Harmonized Scenario-Based Laboratory Coding System to Guide Real-Time Public Health Actions in Quebec Province, Canada

Purpose

Effective public health (PH) response to emerging pathogens requires effective information systems integrating surveillance data from multiple sources. For laboratories, data entry of multiple variables both at pre-analytical steps and again in laboratory information systems (LIS) is time-consuming and difficult to implement in a resource-limited setting and negatively affects the timeliness of the surveillance system. We set up a simple harmonized laboratory query that summarized 22 public-health relevant scenarios and variables, reduced to a two-digit code.

Methods & Materials

Information data specialists were mobilized to integrate data from the 108 different LIS using the harmonized query, which provided timely access to COVID-19 testing indications, volumes, and positivity rates stratified by age, health region, clinical settings, outbreak context or Health-Care worker status. The information system allowed to develop multiple indicators for a better understanding of the pandemic and the COVID-19 transmission in population subgroups.

Results

Dashboards were available for public health and infection prevention and control officers in their location. Multiple stakeholders were able to interpret real-time data for more than 40 000 different qPCR tests every day. The data allowed to adjust prescription practice and promote optimal usage and plan contingencies within Quebec's qPCR lab capacities. It also served as the basis to monitor community transmission through test positivity rate in various settings. The coding system also allowed labs to easily implement sample triage, which reduced turnaround time to less than 24h for most samples. Starting May 2021, public health authorities add monitoring of the positive predictive value of rapid antigen test used at the community level to support evidence-based public health decisions about the best possible use of those assays.

Conclusion

This simple scenario-based coding system allowed timely PH and management of both sampling and processing priorities which proved most useful during surge periods. Quebec Public Health Authorities were better able to target preventive actions and to plan outreach screening activities in subpopulations, neighbourhoods, and communities, while modulating clinical criteria to get access to testing and allowing laboratories to better triage samples.

Melt Conveying in Co-rotating Twin Screw Extruders

Computational fluid dynamics (CFD) based on a finite-volume method was used to simulate three-dimensional pressure and velocity fields for non-Newtonian fluids in fully filled screw elements in a co-rotating twin screw extruder. The employed method also allows the calculation of temperature fields for non-isothermal flow which requires a non-steady state calculation.

The CFD code was first evaluated on simple flow cases such as flow of a Newtonian or non-Newtonian fluid through a cylindrical die or flow in single screw extruders equipped with different screws. The results agreed very well with analytical calculations (die flow) and experimental results (single screw extruder). In a next step, we wanted to establish the reliability of the numerical results for twin screw extruders by performing experiments on a 40 mm and a 58 mm screw diameter machine. Temperature and pressure distribution along the screw in the fully filled section in front of the die were measured. Melt conveying in several screw elements (different pitches) was studied for different materials (amorphous polystyrene and partially crystalline polypropylene) at various flow rates and screw speeds. It was attempted to measure axial pressure build-up for flow rates from nearly zero to beyond the drag capacity of the specific element. The measured bulk values of pressure were then compared to the corresponding values extracted from the CFD simulation results. So far, only isothermal calculations (at different temperatures) have been performed. The temperature profile along the screw was determined by calculating the energy dissipation in isothermal slices and converting the dissipated energy into internal energy (temperature increase, neglecting heat losses at the wall). General agreement between experimental and numerical results is good.

Complex small-world regulatory networks emerge from the 3D organisation of the human genome

The discovery that overexpressing one or a few critical transcription factors can switch cell state suggests that gene regulatory networks are relatively simple. In contrast, genome-wide association studies (GWAS) point to complex phenotypes being determined by hundreds of loci that rarely encode transcription factors and which individually have small effects. Here, we use computer simulations and a simple fitting-free polymer model of chromosomes to show that spatial correlations arising from 3D genome organisation naturally lead to stochastic and bursty transcription as well as complex small-world regulatory networks (where the transcriptional activity of each genomic region subtly affects almost all others). These effects require factors to be present at sub-saturating levels; increasing levels dramatically simplifies networks as more transcription units are pressed into use. Consequently, results from GWAS can be reconciled with those involving overexpression. We apply this pan-genomic model to predict patterns of transcriptional activity in whole human chromosomes, and, as an example, the effects of the deletion causing the diGeorge syndrome.

The impact of an epilepsy nurse competency framework on the costs of supporting adults with epilepsy and intellectual disability: findings from the EpAID study

BACKGROUND

The development of a nurse-led approach to managing epilepsy in adults with an intellectual disability (ID) offers the potential of improved outcomes and lower costs of care. We undertook a cluster randomised trial to assess the impact on costs and outcomes of the provision of ID nurses working to a designated epilepsy nurse competency framework. Here, we report the impact of the intervention on costs.

METHOD

Across the United Kingdom, eight sites randomly allocated to the intervention recruited 184 participants and nine sites allocated to treatment as usual recruited 128 participants. Cost and outcome data were collected mainly by telephone interview at baseline and after 6 months. Total costs at 6 months were compared from the perspective of health and social services and society, with adjustments for pre-specified participant and cluster characteristics at baseline including costs. Missing data were imputed using multiple imputation. Uncertainty was quantified by bootstrapping.

RESULTS

The intervention was associated with lower per participant costs from a health and social services perspective of -£357 (2014/2015 GBP) (95% confidence interval -£986, £294) and from a societal perspective of -£631 (95% confidence interval -£1473, £181). Results were not sensitive to the exclusion of accommodation costs.

CONCLUSIONS

Our findings suggest that the competency framework is unlikely to increase the cost of caring for people with epilepsy and ID and may reduce costs.

Training nurses in a competency framework to support adults with epilepsy and intellectual disability: the EpAID cluster RCT

BACKGROUND

People with an intellectual (learning) disability (ID) and epilepsy have an increased seizure frequency, higher frequencies of multiple antiepileptic drug (AED) use and side effects, higher treatment costs, higher mortality rates and more behavioural problems than the rest of the population with epilepsy. The introduction of nurse-led care may lead to improvements in outcome for those with an ID and epilepsy; however, this has not been tested in a definitive clinical trial.

OBJECTIVE

To determine whether or not ID nurses, using a competency framework developed to optimise nurse management of epilepsy in people with an ID, can cost-effectively improve clinical and quality-of-life outcomes in the management of epilepsy compared with treatment as usual.

DESIGN

Cluster-randomised two-arm trial.

SETTING

Community-based secondary care delivered by members of community ID teams.

PARTICIPANTS

Participants were adults aged 18-65 years with an ID and epilepsy under the care of a community ID team and had had at least one seizure in the 6 months before the trial.

INTERVENTIONS

The experimental intervention was the Learning Disability Epilepsy Specialist Nurse Competency Framework. This provides guidelines describing a structure and goals to support the delivery of epilepsy care and management by ID-trained nurses.

MAIN OUTCOME MEASURES

The primary outcome was the seizure severity scale from the Epilepsy and Learning Disabilities Quality of Life questionnaire. Measures of mood, behaviour, AED side effects and carer strain were also collected. A cost-utility analysis was undertaken along with a qualitative examination of carers' views of participants' epilepsy management.

RESULTS

In total, 312 individuals were recruited into the study from 17 research clusters. Using an intention-to-treat analysis controlling for baseline individual-level and cluster-level variables there was no significant difference in seizure severity score between the two arms. Altogether, 238 complete cases were included in the non-imputed primary analysis. Analyses of the secondary outcomes revealed no significant differences between arms. A planned subgroup analysis identified a significant interaction between treatment arm and level of ID. There was a suggestion in those with mild to moderate ID that the competency framework may be associated with a small reduction in concerns over seizure severity (standard error 2.005, 95% confidence interval -0.554 to 7.307; p = 0.092). However, neither subgroup showed a significant intervention effect individually. Family members' perceptions of nurses' management depended on the professional status of the nurses, regardless of trial arm. Economic analysis suggested that the competency framework intervention was likely to be cost-effective, primarily because of a reduction in the costs of supporting participants compared with treatment as usual.

LIMITATIONS

The intervention could not be delivered blinded. Treatment as usual varied widely between the research sites.

CONCLUSIONS

Overall, for adults with an ID and epilepsy, the framework conferred no clinical benefit compared with usual treatment. The economic analysis suggested that there may be a role for the framework in enhancing the cost-effectiveness of support for people with epilepsy and an ID. Future research could explore the specific value of the competency framework for those with a mild to moderate ID and the potential for greater long-term benefits arising from the continuing professional development element of the framework.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN96895428.

FUNDING

This trial was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 10. See the NIHR Journals Library website for further project information.

[Intravesical salpingiosis: case report and review of the literature]

Endosalpingiosis of the urinary bladder is a rare benign condition characterised by the presence of ectopic endosalpingeal tissue in the bladder. If histology shows two or more Müllerian-derived components, this condition is referred to as Müllerianosis.To our knowledge less than 20 cases of Müllerianosis and 5 cases of endosalpingiosis have been documented in the literature.Although the pathogenesis remains unclear, two theories exist. The implantation theory assumes that Müllerian-derived tissue gets implanted in the wall of the urinary bladder during pelvic surgery. The second theory proposes a metaplastic origin of the disease.Patients suffering from endosalpingiosis or Müllerianosis may present with symptoms such as suprapubic pain, frequent urination, dysuria or gross haematuria, possibly with a cyclical appearance.We present the case of a 40-year-old female patient, who primarily presented with painful haematuria and was diagnosed with endosalpingiosis and treated by transurethral resection. Also we review the current literature.

[Should cytoreductive nephrectomy be performed in patients with metastatic renal cell carcinoma and what is the scientific rationale?]

Between 15 and 20% of patients diagnosed with renal cell carcinoma suffer from metastatic disease by the time of diagnosis. In the immunotherapy era, the standard treatment was to perform cytoreductive nephrectomy (CN) followed by treatment with interferon α. This was based on two prospective randomized trials and their combined analysis. Since the introduction of targeted therapy, the use of CN came into question and the number of performed CN has declined. Two trials (CARMENA and SURTIME) evaluating the role of CN in the times of targeted therapy have either closed early or are recruiting slowly and will probably not be able to answer this question. Thus, we need to focus on retrospective data consisting of several analyses with large numbers of patients. These analyses all seem to show a benefit in overall survival, and adjusted for prognostic factors CN represents an independent predictor of longer survival. A correlation between expected life span and efficacy of CN has been shown with a survival rate that is three times higher after 3 years. Only patients with low performance status, low life expectancy, cerebral metastases, and old age did not benefit from CN. Furthermore, symptom control of large primary tumors without response to systemic therapy and the fact that all reports of long-term remission or long survival rates are associated with the use of CN are theoretical aspects speaking in favor of this treatment. This leads to the recommendation to perform CN in all patients with good performance status in all important guidelines.

Stochastic Model of Supercoiling-Dependent Transcription

We propose a stochastic model for gene transcription coupled to DNA supercoiling, where we incorporate the experimental observation that polymerases create supercoiling as they unwind the DNA helix and that these enzymes bind more favorably to regions where the genome is unwound. Within this model, we show that when the transcriptionally induced flux of supercoiling increases, there is a sharp crossover from a regime where torsional stresses relax quickly and gene transcription is random, to one where gene expression is highly correlated and tightly regulated by supercoiling. In the latter regime, the model displays transcriptional bursts, waves of supercoiling, and up regulation of divergent or bidirectional genes. It also predicts that topological enzymes which relax twist and writhe should provide a pathway to down regulate transcription.

Improving outcomes in adults with epilepsy and intellectual disability (EpAID) using a nurse-led intervention: study protocol for a cluster randomised controlled trial

Background

In adults with intellectual disability (ID) and epilepsy there are suggestions that improvements in management may follow introduction of epilepsy nurse-led care. However, this has not been tested in a definitive clinical trial and results cannot be generalised from general population studies as epilepsy tends to be more severe and to involve additional clinical comorbidities in adults with ID. This trial investigates whether nurses with expertise in epilepsy and ID, working proactively to a clinically defined role, can improve clinical and quality of life outcomes in the management of epilepsy within this population, compared to treatment as usual. The trial also aims to establish whether any perceived benefits represent good value for money.

Methods/design

The EpAID clinical trial is a two-arm cluster randomised controlled trial of nurse-led epilepsy management versus treatment as usual. This trial aims to obtain follow-up data from 320 participants with ID and drug-resistant epilepsy. Participants are randomly assigned either to a ‘treatment as usual’ control or a ‘defined epilepsy nurse role’ active arm, according to the cluster site at which they are treated. The active intervention utilises the recently developed Learning Disability Epilepsy Specialist Nurse Competency Framework for adults with ID. Participants undergo 4 weeks of baseline data collection, followed by a minimum of 20 weeks intervention (novel treatment or treatment as usual), followed by 4 weeks of follow-up data collection. The primary outcome is seizure severity, including associated injuries and the level of distress manifest by the patient in the preceding 4 weeks. Secondary outcomes include cost-utility analysis, carer strain, seizure frequency and side effects. Descriptive measures include demographic and clinical descriptors of participants and clinical services in which they receive their epilepsy management. Qualitative study of clinical interactions and semi-structured interviews with clinicians and participants’ carers are also undertaken.

Discussion

The EpAID clinical trial is the first cluster randomised controlled trial to test possible benefits of a nurse-led intervention in adults with epilepsy and ID. This research will have important implications for ID and epilepsy services. The challenges of undertaking such a trial in this population, and the approaches to meeting these are discussed.

Trial registration

International Standard Randomised Controlled Trial Number: ISRCTN96895428 version 1.1. Registered on 26 March 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1429-7) contains supplementary material, which is available to authorized users.

PrÉvalence Et DÉterminants De La Non-Vaccination Contre L’hÉpatite B Chez Les Adolescents Au Canada, 2013

HISTORIQUE: Le Comité consultatif national de l’immunisation (CCNI) recommande depuis 1993 la mise en place de programmes de vaccination universelle contre l’hépatite B au Canada. Depuis 1998, des programmes de vaccination universelle contre l’hépatite B sont place partout au pays. Les calendriers de vaccination systématique ne sont toutefois pas harmonisés.

OBJECTIFS: Mesurer la couverture vaccinale pour l’hépatite B rapportés et identifier les facteurs de risques associés à la non-vaccination.

MATÉRIALS/MÉTHODE: Nous avons analysé les données de 6805 adolescents de 17 ans inclus dans l’enquête nationale sur la couverture vaccinale des enfants (ENCVE) de 2013 pour identifier les facteurs socio-démographiques associés à la non-vaccination, c’est-à-dire n’avoir reçu aucune dose du vaccin contre l’hépatite B. Les variables indépendantes incluses dans l’analyse étaient les provinces et territoires, le fait que les adolescents ou les parents soient nés à l’extérieur du Canada ou non, le statut matrimonial des parents et le niveau d’éducation de ces derniers en plus du revenu familial moyen. Les rapports de cotes ont été calculés au moyen de regressions logistiques simples et multiples. Les intervalles de confiance ont été estimés par la méthode bootstrap.

RÉSULTATS: En tout, 87.9% des adolescents avaient reçu au moins une dose du vaccin. Il n’y avait pas d’association significative entre le statut socioéconomique et le statut vaccinal des enfants pour l’hépatite B. Il existe cependant des différences au niveau de couverture vaccinale pour ce vaccin entre les différentes provinces et territoires du Canada. De plus, à 17 ans le fait d’être né à l’extérieur du Canada était associé à un risque plus élevé d’être non-vacciné comparativement aux enfants nés au Canada, et ce à la limite du seuil de signification (p=0.556).

CONCLUSION: Il existe des différences entre les taux de couvertures des provinces et territoires malgré des programmes de vaccination systéma-tique contre l’hépatite B dans toutes les juridictions. Par contre, il ne semble pas y avoir d’inégalité socioéconomique en lien avec le statut vac-cinal de l’hépatite B des adolescents. Ceci est un fait encourageant pour les programmes de promotion en place dans le pays.

A simple method to overcome the inhibitory effect of heparin on DNA amplification

BACKGROUND

Genetic material from large patient cohorts is increasingly central to translational genetic research. However, patient blood samples are a finite resource and their supply and storage are often dictated by clinical and not research protocols. Our experience supports difficulty in amplifying DNA from blood stored in herparin; a scenario that other researchers may have or will encounter. This technical note describes a number of simple steps that enable successful PCR amplification.

METHODS

DNA was extracted using the Illustra Nucleon Genomic DNA Extraction Kit. PCR amplification was attempted using a number of commercially available PCR mastermixes.

RESULTS

PCR DNA amplification failed using ReddyMix™ PCR Master Mix, Thermo-Start® (Thermo Scientific Inc. US) and ZymoTaq™ (Zymo research, US) PCR mastermixes, as demonstrated absence of products on gel electrophoresis. However, using the Invitrogen™ (Thermo Scientific Inc., US) Platinum® Taq DNA Polymerase, PCR products were identified on a 1% agarose gel for all samples. PCR products were cleaned with ExoSAP-IT® (Affymetrix Inc., US) and a sequencing reaction undertaken using a standard Big Dye protocol. Subsequent genotyping was successful for all samples for alleles at the CDH1 locus.

CONCLUSION

From our experience a standard phenol/chloroform purification and using the Invitrogen™ Platinum® Taq has enabled the amplification of whole blood samples taken into lithium heparin and stored frozen for up to a month. This simple method may enable investigators to utilise blood taken in lithium heparin for DNA extraction and amplification.

Surveillance of Barrett's oesophagus: exploring the uncertainty through systematic review, expert workshop and economic modelling

OBJECTIVES

To assess what is known about the effectiveness, safety, affordability, cost-effectiveness and organisational impact of endoscopic surveillance in preventing morbidity and mortality from adenocarcinoma in patients with Barrett's oesophagus. In addition, to identify important areas of uncertainty in current knowledge for these programmes and to identify areas for further research.

DATA SOURCES

Electronic databases up to March 2004. Experts in Barrett's oesophagus from the UK.

REVIEW METHODS

A systematic review of the effectiveness of endoscopic surveillance of Barrett's oesophagus was carried out following methodological guidelines. Experts in Barrett's oesophagus from the UK were invited to contribute to a workshop held in London in May 2004 on surveillance of Barrett's oesophagus. Small group discussion, using a modified nominal group technique, identified key areas of uncertainty and ranked them for importance. A Markov model was developed to assess the cost-effectiveness of a surveillance programme for patients with Barrett's oesophagus compared with no surveillance and to quantify important areas of uncertainty. The model estimates incremental cost--utility and expected value of perfect information for an endoscopic surveillance programme compared with no surveillance. A cohort of 1000 55-year-old men with a diagnosis of Barrett's oesophagus was modelled for 20 years. The base case used costs in 2004 and took the perspective of the UK NHS. Estimates of expected value of information were included.

RESULTS

No randomised controlled trials (RCTs) or well-designed non-randomised controlled studies were identified, although two comparative studies and numerous case series were found. Reaching clear conclusions from these studies was impossible owing to lack of RCT evidence. In addition, there was incomplete reporting of data particularly about cause of death, and changes in surveillance practice over time were mentioned but not explained in several studies. Three cost--utility analyses of surveillance of Barrett's oesophagus were identified, of which one was a further development of a previous study by the same group. Both sets of authors used Markov modelling and confined their analysis to 50- or 55-year-old white men with gastro-oesophageal reflux disease (GORD) symptoms. The models were run either for 30 years or to age 75 years. As these models are American, there are almost certainly differences in practice from the UK and possible underlying differences in the epidemiology and natural history of the disease. The costs of the procedures involved are also likely to be very different. The expert workshop identified the following key areas of uncertainty that needed to be addressed: the contribution of risk factors for the progression of Barrett's oesophagus to the development of high-grade dysplasia (HGD) and adenocarcinoma of the oesophagus; possible techniques for use in the general population to identify patients with high risk of adenocarcinoma; effectiveness of treatments for Barrett's oesophagus in altering cancer incidence; how best to identify those at risk in order to target treatment; whether surveillance programmes should take place at all; and whether there are clinical subgroups at higher risk of adenocarcinoma. Our Markov model suggests that the base case scenario of endoscopic surveillance of Barrett's oesophagus at 3-yearly intervals, with low-grade dysplasia surveyed yearly and HGD 3-monthly, does more harm than good when compared with no surveillance. Surveillance produces fewer quality-adjusted life-years (QALYs) for higher cost than no surveillance, therefore it is dominated by no surveillance. The cost per cancer identified approaches pound 45,000 in the surveillance arm and there is no apparent survival advantage owing to high recurrence rates and increased mortality due to more oesophagectomies in this arm. Non-surveillance continues to cost less and result in better quality of life whatever the surveillance intervals for Barrett's oesophagus and dysplastic states and whatever the costs (including none) attached to endoscopy and biopsy as the surveillance test. The probabilistic analyses assess the overall uncertainty in the model. According to this, it is very unlikely that surveillance will be cost-effective even at relatively high levels of willingness to pay. The simulation showed that, in the majority of model runs, non-surveillance continued to cost less and result in better quality of life than surveillance. At the population level (i.e. people with Barrett's oesophagus in England and Wales), a value of pound 6.5 million is placed on acquiring perfect information about surveillance for Barrett's oesophagus using expected value of perfect information (EVPI) analyses, if the surveillance is assumed to be relevant over 10 years. As with the one-way sensitivity analyses, the partial EVPI highlighted recurrence of adenocarcinoma of the oesophagus (ACO) after surgery and time taken for ACO to become symptomatic as particularly important parameters in the model.

CONCLUSIONS

The systematic review concludes that there is insufficient evidence available to assess the clinical effectiveness of surveillance programmes of Barrett's oesophagus. There are numerous gaps in the evidence, of which the lack of RCT data is the major one. The expert workshop reflected these gaps in the range of topics raised as important in answering the question of the effectiveness of surveillance. Previous models of cost-effectiveness have most recently shown that surveillance programmes either do more harm than good compared with no surveillance or are unlikely to be cost-effective at usual levels of willingness to pay. Our cost--utility model has shown that, across a range of values for the various parameters that have been chosen to reflect uncertainty in the inputs, it is likely that surveillance programmes do more harm than good -- costing more and conferring lower quality of life than no surveillance. Probabilistic analysis shows that, in most cases, surveillance does more harm and costs more than no surveillance. It is unlikely, but still possible, that surveillance may prove to be cost-effective. The cost-effectiveness acceptability curve, however, shows that surveillance is unlikely to be cost-effective at either the 'usual' level of willingness to pay ( pound 20,000-30,000 per QALY) or at much higher levels. The expected value of perfect information at the population level is pound 6.5 million. Future research should target both the overall effectiveness of surveillance and the individual elements that contribute to a surveillance programme, particularly the performance of the test and the effectiveness of treatment for both Barrett's oesophagus and ACO. In addition, of particular importance is the clarification of the natural history of Barrett's oesophagus.

First experience with an oral combination therapy using bosentan and sildenafil for pulmonary arterial hypertension

BACKGROUND

New oral substances such as beraprost, bosentan and sildenafil have proven effective in different forms of pulmonary arterial hypertension (PAH), both alone and in combination with standard treatment such as intravenous and inhaled prostacyclins. However, there are few reports so far on the effect of a combination of exclusively oral substances. In this paper, we present our initial findings of treatment using a combination of these oral substances in a heterogeneous group of patients with different forms of PAH.

MATERIALS AND METHODS

Eleven patients with a median age of 12.9 years (5.5-54.7 years) with both idiopathic PAH and forms associated with congenital cardiac defects (PAH-CHD) with a mean pulmonary arterial pressure > 25 mmHg were enrolled in an observational, open-label, prospective, single-centre study. Either combination treatment with bosentan and sildenafil was started initially, or an existing bosentan treatment was complemented with sildenafil given as an add-on therapy. Mean doses given were 2.3 +/- 0.6 mg kg(-1) for bosentan and 2.1 +/- 0.9 mg kg(-1) for sildenafil. Clinical status, exercise capacity, and haemodynamics were assessed at baseline and at the end of the observation period after a mean follow-up time of 1.1 years (0.5-2.5 years).

RESULTS

No major side effects regarding liver function and blood pressure regulation were noted. One patient died of sudden death elsewhere. Most patients were in New York Heart Association (NYHA) functional class III. Clinical improvement was about one NYHA class (mean 2.8 +/- 0.4-1.6 +/- 0.8, P = 0.001), which was associated with an increase of transcutaneous oxygen saturation (89.9 +/- 9.9-92.3 +/- 7.1%; P = 0.037), maximum oxygen uptake (18.1 +/- 6.8-22.8 +/- 10.4 mL kg(-1) x min; P = 0.043), and 6-minute walking distance (351 +/- 58-451 +/- 119 m; P = 0.039). Mean pulmonary arterial pressure measured invasively decreased (62 +/- 12-46 +/- 18 mmHg; P = 0.041).

CONCLUSIONS

In our patient group, a combination of oral bosentan and sildenafil proved to be safe and effective. Clearly, randomized, double-blind, placebo-controlled studies are warranted to define the role and type of combination therapies in PAH.

Initial experience with bosentan (Tracleer) as treatment for pulmonary arterial hypertension (PAH) due to congenital heart disease in infants and young children

INTRODUCTION

Bosentan, a dual endothelin-receptor antagonist, has been shown to be an effective treatment option in patients with the idiopathic form of pulmonary arterial hypertension (PAH). We used bosentan as compassionate treatment in infants and young children with congenital heart disease (CHD) who had a) PAH preoperatively representing a contraindication to corrective surgery or b) persisting PAH after corrective surgery causing right heart failure and reduced exercise tolerance.

METHODS

Seven children with PAH due to CHD (median age 3.8 years; range 1.5 to 6.4 years) received 3 mg/kg/d bosentan (Tracleer) orally. Clinical, echocardiographic and hemodynamic parameters were measured and laboratory tests performed before treatment and during steady state while on treatment. Routine liver function parameters were monitored monthly.

RESULTS

Mean bosentan treatment time was 8.6+/-5 months. During bosentan therapy there were no significant adverse events. The clinical status remained stable or improved in all patients: NYHA class decreased from 2.6+/-0.6 to 1.7+/-0.6 (p<0.05). This was associated with a mean reduction of the right ventricular systolic pressure (RVSP) from 96+/-11 mmHg to 71+/-26 mmHg (p<0.05).

CONCLUSIONS

Treatment with bosentan in infants and young children with PAH due to congenital heart disease was tolerated without significant side effects and resulted in stabilization of clinical status. A significant reduction in right ventricular systolic pressure (RVSP) could be demonstrated. These results suggest that the dose regimen used is appropriate and safe for the treatment of infants and children with PAH, resulting in a reduction of pathologically increased pulmonary vascular resistance.

HBV DNA levels and transmission of hepatitis B by health care workers

BACKGROUND

Laboratory-based study funded by the Research and Development Division of the Department of Health to inform the decision making on guidelines for the conduct of exposure prone procedures (EPPs) by health care workers who are hepatitis B carriers.

OBJECTIVES

Define the quantity and nature of hepatitis B virus (HBV) DNA in hepatitis carriers whose serum does not contain hepatitis B e antigen (HBeAg) and in surgeons previously cleared to conduct EPPs who have transmitted HBV to their patients.

STUDY DESIGN

Cross-sectional survey using HBV DNA quantification, genotyping and sequencing comparing transmitting surgeons and asymptomatic carriers.

RESULTS

HBV DNA could be detected and quantified in 64.5% (136 of 211) of carriers whose serum did not contain HBeAg with a median level 3.6 log(10) copies/ml (range of 5.7 log(10) copies). Pre-core mutation appeared not to affect the HBV DNA level, however, all surgeons carried codon 28 variants and transmitted these variants to their patients. The lowest HBV DNA level in a transmitting surgeon was 4 x 10(4) copies/ml.

CONCLUSIONS

Pre-core mutations are common in carriers whose serum does not contain HBeAg and do not specifically identify carriers whose HBV DNA levels are high. It was possible to define a level of virus above which transmission of hepatitis B during conduct of EPPs could not be excluded.

Comparison of commercial assays for the quantification of HBV DNA load in health care workers: calibration differences

Until recently, carriers of hepatitis B virus (HBV) were allowed to undertake exposure prone procedures providing their serum did not contain HBeAg. However, the recent description of hepatitis B transmission events occurring from HBV-infected health care workers who conduct exposure prone procedures demonstrated that the then current Department of Health guidelines needed to be revised. As part of a series of studies carried out to determine if viral load measurements are a more secure means of assessing the conduct of exposure prone procedures, the suitability of commercially available assays for HBV DNA detection and quantification were investigated. This study describes a comparative analysis on the performances of three assays each based on a different methodology. The assays included the QUANTIPLEX HBV DNA Assay (bDNA), (Chiron Diagnostics Ltd.), the AMPLICOR HBV Monitor Test, (Roche Diagnostics Systems) and the Digene Hybrid Capture System HBV DNA Assay (Digene Corporation). Calibration curves from experiments using the Eurohep ad and ay HBV DNA standard controls indicated a close correlation between the three assays over the dynamic ranges claimed by the manufacturers, although the Quantiplex assay did appear to be over-reporting. This became more apparent when testing patients undergoing anti-viral therapy where the Quantiplex assay consistently over-reported by 0.5 log(10) when compared with the Amplicor assay. The results of this study indicate that based on its dynamic range, the Amplicor HBV Monitor test is the most appropriate assay for the routine investigation of anti-HBe carriers, which will have lower levels of HBV DNA. The investigation also highlights the need for using accepted standard HBV DNA control sera. This will be essential when using an assay to establish whether health care workers who are hepatitis B carriers can be allowed to perform exposure prone procedures under the new guidelines of the UK Department of Health.

Distinctive higher-order chromatin structure at mammalian centromeres

The structure of the higher-order chromatin fiber has not been defined in detail. We have used a novel approach based on sucrose gradient centrifugation to compare the conformation of centromeric satellite DNA-containing higher-order chromatin fibers with bulk chromatin fibers obtained from the same mouse fibroblast cells. Our data show that chromatin fibers derived from the centromeric domain of a chromosome exist in a more condensed structure than bulk chromatin whereas pericentromeric chromatin fibers have an intermediate conformation. From the standpoint of current models, our data are interpreted to suggest that satellite chromatin adopts a regular helical conformation compatible with the canonical 30-nm chromatin fiber whereas bulk chromatin fibers appear less regularly folded and are perhaps intermittently interrupted by deformations. This distinctive conformation of the higher-order chromatin fiber in the centromeric domain of the mammalian chromosome could play a role in the formation of heterochromatin and in the determination of centromere identity.

SMN gene duplication and the emergence of the SMN2 gene occurred in distinct hominids: SMN2 is unique to Homo sapiens

The spinal muscular atrophy (SMA) region on chromosome 5q13 contains an inverted duplication of about 500 kb, and deleterious mutations in the survival motor neuron 1 (SMN1) gene cause SMA, a common lethal childhood neuropathy. We have used a number of approaches to probe the evolutionary history of these genes and show that SMN gene duplication and the appearance of SMN2 occurred at very distinct evolutionary times. Molecular fossil and molecular clock data suggest that this duplication may have occurred as recently as 3 million years ago in that the position and identity repetitive elements are identical for both human SMN genes and overall sequence divergence ranged from 0.15% to 0.34%. However, these approaches ignore the possibility of sequence homogenization by means of gene conversion. Consequently, we have used quantitative polymerase chain rection and analysis of allelic variants to provide physical evidence for or against SMN gene duplication in the chimpanzee, mankind's closest relative. These studies have revealed that chimpanzees have 2-7 copies of the SMN gene per diploid genome; however, the two nucleotides diagnostic for exons 7-8 and the SMNdelta7 mRNA product of the SMN2 gene are absent in non-human primates. In contrast, the SMN2 gene has been detected in all extant human populations studied to date, including representatives from Europe, the Central African Republic, and the Congo. These data provide conclusive evidence that SMN gene duplication occurred more than 5 million years ago, before the separation of human and chimpanzee lineages, but that SMN2 appears for the first time in Homo sapiens.

Human L1 retrotransposition: cis preference versus trans complementation

Long interspersed nuclear elements (LINEs or L1s) comprise approximately 17% of human DNA; however, only about 60 of the approximately 400,000 L1s are mobile. Using a retrotransposition assay in cultured human cells, we demonstrate that L1-encoded proteins predominantly mobilize the RNA that encodes them. At much lower levels, L1-encoded proteins can act in trans to promote retrotransposition of mutant L1s and other cellular mRNAs, creating processed pseudogenes. Mutant L1 RNAs are mobilized at 0.2 to 0.9% of the retrotransposition frequency of wild-type L1s, whereas cellular RNAs are mobilized at much lower frequencies (ca. 0.01 to 0.05% of wild-type levels). Thus, we conclude that L1-encoded proteins demonstrate a profound cis preference for their encoding RNA. This mechanism could enable L1 to remain retrotransposition competent in the presence of the overwhelming number of nonfunctional L1s present in human DNA.

Evolutionary inventions and continuity of CORE-SINEs in mammals

We characterized short interspersed elements (SINEs), of the CORE-suprafamily in egg-laying (monotremes), pouched (marsupials) and placental mammals. Five families of these repeats distinguished by the presence of distinct LINE-related 3'-segments shared tRNA-like promoter and the central core region. The putative active elements were reconstructed from the alignment of genomic repeats representing molecular fossils of sequences that amplified in the past and since then underwent multiple mutations. Their mode of proliferation by retroposition was indicated by the presence of: (1) internal RNA PolIII promoter; (2) simple sequence repeated tail; (3) direct repeats; and (4) subfamilies recording the evolution of elements. The copy number of CORE-SINEs in placental genomes was estimated at about 300,000; they were highly divergent and apparently ceased to amplify before radiation of these lineages. On the other hand, among almost half a million fossil elements present in marsupials and monotremes, the youngest subfamilies could still be retropositionally active. CORE-SINEs terminate in sequence repeats of a few nucleotides similar to their 3'-segment LINE-homologues, CR1, L2 and Bov-B. These three LINE elements fall into clades distinct from that of L1 elements which, similar to their co-amplifying SINEs, end in a poly(A) tail. We propose a model in which new CORE-families, with distinct 3'-segments, are created at the RNA level due to template switching between LINE and CORE-RNA during reverse transcription. The proposed mechanism suggests that such an adaptation to the changing amplification machinery facilitated the survival and prosperity of CORE-elements over long evolutionary periods in different lineages.

Saskatchewan physicians' attitudes and knowledge regarding assessment of medical fitness to drive

BACKGROUND

Although legislation has been introduced in Saskatchewan for mandatory reporting by physicians of patients considered medically unfit to drive, little is known about physicians' attitudes, knowledge or resources with regard to evaluating medical fitness to drive.

METHODS

The objective of this study was to determine Saskatchewan physicians' attitudes, knowledge, training, resources and current educational needs with regard to evaluating medical fitness to drive. A questionnaire survey of all physicians in the province who were identified as likely to be involved in determining medical fitness to drive was conducted between October and December 1996.

RESULTS

Of the 1102 physicians who received a questionnaire, 690 (62.6%) responded, of whom 167 were excluded because they were not involved in assessing fitness to drive. Thus, 523 (55.9%) of the 935 eligible physicians surveyed completed the questionnaire. Most (57.6% [298/517]) of the respondents indicated that they do not hesitate to report patients medically unfit to drive; however, 59.5% (307/516) felt that the physician-patient relationship is negatively affected by reporting. Overall, 85.5% (444/519) of the respondents felt that restricted licensing is a fair alternative for people who might otherwise be denied a full licence. The availability of restricted licensing positively influenced the decision to report for 60.3% (313/519) of the respondents. Significantly more rural physicians than urban physicians believed that the need to drive was greater for rural residents than for urban dwellers (81.2% [95/117] v. 64.2% [257/400], p < 0.001). Physician knowledge regarding specific medical conditions and fitness to drive was generally poor. The resource most commonly used in determining medical fitness to drive was the Physicians' Guide to Driver Examination (71.1% [361/508] of respondents). The most useful continuing medical education methods indicated by physicians for assessing medical fitness to drive included conference presentations, workshops and journal articles.

INTERPRETATION

Most of the Saskatchewan physicians surveyed supported restricted licensing, and the availability of restricted licensing made them more likely to report patients considered medically unfit to drive. The physician-patient relationship was felt to be negatively affected by reporting.

CORE-SINEs: eukaryotic short interspersed retroposing elements with common sequence motifs

A 65-bp "core" sequence is dispersed in hundreds of thousands copies in the human genome. This sequence was found to constitute the central segment of a group of short interspersed elements (SINEs), referred to as mammalian-wide interspersed repeats, that proliferated before the radiation of placental mammals. Here, we propose that the core identifies an ancient tRNA-like SINE element, which survived in different lineages such as mammals, reptiles, birds, and fish, as well as mollusks, presumably for >550 million years. This element gave rise to a number of sequence families (CORE-SINEs), including mammalian-wide interspersed repeats, whose distinct 3' ends are shared with different families of long interspersed elements (LINEs). The evolutionary success of the generic CORE-SINE element can be related to the recruitment of the internal promoter from highly transcribed host RNA as well as to its capacity to adapt to changing retropositional opportunities by sequence exchange with actively amplifying LINEs. It reinforces the notion that the very existence of SINEs depends on the cohabitation with both LINEs and the host genome.

Plant S1 SINEs as a model to study retroposition

The S1 element is a plant SINE (Short INterspersed Element) that was first described and studied in Brassica napus and is widely distributed among Cruciferae, especially in species of the Brassiceae tribe. We propose that S1 amplification in Cruciferae could represent a good eukaryotic model to study retroposition. This is based on the fact that S1 elements share clear structural and evolutionary characteristics with mammalian SINEs but are present in a much lower copy number (500 loci by haploid genome for the S1 element in B. napus compared to 700,000 loci by haploid genome for the Alu element in human). This low copy number allows the characterization of a large portion of SINEs from a given plant species. This can lead to a more precise understanding of the evolutionary history of SINE amplification and can more easily allow an evaluation of the impact of retroposition on the evolution of that species. It can also lead more rapidly to the characterization of genomic elements active in transcription and retroposition so that the cellular control of these elements can be addressed. Finally, we show that the study of S1 insertion sites can reveal information on the RNA reverse transcription and integration step of the retroposition process.

A transcriptional analysis of the S1Bn (Brassica napus) family of SINE retroposons

S1Bn is a plant short interspersed element (SINE) whose amplification probably involves the reverse transcription of an RNA intermediate. In this report, we identified and characterized S1Bn transcripts from different Brassica napus tissues. Despite the presence of a consensus internal POL III promoter in a large number of genomic S1Bn elements, we observed that S1Bn transcripts are rare in B. napus cells. The use of two very sensitive methods (RT-PCR and RACE PCR) allowed the characterization of 102 independent S1Bn cDNA clones from three different tissues (shoot, root and callus). From this analysis, we conclude that the majority of S1Bn transcripts probably result from a small number of cotranscriptional events where an S1Bn element is transcribed due to its presence in a POL II transcriptional unit. Specific POL III RNA transcripts, initiating at the first 5' nucleotide of the DNA element, are also present in the tested tissues and possibly result from the transcriptional activity of as few as three genomic elements. Two of these transcripts could represent master transcripts responsible for the amplification of S1Bn subfamilies. We also observed that the population of specific POL III transcripts varies among the three tested tissues and that some transcripts appear completely tissue-specific.

Hepatitis B virus surface mutations associated with infection after liver transplantation

BACKGROUND/AIMS

Liver transplantation for chronic liver disease due to hepatitis B virus infection is associated with a high risk of graft infection, graft failure and death. Many centres restrict this procedure to those seronegative for HBV-DNA (by hybridisation assay) and use prophylactic polyclonal human hepatitis B specific immunoglobulin to prevent infection of the graft, despite the very high cost.

METHODS

We describe three patients who underwent liver transplantation for chronic HBV-related disease in whom death was due to fibrosing cholestatic hepatitis following graft infection with hepatitis B virus, despite receiving hepatitis B specific immunoglobulin. Variation within the immunodominant a epitope of HBsAg was sought by analysis of hepatitis B virus sequences and the use of a point mutation assay, following amplification from serum by the polymerase chain reaction.

RESULTS

Prior to transplantation, Cases 1 and 2 had mutations at nucleotide 1902 (codon 145), resulting in G-C substitutions, which persisted at a low level after transplantation. In Case 2 a second mutant type with a G-A substitution at nucleotide 1902, became the predominant viral type post transplant. Case 3 had exclusively wild type virus before and after transplantation. The emergence of mutant type virus in Case 2 may have occurred because of immune pressure exerted by high titre anti-HBs detectable for more than 7 months. Cases 1 and 3 received only brief courses of anti-HBs therapy. The mutant viral surface antigen was not detected by a monoclonal antibody-based assay, and therefore the choice of HBsAg assay for post-transplant monitoring of patients who receive liver grafts for hepatitis B virus disease is important.

CONCLUSIONS

A search for mutations affecting the a determinant prior to liver transplantation for HBV-related liver disease may help to identify those at risk of failure of prophylaxis. Monoclonal antibodies specific to the codon 145-mutant surface antigen might prevent graft infection, but other mutations might then emerge.

Haemoglobin-based blood substitutes and sepsis

An important concern that has received little attention is the possible increased susceptibility to bacterial infections of patients infused with cell-free haemoglobin-based blood substitutes. We show that pyridoxalated polymerised human haemoglobin promotes fulminating Escherichia coli septicaemia in mice, which draws attention to the potential danger of such products in the clinic.

Three-dimensional co-location of RNA polymerase I and DNA during interphase and mitosis by confocal microscopy

The relative three-dimensional co-location of RNA polymerase I (RPI) and DNA was studied using confocal laser scanning microscopy during interphase and all the steps of mitosis in human cancerous cells. For each step of the cell cycle, immunolabeled RPI molecules and DNA specifically stained with chromomycin A3 were simultaneously imaged at high resolution through numerous optical sections. Then, all the data obtained were used to generate transverse sections, anaglyphs and volumic representations, which are all prerequisite approaches to a representative study of the three-dimensional organization of the nucleolus and the mitotic chromosomes. Our results indicated that in the interphasic nuclei, in which DNA is organized as a regular 3-D network, RPI was present within numerous irregular spheres arranged as several twisted necklaces. During metaphase, RPI labeling was segregated into pairs of spheres and typical crescent-shaped structures; both were centrally located within the set of chromosomes. During anaphase and telophase, a typical central and symmetric arrangement of labeled structures was systematically seen among the decondensing chromosomes, arranged as a regular cylinder and as a hollow half-sphere, respectively. This typical 3-D organization of structures containing RPI relative to DNA is another strong example of the non-random organization of the genome during interphase and mitosis.

Gelatinase A expression and localization in human breast cancers. An in situ hybridization study and immunohistochemical detection using confocal microscopy

The gelatinase A (72 kDa type IV collagenase) is a matrix metallo-proteinase which degrades basement membrane collagens. Various studies emphasize its role in stromal invasion of cancers, but there is some controversy about its origin. Gelatinase A was localized by immunohistochemistry using confocal microscopy in 15 human mammary carcinomas. In addition, the cells responsible for the synthesis of this enzyme were detected by in situ hybridization. Most invasive and non-invasive tumour cells were labelled by immunohistochemistry. Of particular interest was the pattern observed in some pre-invasive areas. Gelatinase A was found in fibroblasts in close contact with pre-invasive tumour clusters. Confocal observation allowed a more precise localization of gelatinase A to the periphery of tumour clusters along the basement membranes and in peritumour fibroblasts. The malignant epithelial cells were negative by immunohistochemistry in these areas. By in situ hybridization, mRNAs encoding gelatinase A were detected only in fibroblasts in close contact with pre-invasive and well differentiated tumour clusters. These findings support the hypothesis that peritumour fibroblasts produce gelatinase A and that breast cancer cells may bind this enzyme to their cell surface and/or internalize it.

The relation between climatic temperature and sudden infant death syndrome differs among communities: results from an ecologic analysis

We examined the negative relation between temperature and the sudden infant death syndrome (SIDS) in 22 communities in seven countries. We estimated the percentage increase in SIDS rate for a 1 degree C drop in climatic temperature. The relation differed substantially among communities. In New Zealand and Australia (10 communities), the association was consistently strong; in Europe (seven communities), it varied from strong to weak; and in the USA (five communities), it was moderate or weak. We postulate that low climatic temperature indirectly increases the incidence of SIDS, particularly in countries where outdoor climatic temperature modifies the indoor temperature and clothing habits.

Three-dimensional co-localization of nucleolar argyrophilic components and DNA in cell nuclei by confocal microscopy

Silver dots deposited specifically on proteins of the nucleolar organizer regions (Ag-NOR proteins) after a one-step silver staining technique were visualized in cells in culture, in cells in smears, and in tissue sections, with a scanning laser confocal microscope working in the reflectance mode. After specific labeling of DNA with the fluorescent dye chromomycin A3, DNA and silver dots could be observed either individually or simultaneously. Therefore, it was possible to study the three-dimensional organization of nucleolar silver-stained structures relative to DNA with a high X, Y, and Z resolution. Our results showed that the argyrophilic components are organized as a twisted necklace structure within interphase nucleoli of cells in culture. We also demonstrated a striking three-dimensional symmetric disposition of NORs within the two sets of chromosomes in telophase cells. Similar results were obtained for cells in smears, although their three-dimensional organization was somewhat disturbed due to air-drying. We also demonstrated that silver dots cannot be visualized in the reflectance mode within sections of paraffin-embedded tissues. However, their simultaneous demonstration in non-confocal transmitted light, together with that of DNA in confocal mode, appeared very useful to study their localization within nuclei and mitotic chromosomes.

Power and limits of laser scanning confocal microscopy

In confocal microscopy, the object is illuminated and observed so as to rid the resulting image of the light from out-of-focus planes. Imaging may be performed in the reflective or in the fluorescence mode. Confocal microscopy allows accurate and non-destructive optical sectioning in a plane perpendicular or parallel to the optical axis of the microscope. Further digital three-dimensional treatments of the data may be performed so as to visualize the specimen from a variety of angles. Several examples illustrating each of these possibilities are given. Three-dimensional reconstitution of nuclear components using a cubic representation and a ray-tracing based method are also given. Instrumental and experimental factors can introduce some bias into the acquisition of the 3-D data set: self-shadowing effects of thick specimens, spherical aberrations due to the sub-optimum use of the objective lenses and photo-bleaching processes. This last phenomenon is the one that most heavily hampers the quantitative analysis needed for a 3-D reconstruction. We delineate each of these problems and indicate to what extent they can be solved. Some tips are given for the practice of confocal microscope and image recovery: how to determine empirically the thickness of the optical slices, how to deal with extreme contrasts in an image, how to prevent artificial flattening of the specimens. Finally, future prospects in the field are outlined. Particular mention of the use of pulsed lasers is made as they may be an alternative to UV-lasers and a possible means to attenuate photodamage to biological specimens.

Climatic temperature and variation in the incidence of sudden infant death syndrome between the Australian states

OBJECTIVE

To describe the relationship between climatic temperature and the incidence of sudden infant death syndrome (SIDS) for the Australian States and examine the extent to which differences in climatic temperature might explain the regional variation of SIDS in Australia.

DESIGN

Case series study. A generalised linear model was used to model the association between monthly average temperature and the incidence of SIDS.

SETTING

The report is population based. Data are available from all Australian States.

SUBJECTS

Cases of SIDS from birth to less than 12 months of age occurring in Queensland (1981-1987), New South Wales (1981-1987), Victoria (1984-1987), Tasmania (1975-1989), South Australia (1980-1989), and Western Australia (1980-1988).

RESULTS

Every one degree Celsius decrease in average monthly temperature within the range 9 degrees C to 25 degrees C is associated with a 10.6% (95% confidence interval, 9.6%-11.7%) increase in the incidence of SIDS. Climatic temperature accounts for 84% of the interstate variation in the rate of SIDS. After controlling for the effect of temperature, a significant overall difference in SIDS incidence remains (P less than 0.0001) for the Australian States.

CONCLUSION

Climatic temperature accounts for most but not all of the regional variation of SIDS incidence in the Australian States. The remaining variation may reflect differences in the maternal and infant characteristics of the State populations.

Sudden infant death syndrome: factors contributing to the difference in incidence between Victoria and Tasmania

OBJECTIVE

To examine how much of the difference in incidence of sudden infant death syndrome (SIDS) between Tasmania and Victoria could be accounted for by the effect of differing climatic temperature and the effect of the differing prevalence of maternal and infant characteristics in the two State populations.

DESIGN

A two population ecological comparison. Two previously published predictive models were applied to quantify the contribution of several factors to the higher incidence of SIDS in Tasmania compared with Victoria.

SETTING

A population based study involving the two Australian States of Tasmania and Victoria.

PATIENTS

The characteristics of the 1985 to 1987 live birth cohorts of Tasmania and Victoria were examined. Cases were defined as all infants dying in 1985 to 1987 whose cause of death was stated as SIDS.

RESULTS

The rate of SIDS for Tasmania and Victoria 1985 to 1987 was 3.76 per 1000 live births and 2.18 per 1000 live births respectively. Adjustment of the Tasmanian rate for the effect of the interstate difference in climatic temperature resulted in a lower Tasmanian rate of 2.92 per 1000 live births. Adjustment for the effect of interstate differences in maternal age, birthweight, infant sex, month of birth and intention to breast-feed at hospital discharge decreased the Tasmanian rate to 2.47 per 1000 live births.

CONCLUSION

Approximately 82% of the interstate difference in SIDS incidence between Tasmania and Victoria from 1985 to 1987 can be accounted for by differences in climatic temperature, maternal age, birth-weight, infant sex, month of birth and feeding intention at hospital discharge.

Interstate differences in trends in coronary mortality and risk factors in Australia

Mortality from coronary heart disease has declined by approximately 50% in Australia over the past 20 years and now accounts for approximately 25% of all deaths. Most of the decline in mortality from all causes in each State of Australia over the period 1972-1988 is due to the decline in mortality from coronary heart disease. In Tasmania, the rate of decline in mortality from all causes is significantly less in both sexes (P less than 0.01) than in the mainland States, and the discrepancy is due to a lesser decline in mortality from coronary heart disease (P less than 0.01). Trends in deaths related to hypertension show no differences between Tasmania and the other States, which suggests that the discrepancy with coronary heart disease is due to factors other than the prevalence and/or treatment of hypertension. Analysis of trends data on cigarette smoking prevalence, and cross-sectional data on plasma cholesterol levels and diet, shows that Tasmanian differences in food intake (including fat and cholesterol), in plasma cholesterol levels and (to a lesser extent) in cigarette smoking are consistent with, but are unlikely to explain completely, the slower rate of decline in mortality from coronary heart disease.