Experiences and impacts of out-of-pocket healthcare expenditure on remote Aboriginal families

INTRODUCTION

Aboriginal Australians face significant health disparities, with hospitalisation rates 2.3 times greater, and longer hospital length of stay, than non-Indigenous Australians. This additional burden impacts families further through out-of-pocket healthcare expenditure (OOPHE), which includes additional healthcare expenses not covered by universal taxpayer insurance. Aboriginal patients traveling from remote locations are likely to be impacted further by OOPHE. The objective of this study was to examine the impacts and burden of OOPHE for rurally based Aboriginal individuals.

METHODS

Participants were recruited through South Australian community networks to participate in this study. Decolonising methods of yarning and deep listening were used to centralise local narratives and language of OOPHE. Qualitative analysis software was used to thematically code transcripts and organise data.

RESULTS

A total of seven yarning sessions were conducted with 10 participants. Seven themes were identified: travel, barriers to health care, personal and social loss, restricted autonomy, financial strain, support initiatives and protective factors. Sleeping rough, selling assets and not attending appointments were used to mitigate or avoid OOPHE. Government initiatives, such as the patient assistance transport scheme, did little to decrease OOPHE burden on participants. Family connections, Indigenous knowledges and engagement with cultural practices were protective against OOPHE burden.

CONCLUSION

Aboriginal families are significantly burdened by OOPHE when needing to travel for health care. Radical change of government initiative and policies through to health professional awareness is needed to ensure equitable healthcare access that does not create additional financial hardship in communities already experiencing economic disadvantage.

Characterising the Aboriginal and Torres Strait Islander patient journey after a serious road traffic injury and barriers to access to compensation: a protocol

INTRODUCTION

Road safety has been a long-enduring policy concern in Australia, with significant financial burden of road trauma and evident socioeconomic disparities. Transport injuries disproportionately impact individuals in remote areas, those in lower socioeconomic situations, and Aboriginal and Torres Strait Islander populations. There is a lack of insight into transport injuries in Aboriginal and Torres Strait Islander communities, absence of Indigenous perspective in published research and limited utilisation of linked data assets to address the inequity. Aim 1 is to determine the breadth, cost and causal factors of serious injury from road traffic crashes in South Australia (SA) and New South Wales (NSW) with a focus on injury prevention. Aim 2 is to identify enablers and barriers to compensation schemes for Aboriginal and Torres Strait Islander patients in SA and NSW.

METHODS AND ANALYSIS

This study will be guided by an Aboriginal and Torres Strait Islander Governance Group, applying Knowledge Interface Methodology and Indigenous research principles to ensure Indigenous Data Sovereignty and incorporation of informed perspectives. A mixed-method approach will be undertaken to explore study aims including using big data assets and mapping patient journey.

CONCLUSION

The results of this study will provide valuable insights for the development of focused injury prevention strategies and policies tailored to Aboriginal and Torres Strait Islander communities. By addressing the specific needs and challenges faced by these communities, the study aims to enhance road safety outcomes and promote equitable access to healthcare and compensation for affected individuals and their families.

Community Engagement and Psychometric Methods in Aboriginal and Torres Strait Islander Patient-Reported Outcome Measures and Surveys-A Scoping Review and Critical Analysis

(1) Background: In healthcare settings, patient-reported outcome measures (PROMs) and surveys are accepted, patient-centered measures that provide qualitative information on dimensions of health and wellbeing. The level of psychometric assessment and engagement with end users for their design can vary significantly. This scoping review describes the psychometric and community engagement processes for PROMs and surveys developed for Aboriginal and Torres Strait Islander communities. (2) Methods: The PRISMA ScR guidelines for scoping reviews were followed, aimed at those PROMs and surveys that underwent psychometric assessment. The Aboriginal and Torres Strait Islander Quality Appraisal Tool and a narrative synthesis approach were used. (3) Results: Of 1080 articles, 14 were eligible for review. Most articles focused on a validity assessment of PROMs and surveys, with reliability being less common. Face validity with Aboriginal and Torres Strait Islander communities was reported in most studies, with construct validity through exploratory factor analyses. Methodological design risks were identified in the majority of studies, notably the absence of explicit Indigenous knowledges. Variability existed in the development of PROMs and surveys for Aboriginal and Torres Strait Islander communities. (4) Conclusions: Improvement in inclusion of Indigenous knowledges and research approaches is needed to ensure relevance and appropriate PROM structures. We provide suggestions for research teams to assist in future design.

A population framework for predicting the proportion of people infected by the far-field airborne transmission of SARS-CoV-2 indoors

The number of occupants in a space influences the risk of far-field airborne transmission of SARS-CoV-2 because the likelihood of having infectious and susceptible people both correlate with the number of occupants. This paper explores the relationship between occupancy and the probability of infection, and how this affects an individual person and a population of people. Mass-balance and dose-response models determine far-field transmission risks for an individual person and a population of people after sub-dividing a large reference space into 10 identical comparator spaces. For a single infected person, the dose received by an individual person in the comparator space is 10 times higher because the equivalent ventilation rate per infected person is lower when the per capita ventilation rate is preserved. However, accounting for population dispersion, such as the community prevalence of the virus, the probability of an infected person being present and uncertainty in their viral load, shows the transmission probability increases with occupancy and the reference space has a higher transmission risk. Also, far-field transmission is likely to be a rare event that requires a high emission rate, and there are a set of Goldilocks conditions that are just right when equivalent ventilation is effective at mitigating against transmission. These conditions depend on the viral load, because when they are very high or low, equivalent ventilation has little effect on transmission risk. Nevertheless, resilient buildings should deliver the equivalent ventilation rate required by standards as minimum.

Cystatin C as a biomarker for cardiorenal syndrome diseases quantitative diagnostics and monitoring via point-of-care

With heart failure (HF) and renal malfunction becoming global public health issues, there is an urgent need to monitor diseases at home or in the community. Point-of-care testing (POC) would shorten the patients waiting time compared with laboratory molecular analysis. This work evaluates two types of gold nanomaterials, and two assay protocols, to develop a lateral flow (LF) system for Cystatin C (CysC) quantification. Of the protocols, the 'delayed-release' shows the alleviation of the hook effects with 1% BSA running buffer (RB), albeit at increased complexity with three steps of washing. The standard method with sample dilution (1: 150 sample dilution for GNPs, and 1:10 sample dilution for GNRs) can ensure the clinical range detection of CysC as 1 mg/L with partial LF assays. GNPs have stronger optical signal intensity compared with GNRs and developed full LF assays with GNPs require 1:1.5 sample dilution in recombinant Cys C detection. The ideal sample dilution ratio is different for partial and full LF assays. Clinical Relevance- This work is the basis of future work that will use LF devices for human serum/plasma monitoring to assess kidney function related to heart failure during medication. The specificity, sensitivity, and limit of detection will be validated via a clinical trial before potential clinical use.

Modelling uncertainty in the relative risk of exposure to the SARS-CoV-2 virus by airborne aerosol transmission in well mixed indoor air

We present a mathematical model and a statistical framework to estimate uncertainty in the number of SARS-CoV-2 genome copies deposited in the respiratory tract of a susceptible person, ∑ n , over time in a well mixed indoor space. By relating the predicted median ∑ n for a reference scenario to other locations, a Relative Exposure Index (REI) is established that reduces the need to understand the infection dose probability but is nevertheless a function of space volume, viral emission rate, exposure time, occupant respiratory activity, and room ventilation. A 7  h day in a UK school classroom is used as a reference scenario because its geometry, building services, and occupancy have uniformity and are regulated. The REI is used to highlight types of indoor space, respiratory activity, ventilation provision and other factors that increase the likelihood of far field ( > 2  m) exposure. The classroom reference scenario and an 8  h day in a 20 person office both have an REI ≃ 1 and so are a suitable for comparison with other scenarios. A poorly ventilated classroom (1.2 l s^-1 per person) has REI > 2 suggesting that ventilation should be monitored in classrooms to minimise far field aerosol exposure risk. Scenarios involving high aerobic activities or singing have REI > 1 ; a 1  h gym visit has a median REI = 1 . 4 , and the Skagit Choir superspreading event has REI > 12 . Spaces with occupancy activities and exposure times comparable to those of the reference scenario must preserve the reference scenario volume flow rate as a minimum rate to achieve REI = 1 , irrespective of the number of occupants present.

An ovine model for total hip replacement: operative procedure and complications

A cranio-lateral curvilinear incision in the skin was centered over the greater trochanter. The subsequent approach to the acetabulum involved blunt dissection and avoided the need for significant muscular incision. The major post-operative complications encountered were fracturing of the proximal (2/37) and distal femur (4/37), caudal neuropathy (2/37) and septic femoral stem loosening (1/37). At two years post-operatively, the morbidity rate was 24% and the mortality rate 19%.

A regime of analgesia, involving constant infusion of xylazine, was developed and appeared very effective.

Thirty-seven mature Merino wethers were utilized for an evaluation of a new acetabular cup design using a modular cemented total hip replacement system. The ovine model for total hip replacement provided a reliable and manageable method for the evaluation of component design and tissue response.

The alanine detector in BNCT dosimetry: dose response in thermal and epithermal neutron fields

PURPOSE

The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different neutron beams to explore the alanine dose response behavior and to validate model predictions. Additionally, application in medical neutron fields for boron neutron capture therapy is discussed.

METHODS

Alanine detectors have been irradiated in the thermal neutron field of the research reactor TRIGA Mainz, Germany, in five experimental conditions, generating different secondary particle spectra. Further irradiations have been made in the epithermal neutron beams at the research reactors FiR 1 in Helsinki, Finland, and Tsing Hua open pool reactor in HsinChu, Taiwan ROC. Readout has been performed with electron spin resonance spectrometry with reference to an absorbed dose standard in a (60)Co gamma ray beam. Absorbed doses and dose components have been calculated using the Monte Carlo codes fluka and mcnp. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using the Hansen & Olsen alanine response model.

RESULTS

The measured dose response of the alanine detector in the different experiments has been evaluated and compared to model predictions. Therefore, a relative effectiveness has been calculated for each dose component, accounting for its dependence on particle type and energy. Agreement within 5% between model and measurement has been achieved for most irradiated detectors. Significant differences have been observed in response behavior between thermal and epithermal neutron fields, especially regarding dose composition and depth dose curves. The calculated dose components could be verified with the experimental results in the different primary and secondary particle fields.

CONCLUSIONS

The alanine detector can be used without difficulty in neutron fields. The response has been understood with the model used which includes the relative effectiveness. Results and the corresponding discussion lead to the conclusion that application in neutron fields for medical purpose is limited by its sensitivity but that it is a useful tool as supplement to other detectors and verification of neutron source descriptions.

The effect of increased dietary fruit and vegetable consumption on endothelial activation, inflammation and oxidative stress in hypertensive volunteers

BACKGROUND AND AIMS

Public health campaigns recommend increased fruit and vegetable (FV) consumption as an effective means of cardiovascular risk reduction. During an 8 week randomised control trial among hypertensive volunteers, we noted significant improvements in endothelium-dependent vasodilatation with increasing FV consumption. Circulating indices of inflammation, endothelial activation and insulin resistance are often employed as alternative surrogates for systemic arterial health. The responses of several such biomarkers to our previously described FV intervention are reported here.

METHODS AND RESULTS

Hypertensive volunteers were recruited from medical outpatient clinics. After a common 4 week run-in period during which FV consumption was limited to 1 portion per day, participants were randomised to 1, 3 or 6 portions daily for 8 weeks. Venous blood samples for biomarker analyses were collected during the pre and post-intervention vascular assessments. A total of 117 volunteers completed the 12 week study. Intervention-related changes in circulating levels of high sensitivity C-reactive protein (hsCRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), von Willebrand factor (vWF) and plasminogen activator inhibitor-1 (PAI-1) did not differ significantly between FV groups. Similarly, there were no significant between group differences of change in homeostasis model assessment (HOMA) scores.

CONCLUSIONS

Despite mediating a significant improvement in acetylcholine induced vasodilatation, increased FV consumption did not affect a calculated measure of insulin resistance or concentrations of the circulating biomarkers measured during this study. Functional indices of arterial health such as endothelium-dependent vasomotion are likely to provide more informative cardiovascular end-points during short-term dietary intervention trials.

Long-term effects of feeding diets without mineral phosphorus supplementation on the performance and phosphorus excretion in high-yielding dairy cows

The objective of this study was to assess the long-term effects of feeding a diet with no mineral phosphorus (P) supplementation on performance and P excretion in high-yielding dairy cows. In exp. 1, 24 primiparous (PP) and 40 multiparous (MP) Holstein cows were allocated to one of two treatments at calving: (1) regular corn silage and alfalfa haylage based milking cow total mixed ration (TMR; 0.42% P diet) or (2) milking cow total mixed ration (TMR) without supplemental mineral P (0.35% P diet) in a completely randomized design. The trial lasted until after two lactations were completed or the cow was culled. In exp. 2, eight MP Holstein cows (108 ± 8.0 d in milk) were used to determine P digestibility and retention in a completely randomized block design. In exp. 1, the 0.35% P diet cows had lower body weight, body condition score and milk urea nitrogen and higher faecal P than the 0.42% P cows. The dry matter intake (DMI) of PP cows on the 0.35% P diet was lower than that of PP cows on the 0.42% P diet. There was no difference in the DMI of MP cows. The P intake of 0.35% P diet PP cows was 30% lower than that of 0.42% P diet PP cows. The P intake of 0.35% P diet MP cows was 20% lower than that of 0.42% P diet MP. The digestibility coefficient of P for the 0.35% P diet was higher than that for the 0.42% P diet. These results suggest that the forages used in the present study contained adequate amounts of P to sustain milk production in high-yielding MP cows. However, for PP cows some mineral P supplementation is recommended especially during early lactation. Key words: Phosphorus, environmental pollution, intensive dairy operations

Final results of a phase I clinical trial of the bioreductive drug RH1

2514

Background: RH1 (2,5-diaziridinyl-3-[hydroxymethyl]-6-methyl-1,4-benoquinone) is a novel bioreductive drug which is activated by the two electron reductase, DT-diaphorase (DTD) (NAD(P)H:quinone oxidoreductase). DTD is over-expressed in many tumors relative to normal tissue, especially lung, breast and colorectal tumors, so it is hoped that RH1 is selectively activated in such tumours with minimal normal tissue toxicity. Methods: Under the auspices of the CR-UK Drug Development Office, a dose escalation phase I trial of RH1 was performed at two centres. The primary objective was to establish the maximum tolerated dose (MTD) of RH1 given as a 10–30 minute infusion for 5 days every 3 weeks. Toxicity was assessed according to NCI CTC V2.0 criteria. Secondary objectives were to determine RH1 pharmacokinetics (PK), DNA cross-linking in peripheral blood lymphocytes and tumour cells, DTD activity in tumour, NQO1 polymorphism status and document any anti-tumour activity. Results: Eighteen patients of WHO performance status 0–1 with advanced refractory solid malignancies were enrolled. 14 patients were male and eight patients had colorectal adenocarcinoma. The MTD was 1,430 mcg/m2/day and the dose-limiting toxicity (DLT) was bone marrow suppression. DLT occurred in both patients treated at 1,905 mcg/m2/day: one developed grade 3 thrombocytopenia with haemorrhage and grade 3 anaemia; the other died from neutropenic sepsis. Other clinically significant drug-related toxicities included moderate phlebitis and fatigue. Plasma PK analysis on days 1 and 5 in cycle 1 showed rapid plasma clearance of RH1 (t1/2=12.3 mins) with AUC increasing proportionately with dose. The comet-X assay showed increases in DNA inter-stand cross-linking in peripheral blood lymphocytes treated at 200 mcg/m2/day or above. These cross-links were detectable within one hour of commencement of dosing and reached a maximum of 30%. DNA cross-linking after RH1 was seen in tumour samples, even with low levels of DTD. One patient was homozygous for the NQO1 polymorphism. No objective tumour responses were recorded. Conclusions: The MTD of 1,430 mcg/m2/day is the dose recommended for phase II clinical trials. Tested doses were associated with DNA cross-linking in both peripheral blood lymphocytes and tumour cells.

No significant financial relationships to disclose.

A systematic review of guidelines for the prevention of heat illness in community-based sports participants and officials

This paper presents the findings of a systematic review of guidelines on preventing heat illness in sports participants and officials. University library databases and Internet sources were searched for guidelines pertaining to community-based sports, and occupational health and safety, using a comprehensive list of search terms. Guidelines were included if they met the criteria of English language, full text and fully referenced, and dealt specifically with, or could be extrapolated to, prevention of heat illness in sports participants and officials. Guideline inclusion was evaluated by two independent reviewers, who also independently assessed guideline quality using the AGREE instrument. Common guideline themes were identified by synthesis and recommendations for each theme were extracted. A synthesis of recommendations for common themes was then undertaken. Thirteen eligible guidelines were included. Thirty-two guidelines were excluded, as they did not provide sufficient information on construction or references. The methodological quality of the included guidelines was variable. The evidence-base of the guidelines varied, reflecting primary and secondary research. While five common heat-illness prevention themes were identified (fluid intake, heat limits, clothing, acclimatisation, precautionary interventions), variable recommendations were made pertaining to these themes. This potentially reflected the variable underpinning evidence of the guidelines. This review highlighted the need for better quality guideline construction related to defensible and transparent evidence sources regarding sports participation in hot weather. The synthesised recommendations cautiously provide a framework of current best evidence upon which sporting organisations internationally can base strategies for safe participation in the heat.

Prevalence of hot weather conditions related to sports participation guidelines: A South Australian investigation

BACKGROUND

There is scant guidance in the literature on the most appropriate Australian measures of, and thresholds for, extreme heat regarding giving advice on safe sports participation in hot weather. The purpose of this paper is to present a process for investigating two common measures of heat (air temperature, wet bulb globe temperature (WGBT)) in one state in Australia (South Australia), regarding their usefulness in making decisions regarding sports participation in the heat.

METHOD

Commonly reported measures and thresholds of extreme heat were identified from a systematic review of guidelines regarding sports participation in hot weather. Dry air temperature (threshold of 35 degrees C), and WBGT index (threshold of 28 degrees C) were highlighted. Repeated daily measures of dry air temperature by the Bureau of Meteorology (BoM) and WBGT index from 12 meteorological recording sites in South Australia (SA) for four consecutive summer periods (2000-2004) were analysed using these thresholds to investigate the prevalence of extremely hot temperatures in SA during these periods. The extremely hot hours-per-day data were standardised using a denominator of per-day-month across the 12 SA recording regions.

RESULTS

Across the four summer seasons of data in SA, there were similar standardised numbers of hours-per-day of extremely hot dry air temperature and WBGT index. There was a high correlation between these hours of hot weather measures, highlighting the congruence between hot air and humidity measures. Three distinct regional site groupings were identified, in which there was a different prevalence of extremely hot weather conditions.

CONCLUSION

In SA, dry air temperature is an appropriate and robust measure of extreme heat related to sports participation, this measure providing as much information as WBGT in identifying extremely hot periods of weather. Dry air temperature can be readily measured by sports participants or officials irrespective of the geographical location in SA. Three SA regions demonstrated distinct differences in prevalence of extremely hot conditions, suggesting the need for site-specific interpretation of heat participation guidelines to ensure sports safety in hot weather. Other states in Australia could use the approach outlined in this paper to identify the most appropriate measure of extreme heat relevant to local conditions, and to assist in interpreting heat limit guidelines in a local context.

Differences in risk factors between early and late diagnosed developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia of the hip (DDH) is common, affecting 7.3 per 1000 births in South Australia. Clinical screening programmes exist to identify the condition early to gain the maximum benefit from early treatment. Although these screening programmes are effective, there are still cases that are missed. Previous research has highlighted key risk factors in the development of DDH.

OBJECTIVE

To compare the risk factors of cases of DDH identified late with those that were diagnosed early.

METHODS

A total of 1281 children with DDH born in 1988-1996 were identified from the South Australian Birth Defects Register. Hospital records of those who had surgery for DDH within 5 years of life were examined for diagnosis details. Twenty seven (2.1%) had been diagnosed at or after 3 months of age and were considered the late DDH cases (a prevalence of 0.15 per 1000 live births). Various factors were compared with early diagnosed DDH cases.

RESULTS

Female sex, vertex presentation, normal delivery, rural birth, and discharge from hospital less than 4 days after birth all significantly increased the risk of late diagnosis of DDH.

CONCLUSIONS

The results show differences in the risk factors for early and late diagnosed DDH. Some known risk factors for DDH are in fact protective for late diagnosis. These results highlight the need for broad newborn population screening and continued vigilance and training in screening programmes.

Effects of pre-eclampsia on maternal plasma, cerebrospinal fluid, and umbilical cord urotensin II concentrations: a pilot study † †This work was presented at the Liverpool meeting of the Anaesthetic Research Society, July 8–9, 2004 (E. Cowley, J. Waugh, N. Ali, P. Sharpe, J. P. Thompson and D. G. Lambert. Urotensin II concentrations are not elevated in pre-eclampsia. Br J Anaesth 2004; 612P)

BACKGROUND

Urotensin II (UII) is the most potent endogenous vasoconstrictor identified to date. Pre-eclampsia is associated with arteriolar vasospasm but the precise underlying mechanism is uncertain and we hypothesized that UII concentrations might also be elevated. In this study we measured UII concentrations in maternal plasma and cerebrospinal fluid (CSF), and umbilical vein plasma from pre-eclamptic (PET) and normotensive patients undergoing elective Caesarean section under spinal or combined spinal-epidural anaesthesia.

METHODS

With LREC approval and informed consent we recruited two groups of 10 patients; control [mean (range) age, 29 (22-43) yr; BMI, 25 (20-32); gestation, 273 (267-281) days; mean arterial pressure (MAP) on day of delivery, 81 (75-96) mm Hg] and PET [age, 34 (22-40) yr; BMI, 25 (21-46); gestation, 253 (203-289) days; MAP on day of delivery, 106 (88-128) mm Hg]. Maternal blood and CSF samples and umbilical vein blood samples were taken. UII was extracted and concentrations measured using a radioimmunoassay.

RESULTS

Two plasma and two CSF samples in the control and two CSF samples in the PET group were below the assay detection limits. There were no differences in maternal plasma or CSF or umbilical vein UII concentrations between the groups. However, there was a small ( approximately 40%) but significant increase in cord UII concentrations when compared with paired plasma in the PET group. There was a weak but significant negative correlation (r=-0.4, P=0.049) between cord UII concentrations and gestation in the PET group. In addition, we observed a significant positive correlation between plasma and CSF (r(2)=+0.57, P=0.0009, n=16), plasma and cord (r(2)=+0.43, P=0.0031, n=18) and CSF and cord (r(2)=+0.32, P=0.022, n=16) UII concentrations for the whole data set.

CONCLUSIONS

Collectively the data indicate that UII concentrations do not increase in PET compared with controls but, in PET patients, cord UII concentrations are elevated relative to paired plasma samples. Elevated umbilical vein UII concentrations may simply indicate reduced placental viability and possibly UII metabolism as a result of reduced blood flow or possibly that the placenta is producing UII.

A South Australian population-based study of congenital talipes equinovarus

The aims of this study were to provide a population-based prevalence for congenital talipes equinovarus (CTEV), to conduct an epidemiological investigation into the risk factors for CTEV and describe associated features. The study used a retrospective case-control design of CTEV notified to the South Australian Birth Defects Register between 1986 and 1996 inclusive, linking characteristics of mother and baby from the perinatal data collection. The prevalence of isolated CTEV was 1.1/1000 total births (n = 231). Four factors were significantly associated with an increased risk of CTEV: maternal Aboriginal race (ORadj = 2.0; 95% CI 1.1, 3.6), male gender (ORadj = 2.4; 95% CI 1.8, 3.2), maternal anaemia (ORadj = 1.8; 95% CI 1.0, 2.9) and maternal hyperemesis (ORadj = 3.6; 95% CI 1.3, 9.8). The prevalence of CTEV associated with another birth defect or syndrome (n = 157) was 0.7/1000 total births. CTEV was associated with specific birth defects and also with oligohydramnios when another birth defect was present.

Cross-talk between Msx/Dlx homeobox genes and vitamin D during tooth mineralization

Rickets is associated with site-specific disorders of enamel and dentin formation, which may reflect the impact of vitamin D on a morphogenetic pathway. This study is devoted to potential cross-talk between vitamin D and Msx/Dlx transcription factors. We raised the question of a potential link between tooth defects seen in mice with rickets and Msx2 gene misexpression, using mutant mice lacking the nuclear vitamin D receptor as an animal model. Our data showed a modulation of Msx2 expression. In order to search for a functional impact of this Msx2 misexpression secondary to rickets, we focused our attention on osteocalcin as a target gene for both vitamin D and Msx2. Combining Msx2 overexpression and vitamin D addition in vitro, we showed an inhibitory effect on osteocalcin expression in immortalized MO6-G3 odontoblasts. Finally, in the same cells, such combinations appeared to modulate VDR expression outlining the existence of complex cross-regulations between vitamin D and Msx/Dix pathways.

Intravesical pH: a potentially important variable affecting efficacy and the further development of anthracycline chemotherapy for superficial bladder cancer

OBJECTIVE

To assess, using epirubicin-sensitive and multidrug resistant (MDR) derivatives of human bladder cancer cell lines in vitro, the probable effect of intravesical pH changes, with and without the MDR antagonist verapamil, on the uptake, intracellular distribution and cytotoxicity of epirubicin during intravesical chemotherapy.

MATERIALS AND METHODS

Incubations for cytotoxicity testing were carried out in buffered medium containing epirubicin, at pH values of 6.0-8.5, with verapamil where appropriate. The cytotoxicity of epirubicin, with and without verapamil, was determined using the tetrazolium cytotoxicity assay. Intracellular epirubicin fluorescence was assessed using flow cytometry and confocal microscopy. Flow cytometric total intracellular epirubicin fluorescence was measured at pH 6.0, 6.4, 6.8, 7.2, and 7.6, and confocal microscopy was carried out at pH 6.0 and 8.0. The MDR-reversing agent verapamil was added at 100 micro g/mL to some incubations.

RESULTS

Epirubicin cytotoxicity in resistant cell lines appears considerably enhanced by adding verapamil and further improved, especially in MDR cells, by alkalinization of the drug solution to pH 8.0. Flow cytometry results showed striking and consistent differences in epirubicin handling with pH. Sensitive cells can be induced to absorb considerably more drug at alkaline pH, whilst resistant cells show no such behaviour. Nuclear drug fluorescence was greater in sensitive cells at alkaline pH, but cytoplasmic drug fluorescence in the resistant cells was little changed by pH. Adding verapamil to resistant cells restored the sensitive phenotype of drug handling.

CONCLUSION

Buffering epirubicin to an alkaline pH before intravesical application should increase its intrinsic cytotoxicity. The potential for synergy at certain drug combinations will be enhanced by applying these findings. MDR reversal and fatty acid augmentation of drug uptake are discussed as examples.

Iontophoretically applied lidocaine and the prevention of pain associated with the injection of intravenous propofol: a comparison with intravenous lidocaine

BACKGROUND AND OBJECTIVE

Pain following the injection of propofol is a common problem. It is often treated by the coadministration of intravenous lidocaine. Iontophoresis, which facilitates the delivery of charged molecules such as lidocaine to body tissues, may be a practical alternative to lessen the pain.

METHODS

The iontophoretic application of lidocaine was compared with intravenous lidocaine to assess the relative efficacy of reducing pain during propofol administration.

RESULTS

The incidence rate of moderate or severe pain was significantly greater in the iontophoresis group (26.7 compared with 6.9% in the intravenous lidocaine group) (P < 0.05).

CONCLUSIONS

The iontophoretic administration of lidocaine 60 mg does not compare favourably with lidocaine 40 mg mixed with propofol for the reduction of pain on administration of propofol.

Longitudinal changes in isokinetic leg strength in 10-14-year-olds

This study used multilevel regression modelling to longitudinally investigate the influences of age, sex, body size, skinfold thicknesses and maturity on the development of isokinetic knee extension and flexion on eight occasions over a 4-year period. Forty-one subjects (20 boys and 21 girls) were measured and 295 isokinetic leg strength tests and associated measures were successfully completed. Subjects were aged 10.0 +/- 0.3 years at the onset of the study. Stature, body mass, triceps and subscapular skinfold thicknesses, and sexual maturation (according to pubic hair development) were assessed at each test occasion. Isokinetic concentric knee extension and flexion of the dominant leg were determined to elicit maximal peak extension (PET) and flexion torque (PFT). Statistical significance was accepted at p < 0.05. Multilevel regression modelling indicated that stature and mass were significant predictors of both PET and PFT. Age and maturity were non-significant explanatory variables once stature and mass had been accounted for. Skinfold thickness exerted a significant negative effect independent of mass and stature on PFT but not PET. At test occasion 8, cross-sectional areas (CSAs) of the knee extensors (ExCSA) and flexors (FlexCSA) were determined using magnetic resonance imaging on 23 boys and 14 girls and examined as predictors of isokinetic leg strength. There were no significant sex-related differences in PET or PFT. Pearson product moment correlation coefficients indicated a significant relationship between ExCSA and PET and FlexCSA and PFT for both boys and girls. Analysis of covariance (ANCOVA) demonstrated that ExCSA and FlexCSA were significant explanatory variables for PET and PFT, respectively, but became non-significant once stature and mass had been introduced into the analysis. To conclude, there were no significant sex differences in PET or PFT between the ages of 10 and 14 years and the development of PET and PFT could be accounted for by the increase in stature and mass. Age, maturity and thigh muscle CSA were all non-explanatory variables in the production of PET and PFT once body size had been controlled for.

Analgesia for circumcision in a paediatric population: comparison of caudal bupivacaine alone with bupivacaine plus two doses of clonidine

BACKGROUND

Clonidine is often used to improve the duration and quality of analgesia produced by caudal epidural blockade, although the optimum dose of clonidine with bupivacaine remains uncertain.

METHODS

We compared the effect of clonidine, 1 and 2 microg x kg(-1), added to bupivacaine (1.25 mg x kg(-1)) with that of bupivacaine alone in 75 male children undergoing elective circumcision.

RESULTS

There was a trend towards increasing duration of analgesia with increasing dose of clonidine [group B (bupivacaine) 280.7 (171.6) min, C1 (bupivacaine + clonidine 1 microg x kg(-1)) 327.8 (188.3) min and C2 (bupivacaine + clonidine 2 microg x kg(-1)) 382.0 (200.6) min], although this difference was not statistically significant. Mean time to arousal from anaesthesia was significantly prolonged with clonidine 2 microg kg(-1) (group C2 21.3 (13-36) min, group C1 14.0 (6-25) min and group B 14.4 (2-32) min. Supplementary analgesic requirements and incidence of adverse effects were low, with no differences between the groups.

CONCLUSIONS

For paediatric circumcision, under general anaesthesia, the addition of clonidine 2 microg x kg(-1) to low volume (0.5 ml x kg(-1)) caudal anaesthetics has a limited clinical benefit for children undergoing circumcision.

Changes in short-term power output in 10- to 12-year-olds

In this study, we used multi-level regression modelling to assess the influence of age, sex, body size, skinfold thicknesses, maturity, thigh muscle volume and isokinetic leg strength on the development of load- and inertia-adjusted peak (1 s) and mean power (30 s) determined using the Wingate anaerobic test. Fifteen males and 19 females were measured twice, first aged 10.0 +/- 0.3 years and then aged 11.8 +/- 0.3 years. Initial models identified body mass and height as significant explanatory variables (P < 0.05) for peak power and mean power, with an additional age effect for the former. No significant differences between the sexes or maturity effects were observed for either peak or mean power (P > 0.05). The introduction of sum of skinfolds improved the fit of the model and rendered the height term non-significant for both peak and mean power (P> 0.05). An age effect became apparent for mean power. When isokinetic leg strength and thigh muscle volume were entered into the model, the latter exerted a significant effect on both peak and mean power (P< 0.05), whereas isokinetic leg strength was not a significant explanatory variable for either (P> 0.05). In conclusion, thigh muscle volume exerts a positive influence on young people's short-term power output, which is additional to the effects of body mass, sum of skinfolds and age.

Buscopan for the treatment of pain after laparoscopic sterilisation

We investigated the effect of Buscopan 20 mg, given at the end of surgery, on analgesic requirements in 44 ASA I and II patients presenting as day cases for laparoscopic sterilisation using Filshie clips. Patients were randomly allocated to receive either intravenous Buscopan 20 mg or saline placebo at the end of surgery. There was no significant difference in pain scores, analgesic requirements or the incidence of nausea and vomiting between the two groups. We conclude that intravenous Buscopan 20 mg was not effective for pain relief following laparoscopic sterilisation.

Assessment of abdominal fat development in young adolescents using magnetic resonance imaging

OBJECTIVE

To determine the patterns of change and the best anthropometric indicators of intra-abdominal fat deposition in young adolescents from ages 11-13 y.

SUBJECTS

Subjects were 25 boys (mean age 13.7 +/- 0.32 y) and 17 girls (mean age of 13.7 +/- 0.23 y) who had taken part in a similar study 2 y earlier at ages 11.5 +/- 0.33 y and 11.5 +/- 0.27 y, respectively.

METHODS

Intra-abdominal (IA) and subcutaneous adipose (SA) tissue areas and IA/SA ratio were determined through four tranverse magnetic resonance imaging scans on two occasions. Differences were investigated using t-tests and ANOVA. Skinfolds, girths and circumferences, body mass index and hydrostatic weighing were also recorded. Pearson correlation coefficients and regression equations were calculated to determine the best anthropometric indicators of intra-abdominal fat deposition.

RESULTS

Intra-abdominal fat and subcutaneous fat areas had significantly increased in boys and girls by the second measure. Boys had deposited greater amounts of fat in intra-abdominal depots so that their intra-abdominal/subcutaneous ratio had increased significantly from 0.31 to 0.39. This had reduced in girls from 0.39 to 0.35. However, patterns of change were variable within sexes. Truncal skinfold sites (r = 0.54-0.70) emerged as the best field indicators of intra-abdominal fat deposition.

CONCLUSIONS

Patterns of intra-abdominal and subcutaneous fat distribution are identifiable in pubescent children using magnetic resonance imaging. An acceptable indication is provided by truncal skinfolds.

An automated system for the measurement of alanine/EPR dosimeters

NPL for several years has offered mailed reference dosimetry services based on alanine/EPR dosimeters, both at industrial and therapy dose levels. Compared to other methods of reference dosimetry, operator involvement in alanine/EPR has been found to be relatively high, and contributes significantly to the overall economics of the process. Commercially available sample changers are not suitable for high accuracy applications, and it has proved necessary to develop a dedicated automation system to handle NPL alanine dosimeter pellets. In this paper we describe an automatic sample changer for placing and retrieving alanine pellets into and out of the cavity of a standard research grade EPR spectrometer. Up to 32 pellets can be held in each removable sample tray. The sample changer software has been interfaced into the spectrometer control software to enable complete automation of the measurement process, including the optimization of spectrometer settings and rotation of the sample within the cavity.

Biomineralization, life-time of odontogenic cells and differential expression of the two homeobox genes MSX-1 and DLX-2 in transgenic mice

Msx and Dlx homeobox genes encode for transcription factors that control early morphogenesis. More specifically, Msx-1, Msx-2, and Dlx-2 homeobox genes contribute to the initial patterning of the dentition. The present study is devoted to the potential role of those homeobox genes during the late formation of mineralized tissues, using the rodent incisor as an experimental system. The continuously erupting mandibular incisor allows (1) the coinvestigation of the whole sequences of amelogenesis and dentinogenesis, aligned along the main dental axis in a single sample in situ and (2) the differential characterization of transcripts generated by epithelial and ectomesenchymal odontogenic cells. Northern blot experiments on microdissected cells showed the continuing expression of Msx-2 and Dlx-2 in the later stages of dental biomineralization, differentially in epithelial and ectomesenchymal compartments. Transgenic mice produced with LacZ reporter constructs for Dlx-2 and Msx-1 were used to detect different components of the gene expression patterns with the sensitive beta-galactosidase histoenzymology. The results show a prominent epithelial involvement of Dlx-2, with stage-specific variations in the cells involved in enamel formation. Quantitative analyses identified specific modulations of Dlx-2 expression in ameloblasts depending on the anatomical sites of the incisor, showing more specifically an inverse linear relationship between the Dlx-2 promoter activity level and enamel thickness. This investigation extends the role of homeoproteins to postmitotic stages, which would control secretory cell activity, in a site-specific manner as shown here for Dlx-2.

Epithelial Dlx-2 homeogene expression and cementogenesis

The Dlx-2 (distal-less gene) homeoprotein transcription factor controls early tooth development but has not been studied during the late stages of biomineralization. Transgenic mice containing a Dlx-2/LacZ reporter construct were used to map the Dlx-2 expression pattern in cementoblasts, the dental cells most closely related to bone cells and therefore suggested to be uniquely positioned osteoblasts. During initial root formation, marked expression of Dlx-2 was evident in molar and incisor root epithelium, whereas dental papilla and follicle were negative. Dlx-2 was expressed in this epithelium from the apical loop to the area of its disruption. During acellular cementum formation in both incisors and molars, Dlx-2 expression was observed in the majority of differentiated cementoblasts from the apical region to the erupting zones. During cellular cementum formation, the presence of which characterizes growth-limited molars, Dlx-2 expression was restricted to the innermost cementoblasts and entrapped cementocytes. These data further support the hypothesis of a complex origin and fate of cementum-forming cells, as previously suggested by the expression patterns of a set of mesenchymal and epithelial markers, notably ameloblastin as shown here. Dlx-2 expression might constitute a landmark of cementoblast subpopulations of epithelial origin. (J Histochem Cytochem 48:277-283, 2000)