nine patients (98%) survived, and 134 (94%) experienced relief of symptoms. Follow-up was obtained for 136 patients for periods up to 22 years (mean of 7.5 years). Of these, 113 patients remained asymptomatic, eight developed transient strokes, four developed persistent strokes, and 11 (8%) died of stroke. The mean interval after operation in the latter cases was 9.3 years. Survival rates at 5, 10, and 15 years were 85%, 58%, and 25%, respectively.

Altered clearance of theophylline in children with Down syndrome: a case series.

Down syndrome (DS) is a common cause of mental retardation resulting from trisomy 21. Previous reports have described altered pharmacokinetics and pharmacodynamics in patients with DS. The authors report six cases of infants (2-19 months) with DS who demonstrated altered theophylline pharmacokinetics. Clearance was prolonged in most of these patients. No overt toxicity to theophylline was noted in any of the cases. The authors propose that patients with DS are at increased risk for altered theophylline pharmacokinetics. The etiology for altered pharmacokinetics of theophylline may be due to the interface between normal developmental changes and pharmacogenetic differences associated with DS and/or the secondary disease states and concomitant drug therapy.

Altered phenytoin pharmacokinetics in children with severe, acute traumatic brain injury.

The purpose of this study was to determine if phenytoin protein binding and metabolism were altered in prepubescent pediatric patients within the first 10 days following severe, acute traumatic brain injury. Patients (n = 10) received phenytoin loading doses (15-20 mg/kg) followed by a maintenance regimen (7 mg/kg/day) initiated within 12 hours of the loading dose. Phenytoin serum concentrations were measured serially on days 1, 2, 3, 5, 7, 9, and 10 at 1, 6, and 12 hours. Time-invariant and time-variant Michaelis-Menten pharmacokinetic models were fit to the unbound phenytoin concentration-time data (ADAPT II). Albumin concentrations significantly decreased over time (p < 0.001) and were predictive of the phenytoin binding ratio (r2 = 0.373, p < 0.0001). The time-variant model provided a superior fit of the data in 7 patients with no difference between models in 3 patients. Rapid inhibition of metabolism (Vmaxbaseline = 2.82 +/- 2.35 mg/kg/day) was observed initially following injury. This was followed by induction of metabolism as reflected by a Vmaxinduced of 20.79 +/- 13.71 mg/kg/day, which was approximately twofold higher than reported values for nonstressed children. Children with severe, acute neurotrauma were found to have markedly altered protein binding and phenytoin metabolism.

The pharmacokinetics of oral ranitidine in children and adolescents with cystic fibrosis.

The pharmacokinetics of oral ranitidine were studied in 9 patients (ages 9.9 to 19.6 years) with cystic fibrosis (CF). Patients were evaluated at steady-state conditions, and the mean maximum serum concentration (Cmax) was 845.7 +/- 448.1 ng/mL. To adjust for the variable drug dosing used among study patients, both Cmax and area under the concentration curve (AUC) were standardized to dose (CmaxST and AUCST, respectively) and were 217.9 +/- 87.9 ng/mL and 1038.0 +/- 242.2 ng/mL.h. The elimination half-life (t1/2) was 2.7 +/- 1.4 hours, and the apparent steady-state volume of distribution (Vdss) was 4.6 +/- 1.7 L/kg. The plasma clearance was 1.022 +/- 0.290 L/kg/h. The Vdss in this study was greater than that previously reported in children with peptic ulcer disease. Statistically significant relationships between pharmacokinetic parameters and measures of disease severity were not observed in the study population. The pharmacokinetics of ranitidine in children and adolescents with CF may differ from those in children and adolescents without CF.

Pharmacokinetics and pharmacodynamics of famotidine in infants.

The pharmacokinetics and pharmacodynamics of intravenous famotidine were evaluated in 10 infants ranging from 5 to 19 days of age who had a therapeutic indication for the prophylactic treatment of stress ulceration. After a 0.5-mg/kg infusion of famotidine, timed serum (n = 6), urine (24-hour collection), and repeated measurements of gastric pH were obtained. The mean +/- standard deviation maximum plasma concentration (Cmax) was 640.66 +/- 250.66 ng/mL, the elimination half-life (t1/2 beta) was 10.51 +/- 5.43 hours, and the apparent volume of distribution at steady state (Vdss) was 0.82 +/- 0.29 L/kg. Plasma clearance (Cl) and renal clearance (ClR) were 0.132 +/- 0.061 L/hr/kg and 0.093 +/- 0.056 L/hr/kg, respectively. No significant correlations were found between t1/2 beta, Vdss, Cl, and ClR and age. Six of the nine infants who had intragastric pH monitoring maintained a gastric pH > 4 until the final 24-hour sampling point. In this study, the t1/2 beta of famotidine was prolonged and the Vdss, Cl, ClR were reduced compared with corresponding parameters in previously reported studies of children older than one year of age and adults.

Surgical management of ascending and aortic arch disease: refined techniques with improved results.

BACKGROUND: Treatment of aneurysms of the ascending aorta, arch aorta, or both is surgically challenging and has traditionally carried a high hospital mortality rate. The use of refined operative techniques, including improved grafts, enhanced myocardial protection, retrograde cerebral perfusion with circulatory arrest, transesophageal echocardiography, and control of hematologic factors, has resulted in reduced hospital mortality rates. METHODS: We conducted a retrospective analysis of records of 117 consecutive patients who underwent 118 procedures between March 1987 and September 1997, for graft replacement of the ascending or transverse aortic arch with or without aortic valve reconstruction or replacement. There were 67 men (57.3%) and 50 women (42.7%). The mean age was 61.4 years (range, 16 to 81 years). Aortic abnormalities were medial degeneration in 59 patients (50.0%), dissection in 28 patients (23.7%), atherosclerosis in 16 patients (13.6%), Marfan's syndrome in 8 patients (6.8%), and other in 7 patients (5.9%). RESULTS: The ascending aorta alone was replaced in 58 patients (49.2%), ascending and arch aorta in 56 patients (47.5%), and isolated arch aorta in 4 patients (3.4%). Twenty-six patients (22.0%) required aortic valve reconstruction, 17 patients (14.4%) had separate aortic valve replacement, and 37 patients (31.4%) received a valve conduit. Overall hospital mortality rate was 3.4% (4 of 117 patients). Postoperative complications included myocardial infarction in 3 patients (2.5%), stroke in 7 patients (5.9%), pulmonary insufficiency in 22 patients (18.6%), renal insufficiency in 4 patients (3.4%), and reoperation for bleeding in 8 patients (6.8%). There were no deep sternal wound infections. Follow-up was completed for 112 (99.1%) of 113 survivors and ranged from 1 month to 10.6 years (mean, 39.5 months). Actuarial survival for patients discharged from the hospital was 87.9%+/-3.7% (standard error of the mean) at 3 years and 79.7%+/-5.8% at 6 years. CONCLUSIONS: Graft replacement of the ascending and transverse aortic arch, although technically demanding, can be performed with low hospital mortality and morbidity rates.

Mitral valve reconstruction in the elderly population.

The technique, efficacy, and long-term results of mitral valve reconstruction have been well demonstrated and reported by Carpentier and other investigators. However, most of the results reported have been in patients aged less than 65 years. Between April 1985 and September 1988, we performed mitral valve reconstruction in 176 patients using Carpentier's classification and technique for repair. Ages ranged from 15 to 86 years (mean age, 63 years). Of the repairs, 96/176 (55%) had concomitant cardiac procedures. Patients aged 65 years or more accounted for 52% (92/176) of the population and 35% (65/176) were more than 70 years old. Hospital mortality (30 day) was 4% (4/84) in the group aged less than 65 years. Hospital mortality for the group aged more than 65 years was 12% (11/92), compared with an overall 8.5% mortality. These results suggest an increased morbidity with mitral valve repair in the patients aged more than 65 years, but this group represents an even higher risk group with mitral valve replacement.

Hemodynamic response to intentionally altered flow continuity of dobutamine and dopamine by an infusion pump in infants.

STUDY OBJECTIVE: To evaluate the effect of an intentional alteration in infusion pump flow continuity on the hemodynamic stability of infants receiving either dobutamine or dopamine. DESIGN: Prospective, open-label study. SETTING: A university-affiliated children's hospital. PATIENTS: Ten hemodynamically stable infants (age 2 wks-10 mo) in intensive care receiving dobutamine (5) or dopamine (5). Three patients received both agents and were studied at independent times. INTERVENTIONS: Dobutamine and dopamine were administered using the Flo-Gard VP pump that delivers an intentional alteration of flow continuity (rate pulse). Heart rate and mean arterial pressure (MAP) were recorded every second. Analysis was based on the measurements obtained from the first 5 minutes on the study pump and the 2 minutes before and after the rate pulse. MEASUREMENTS AND MAIN RESULTS: Although hemodynamic changes in pre- and post-rate pulses were statistically significant (p < 0.05) in some individuals, only one infant had a greater that 10% change in MAP 2 minutes after the rate pulse. Alterations in hemodynamics were not consistent among or within patients. CONCLUSION: In infants requiring dobutamine or dopamine, no clinically significant pharmacodynamic effects were associated with alteration in continuity of drug delivery caused by the single positive rate pulse. Therefore, we conclude there is no contraindication to the use of this infusion pump in hemodynamically stable infants receiving these drugs.