Congenital thyrotoxicosis in premature infants

OBJECTIVES Graves' disease (GD) complicates 0.1% to 0.2% of pregnancies, but congenital thyrotoxicosis is rare occurring in one in 70 of these pregnancies independent of maternal disease status. Antenatal prediction of affected infants is imprecise; however, maternal history, coupled with a high maternal serum TSH receptor binding immunoglobulin index (TBII) predict adverse neonatal outcome. Mortality is reported to be as high as 25% in affected infants and would therefore be expected to be higher in premature infants. This study illustrates that in sick, premature, extreme low birth weight (ELBW) or intrauterine growth retarded (IUGR) infants, the diagnosis maybe overlooked especially in the absence of antenatal risk assessment and management of thyrotoxicosis in this setting is complex. DESIGN and PATIENTS The records of premature neonates born at the three main maternity units in Brisbane, between January 1996 and July 1998 diagnosed with congenital thyrotoxicosis were reviewed. Data were recorded on gestational age, birth weight (B Wt), maternal thyroid history and current status, and neonatal course. Thyroid function and TBII status was assessed using standard biochemical assays. RESULTS Seven neonates from five pregnancies were identified (four female, three male). Mean gestational age was 30 week (25-36 week) and median B Wt was 1.96 kg (0.50-2.62 kg). Only one mother received formal antenatal counselling by a paediatric endocrine service and had a TBII (54%) measured prior to delivery. Three of five mothers had elevated TBII measured after diagnosis in their offspring (57%, 65%, 83%) and in one mother, a TBII was not performed. All mothers were biochemically euthyroid at delivery. Mean age at diagnosis was 9 days (1-16 days) and mean age at commencement of treatment was 12 days (7-26 days). Two infants received propylthiouracil and five received a combination of carbimazole and propranolol. Pour became biochemically hypothyroid, in three this resolved with cessation of the antithyroid drug (ATD), and one required ongoing T4 supplementation. Only one infant required treatment for cardiac failure and there were no deaths in this cohort. CONCLUSIONS This is a large series of extremely small and premature infants with neonatal thyrotoxicosis. Presentation was nonspecific. The diagnosis was delayed because of low birth weight, prematurity, multiple birth and/or an unrecognized maternal history of Graves' disease. The treatment of neonatal thyrotoxicosis was difficult in these extreme law birth weight infants yet no infant died and significant morbidity was confined to high output cardiac failure in one infant. With antenatal recognition of past or active Graves' disease, assessment of maternal TSH receptor binding immunoglobulin index prior to delivery and postnatal monitoring of cord TSH and venous fT4 and TSH on days 4 and 7 rapid treatment of affected infants may have further reduced neonatal morbidity.

A zero-augmented gamma mixed model for longitudinal data with many zeros

In many occupational safety interventions, the objective is to reduce the injury incidence as well as the mean claims cost once injury has occurred. The claims cost data within a period typically contain a large proportion of zero observations (no claim). The distribution thus comprises a point mass at 0 mixed with a non-degenerate parametric component. Essentially, the likelihood function can be factorized into two orthogonal components. These two components relate respectively to the effect of covariates on the incidence of claims and the magnitude of claims, given that claims are made. Furthermore, the longitudinal nature of the intervention inherently imposes some correlation among the observations. This paper introduces a zero-augmented gamma random effects model for analysing longitudinal data with many zeros. Adopting the generalized linear mixed model (GLMM) approach reduces the original problem to the fitting of two independent GLMMs. The method is applied to evaluate the effectiveness of a workplace risk assessment teams program, trialled within the cleaning services of a Western Australian public hospital.

Quality of care of patients hospitalized with acute coronary syndromes

Background: Measurement and improvement of quality of care is a priority issue in health care. Patients hospitalized with acute coronary syndromes (ACS) constitute a high-risk population whose care, if shown to be suboptimal on the basis of available research evidence, may benefit from quality improvement interventions. Aim: To evaluate the quality of in-hospital care for patients with ACS, using explicit quality indicators. Methods: Retrospective case note review was undertaken of 397 patients admitted to three teaching hospitals in Brisbane, Queensland, Australia, between 1 October 2000 and 17 April 2001. The main out-come measures were 12 process-of-care quality indicators, calculated as either: (i) the proportion of all patients who received specific interventions or (ii) the proportion of ideal patients who received -specific interventions (i.e. patients with clear indi-cations and lacking contraindications). Results: Quality indicators with values above 80% included: (i) patient selection for thrombolysis (100%) and discharge prescription of beta-blockers (84%), (ii) antiplatelet agents (94%) and (iii) lipid-lowering agents (82%). Indicators with values between 50% and 80% included: (i) timely per-formance of electrocardiogram (ECG) on admission (61%), (ii) early coronary angiography (75%), (iii) measurement of serum lipids (71%) and (iv) discharge prescription of angiotensin-converting-enzyme (ACE) inhibitors (73%). Indicators with values <50% included: (i) timely administration of thrombolysis (35%), (ii) non-invasive risk assessment (23%) and (ii) formal in-hospital and post-hospital cardiac rehabilitation (47% and 7%, respectively). Conclusion: There were delays in performing ECG and administering thrombolysis to patients who presented to emergency departments with ACS. Improvement is warranted in use of non-invasive procedures for identifying high-risk patients who may benefit from coronary revascularization as well as use of serum lipid measurements, ACE inhibitors and cardiac rehabilitation.

A field study conducted at Kidston Gold Mine, to evaluate the impact of arsenic and zinc from mine tailing to grazing cattle

The grazing trial at Kidston Gold Mine, North Queensland, was aimed specifically to assess the uptake of metals from the tailing and the potential for unacceptable contamination of saleable meat. Further aims included estimating metal dose rates and identifying potential exposure pathways including plant uptake of heavy metals, mine tailings adhered to plants and direct ingestion of mine tailing. It was found that of the 11 metals analysed (As, Zn, Co, Cd, Cr, Sn, Pb, Sb, Hg, Se and Ni) in the animal's liver, muscle and blood during the 8-month trial period, only accumulation of arsenic and zinc occurred. A risk assessment including these two metals was conducted to determine the potential for chronic metal toxicity and long-term contamination, using the estimates of metal dose rate. It was concluded that no toxicity or long-term contamination in cattle was likely at this site. Management procedures were therefore not required at this site; however, the results highlight percent ground cover and standing dry matter (DM) as important factors in decreasing metal exposure from direct ingestion of tailings and dust adhered to plants. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

A probabilistic analysis of Clostridium perfringens growth during food service operations

The purpose of this study was threefold: first, the study was designed to illustrate the use of data and information collected in food safety surveys in a quantitative risk assessment. In this case, the focus was on the food service industry; however, similar data from other parts of the food chain could be similarly incorporated. The second objective was to quantitatively describe and better understand the role that the food service industry plays in the safety of food. The third objective was to illustrate the additional decision-making information that is available when uncertainty and variability are incorporated into the modelling of systems. (C) 2002 Elsevier Science B.V. All rights reserved.

An overview of APSIM, a model designed for farming systems simulation

The Agricultural Production Systems Simulator (APSIM) is a modular modelling framework that has been developed by the Agricultural Production Systems Research Unit in Australia. APSIM was developed to simulate biophysical process in farming systems, in particular where there is interest in the economic and ecological outcomes of management practice in the face of climatic risk. The paper outlines APSIM's structure and provides details of the concepts behind the different plant, soil and management modules. These modules include a diverse range of crops, pastures and trees, soil processes including water balance, N and P transformations, soil pH, erosion and a full range of management controls. Reports of APSIM testing in a diverse range of systems and environments are summarised. An example of model performance in a long-term cropping systems trial is provided. APSIM has been used in a broad range of applications, including support for on-farm decision making, farming systems design for production or resource management objectives, assessment of the value of seasonal climate forecasting, analysis of supply chain issues in agribusiness activities, development of waste management guidelines, risk assessment for government policy making and as a guide to research and education activity. An extensive citation list for these model testing and application studies is provided. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.

Key issues in determining the ethics of research subject payment: the special case of drug abuse epidemiology

The authors identify key issues that researchers, funding bodies, ethics committees and ethicists might consider in contemplating research subject payment ethics. They argue that what is missing from the broader debate is due consideration of ethics committee decision processes; research subject reasons for participation; and current research practices. The authors explore these issues and how they relate to existing guidelines on voluntary consent, and arguments that have been proposed for and against research subject payments. (non- author abstract)

Clinical and economic impact of exercise electrocardiography and exercise echocardiography in clinical practice

Background Patients with known or suspected coronary disease are often investigated to facilitate risk assessment. We sought to examine the cost-effectiveness of strategies based on exercise echocardiography and exercise electrocardiography. Methods and results We studied 7656 patients undergoing exercise testing; of whom half underwent exercise echocardiography. Risk was defined with the Duke treadmill score for those undergoing exercise electrocardiography alone, and by the extent of ischaemia by exercise echocardiography. Cox proportional hazards models, risk adjusted for pretest likelihood of coronary artery disease, were used to estimate time to cardiac death or myocardial infarction. Costs (including diagnostic and revascularisation procedures, hospitalisations, and events) were calculated, inflation-corrected to year 2000 using Medicare trust fund rates and discounted at a rate of 5%. A decision model was employed to assess the marginal cost effectiveness (cost/life year saved) of exercise echo compared with exercise electrocardiography. Exercise echocardiography identified more patients as low-risk (51% vs 24%, p<0.001), and fewer as intermediate- (27% vs 51%, p<0.001) and high-risk (22% vs 4%); survival was greater in low- and intermediate- risk and less in high-risk patients. Although initial procedural costs and revascularisation costs (in intermediate- high risk patients) were greater, exercise echocardiography was associated with a greater incremental life expectancy (0.2 years) and a lower use of additional diagnostic procedures when compared with exercise electrocardiography (especially in lower risk patients). Using decision analysis, exercise echocardiography (Euro 2615/life year saved) was more cost effective than exercise electrocardiography. Conclusion Exercise echocardiography may enhance cost-effectiveness for the detection and management of at risk patients with known or suspected coronary disease. (C) 2003 Published by Elsevier Science Ltd on behalf of The European Society of Cardiology.

Feline aortic thromboembolism

Aortic thromboembolism is one of the most serious and difficult-to-manage complications. of feline cardiac disease. Most, but not all, cats presenting with signs of aortic thromboembolism are found to have underlying cardiac disease at the time of presentation. In most cases no underlying disease has been diagnosed prior to presentation with paresis/paralysis and profound anxiety. This article will review commonly used treatments for thromboembolism and agents proposed for prophylaxis. Many of the proposed treatments are themselves associated with a high morbidity rate and long term clinical trials are required to make comparative risk-to-benefit ratio assessments of these different options. In cats which do survive the initial treatment, clinicians are still faced with the perplexing problem of long term thrombus prevention, as a majority of cats have been shown to re-embolise despite prophylaxis.

Prediction of mortality in patients without angina: Use of an exercise score and exercise echocardiography

Background Exercise testing has limited efficacy for identifying coronary artery disease (CAD) in the absence of anginal. symptoms. Exercise echocardiography is more accurate than standard exercise testing, but its efficacy in this situation has not been defined. We sought to identify whether the Duke treadmill. score or exercise echocardiography (ExE) could be used to identify risk in patients without anginal symptoms. Methods We studied 1859 patients without typical or atypical angina, heart failure, or a history or ECG evidence of infarction or CAD, who were referred for ExE, of whom 1832 (age 51 15 years, 944 men) were followed for up to 10 years. The presence and extent of ischaemia and scar were interpreted by expert reviewers at the time of the original study. Results Exercise provoked significant (>0.1 mV) ST segment depression in 215 patients (12%), and wall motion abnormalities in 137 (8%). Seventy-eight patients (4%) died before revascularization, only 17 from known cardiac causes. The independent predictors of death were age (RR 1.1, p

Quantification of Listeria spp. contamination on shell and flesh of cooked black tiger prawns (Penaeus monodon)

Aims: To quantify Listeria levels on the shell and flesh of artificially contaminated cooked prawns after peeling, and determine the efficacy of Listeria innocua as a model for L. monocytogenes in this system. Methods and Results: A L. monocytogenes and L. innocua strain were inoculated separately onto cooked black tiger prawns using two protocols ( immersion or swabbing with incubation). Prawns were peeled by two methods ( gloved hand or scalpel and forceps) and numbers of Listeria on shells, flesh and whole prawn controls were determined. Prawns were exposed to crystal violet dye to assess the penetration of liquids. Regardless of preparation method or bacterial strain there were ca 1log(10) CFU more Listeria per shell than per peeled prawn. Dye was able to penetrate to the flesh in all cases. Conclusions: Shell-on prawns may be only slightly safer than shell-off prawns. Listeria innocua is an acceptable model for L. monocytogenes in this system. Significance and Impact of the Study: Reduced risk from L. monocytogenes on prawns can only be assured by adequate hygiene or heating.