Circular 101

This study was made possible by the financial support of the Alaska Science and Technology Foundation

Growth Performance of Holstein Dairy Calves Supplemented with a Probiotic

Administration of antibiotics in both therapeutic and sub-therapeutic doses has been the standard practice for dealing with pathogenic bacteria problems in farm animals since the 1940s. Several types of antibiotics are currently used to promote weight gain and feed efficiency in domestic livestock. There is growing concern that the use of antibiotics as growth promoters may result in the development of resistant populations of pathogenic bacteria and, in turn, influence the therapeutic use of antibiotics. The indiscriminate and improper use of antibiotics in food-producing animals could result in the presence of residues in milk, meat, and other animal food products consumed by humans. One possible alternative to antibiotics is the use of probiotics. Probiotics can be defined as “live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance” (Fuller, 1989). Probiotics introduce beneficial microorganisms into the gut which act to maintain optimal conditions within the gastrointestinal tract and inhibit the growth of pathogenic or other undesirable bacteria

Revealed Preferences for Risk and Ambiguity

We replicate the essentials of the Huettel et al. (2006) experiment on choice under uncertainty with 30 Yale undergraduates, where subjects make 200 pair-wise choices between risky and ambiguous lotteries. Inferences about the independence of economic preferences for risk and ambiguity are derived from estimation of a mixed logit model, where the choice probabilities are functions of two random effects: the proxies for risk-aversion and ambiguity-aversion. Our principal empirical finding is that we cannot reject the null hypothesis that risk and ambiguity are independent in economic choice under uncertainty. This finding is consistent with the hypothesized independence of the neural mechanisms governing economic choices under risk and ambiguity, suggested by the double dissociation-fMRI study reported in Huettel et al.Mixed logit, Risk-aversion, Ambiguity-aversion

Is non-therapeutic aspirin use in children a problem in South Africa?

Background. Aspirin should not be used in children except for specific therapeutic reasons. We report on a severely ill infant who had ingested aspirin contained in a traditional medicine and review 21 other patients with pre-admission non-therapeutic salicylate exposure. Objectives and methods. We reviewed laboratory, clinical and poisons unit records to determine how many children were admitted to our hospital over an 18-month period with evidence of salicylate ingestion not prescribed for therapeutic reasons. We determined the source of the salicylate, elapsed time between ingestion and laboratory assay, morbidity and mortality and final diagnosis. Results. Twenty-one children meeting our criteria, including 9 under 6 months of age, were admitted during this period. The most prevalent source of salicylate was over-the-counter (OTC) aspirin, but some had reportedly only been given traditional medicines. Nineteen were seriously ill, 4 died and 3 had severe brain injury. Two, initially diagnosed with Reye’s syndrome, probably had inherited metabolic disorders. Only 2 patients had salicylate levels that at the time of measurement are normally considered toxic; however, the literature suggests that lower levels may exacerbate illness severity in young children. Conclusions. We found inappropriate use of OTC aspirin in children that requires explanation. There may be policy implications for the content and presentation of patient information; the incorporation of pharmaceuticals in traditional medicines merits further study. Salicylate toxicity should be considered in children with unexplained metabolic acidosis out of keeping with the severity of their acute illness

Public perceptions of changing the terminology for low-risk thyroid cancer: A qualitative focus group study

Objectives To investigate public perceptions of overdiagnosis and overtreatment in low-risk thyroid cancer and explore opinions regarding the proposed strategy to change the terminology of low-risk cancers. Design Qualitative study using focus groups that included a guided group discussion and presentation explaining thyroid cancer, overdiagnosis and overtreatment, and proposed communication strategies. Transcripts were analysed thematically. Setting Sydney, Australia. Participants Forty-seven men and women of various ages from a range of socioeconomic backgrounds with no personal history of thyroid cancer. Results Participants had low pre-existing general awareness of concepts of overdiagnosis and overtreatment and expressed concern regarding this new information in relation to thyroid cancer. Overall, participants understood why the strategy to change the terminology was being proposed and could see potential benefits including reducing the negative psychological impact and stigma associated with the term 'cancer'; however, many still had reservations about the strategy. The majority of the concerns were around their worry about the risk of further disease progression and that changing the terminology may create confusion and cause patients not to take the diagnosis and its associated managements seriously. Despite varied views towards the proposed strategy, there was a strong overarching desire for greater patient and public education around overdiagnosis and overtreatment in both thyroid cancer and cancer generally in order to complement any revised terminology and/or other mitigation strategies. Conclusions We found a strong and apparently widely held desire for more information surrounding the topic of overdiagnosis and overtreatment. Careful consideration of how to inform both the public and current patients about the implications of a change in terminology, including changes to patients' follow-up or treatments, would be needed if such a change were to go ahead

Revealed Preferences for Risk and Ambiguity

We replicate the essentials of the Huettel et al. (2006) experiment on choice under uncertainty with 30 Yale undergraduates, where subjects make 200 pair-wise choices between risky and ambiguous lotteries. Inferences about the independence of economic preferences for risk and ambiguity are derived from estimation of a mixed logit model, where the choice probabilities are functions of two random effects: the proxies for risk-aversion and ambiguity-aversion. [Our principal empirical finding is that we cannot reject the null hypothesis that risk and ambiguity are independent in economic choice under uncertainty. This finding is consistent with the hypothesized independence of the neural mechanisms governing economic choices under risk and ambiguity, suggested by the double dissociation-fMRI study reported in Huettel et al

Pediatric cerebral palsy in Africa: A systematic review

Cerebral palsy is a common neurologic problem in children and is reported as occurring in approximately 2-2.5 of 1000 live births globally. As is the case with many pediatric neurologic conditions, very little has been reported on this condition in the African context. Resource-limited settings such as those found across the continent are likely to result in a different spectrum of etiologies, prevalence, severity as well as management approaches. This review aims to establish what has been reported on this condition from the African continent so as to better define key clinical and research questions

Parental Understanding of Tuberous Sclerosis Complex

Tuberous sclerosis complex is a genetic disorder with multisystem involvement that poses significant challenges to the affected child and family. Caregiver knowledge in the South African population has not previously been reported. A prospective study of the parents of 21 children with tuberous sclerosis complex was undertaken. Median parental age was 38 (interquartile range 34.5-45) years. Parents were randomly allocated to receive written information about the condition, or to receive verbal counselling already established in clinic. A significant difference (P ¼ .001) was observed in the change in the mean knowledge scores for the parent group that received written information (34.2 at baseline, 51.7 at the second visit. This impact was higher in parents with an education level of at least grade 8 (P ¼ .003). Parental understanding of tuberous sclerosis complex can be improved by provision of written information and should be routinely available in a readily understandable format

Resolved lower limb muscle tone abnormalities in children with HIV encephalopathy receiving standard antiretroviral therapy

BackgroundThis short report arose from a follow-up study of children previously diagnosed with human immunodeficiency virus (HIV) encephalopathy and spastic diplegia and is among the first to describe that increased lower limb muscle tone in children with a confirmed HIV encephalopathy diagnosis may resolve over time in some cases.ResultsOf 19 children previously diagnosed with HIV encephalopathy and increased lower limb muscle tone, some were found to have resolved muscle tone abnormalities during a follow-up physical examination [resolved group, n=13, median age 9years 7months (interquartile range 7years 3months–10years 9months)] whereas others continued to show increased lower limb muscle tone at follow-up [unresolved group, n=6 median age 8years 6months (interquartile range 7years 9months–9years 7months)]. A review of clinical records showed no significant differences in age or follow-up time between the resolved and unresolved groups. However, the unresolved group appeared to have severe disease at an earlier age than the resolved group, based on the age at antiretroviral treatment initiation [median age at start of treatment 2years 3months (interquartile range 7months–5years 3months) vs. 8months (interquartile range 6–12months), p=0.08] and had more severe neurological signs at the initial assessment.ConclusionsIt is anticipated that this information may be of immediate value to those involved in the treatment of children with HIV encephalopathy and increased lower limb muscle tone whilst awaiting the outcome of future controlled clinical trials