Drivers of natural disaster risk-reduction actions and their temporal dynamics: Insights from surveys during an imminent hurricane threat and its aftermath

To improve preparedness for natural disasters, it is imperative to understand the factors that enable individual risk-reduction actions. This study offers such insights using innovative real-time (N = 871) and repeated (N = 255) surveys of a sample of coastal residents in Florida regarding flood preparations and their drivers during an imminent threat posed by Hurricane Dorian and its aftermath. Compared with commonly employed cross-sectional surveys, our methodology better represents relationships between preparedness actions undertaken during the disaster threat and their drivers derived from an extended version of Protection Motivation Theory (PMT). The repeated survey allows for examining temporal dynamics in these drivers. Our results confirm the importance of coping appraisals and show that risk perceptions relate more strongly to emergency protection decisions made during the period of the disaster threat than to decisions made well before. Moreover, we find that several personal characteristics that we add to the standard PMT framework significantly relate to undertaking preparedness actions, especially locus of control and social norms. Significant changes in key explanatory variables occur following the disaster threat, including a decline in risk perception, a potential learning effect in coping appraisals, and a decline in risk aversion. Our results confirm the advantage of the real-time and repeated survey approach in understanding both short- and long-term disaster preparedness actions.

Insights into the complementarity of natural disaster insurance purchases and risk reduction behavior

While flooding is the costliest natural disaster risk, public-sector investments provide incomplete protection. Moreover, individuals are in general reluctant to voluntarily invest in measures which limit damage costs from natural disasters. The moral hazard hypothesis argues that insured individuals take fewer other preparedness measures based on their assumption that their losses will be covered anyway. Conversely, the advantageous selection hypothesis argues that individuals view insurance and other risk reduction measures as complements. This study offers a comprehensive assessment of factors related to the separate uptake of natural disaster insurance and the flood-proofing of homes as well as why people may take both of these measures together. We use data from a survey conducted in Paris, France, in 2018, after several flood events, for a representative sample of 2976 residents facing different levels of flood risk. We perform both main effects regressions and interaction analyses to reveal that home adaptation to flooding is positively associated with comprehensive insurance coverage, which includes financial protection against natural disasters. Furthermore, actual and perceived risks, as well as awareness of official information on flood risk, are found to explain some of the relationship between home adaptation and comprehensive insurance purchase. We suggest several recommendations to policymakers based on these insights which aim to address insurance coverage gaps and the failure to take disaster risk reduction measures. In particular, groups in socially vulnerable situations may benefit from subsidized insurance, low interest loans, and decision aids to implement costly adaptation measures.

Evaluation of Human Performance Aiding Live Synthetically Engineered Bacteria in a Gut-on-a-Chip

Synbiotics are a new class of live therapeutics employing engineered genetic circuits. The rapid adoption of genetic editing tools has catalyzed the expansion of possible synbiotics, exceeding traditional testing paradigms in terms of both throughput and model complexity. Herein, we present a simplistic gut-chip model using common Caco2 and HT-29 cell lines to establish a dynamic human screening platform for a cortisol sensing tryptamine producing synbiotic for cognitive performance sustainment. The synbiotic, SYN, was engineered from the common probiotic E. coli Nissle 1917 strain. It had the ability to sense cortisol at physiological concentrations, resulting in the activation of a genetic circuit that produces tryptophan decarboxylase and converts bioavailable tryptophan to tryptamine. SYN was successfully cultivated within the gut-chip showing log-phase growth comparable to the wild-type strain. Tryptophan metabolism occurred quickly in the gut compartment when exposed to 5 μM cortisol, resulting in the complete conversion of bioavailable tryptophan into tryptamine. The flux of tryptophan and tryptamine from the gut to the vascular compartment of the chip was delayed by 12 h, as indicated by the detectable tryptamine in the vascular compartment. The gut-chip provided a stable environment to characterize the sensitivity of the cortisol sensor and dynamic range by altering cortisol and tryptophan dosimetry. Collectively, the human gut-chip provided human relevant apparent permeability to assess tryptophan and tryptamine metabolism, production, and transport, enabled host analyses of cellular viability and pro-inflammatory cytokine secretion, and succeeded in providing an efficacy test of a novel synbiotic. Organ-on-a-chip technology holds promise in aiding traditional therapeutic pipelines to more rapidly down select high potential compounds that reduce the failure rate and accelerate the opportunity for clinical intervention.

Behavioral biases and heuristics in perceptions of COVID-19 risks and prevention decisions

This study adds to an emerging literature on the factors associated with individual perceptions of COVID-19 risks and decision-making processes related to prevention behaviors. We conducted a survey in the Netherlands (N = 3600) in June-July 2020 when the first peak of COVID-19 infections, hospitalizations, and deaths had passed, and lockdown measures had been eased. Dutch policies relied heavily on individual prevention behaviors to mitigate a second infection wave. We examine whether biases and heuristics that have been observed in how people perceive and respond to other risks also apply to the newly emergent risks posed by COVID-19. The results indicate that people simplify risk using threshold models and that risk perceptions are related with personal experiences with COVID-19 and experiences of close others, supporting the availability heuristic. We also observe that prevention behavior is more strongly associated with COVID-19 risk perceptions and feelings toward the risk than with local indicators of COVID-19 risks, and that prevention behavior is related with herding. Support for government lockdown measures is consistent with preferences that may contribute to the not-in-my-term-of-office bias. In addition, we offer insights into the role of trust, worry, and demographic characteristics in shaping perceptions of COVID-19 risks and how these factors relate with individual prevention behaviors and support for government prevention measures. We provide several lessons for the design of policies that limit COVID-19 risks, including risk communication strategies and appeals to social norms. Perhaps more importantly, our analysis allows for learning lessons to mitigate the risks of future pandemics.

Individual hurricane evacuation intentions during the COVID-19 pandemic: insights for risk communication and emergency management policies

The U.S. 2020 hurricane season was extraordinary because of a record number of named storms coinciding with the COVID-19 pandemic. This study draws lessons on how individual hurricane preparedness is influenced by the additional risk stemming from a pandemic, which turns out to be a combination of perceptions of flood and pandemic risks that have opposite effects on preparedness behavior. We conducted a survey in early June 2020 of 600 respondents in flood-prone areas in Florida to obtain insights into households' risk perceptions and preparedness for the upcoming hurricane season under COVID-19. The results show that concerns over COVID-19 dominated flood risk perceptions and negatively impacted people's evacuation intentions. Whereas hotel costs were the main obstacle to evacuating during Hurricane Dorian in 2019 in the same geographic study area, the main evacuation obstacle identified in the 2020 hurricane season is COVID-19. Our statistical analyses investigating the factors influencing evacuation intentions show that older individuals are less likely to evacuate under a voluntary order, because they are more concerned about the consequences of becoming infected by COVID-19. We observe similar findings based on a real-time survey we conducted in Florida with another group of respondents under the threat of Hurricane Eta at the end of the hurricane season in November 2020. We discuss the implications of our findings for risk communication and emergency management policies that aim to improve hurricane preparedness when dealing with additional health risks such as a pandemic, a situation that may be exacerbated under the future climate.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11069-021-05064-2.

Magnetic Control of MOF Crystal Orientation and Alignment

Most metal-organic frameworks (MOFs) possess anisotropic properties, the full exploitation of which necessitates a general strategy for the controllable orientation of such MOF crystals. Current methods largely rely upon layer-by-layer MOF epitaxy or tuning of MOF crystal growth on appropriate substrates, yielding MOFs with fixed crystal orientations. Here, the dynamic magnetic alignment of different MOF crystals (NH₂ -MIL-53(Al) and NU-1000) is shown. The MOFs were magnetized by electrostatic adsorption of iron oxide nanoparticles, dispersed in curable polymer resins (Formlabs 1+ clear resin/ Sylgard 184), magnetically oriented, and fixed by resin curing. The importance of crystal orientation on MOF functionality was demonstrated whereby magnetically aligned NU-1000/Sylgard 184 composite was excited with linearly polarized 405 nm light, affording an anisotropic fluorescence response dependent on the polarization angle of the excitation beam relative to NU-1000 crystal orientation.

Sudden cardiac death in adults with congenitally corrected transposition of the great arteries

Background

Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital heart disease. There have been only few reports of sudden cardiac death (SCD) in patients with ccTGA and reasonable ventricular function.

Methods

A retrospective review of the medical records of all patients attending our adult congenital heart centre, with known ccTGA.

Results

From a database of over 3500 adult patients with congenital heart disease, we identified 39 (∼1%) with ccTGA and ‘two-ventricle’ circulations. 65% were male. The mean age at diagnosis was 12.4±11.4 years and the mean age at last time of review was 34.3±11.3 years. 24 patients (56%) had a history of surgical intervention. 8 (19%) had had pacemaker implantation and 2 had had a defibrillator implanted for non-sustained ventricular tachycardia (NSVT). In 544 years of patient follow-up, there had been five cases of SCD in our population; 1 death per 109 patient-years. Two of these patients had had previously documented supraventricular or NSVT. However, they were all classified as New York Heart Association (NYHA) class I or II, and systemic (right) ventricular function had been recorded as normal, mildly or mildly–moderately impaired, at most recent follow-up.

Conclusions

Our experience suggests the need for improved risk stratification and/or surveillance for malignant arrhythmia in adults with ccTGA, even in those with reasonable functional class on ventricular function.

Right Ventricular Mass is Associated with Exercise Capacity in Adults with Repaired Tetralogy of Fallot

The relationship between exercise capacity and right ventricular (RV) structure and function in adult repaired tetralogy of Fallot (TOF) is poorly understood. We therefore aimed to examine the relationships between cardiac MRI and cardiopulmonary exercise test variables in adult repaired TOF patients. In particular, we sought to determine the role of RV mass in determining exercise capacity. Eighty-two adult repaired TOF patients (age at evaluation 26 ± 10 years; mean age at repair 2.5 ± 2.8 years; 23.3 ± 7.9 years since repair; 53 males) (including nine patients with tetralogy-type pulmonary atresia with ventricular septal defect) were prospectively recruited to undergo cardiac MRI and cardiopulmonary exercise testing. As expected, these repaired TOF patients had RV dilatation (indexed RV end-diastolic volume: 153 ± 43.9 mL/m(2)), moderate-severe pulmonary regurgitation (pulmonary regurgitant fraction: 33 ± 14 %) and preserved left (LV ejection fraction: 59 ± 8 %) and RV systolic function (RV ejection fraction: 51 ± 7 %). Exercise capacity was near-normal (peak work: 88 ± 17 % predicted; peak oxygen consumption: 84 ± 17 % predicted). Peak work exhibited a significant positive correlation with RV mass in univariate analysis (r = 0.45, p < 0.001) and (independent of other cardiac MRI variables) in multivariate analyses. For each 10 g higher RV mass, peak work was 8 W higher. Peak work exhibits a significant positive correlation with RV mass, independent of other cardiac MRI variables. RV mass measured on cardiac MRI may provide a novel marker of clinical progress in adult patients with repaired TOF.

Small molecules demonstrate the role of dynamin as a bi-directional regulator of the exocytosis fusion pore and vesicle release

Hormones and neurotransmitters are stored in specialised vesicles and released from excitable cells through exocytosis. During vesicle fusion with the plasma membrane, a transient fusion pore is created that enables transmitter release. The protein dynamin is known to regulate fusion pore expansion (FPE). The mechanism is unknown, but requires its oligomerisation-stimulated GTPase activity. We used a palette of small molecule dynamin modulators to reveal bi-directional regulation of FPE by dynamin and vesicle release in chromaffin cells. The dynamin inhibitors Dynole 34-2 and Dyngo 4a and the dynamin activator Ryngo 1-23 reduced or increased catecholamine released from single vesicles, respectively. Total internal reflection fluorescence (TIRF) microscopy demonstrated that dynamin stimulation with Ryngo 1-23 reduced the number of neuropeptide Y (NPY) kiss-and-run events, but not full fusion events, and slowed full fusion release kinetics. Amperometric stand-alone foot signals, representing transient kiss-and-run events, were less frequent but were of longer duration, similarly to full amperometric spikes and pre-spike foot signals. These effects are not due to alterations in vesicle size. Ryngo 1-23 action was blocked by inhibitors of actin polymerisation or myosin II. Therefore, we demonstrate using a novel pharmacological approach that dynamin not only controls FPE during exocytosis, but is a bi-directional modulator of the fusion pore that increases or decreases the amount released from a vesicle during exocytosis if it is activated or inhibited, respectively. As such, dynamin has the ability to exquisitely fine-tune transmitter release.

Intended follow up of women with breast cancer at low risk of recurrence and at least 5 years from diagnosis

BACKGROUND

Although there is evidence that minimal surveillance is compatible with an optimal outcome in women after early stage breast cancer, little is known of the surveillance that these women receive.

AIMS

To describe the intended clinical follow up and patterns of use of imaging modalities in low-risk breast cancer survivors who are at least 5 years from diagnosis.

METHODS

Participants in the Bupa Health Foundation Health and Wellbeing After Breast Cancer Study with stage 1 invasive breast cancer at diagnosis, who had survived free of recurrence or new primary breast cancer for at least 5 years, provided information for this analysis.

RESULTS

The most common choice of physician follow up was with one doctor only (54%). Within this group, the most frequent choice was a general practitioner (GP) (63%) followed by medical oncologist (23%). Thirty-five per cent of women said that they intended to consult two doctors and within this group, the most common combination was a GP and a medical oncologist (45%). This was despite two out of three women reporting being advised that there was no need to consult a medical oncologist. Over 90% of women reported having a mammogram with, or without, breast ultrasound in the previous 12 months. There was a low rate of use of other imaging tests in the absence of clear indications.

CONCLUSIONS

Minimising unnecessary medical consultations by women with breast cancer at low risk of recurrence 5 years from diagnosis will require education about the benefits of a minimal surveillance strategy.

Minimal-trauma fracture in women with breast cancer surviving for at least 5 years from diagnosis

SUMMARY

Minimal-trauma fracture is an important issue in breast cancer survivors, especially rib fracture. The likelihood of fracture is affected by menopausal status and a diagnosis of osteoporosis prior to breast cancer. Most women reported at least one assessment of bone mineral density.

INTRODUCTION

We have investigated the self-reported frequency and pattern of minimal-trauma fracture (MTF) in breast cancer (BC) survivors at least 5 years from diagnosis, along with the use of bone mineral density (BMD) assessment.

METHODS

This study was carried out within the Bupa Health Foundation Health and Wellbeing After Breast Cancer Study which is a questionnaire-based prospective cohort study of 1683 women diagnosed with their first invasive breast cancer between 2004 and 2006 and followed for at least 5 years.

RESULTS

One thousand two hundred and five women, who remained free of recurrence or new breast cancer, completed the fifth annual follow-up. One hundred sixty-four (13.6%) reported at least one MTF. Rib fracture was the most common (52 fractures in 46 women). Compared with women who remained pre-/peri-menopausal, either being postmenopausal at diagnosis (OR 3.53, 95% Confidence Interval (CI) 1.09-11.44, p=0.036) or changing from pre- to postmenopausal during follow-up (OR 3.97, 95% CI 1.21-13.10, p=0.023) was associated with a higher likelihood of fracture, as was having a diagnosis of osteoporosis at the time of diagnosis (OR 1.74, 95% CI 1.00-2.99, p=0.047). Most women (64.9%) reported at least one BMD assessment.

CONCLUSIONS

Overall MTF is a problem for breast cancer survivors, with rib fracture a particular issue for women in our study. Both pre-existing osteoporosis and being postmenopausal are risk factors for subsequent MTF in women treated for breast cancer. Clinicians need to be mindful of fracture prevention medication in these groups.

Mechanisms of maintained exercise capacity in adults with repaired tetralogy of Fallot

BACKGROUND

The mechanisms whereby cardiac output is augmented with exercise in adult repaired tetralogy of Fallot (TOF) are poorly characterised.

METHODS

16 repaired TOF patients (25 ± 7 years of age) and 8 age and sex matched controls (25 ± 4 years of age) underwent cardiopulmonary exercise testing and then real-time cardiac MRI (1.5 T) at rest and whilst exercising within the scanner, aiming for 30% heart rate reserve (Level 1) and 60% heart rate reserve (Level 2), using a custom-built MRI compatible foot pedal device.

RESULTS

At rest, TOF patients had severely dilated RVs (indexed RV end-diastolic volume: 149 ± 37 mL/m(2)), moderate-severe PR (regurgitant fraction 35 ± 12%), normal RV fractional area change (FAC) (52 ± 7%) and very mildly impaired exercise capacity (83 ± 15% of predicted maximal work rate). Heart rate and RV FAC increased significantly in TOF patients (75 ± 10 vs 123 ± 17 beats per minute, p<0.001; 44 ± 7 vs 51 ± 10%, p=0.025), and similarly in control subjects (70 ± 11 vs 127 ± 12 beats per minute, p<0.001; 49 ± 7 vs 61 ± 9%, p=0.003), when rest was compared to Level 2. PR fraction decreased significantly but only modestly, from rest to Level 2 in TOF patients (37 ± 15 to 31 ± 15%, p=0.002). Pulmonary artery net forward flow was maintained and did not significantly increase from rest to Level 2 in TOF patients (70 ± 19 vs 69 ± 12 mL/beat, p=0.854) or controls (93 ± 9 vs 95 ± 21 mL/beat, p=0.648).

CONCLUSIONS

During exercise in repaired TOF subjects with dilated RV and free PR, increased total RV output per minute was facilitated by an increase in heart rate, an increase in RV FAC and a decrease in PR fraction.

Potential new therapeutic modality revealed through agent-based modeling of the neuromuscular junction and acetylcholinesterase inhibition

Background

One of the leading causes of death and illness within the agriculture industry is through unintentionally ingesting or inhaling organophosphate pesticides. OP intoxication directly inhibits acetylcholinesterase, resulting in an excitatory signaling cascade leading to fasciculation, loss of control of bodily fluids, and seizures.

Methods

Our model was developed using a discrete, rules-based modeling approach in NetLogo. This model includes acetylcholinesterase, the nicotinic acetylcholine receptor responsible for signal transduction, a single release of acetylcholine, organophosphate inhibitors, and a theoretical novel medical countermeasure. We have parameterized the system considering the molecular reaction rate constants in an agent-based approach, as opposed to apparent macroscopic rates used in differential equation models.

Results

Our model demonstrates how the cholinergic crisis can be mitigated by therapeutic intervention with an acetylcholinesterase activator. Our model predicts signal rise rates and half-lives consistent with in vitro and in vivo data in the absence and presence of inhibitors. It also predicts the efficacy of theoretical countermeasures acting through three mechanisms: increasing catalytic turnover of acetylcholine, increasing acetylcholine binding affinity to the enzyme, and decreasing binding rates of inhibitors.

Conclusion

We present a model of the neuromuscular junction confirming observed acetylcholine signaling data and suggesting that developing a countermeasure capable of reducing inhibitor binding, and not activator concentration, is the most important parameter for reducing organophosphate (OP) intoxication.

Electronic supplementary material

The online version of this article (doi:10.1186/1742-4682-11-42) contains supplementary material, which is available to authorized users.

Associations between ozone and morbidity using the Spatial Synoptic Classification system

BACKGROUND

Synoptic circulation patterns (large-scale tropospheric motion systems) affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses) on the association between ozone and hospital admissions for asthma and myocardial infarction (MI) among adults in North Carolina.

METHODS

Daily surface meteorology data (including precipitation, wind speed, and dew point) for five selected cities in North Carolina were obtained from the U.S. EPA Air Quality System (AQS), which were in turn based on data from the National Climatic Data Center of the National Oceanic and Atmospheric Administration. We used the Spatial Synoptic Classification system to classify each day of the 9-year period from 1996 through 2004 into one of seven different air mass types: dry polar, dry moderate, dry tropical, moist polar, moist moderate, moist tropical, or transitional. Daily 24-hour maximum 1-hour ambient concentrations of ozone were obtained from the AQS. Asthma and MI hospital admissions data for the 9-year period were obtained from the North Carolina Department of Health and Human Services. Generalized linear models were used to assess the association of the hospitalizations with ozone concentrations and specific air mass types, using pollutant lags of 0 to 5 days. We examined the effect across cities on days with the same air mass type. In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions.

RESULTS

Ozone was associated with asthma under dry tropical (1- to 5-day lags), transitional (3- and 4-day lags), and extreme moist tropical (0-day lag) air masses. Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses.

CONCLUSIONS

Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass. Certain synoptic circulation patterns/air masses in conjunction with ambient ozone levels were associated with increased asthma and MI hospitalizations.

Quantitative structure-activity relationships for organophosphates binding to trypsin and chymotrypsin

Organophosphate (OP) nerve agents such as sarin, soman, tabun, and O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) do not react solely with acetylcholinesterase (AChE). Evidence suggests that cholinergic-independent pathways over a wide range are also targeted, including serine proteases. These proteases comprise nearly one-third of all known proteases and play major roles in synaptic plasticity, learning, memory, neuroprotection, wound healing, cell signaling, inflammation, blood coagulation, and protein processing. Inhibition of these proteases by OP was found to exert a wide range of noncholinergic effects depending on the type of OP, the dose, and the duration of exposure. Consequently, in order to understand these differences, in silico biologically based dose-response and quantitative structure-activity relationship (QSAR) methodologies need to be integrated. Here, QSAR were used to predict OP bimolecular rate constants for trypsin and α-chymotrypsin. A heuristic regression of over 500 topological/constitutional, geometric, thermodynamic, electrostatic, and quantum mechanical descriptors, using the software Ampac 8.0 and Codessa 2.51 (SemiChem, Inc., Shawnee, KS), was developed to obtain statistically verified equations for the models. General models, using all data subsets, resulted in R(2) values of .94 and .92 and leave-one-out Q(2) values of 0.9 and 0.87 for trypsin and α-chymotrypsin. To validate the general model, training sets were split into independent subsets for test set evaluation. A y-randomization procedure, used to estimate chance correlation, was performed 10,000 times, resulting in mean R(2) values of .24 and .3 for trypsin and α-chymotrypsin. The results show that these models are highly predictive and capable of delineating the complex mechanism of action between OP and serine proteases, and ultimately, by applying this approach to other OP enzyme reactions such as AChE, facilitate the development of biologically based dose-response models.

Hilar cholangiocarcinoma: MR correlation with surgical and histological findings

AIM

To evaluate magnetic resonance cholangiography (MRC) with high-resolution dynamic gadolinium-enhanced magnetic resonance imaging (MRI) in determining the imaging features of hilar cholangiocarcinoma that relate to tumour extent and influence resectability.

MATERIALS AND METHODS

Twenty-six patients that underwent resection were reviewed. Tumour location and extent, lobar atrophy, the degree of portal vein and hepatic artery involvement were recorded. The findings were correlated with surgical and histopathological findings.

RESULTS

Biliary assessment was concordant in 14 and discordant in eight of 14 stented and four of 12 non-stented patients. In 63/82 veins and 43/74 arteries results were fully concordant. The mean sensitivity, specificity, positive and negative predictive values (PPV, NPV) in predicting involvement of the main portal vein (MPV) at surgery were 83.3, 100, 100, and 92.5%; of the left main branch of the portal vein (LPV) were 100, 91.6, 93.3, and 100%; and of the right branch of the portal vein (RPV) were 87.5, 100, 100, and 87.5%. The sensitivity, specificity, PPV and NPV of MRI in determining histological involvement of the MPV was 75, 90.9, 60, and 92.5%; 100, 73.3, 73, and 100% for the LPV, and 100, 66.6, 42.8, and 100% for the RPV, respectively.

CONCLUSION

MRC with high-resolution dynamic gadolinium-enhanced MRI is effective in determining tumour extent and vascular involvement, but prior stenting may lead to overestimation.

Genotoxic stress-induced nuclear localization of oncoprotein YB-1 in the absence of proteolytic processing

Y-box-binding protein 1 (YB-1) is an oncogenic transcription factor whose overexpression and nuclear localization is associated with tumor progression and drug resistance. Transcriptional activation of YB-1 in response to genotoxic stress is believed to occur in the cytoplasm through sequence-specific endoproteolytic cleavage by the 20S Proteasome, followed by nuclear translocation of cleaved YB-1. To study the proteolysis model, we developed a two-step affinity purification of endogenous YB-1 protein species and characterized the products using mass spectrometry. Whereas full-length YB-1 was readily identified, the smaller protein band thought to be activated YB-1 was identified as hnRNP A1. An antibody specific for YB-1 was generated, which revealed only one YB-1 species, even after genotoxic stress-induced nuclear YB-1 translocation. These findings warrant re-evaluation of the mechanism of YB-1 nuclear translocation and transcriptional activation. The relationship between nuclear YB-1 and tumor progression may also have to re-evaluated in some cases.

A new scoring system in Cystic Fibrosis: statistical tools for database analysis - a preliminary report

Background

Cystic fibrosis is the most common fatal genetic disorder in the Caucasian population. Scoring systems for assessment of Cystic fibrosis disease severity have been used for almost 50 years, without being adapted to the milder phenotype of the disease in the 21^st century. The aim of this current project is to develop a new scoring system using a database and employing various statistical tools. This study protocol reports the development of the statistical tools in order to create such a scoring system.

Methods

The evaluation is based on the Cystic Fibrosis database from the cohort at the Royal Children's Hospital in Melbourne. Initially, unsupervised clustering of the all data records was performed using a range of clustering algorithms. In particular incremental clustering algorithms were used. The clusters obtained were characterised using rules from decision trees and the results examined by clinicians. In order to obtain a clearer definition of classes expert opinion of each individual's clinical severity was sought. After data preparation including expert-opinion of an individual's clinical severity on a 3 point-scale (mild, moderate and severe disease), two multivariate techniques were used throughout the analysis to establish a method that would have a better success in feature selection and model derivation: 'Canonical Analysis of Principal Coordinates' and 'Linear Discriminant Analysis'. A 3-step procedure was performed with (1) selection of features, (2) extracting 5 severity classes out of a 3 severity class as defined per expert-opinion and (3) establishment of calibration datasets.

Results

(1) Feature selection: CAP has a more effective "modelling" focus than DA.

(2) Extraction of 5 severity classes: after variables were identified as important in discriminating contiguous CF severity groups on the 3-point scale as mild/moderate and moderate/severe, Discriminant Function (DF) was used to determine the new groups mild, intermediate moderate, moderate, intermediate severe and severe disease. (3) Generated confusion tables showed a misclassification rate of 19.1% for males and 16.5% for females, with a majority of misallocations into adjacent severity classes particularly for males.

Conclusion

Our preliminary data show that using CAP for detection of selection features and Linear DA to derive the actual model in a CF database might be helpful in developing a scoring system. However, there are several limitations, particularly more data entry points are needed to finalize a score and the statistical tools have further to be refined and validated, with re-running the statistical methods in the larger dataset.

Informed consent for the study of retained tissues from postmortem examination following sudden infant death

OBJECTIVE

To develop an approach for seeking informed consent to examine tissues retained from a previous study of sudden infant death syndrome (SIDS) as part of a study on asthma, and to document responses and participation rate.

DESIGN

Pilot open-ended approach to 10 volunteer SIDS parents, followed by staged approach (newsletter, mail and telephone call) to seek consent from the target SIDS families for the asthma study.

PARTICIPANTS

Parents (n = 10) of SIDS infants known to SIDS and Kids Victoria and parents of SIDS infants (n = 107) from the 1991-2 SIDS in Victoria case-control study.

MAIN OUTCOMES

Qualitative responses of the piloted parents and study parents, and participation rates.

RESULTS

The pilot group responses were used to refine the written material to be provided. Of the 72 families for which contact details were available, 45 gave verbal consent for contact by the Victorian Institute of Forensic Medicine regarding the asthma study, three refused and 24 did not respond to two letters. Thirty-three completed consent forms, all positive for participation in the asthma study, giving a positive response rate of 73% (33/45).

CONCLUSIONS

The use of postmortem tissue for research is acceptable to the next of kin when an approach is sensitive to their concerns and needs and is made by experienced counsellors from a familiar organisation. Despite the painful memories evoked by the approach of the research group, the acceptance rate among those who could be contacted was high.

Spontaneous pneumothorax in children: when is invasive treatment indicated?

A retrospective review of pneumothoraces in children presenting to a major tertiary children's hospital is described. A total of 35 cases in 31 patients of spontaneous pneumothorax were identified over a 10-year period. There was one case of bilateral pneumothorax and three cases of recurrent pneumothoraces. Twenty-four cases (69%) required intercostal tube catheter drainage for a mean of 4.9 days (range 2-10 days). Eleven cases, including two cases in CF patients, and three cases in patients with Marfan's Syndrome proceeded to a secondary surgical procedure after a continuing air leak was present for an average of 5.9 days (range 2-16 days). In follow-up studies on 11 cases, 5 (45%) were found to have apical abnormalities of the lung on CT scanning. Pneumothoraces were identified in six cases of patients with cystic fibrosis as well as four in patients with Marfan's Syndrome. This present study has suggested that unless intercostal catheter treatment resolves the air leak associated with a spontaneous pneumothorax within 5 days that surgical intervention is most likely to be required to achieve a full resolution.

Abnormal Right Ventricular Tissue Velocities After Repair of Congenital Heart Disease—Implications for Late Outcomes

BACKGROUND

Although repair of Tetralogy of Fallot (TOF) and transposition of the great arteries (TGA) has facilitated survival into adulthood, many survivors have residual haemodynamic abnormalities, including exercise intolerance and late right ventricular (RV) failure.

METHODS

We studied 40 asymptomatic adult subjects (31.3+/-1.5 years) after congenital heart disease (CHD) surgery during childhood, using tissue Doppler echocardiography (TDE). We compared systolic (S') and diastolic (E' for early filling) RV and LV velocities, with 40 age matched controls (29.5+/-1.0 years).

RESULTS

Both RV S' and E' velocities were significantly slower in the CHD group compared to controls (6.3+/-0.4 cm/s vs. 9.3+/-0.3 cm/s; 8.5+/-0.5 cm/s vs. 10.9+/-0.4 cm/s, respectively, p<0.001 for both). By contrast, LV S' and E' velocities were similar in both groups. Interestingly, in 50% of CHD subjects where RV function was reported as 'normal', both RV S' and E' velocities were significantly slower compared with controls (6.5+/-0.6 cm/s vs. 9.3+/-0.3 cm/s, p<0.0001 and 9.4+/-0.7 cm/s vs. 10.9+/-0.4 cm/s, p<0.05 respectively).

CONCLUSIONS

RV S' and E' velocities are frequently abnormal in asymptomatic survivors of TOF and TGA repair, even where RV function appears 'normal'. Hence TDE during follow up may be a sensitive means of detecting pre-clinical abnormalities in RV performance.

Radiological anatomy of the anterior ethmoidal artery for functional endoscopic sinus surgery

AIM

This study investigated the extent to which the anterior ethmoidal artery and anterior ethmoidal foramen could be reliably identified on routine coronal sinus computed tomography scans. Where they could be identified, the relationship of these structures with the vertical height of the skull base, and their distance from an anterior landmark, were measured.

METHODS

Fifty consecutive coronal sinus computed tomography scans were viewed independently by two observers. Scans were reviewed when the observers' opinions differed.

RESULTS

Inter-observer concordance was high. The anterior ethmoidal foramen was visualised in 95 per cent of cases bilaterally and in the remaining 5 per cent unilaterally. The anterior ethmoidal artery was visualised in 33 per cent of scans. The anterior ethmoidal foramen was at skull base level in 72 per cent of sides studied, and below it in the remainder. The distance from the lacrimal crest to the anterior ethmoidal foramen was 22.4 mm (mean; standard deviation 3.7).

CONCLUSION

The anterior ethmoidal foramen is a reliable landmark on coronal computed tomography scans of the paranasal sinuses. From this, the position of the anterior ethmoidal artery can be inferred.

Perchlorate and radioiodide kinetics across life stages in the human: using PBPK models to predict dosimetry and thyroid inhibition and sensitive subpopulations based on developmental stage

Perchlorate (ClO4(-)) is a drinking-water contaminant, known to disrupt thyroid hormone homeostasis in rats. This effect has only been seen in humans at high doses, yet the potential for long term effects from developmental endocrine disruption emphasizes the need for improved understanding of perchlorate's effect during the perinatal period. Physiologically based pharmacokinetic/dynamic (PBPK/PD) models for ClO4(-) and its effect on thyroid iodide uptake were constructed for human gestation and lactation data. Chemical specific parameters were estimated from life-stage and species-specific relationships established in previously published models for various life-stages in the rat and nonpregnant adult human. With the appropriate physiological descriptions, these kinetic models successfully simulate radioiodide data culled from the literature for gestation and lactation, as well as ClO4(-) data from populations exposed to contaminated drinking water. These models provide a framework for extrapolating from chemical exposure in laboratory animals to human response, and support a more quantitative understanding of life-stage-specific susceptibility to ClO4(-). The pregnant and lactating woman, fetus, and nursing infant were predicted to have higher blood ClO4(-) concentrations and greater thyroid iodide uptake inhibition at a given drinking-water concentration than either the nonpregnant adult or the older child. The fetus is predicted to receive the greatest dose (per kilogram body weight) due to several factors, including placental sodium-iodide symporter (NIS) activity and reduced maternal urinary clearance of ClO4(-). The predicted extent of iodide inhibition in the most sensitive population (fetus) is not significant (approximately 1%) at the U.S. Environmental Protection Agency reference dose (0.0007 mg/kg-d).

Pneumothorax in cystic fibrosis: a retrospective case series

Pneumothorax is a known complication in cystic fibrosis (CF), associated with poor outcome. Records of CF patients with pneumothorax at the Royal Children's Hospital, Melbourne between 1990 and 2004 were reviewed, and the characteristics, sputum culture results, lung function, treatment, and outcome for the 11 patients who had pneumothoraces were described.

Does splenectomy in cystic fibrosis related liver disease improve lung function and nutritional status? A case series

AIMS

To review the effect of total splenectomy on lung function and nutrition in children with cystic fibrosis related liver disease (CFLD) and associated portal hypertension. The stated indications for surgery and the short and long term risks of the procedure were also documented.

METHOD

Over a 25 year period from January 1980 to June 2005, approximately 650 patients with cystic fibrosis (CF) were treated at the Royal Children's Hospital, Melbourne, Australia. Nine patients with CFLD who underwent a splenectomy during that time were identified and their medical records were reviewed.

RESULTS

FEV1% predicted dropped by -16+/-11% in the two years pre-splenectomy. This contrasts with the increase in FEV1% predicted of 2+/-16% in the two years post-splenectomy (p = 0.05). The cumulative gain in WAZ score (DeltaWAZ pre) over the two years prior to splenectomy of 0.045+/-0.69 was not significantly different from the cumulative gain in WAZ score (DeltaWAZ post) for the two years after splenectomy of 0.15+/-0.36 (p = 0.65). The average age at splenectomy was 14.8 years (SD = 3 years). The average weight of an excised spleen was 983 g (SD = 414 g). There were no deaths associated with splenectomy. The median length of follow up post-splenectomy was 6.0 years (range 0.7-15.8). There were no episodes of bacterial peritonitis or overwhelming sepsis.

CONCLUSIONS

Splenectomy may have a beneficial effect on lung function although this may not manifest itself until the second year post-splenectomy. Splenectomy in patients with CFLD appears to be a safe procedure.

Analysis of algorithms predicting blood:air and tissue:blood partition coefficients from solvent partition coefficients for prevalent components of JP-8 jet fuel

Algorithms predicting tissue and blood partition coefficients (PCs) from solvent properties were compared to assess their usefulness in a petroleum mixture physiologically based pharmacokinetic/pharmacodynamic model. Measured blood:air and tissue:blood PCs for rat and human tissues were sought from literature resources for 14 prevalent jet fuel (JP-8) components. Average experimental PCs were compared with predicted PCs calculated using algorithms from 9 published sources. Algorithms chosen used solvent PCs (octanol:water, saline or water:air, oil:air coefficients) due to the relative accessibility of these parameters. Tissue:blood PCs were calculated from ratios of predicted tissue:air and experimental blood:air values (PCEB). Of the 231 calculated values, 27% performed within +/- 20% of the experimental PC values. Physiologically based equations (based on water and lipid components of a tissue type) did not perform as well as empirical equations (derived from linear regression of experimental PC data) and hybrid equations (physiological parameters and empirical factors combined) for the jet fuel components. The major limitation encountered in this analysis was the lack of experimental data for the selected JP-8 constituents. PCEB values were compared with tissue:blood PCs calculated from ratios of predicted tissue:air and predicted blood:air values (PCPB). Overall, 68% of PCEB values had smaller absolute % errors than PCPB values. If calculated PC values must be used in models, a comparison of experimental and predicted PCs for chemically similar compounds would estimate the expected error level in calculated values.

A multivariate analysis of the factors predicting hearing outcome after surgery for cholesteatoma in children

OBJECTIVE

To explore factors influencing hearing outcomes in children treated by canal wall up (CWU) and canal wall down (CWD) mastoid surgery.

METHODS

Retrospective cohort study including three units in Bristol and Bath, UK. Ninety consecutive children underwent cholesteatoma mastoid surgery, with the first procedure between 1998 and 2001; minimum follow up was three disease-free years.

RESULTS

The CWU and CWD cohorts significantly differed in pre-operative stage and hearing. After disease eradication, air conduction (AC) thresholds changed by +4.0 dB (95 per cent confidence intervals (95% CI) -2.0, 10.1) in the CWD group and -5.3 dB (95% CI -9.3, 1.3) in the CWU group (p=0.029). Using multiple linear regression to account for cohort differences, AC thresholds were increased by: pre-operative AC threshold (p<0.0001), initial ossicular stage (p=0.013), and CWD-surgery (p=0.005).

CONCLUSION

Disease-free hearing was better with CWU-surgery, less initial ossicular damage, and better pre-operative hearing. Worse initial disease increased the likelihood of CWD surgery. Wider use of ossiculoplasty in the CWU cohort (51 per cent vs 5 per cent) may partially explain the superior results.

Increased levels of SNAP-25 and synaptophysin in the dorsolateral prefrontal cortex in bipolar I disorder

OBJECTIVE

In order to identify whether the mechanisms associated with neurotransmitter release are involved in the pathologies of bipolar disorder and schizophrenia, levels of presynaptic [synaptosomal-associated protein-25 (SNAP-25), syntaxin, synaptophysin, vesicle-associated membrane protein, dynamin I] and structural (neuronal cell adhesion molecule and alpha-synuclein) neuronal markers were measured in Brodmann's area 9 obtained postmortem from eight subjects with bipolar I disorder (BPDI), 20 with schizophrenia and 20 controls.

METHODS

Determinations of protein levels were carried out using Western blot techniques with specific antibodies. Levels of mRNA were measured using real-time polymerase chain reaction.

RESULTS

In BPDI, levels of SNAP-25 (p < 0.01) and synaptophysin (p < 0.05) increased. There were no changes in schizophrenia or any other changes in BPDI. Levels of mRNA for SNAP-25 were decreased in BPDI (p < 0.05).

CONCLUSION

Changes in SNAP-25 and synaptophysin in BPDI suggest that changes in specific neuronal functions could be linked to the pathology of the disorder.

Clinical assessment alone will not benefit patients with coronary heart disease: failure to achieve cholesterol targets in 12,045 patients--the Healthwise II study

Healthwise II, a nurse-led audit programme in primary care during 1999-2002, assessed the uptake of secondary preventative measures for coronary heart disease (CHD). Risk factors, cardiovascular medications and blood cholesterol were recorded; 'at risk' patients were invited for a review after 6 months. Of 17,570 patients assessed, CHD was clinically present in 12,045 (69%); in these, aspirin usage was high (78%) but fewer patients were on a beta-blocker (40%), angiotensin-converting enzyme inhibitor (27%) or statin (49%). Blood pressure (BP) was controlled (<140/90) in only 41% of patients. Total cholesterol was >5 mmol/l in 49% of all CHD patients, half of whom were taking a statin. In the statin users, total cholesterol was uncontrolled (>5 mmol/l) in 38%. At follow-up, BP control remained at 42%, statin use increased to 57% and cholesterol remained elevated in 46%. Simple assessment in an audit programme fails to trigger change, and risk-factor modification for CHD remains inadequate.

The use of perioperative SofradexR eardrops in preventing tympanostomy tube blockage: a prospective double-blinded randomized-controlled trial

Around 11-12% of tympanostomy tubes are reported to become blocked by middle ear secretions or blood immediately following surgery, and so no longer function. Many otologists routinely instil an antibiotic and steroid-containing solution at the time of surgery in the belief that this may reduce this complication. The aim of the study was to investigate the efficacy of instilling the antibiotic and steroid-containing solution Sofradex at the time of grommet insertion in preventing grommet blockage. Double-blind randomized-controlled trial, comparing rates of grommet blockage in ears treated with Sofradex drops against control (no drops) in patients undergoing bilateral grommet insertion. Sixty-one pairs of results were obtained. There was a significant difference between the rates of grommet blockage in the two groups. Grommets with Sofradex drops instilled perioperatively were nine times less likely to be blocked than controls [1.6%versus 13.1%, odds ratio (Sofradex/control) = 9.06, 95% confidence interval (CI): 1.04-78.82, P = 0.05]. There was no association between grommet blockage and perioperative bleeding or the nature and presence of middle ear secretions. Sofradex eardrops are effective in reducing the rate of grommet blockage when instilled perioperatively.

PBPK model for radioactive iodide and perchlorate kinetics and perchlorate-induced inhibition of iodide uptake in humans

Detection of perchlorate (ClO4-) in several drinking water sources across the U.S. has lead to public concern over health effects from chronic low-level exposures. Perchlorate inhibits thyroid iodide (I-) uptake at the sodium (Na+)-iodide (I-) symporter (NIS), thereby disrupting the initial stage of thyroid hormone synthesis. A physiologically based pharmacokinetic (PBPK) model was developed to describe the kinetics and distribution of both radioactive I- and cold ClO4- in healthy adult humans and simulates the subsequent inhibition of thyroid uptake of radioactive I- by ClO4-. The model successfully predicts the measured levels of serum and urinary ClO4- from drinking water exposures, ranging from 0.007 to 12 mg ClO4-/kg/day, as well as the subsequent inhibition of thyroid 131I- uptake. Thyroid iodine, as well as total, free, and protein-bound radioactive I- in serum from various tracer studies, are also successfully simulated. This model's parameters, in conjunction with corresponding model parameters established for the male, gestational, and lactating rat, can be used to estimate parameters in a pregnant or lactating human, that have not been or cannot be easily measured to extrapolate dose metrics and correlate observed effects in perchlorate toxicity studies to other human life stages. For example, by applying the adult male rat:adult human ratios of model parameters to those parameters established for the gestational and lactating rat, we can derive a reasonable estimate of corresponding parameters for a gestating or lactating human female. Although thyroid hormones and their regulatory feedback are not incorporated in the model structure, the model's successful prediction of free and bound radioactive I- and perchlorate's interaction with free radioactive I- provide a basis for extending the structure to address the complex hypothalamic-pituitary-thyroid feedback system. In this paper, bound radioactive I- refers to I- incorporated into thyroid hormones or iodinated proteins, which may or may not be bound to plasma proteins.

Evidence for competitive inhibition of iodide uptake by perchlorate and translocation of perchlorate into the thyroid

Various published data sets that investigate the potential effect of exogenous perchlorate (ClO4-) on the uptake of iodide in the thyroid and subsequent changes in thyroid hormone levels are available. In order to best use the data towards the prediction of human health effects resulting from ClO4- exposure, the available literature data must be integrated into a self-consistent, coherent, and parsimonious quantitative model based on the most likely mode of action of perchlorate effect on thyroid function. We submit that the simplest mode of action for ClO4- in the thyroid that remains consistent with all available data involves competitive inhibition of iodide transport into the thyroid follicle, transport of perchlorate into the thyroid follicle against a concentration gradient, further transport into the thyroid lumen (where it may again interfere with iodide transport), and, finally, passive diffusion back into the blood. We believe this description of perchlorate's kinetic behavior should serve as the foundation for predictive physiologically based pharmacokinetic (PBPK) models and as a working hypothesis for further experimental exploration.

Cervical lymphadenopathy due to mycobacterial infection: a diagnostic protocol

Mycobacterial cervical lymphadenopathy is relatively uncommon in the United Kingdom; when cases do occur opportunities for early diagnosis and treatment may be missed. We have reviewed twenty-three cases of mycobacterial cervical lymphadenopathy presenting to an urban general hospital over a four-year period. We discuss the techniques available to aid a diagnosis of mycobacterial disease and suggest a protocol to allow efficient use of these techniques.

Canine trachealis muscle shortening and cartilage mechanics

Canine trachealis muscle will shorten by 70% of resting length when maximally stimulated in vitro. In contrast, trachealis muscle will shorten by only 30–40% when stimulated in vivo. To examine the possibility that an elastic load applied by the tracheal cartilage contributes to the in vivo limitation of shortening, single pairs of sonomicrometry crystals were inserted into the trachealis muscle at the level of the fifth cartilage ring in five dogs. The segment containing the crystals was then excised and mounted on a tension-testing apparatus. Points on the active length-tension curve and the passive length-tension relation of the cartilage only were determined. The preload applied to the muscle before contraction varied from 10 to 40 g (mean 21 ± 4 g). The afterload applied by the cartilage during trachealis contraction ranged from 13 to 56 g (30 ± 6 g). The calculated elastic afterloads were substantial and appeared to be sufficient to explain the degree of shortening observed in four of the seven rings; in the remaining three rings, the limitation of shortening was greater than would be expected from the elastic load provided by the cartilage. Additional sources of loading and/or additional mechanisms may contribute to limited in situ shortening. In summary, tracheal cartilage applies a preload and an elastic afterload to the trachealis that are substantial and contribute to the limitation of trachealis muscle shortening in vivo.

Small "indeterminate" lesions on CT of the liver: a follow-up study of stability

Distinguishing between small benign malformations in the liver and early metastatic disease remains difficult. We identified a group of 115 patients with known or suspected malignant disease who had "indeterminate" small liver lesions and who underwent 2-16 CT examinations (median 5) over a follow up period of 6-60 months (median 16). The size, shape, edge, homogeneity and attenuation of each of these lesions was assessed. The lesions were classified by their behaviour on follow up CT as either stable (79%) or unstable (21%). The unstable lesions (n=62) included 37 that grew larger and 25 that became smaller or disappeared in patients undergoing anti-tumour therapy. Image features predictive of stable behaviour were small size and sharp edge. Heterogeneity and soft tissue attenuation were significantly associated with unstable behaviour, but these features were seen in only a small minority of cases. Shape had no predictive value. A logistic regression model was constructed based on size and edge to allow an estimate to be made of the likelihood of an individual lesion being unstable. In patients with known or suspected malignant disease, the majority of isolated small liver lesions found on CT are benign. Although size under 5 mm and a sharp margin are favourable features, this appearance does not exclude malignancy.

Laryngeal foreign bodies in children: first stop before the right main bronchus

Laryngeal foreign bodies may produce either complete or incomplete airways obstruction. In complete airways obstruction the presentation is with calamitous respiratory difficulty. However incomplete laryngeal obstruction may present with less severe symptoms, resulting in possible misdiagnosis and confusion with other causes of upper airway obstruction such as infectious croup. This report describes three cases of incomplete laryngeal obstruction secondary to inhaled foreign bodies. In each case, the diagnosis of an inhaled foreign body was initially missed, resulting in delay in diagnosis and in one case prolonged recovery. The importance of considering laryngeal foreign bodies, both in cases of suspected foreign body inhalation and clinical cases of incomplete laryngeal obstruction are discussed.

PBPK predictions of perchlorate distribution and its effect on thyroid uptake of radioiodide in the male rat

Due to perchlorate's (ClO4-) ability to competitively inhibit thyroid iodide (I-) uptake through the sodium-iodide symporter (NIS), potential human health risks exist from chronic exposure via drinking water. Such risks may include hypothyroidism, goiter, and mental retardation (if exposure occurs during critical periods in neurodevelopment). To aid in predicting perchlorate's effect on normal I- kinetics, we developed a physiologically-based pharmacokinetic (PBPK) model for the adult male rat. The model structure describes simultaneous kinetics for both anions together with their interaction at the NIS, in particular, the inhibition of I- uptake by ClO4-. Subcompartments and Michaelis-Menten (M-M) kinetics were used to describe active uptake of both anions in the thyroid, stomach, and skin. Separate compartments for kidney, liver, plasma, and fat were described by passive diffusion. The model successfully predicts both 36ClO4- and 125I- kinetics after iv doses of 3.3 mg/kg and 33 mg/kg, respectively, as well as inhibition of thyroid 125I- uptake by ClO4- after iv doses of ClO4- (0.01 to 3.0 mg/kg). The model also predicts serum and thyroid ClO4- concentrations from 14-day drinking water exposures (0.01 to 30.0 mg ClO4-/kg/day) and compensation of perchlorate-induced inhibition of radioiodide uptake due to upregulation of the thyroid. The model can be used to extrapolate dose metrics and correlate observed effects in perchlorate toxicity studies to other species and life stages, such as rat gestation (Clewell et al., 2003). Because the model successfully predicts perchlorate's interaction with iodide, it provides a sound basis for future incorporation of the complex hypothalamic-pituitary-thyroid feedback system.

Predicting fetal perchlorate dose and inhibition of iodide kinetics during gestation: a physiologically-based pharmacokinetic analysis of perchlorate and iodide kinetics in the rat

Perchlorate (ClO4-) disrupts endocrine homeostasis by competitively inhibiting the transport of iodide (I-) into the thyroid. The potential for health effects from human exposure to ClO4- in drinking water is not known, but experimental animal studies are suggestive of developmental effects from ClO4- induced iodide deficiency during gestation. Normal hormone-dependent development relies, in part, on synthesis of hormones in the fetal thyroid from maternally supplied iodide. Although ClO4- crosses the placenta, the extent of inhibition in the fetal thyroid is unknown. A physiologically-based pharmacokinetic (PBPK) model was developed to simulate ClO4- exposure and the resulting effect on iodide kinetics in rat gestation. Similar to concurrent model development for the adult male rat, this model includes compartments for thyroid, stomach, skin, kidney, liver, and plasma in both mother and fetus, with additional compartments for the maternal mammary gland, fat, and placenta. Tissues with active uptake are described with multiple compartments and Michaelis-Menten (M-M) kinetics. Physiological and kinetic parameters were obtained from literature and experiment. Systemic clearance, placental-fetal transport, and M-M uptake parameters were estimated by fitting model simulations to experimental data. The PBPK model is able to reproduce maternal and fetal iodide data over five orders of magnitude (0.36 to 33,000 ng/kg 131I-), ClO4- distribution over three orders of magnitude (0.01 to 10 mg/kg-day ClO4-) and inhibition of maternal thyroid and total fetal I- uptake. The model suggests a significant fetal ClO4- dose in late gestation (up to 82% of maternal dose). A comparison of model-predicted internal dosimetrics in the adult male, pregnant, and fetal rat indicates that the fetal thyroid is more sensitive to inhibition than that of the adult.

Decreased phorbol ester binding in the parahippocampal gyrus from subjects with schizophrenia is not associated with changes in protein kinase C

Combining in situ radioligand binding with autoradiography, we previously identified a reduction of [(3)H]phorbol 12,13-dibutyrate binding in the parahippocampal gyrus from schizophrenic subjects. To determine whether these changes were due to decreases in the level of protein kinase C, we measured [(3)H]phorbol 12,13-dibutyrate binding, levels of the protein kinase C isoforms alpha, beta, delta, epsilon, gamma, eta and theta, as well as protein kinase C activity in crude particulate membranes from parahippocampal gyri of 15 schizophrenic and 15 control subjects. There was a significant decrease in the density (mean +/- SEM: 6.56 +/- 0.73 pmol mg(-1) vs 9.68 +/- 1.22 pmol mg(-1); P < 0.05) and affinity (mean K(D) +/- SEM: 4.64 +/- 0.34 nM vs 2.95 +/- 0.35 nM; P < 0.005) of [(3)H]phorbol 12,13-dibutyrate binding in homogenates from schizophrenic subjects. There were no significant changes in levels of the protein kinase C isoforms which are known to bind phorbol esters or in the activity of protein kinase C in membranes from schizophrenic subjects. These results suggest that there are changes in molecules capable of binding [(3)H]phorbol 12,13-dibutyrate, other than protein kinase C, in the parahippocampal gyrus from subjects with schizophrenia.

Assessment of dermal absorption and penetration of components of a fuel mixture (JP-8)

Occupational and environmental multi-chemical exposures are extremely common. Methods for assessment of the risks from dermal exposures to complex mixtures vary depending on the information available. The composition of a volatile mixture (such as JP-8 jet fuel) can change radically, depending on the phase of the mixture - vapor, liquid or aerosol. Assessing the absorption (into the skin) and penetration (through the skin) of components of the mixture can reduce uncertainty in the risk assessment process. Permeability coefficients of the 12 individual components that could be detected to penetrate the skin could be used to assess the toxicity of each individual component in the JP-8. The penetration of each of these components is related to and can be predicted from molecular weight and octanol water partition coefficients of that component. The composition of the components that penetrate the skin would be different from the composition of JP-8 because the permeability of the components differs by two orders of magnitude. Concentrations of the aliphatic chemicals found in the skin correlated well with carbon number. The JP-8 jet fuel is used as an example of how component data on absorption and penetration can be integrated into an assessment (McDougal et al., Toxicol Sci 2000; 55: 247-255). The component approach shows promise for estimating systemic toxicity of mixtures. Local toxicity (irritation, sensitization, etc.) may be better understood in the future when quantitative information becomes available about the duration and magnitude of chemical exposures required to cause local effects.

Pituitary autoantibodies in lymphocytic hypophysitis target both gamma- and alpha-Enolase - a link with pregnancy?

The first target autoantigen to have been identified in lymphocytic hypophysitis is a 49 kDa protein, identified as alpha-enolase. Pituitary autoimmunity is strongly associated with pregnancy and we have shown that pituitary autoantibodies from patients with peripartum lymphocytic hypophysitis also recognise enolase in the placenta. Enolase exists in different forms as a number of isoenzymes, which are homo- or heterodimers of three subunits, alpha, beta and gamma. alphaalpha-enolase is ubiquitous, betabeta-enolase is muscle-specific and gammagamma-enolase, which is restricted to neuronal tissue and neuroendocrine cells, is known as neuron-specific enolase (NSE). NSE is expressed in normal human pituitary and pituitary neoplasms. The current study investigated which isoforms of enolase in pituitary and placenta reacted with the sera of patients with lymphocytic hypophysitis. Immunoblotting of two-dimensional gels of human pituitary cytosolic proteins showed that autoantibodies in patient sera react with both an acidic form, and more neutral forms of enolase. Immunoblotting with a monoclonal antibody to NSE confirmed the identity of the acidic enolase isoform as the gammagamma-isoform in both pituitary and placental samples. Gamma-enolase, i.e. NSE, was detected by immunohistochemistry in term placenta in decidua, syncytiotrophoblasts, anchoring villi and terminal villi. Our study is the first to describe the cellular localisation of NSE in normal human placenta, thus establishing a direct link between pituitary and placental autoantigens. This link provides a theoretical basis for the strong prediliction of lymphocytic hypophysitis to occur during or after pregnancy.

Growth and adrenal suppression in asthmatic children on moderate to high doses of fluticasone propionate

OBJECTIVE

Growth and adrenal suppression have been reported in asthmatic children using high-dose inhaled fluticasone propionate (FP). Inhaled FP, given at moderate doses (250-750 microg/day), has not been documented to be associated with growth or adrenal suppression in asthmatic children until recently. We report three cases illustrating these side effects.

METHODS

Growth and adrenal suppression, after the introduction of inhaled FP, were observed in three prepubertal young asthmatic children referred to our asthma clinic and growth clinic. Growth centile and velocity were assessed by longitudinal stadiometry height measurements. Early morning plasma cortisol levels, and glucagon stimulation tests were used to assess the pituitary adrenal axis.

RESULTS

Severe growth and adrenal suppression were noted in three children while they were on moderate doses of inhaled FP. Improvements in growth and adrenal function were observed following cessation or dose reduction of inhaled FP.

CONCLUSIONS

Unexpected growth and adrenal suppression may occur in young asthmatic children using moderate doses of inhaled FP.

Telemedicine for the delivery of professional development for health, education and welfare professionals in two remote mining towns

Over a two-year period, telemedicine was used to deliver training and development services for health, education and welfare staff in two remote towns in South Australia - Roxby Downs and Coober Pedy. Both are mining towns but they have different profiles in terms of the community's mental health needs. The services were provided by the Child and Adolescent Mental Health Services (CAMHS) from the Women's and Children's Hospital in Adelaide, South Australia. The media used were videoconferencing, telephone, video-tapes, the Internet and printed material. During 1998-9, professional staff in the two locations participated in structured videoconferencing seminars that addressed important mental health topics, chosen in response to surveys of the needs of the participants. The videoconferencing sessions were sometimes used to discuss specific patient cases. Each remote town was also supported via videoconferencing by a nominated office of the CAMHS: Roxby Downs by the suburban office at Port Adelaide and Coober Pedy by the office in the industrial town of Port Pirie. This customized support was an important factor in the success of the professional development network.

3.1 Scholarship and the university

Universities now exist in an environment of increasing accountability for their academic performance, both in teaching and research. Dental schools are expected to meet the academic expectations of their parent university and, in addition, to contribute to the health-care needs of the community. Individual staff members must achieve collectively the performance targets required of their school and individually must develop skills and expertise in their academic and clinical activities to merit tenure and promotion. This discussion examines the issues which impact on current problems of recruitment and retention of academic staff in dental schools internationally. The essential issue is career development in a manner which maintains the values that will ensure the credibility of dentistry as a scientifically based discipline and profession, while balancing the achievable academic needs with the added demands of achieving specialist clinical skills. Central to this balance is recognition that scholarship, which provides the bridge between research and teaching, can be broadly defined and that different individuals can be scholarly in a range of ways. Increasingly, schools are recognizing the importance of providing structured opportunities and guidance for career development of younger staff and of the need for flexibility in their criteria for tenure and promotion, recognizing that a diversity of individual strengths and teamworking are necessary both for the collective performance of the institution and the morale and development of the individual.