Climate-invariant machine learning

Projecting climate change is a generalization problem: We extrapolate the recent past using physical models across past, present, and future climates. Current climate models require representations of processes that occur at scales smaller than model grid size, which have been the main source of model projection uncertainty. Recent machine learning (ML) algorithms hold promise to improve such process representations but tend to extrapolate poorly to climate regimes that they were not trained on. To get the best of the physical and statistical worlds, we propose a framework, termed "climate-invariant" ML, incorporating knowledge of climate processes into ML algorithms, and show that it can maintain high offline accuracy across a wide range of climate conditions and configurations in three distinct atmospheric models. Our results suggest that explicitly incorporating physical knowledge into data-driven models of Earth system processes can improve their consistency, data efficiency, and generalizability across climate regimes.

Breast exam use during the protracted COVID-19 pandemic, by age, race, and geography

In this study we analyzed data collected from the onset of the COVID-19 pandemic through March 31, 2022 to identify temporal shifts in breast exam volume. Screening mammography volume stabilized toward the end of the study period, while diagnostic exam volume varied over time and by age. Older women experienced a decline in diagnostic exam volume between August 2020 and April 2021 that was not observed among women aged 50 years or less (50-69 years, monthly percentage change (MPC): -6.5; and 70+ years, MPC: -15.7). With respect to breast biopsy volume, women younger than 70 years of age had increased exam volume beginning in April 2020 and June 2020, whereas a corresponding increase among older women was delayed until April 2021(70+ years, MPC: 9.3). Findings from our study suggest a temporal shift in the use of breast exams that could result in differential detection of breast cancer by age.

Non-Linear Dimensionality Reduction With a Variational Encoder Decoder to Understand Convective Processes in Climate Models

Deep learning can accurately represent sub-grid-scale convective processes in climate models, learning from high resolution simulations. However, deep learning methods usually lack interpretability due to large internal dimensionality, resulting in reduced trustworthiness in these methods. Here, we use Variational Encoder Decoder structures (VED), a non-linear dimensionality reduction technique, to learn and understand convective processes in an aquaplanet superparameterized climate model simulation, where deep convective processes are simulated explicitly. We show that similar to previous deep learning studies based on feed-forward neural nets, the VED is capable of learning and accurately reproducing convective processes. In contrast to past work, we show this can be achieved by compressing the original information into only five latent nodes. As a result, the VED can be used to understand convective processes and delineate modes of convection through the exploration of its latent dimensions. A close investigation of the latent space enables the identification of different convective regimes: (a) stable conditions are clearly distinguished from deep convection with low outgoing longwave radiation and strong precipitation; (b) high optically thin cirrus-like clouds are separated from low optically thick cumulus clouds; and (c) shallow convective processes are associated with large-scale moisture content and surface diabatic heating. Our results demonstrate that VEDs can accurately represent convective processes in climate models, while enabling interpretability and better understanding of sub-grid-scale physical processes, paving the way to increasingly interpretable machine learning parameterizations with promising generative properties.

Ethnic inequalities in treatment with clozapine

Introduction

Ethnic disparities in treatment with clozapine, the antipsychotic recommended for treatment-resistant schizophrenia (TRS), have been reported. However, these investigations frequently suffer from potential residual confounding. For example, few studies have restricted the analyses to TRS samples and none has controlled for benign ethnic neutropenia.

Objectives

This study investigated if service-users’ ethnicity influenced clozapine prescription in a cohort of people with TRS.

Methods

Information from the clinical records of South London and Maudsley NHS Trust was used to identify a cohort of service-users with TRS between 2007 and 2017. In this cohort, we used logistic regression to investigate any association between ethnicity and clozapine prescription while adjusting for potential confounding variables, including sociodemographic factors, psychiatric multimorbidity, substance use, benign ethnic neutropenia, and inpatient and outpatient care received.

Results

We identified 2239 cases that met the criteria for TRS. Results show that after adjusting for confounding variables, people with Black African ethnicity had half the odds of being treated with clozapine and people with Black Caribbean or Other Black background had about two-thirds the odds of being treated with clozapine compared White British service-users. No disparities were observed regarding other ethnic groups, namely Other White background, South Asian, Other Asian, or any other ethnicity.

Conclusions

There was evidence of inequities in care among Black ethnic groups with TRS. Interventions targeting barriers in access to healthcare are recommended.

Disclosure

During the conduction of the study, DFdF, GKS, and RH received funds from the NIHR Maudsley Biomedical Research Centre. For other activities outside the submitted work, DFdF received research funding from the UK Department of Health and Social Care, Janss

Correlates of late-onset antipsychotic treatment resistance

Introduction

There is emerging evidence of heterogeneity within treatment-resistance schizophrenia (TRS), with some people not responding to antipsychotic treatment from illness onset and a smaller group becoming treatment-resistant after an initial response period. It has been suggested that these groups have different aetiologies. Few studies have investigated socio-demographic and clinical differences between early and late onset of TRS.

Objectives

This study aims to investigate socio-demographic and clinical correlates of late-onset of TRS.

Methods

Using data from the electronic health records of the South London and Maudsley, we identified a cohort of people with TRS. Regression analyses were conducted to identify correlates of the length of treatment to TRS. Analysed predictors include gender, age, ethnicity, positive symptoms severity, problems with activities of daily living, psychiatric comorbidities, involuntary hospitalisation and treatment with long-acting injectable antipsychotics.

Results

We observed a continuum of the length of treatment until TRS presentation. Having severe hallucinations and delusions at treatment start was associated shorter duration of treatment until the presentation of TRS.

Conclusions

Our findings do not support a clear cut categorisation between early and late TRS, based on length of treatment until treatment resistance onset. More severe positive symptoms predict earlier onset of treatment resistance.

Disclosure

DFdF, GKS, EF and IR have received research funding from Janssen and H. Lundbeck A/S. RDH and HS have received research funding from Roche, Pfizer, Janssen and Lundbeck. SES is employed on a grant held by Cardiff University from Takeda Pharmaceutical Comp

Insights from electronic health record data to improve mental health service delivery during the COVID-19 pandemic

Background

Remote consultation technology has been rapidly adopted due to the COVID-19 pandemic. However, some healthcare settings have faced barriers in implementation. We present a study to investigate changes in rates of remote consultation during the pandemic using a large electronic health record (EHR) dataset.

Methods

The Clinical Record Interactive Search tool (CRIS) was used to examine de-identified EHR data of people receiving mental healthcare in South London, UK. Data from around 37,500 patients were analysed for each week from 7th January 2019 and 20th September 2020 using linear regression and locally estimated scatterplot smoothing (LOESS) to investigate changes in the number of clinical contacts (in-person, remote or non-attended) with mental healthcare professionals and prescribing of antipsychotics and mood stabilisers. The data are presented in an interactive dashboard: http://rpatel.co.uk/TelepsychiatryDashboard.

Results

The frequency of in-person contacts was substantially reduced following the onset of the pandemic (β coefficient: -5829.6 contacts, 95% CI -6919.5 to -4739.6, p<0.001), while the frequency of remote contacts increased significantly (β coefficient: 3338.5 contacts, 95% CI 3074.4 to 3602.7, p<0.001). Rates of remote consultation were lower in older adults than in working age adults, children and adolescents. Despite the increase in remote contact, antipsychotic and mood stabiliser prescribing remained at similar levels.

Conclusions

The COVID-19 pandemic has been associated with a marked increase in remote consultation, particularly among younger patients. However, there was no evidence that this has led to changes in prescribing. Further work is needed to support older patients in accessing remote mental healthcare.

Disclosure

All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: RS has received funding from Janssen, GSK and Takeda outside the submitted work. RP has received funding from Janssen, Induction Healthcare and H

Enforcing Analytic Constraints in Neural Networks Emulating Physical Systems

Neural networks can emulate nonlinear physical systems with high accuracy, yet they may produce physically inconsistent results when violating fundamental constraints. Here, we introduce a systematic way of enforcing nonlinear analytic constraints in neural networks via constraints in the architecture or the loss function. Applied to convective processes for climate modeling, architectural constraints enforce conservation laws to within machine precision without degrading performance. Enforcing constraints also reduces errors in the subsets of the outputs most impacted by the constraints.

Population-level impact of coronavirus disease 2019 on breast cancer screening and diagnostic procedures

BACKGROUND

To understand how health care delays may affect breast cancer detection, the authors quantified changes in breast‐related preventive and diagnostic care during the coronavirus disease 2019 (COVID‐19) pandemic.

METHODS

Eligible women (N = 39,444) were aged ≥18 years and received a screening mammogram, diagnostic mammogram, or breast biopsy between January 1, 2019 and September 30, 2020, at 7 academic and community breast imaging facilities in North Carolina. Changes in the number of mammography or breast biopsy examinations after March 3, 2020 (the first COVID‐19 diagnosis in North Carolina) were evaluated and compared with the expected numbers based on trends between January 1, 2019 and March 2, 2020. Changes in the predicted mean monthly number of examinations were estimated using interrupted time series models. Differences in patient characteristics were tested using least squares means regression.

RESULTS

Fewer examinations than expected were received after the pandemic's onset. Maximum reductions occurred in March 2020 for screening mammography (−85.1%; 95% CI, −100.0%, −70.0%) and diagnostic mammography (−48.9%; 95% CI, −71.7%, −26.2%) and in May 2020 for biopsies (−40.9%; 95% CI, −57.6%, −24.3%). The deficit decreased gradually, with no significant difference between observed and expected numbers by July 2020 (diagnostic mammography) and August 2020 (screening mammography and biopsy). Several months after the pandemic's onset, women who were receiving care had higher predicted breast cancer risk (screening mammography, P < .001) and more commonly lacked insurance (diagnostic mammography, P < .001; biopsy, P < .001) compared with the prepandemic population.

CONCLUSIONS

Pandemic‐associated deficits in the number of breast examinations decreased over time. Utilization differed by breast cancer risk and insurance status, but not by age or race/ethnicity. Long‐term studies are needed to clarify the contribution of these trends to breast cancer disparities.

In this observational study, the use of screening mammography, diagnostic mammography, and breast biopsy is significantly lower than expected after the onset of the COVID‐19 pandemic in North Carolina, but the deficits decrease over time. Health insurance status and predicted breast cancer risk are identified as predictors of mammography and biopsy receipt during the pandemic.

Understanding the response of mammography facilities to breast density notification

BACKGROUND

State-specific breast density notification legislation requires that women undergoing mammography be informed about breast density, with variation among states. Because mammography facilities are among the main points of contact for women undergoing mammography, research is needed to understand how facilities communicate information on breast density, cancer risk, and supplemental screening to women.

METHODS

A cross-sectional, 50-item, mailed survey of 156 American College of Radiology-certified mammography facilities in North Carolina was conducted in 2017 via the Tailored Design Method. Breast density notification practices, supplemental screening services, and patient educational materials were compared by supplemental screening availability via t tests and chi-square tests.

RESULTS

All responding facilities (n = 94; 60.3% response rate) notified women of their breast density in the mammography results letter. Breast cancer risk assessments were performed by 36.2% of the facilities, with risk information communicated in the final radiology report for the referring provider to discuss with the woman (79.4%) or in the results letter (58.8%). Supplemental breast cancer screening was offered by 63.8% of the facilities, with use based on multiple factors, including recommendations from the referring physician (63.3%) or reading radiologist (63.3%), breast density (48.3%), other risk factors (48.3%), and patient request (40.0%). Although 75.0% of the facilities offered breast density educational materials, only 36.6% offered educational materials on supplemental screening.

CONCLUSIONS

In a state with a breast density notification law, mammography facilities communicate breast density, cancer risk, and supplemental screening information to women through various approaches. When supplemental screening is offered, facilities use multiple decision-making criteria rather than breast density alone.

Availability Versus Utilization of Supplemental Breast Cancer Screening Post Passage of Breast Density Legislation

Objective: Despite the lack of evidence that supplemental screening in women with dense breasts reduces breast cancer mortality, 38 states have passed breast density legislation, with some including recommendations for supplemental screening. The objective of this study is to compare the availability versus use of supplemental breast cancer screening modalities and determine factors driving use of supplemental screening in rural versus urban settings. Methods: A 50-item mailed survey using the Tailored Design Method was sent to American College of Radiology mammography-accredited facilities in North Carolina in 2017. Respondents included 94 facilities (48 rural and 46 urban locations). Survey questions focused on breast cancer and supplemental screening services, breast density, risk factors/assessment, and facility demographics. Results: The survey response rate was 60.3% (94/156). Among the 94 respondents, 64.0% (n = 60) reported availability of any type of supplemental screening (digital breast tomosynthesis [DBT], ultrasound, or magnetic resonance imaging [MRI]). In facilities where supplemental screening modalities were available, the most commonly utilized supplemental screening modality was DBT (96.4%), compared with ultrasound (35.7%) and MRI (46.7%). Facilities reported using supplemental screening based on patient breast density (48.3%), referring physician recommendation (63.3%), reading radiologist recommendation (63.3%), breast cancer risk factors (48.3%), and patient request (40.0%). Urban facilities were more likely than rural facilities to base supplemental screening on breast cancer risk factors (62.5% vs. 32.1%; p-value = 0.019), referring physician (75.0% vs. 50.0%; p-value = 0.045), and reading radiologist (78.1% vs. 46.4%; p-value = 0.011). Conclusion: In our study, supplemental screening modalities were widely available, with facilities more likely to use DBT for supplemental screening compared to other modalities.

Protocol for CT in the position of discomfort: preoperative assessment of femoroacetabular impingement - how we do it and what the surgeon wants to know

INTRODUCTION

The use of computed tomography of the hip in a position of discomfort (CT-POD) in combination with 2D and 3D surface rendering is a technique increasingly used to aid in the assessment and confirmation of femoral and acetabular bony abnormalities related to femoroacetabular impingement. The purpose of this article is to describe this dynamic method of assessment.

METHODS

Patients referred by orthopaedic surgeons for assessment of femoroacetabular impingement as part of preoperative planning and patients who required postoperative assessment of residual bony abnormalities were selected.

RESULTS

This article describes the CT-POD technique and the information required by the referring surgeon.

CONCLUSION

CT-POD is a new technique that provides valuable preoperative and postoperative information to the surgeon.

The ligamentum teres-its increasing importance

The ligamentum teres (LT) has attracted much greater interest over recent years due to the increased use of hip arthroscopy. There have been advancements in our understanding of the LT's biomechanical function and its role in hip and groin pain. Our ability to suspect LT tears by clinical examination and imaging has improved. Publications by many authors concerning LT tear treatment and outcomes continue to increase. This manuscript is a review of the function, mechanism of injury, clinical assessment, imaging, arthroscopic assessment, treatment, outcomes, reconstruction, and unusual conditions of the LT.

The ligamentum teres test: a novel and effective test in diagnosing tears of the ligamentum teres

BACKGROUND

A ligamentum teres (LT) injury is a common finding at the time of hip arthroscopic surgery in patients with chronic groin and hip pain; however, LT tears have been difficult to identify before surgery. There have been no unique features identified on history assessment, physical examination, or imaging that reliably identify injuries of the LT preoperatively.

PURPOSE

To report a new clinical examination to assess the presence of an LT tear: the LT test.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

The study consisted of 75 patients undergoing hip arthroscopic surgery for multiple lesions. Each patient was evaluated by 2 independent examiners using the LT test, leading to a total of 150 tests being performed. The LT test is conducted with the hip flexed at 70° and 30° short of full abduction; the hip is then internally and externally rotated to its limits of motion. Pain on either internal or external rotation is consistent with a positive LT test result. Hip arthroscopic surgery was then performed and all intra-articular abnormalities noted. Arthroscopic images were taken of each LT and examined by a third independent examiner who determined the presence or absence of a tear. Clinical examination findings were compared with the arthroscopic findings to determine the sensitivity, specificity, and positive and negative predictive values. In addition, the presence of intra-articular pathological lesions was compared with the test results to determine if there was a correlation between the presence of an intra-articular pathological abnormality and a positive LT test result.

RESULTS

Of the 150 examinations performed, the test result was positive 55% of the time (77 examinations). The sensitivity and specificity of the test were 90% and 85%, respectively. The positive predictive value was 84%, and the negative predictive value was 91%. The presence of an LT tear, pincer lesion, and labral tear that required repair was associated with a positive LT test result. The κ coefficient for interobserver reliability was .80.

CONCLUSION

The LT test is an effective way of assessing the presence of LT tears with moderate to high interobserver reliability. In addition to an LT tear, the presence of a pincer lesion or labral tear requiring repair are also associated with a positive LT test result.

Outcome of arthroscopic treatment for cam type femoroacetabular impingement in adolescents

BACKGROUND

Hip arthroscopy has become an established procedure in adults with well-published results. These techniques have been extended to the teenage population, but the literature remains limited in regard to indications, efficacy, outcomes and complications specific to the paediatric population.

HYPOTHESIS/PURPOSE

The purpose of this study was to report the short-term outcome of the arthroscopic treatment of cam-type femoroacetabular impingement (FAI) in the skeletally immature adolescent population with open growth plates, with the hypothesis that it is a safe procedure, with good clinical outcomes and low complication rates.

STUDY DESIGN

The study design of this article was a multicentre prospective longitudinal case series.

METHODS

From 2008-2009, 34 consecutive patients who were 18 years or younger at the date of operation (41 hips) with open proximal femoral growth plates had arthroscopic hip surgery for treatment of cam-type FAI and associated lesions by use of the lateral decubitus position by two surgeons. Data were collected prospectively including the modified Harris hip score (MHHS), nonarthritic hip score (NAHS), satisfaction survey and complications. Mean follow-up was 14 months (range 1-2 years).

RESULTS

All hips were available for review. The mean age of patients was 15.7 years with the most common sport activity being Australian Football League, netball and rugby. All patients had cam-type impingement, with the most common associated lesions being acetabular rim lesions (82.9%) and pincer impingement (22%). The labrum underwent debridement in 31.7% of cases, and was repaired in 17.1%. The MHHS and NAHS improved in all patients post-operatively, 77.39-94.15 and 76.34-93.18, respectively. A percentage of 78.1 were able to return to full sporting activity and 88.2% were satisfied with the operation. There were no complications.

CONCLUSIONS

Using hip arthroscopy to treat cam-type impingement and associated lesions in the adolescent population, we confirmed our hypothesis with observed high satisfaction levels, return to sports, significant improvement in post-operative hip scores (MHHS and NAHS) and no complications.

Smell identification test as a progression marker in Alzheimer's disease

Introduction

Factors influencing or predicting progression in Alzheimer's disease (AD) is not well understood. Olfactory dysfunction, impaired smell identification in particular, is known to occur in AD. Mesial temporal lobe, important for memory function is also critical for the processing of olfactory information. In view of the common anatomical substrate, we hypothesized that olfaction dysfunction worsens faster in people with AD with rapid cognitive decline compared to those with slower cognitive decline.

Aims

To test whether smell identification test can be used as a predictor for illness progression in AD patients.

Methods

Forty one participants with late onset mild to moderate AD were recruited from mental health services for older adults. Subjects were classified as ‘Rapid Progressors’ defined on ‘a-priori’ with a loss of 2 or more points in Mini-Mental State Examination (MMSE) within six months. Assessments included MMSE, Neuropsychiatric Inventory, Bristol Activities of Daily Living, and the University of Pennsylvania Smell Identification Test (UPSIT), at baseline and after 3 months.

Results

Twenty subjects were ‘Rapid Progressors’, and had lower UPSIT scores compared to ‘Non-Rapid Progressors’ both at the baseline (p = 0.02) and at follow up after 3 months (p = 0.05). Baseline UPSIT correlated with follow up UPSIT (r = 0.5, p < 0.01) and MMSE (r = 0.4, p = 0.04). Also it was the baseline UPSIT score that best predicted (p < 0.05) the follow up smell and cognitive function on linear regression analysis.

Conclusions

Smell identification function could be useful as a clinical measure to assess and predict progression in AD.

Measuring anxiety in surgical patients using a visual analogue scale

Since the early days of surgery patients have been anxious about undergoing operations. This feeling remains common today despite advances in medicine and surgical techniques. Numerous studies have shown the effect anxiety has on the human body. It is the responsibility of healthcare professionals to ensure that any patient undergoing an elective surgical procedure is both physically and psychologically prepared. However, with increasing demands on the health service to be more efficient, little time is set aside to meet the psychological needs of the surgical patient. This article focuses on the use of a visual analogue scale to identify pre-operative anxiety in patients, so that healthcare practitioners can implement strategies to reduce anxiety and improve the person's overall experience.

Prediction of the benefit of trastuzumab (T)-based therapy by the change of gene expression of peripheral blood mononuclear cells (PBMC)

e14578

Background: Identification of molecular predictors of response is important in the aspect of personalization of treatment, especially in the era of molecular targeted drugs. Antibody-dependent cell-mediated cytotoxicity (ADCC) is suggested as one of the main mechanism of action of T. Moreover, PBMC specimens can securely be obtained with minimal invasion. We therefore hypothesized that gene expression changes induced by T of PBMC may be useful for prediction of response of T. Methods: 36 HER2-positive metastatic breast cancer (BC) patients were enrolled in this prospective biomarker study. The patients were treated with single-agent T (q1w) for chemotherapy-naïve, hormone refractory metastatic disease. The clinical response was measured after 8 cycles of single-agent T. PBMC were collected prior to and 1-week after the first administration of T. Gene expressions of PBMC were measured using Affimetrix GeneChip Human Genome U133 Plus 2.0 array. Change of gene expressions before and after T was correlated with clinical response using Wilcoxon rank sum test. A multi-gene predictor of response to T was generated using the highly ranked genes. The performance of the predictor was then assessed in patients prospectively treated with neoadjuvant chemotherapy (NAC): HER2- positive BC patients recieved NAC containing T. PBMC were collected prior to NAC and 1-week after the first administration of T. Results: 34 patients were evaluable for clinical outcome. 15 and 19 patients were classified as responders and non- responders, respectively. The top 4 genes differentially regulated by T between responders and non-responders were selected for development of a predictor by leave-one-out cross validation. The 4-gene predictor correctly predicted the pathological complete response (pCR) in 5 out of 5 patients who achieved pCR and residual disease (RD) in 10 out of 12 patients with RD (error rate 12 %) in HER2-positive breast BC patients treated with NAC containing T. However, it was not associated with pathological response in 19 HER2- negative patients treated with NAC without T (error rate 39 %). Conclusions: Change in PBMC gene expression after single dosage of T may be useful as a predictor of response to T-based therapy.

No significant financial relationships to disclose.

The NERC DataGrid services

This short paper outlines the key components of the NERC DataGrid: a discovery service, a vocabulary service and a software stack deployed both centrally to provide a data discovery portal, and at data providers to provide local portals and data and metadata services.

The relationships among religious affiliation, religious angst, and disordered eating

Although religion is thought to be a positive aspect of life, sometimes that is not always the case. One potentially negative effect of religion is the way people learn to perceive their bodies. Although many studies have examined factors that influence disordered eating (e.g., gender, self-esteem), few studies have examined the relationships among disordered eating and religious affiliation and religious angst. In the present study of 330 undergraduates, we found that Catholics and Christians displayed significantly more disordered eating than did other students. In addition, individuals scoring high on religious angst also reported more disordered eating behaviors than did other students. Implications for counseling will be discussed.

Audit of the Douglas Hocking Research Institute bone bank: ten years of non-irradiated bone graft

BACKGROUND

An audit performed in the use of non-irradiated femoral head bone graft at the Geelong Hospital over a 10-year period. While it is thought the non-irradiated bone graft provides a better structural construct there is theoretical increased risk of infection transmission.

METHODS

We performed a retrospective review of prospectively collected data in the use of non-irradiated bone allograft used from the Geelong Hospital Douglas Hocking Research Institute bone bank over a 10-year period. The review was performed using data collected from the bone bank and correlating it with the patient's medical record. All complications, including infections, related to the use of the allograft were recorded.

RESULTS

We found that over the 10 years to 2004 that 811 femoral heads were donated, with 555 being used over 362 procedures in 316 patients. We identified a total of nine deep infections, of which seven were in joint replacements. Overall this was a 2.5% deep infection rate, which was lowered to 1.4% if the previously infected joints that were operated on were excluded.

CONCLUSION

The use of non-irradiated femoral head bone graft was safe in a regional setting.

Disordered eating in men: a look at perceived stress and excessive exercise

Although once considered a 'female' disorder, eating disorders are becoming more prevalent in males. As such, researchers are beginning to focus on factors that predict eating disturbances in males. Previous research has established a relation between eating disorders and stress and exercise dependence. However, few studies have examined the relation between the more common diagnosis of disordered eating and stress and exercise dependence, particularly in men. The purpose of the present study was to investigate the relation between disordered eating, stress, and exercise dependence in undergraduate male students. Implications for counseling men suffering from disordered eating will be discussed.

Down syndrome and the genes of human chromosome 21: current knowledge and future potentials. Report on the Expert workshop on the biology of chromosome 21 genes: towards gene-phenotype correlations in Down syndrome. Washington D.C., September 28-October 1, 2007

Down syndrome (DS), trisomy of human chromosome 21, is the most common genetic cause of intellectual disability. With an incidence in some countries as high as one in approximately 700 live births, and a complex, extensive and variably severe phenotype, Down syndrome is a significant medical and social challenge. In recent years, there has been a rapid increase in information on the functions of the genes of human chromosome 21, as well as in techniques and resources for their analysis. A recent workshop brought together experts on the molecular biology of Down syndrome and chromosome 21 with interested researchers in other fields to discuss advances and potentials for generating gene-phenotype correlations. An additional goal of the workshop was to work towards identification of targets for therapeutics that will correct features of DS. A knowledge-based approach to therapeutics also requires the correlation of chromosome 21 gene function with phenotypic features.

Association of control and risk of severe asthma-related events in severe or difficult-to-treat asthma patients

BACKGROUND

Clinical tools for predicting poor outcomes in asthma patients are lacking. This study investigated the association of asthma control and subsequent severe asthma-related healthcare events in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study.

METHODS

The extent of asthma control problems was determined from baseline values of the Asthma Therapy Assessment Questionnaire (ATAQ). Patients self-reported the presence of severe asthma-related events at 6- and 12-month follow up. Poisson regression models determined the adjusted association between baseline control and the likelihood of severe asthma-related events.

RESULTS

At baseline, 2942 patients (mean age, 49.6 years; female, 71.9%) had an ATAQ score (no control problems, 17.0%; 1 control problem, 20.0%; 2 control problems, 30.8%; 3 or 4 control problems, 32.2%) and at least one severe asthma-related event. After adjustment, subjects with three or four control problems were at greater risk for unscheduled office visits [relative risk (RR) = 2.8; 95% confidence interval (CI): 2.4-3.2], course of oral steroids (RR = 2.9; 95% CI: 2.5-3.3), emergency room visits (RR = 4.1; 95% CI: 2.7-6.2) or hospitalization (RR = 13.6; 95% CI: 7.4-24.9), vs no control problems. Progressively poorer levels of asthma control are associated with increasing risk of severe asthma-related events.

CONCLUSIONS

This study provides evidence of an association between poor asthma control and future severe asthma-related healthcare events. A validated questionnaire may help clinicians identify patients requiring intervention to prevent future severe asthma-related events.

Gender differences in disordered eating and its correlates

The goal of this study was to examine gender differences in the prevalence of disordered eating and body dissatisfaction as well as examine gender differences in several risk factors: mass media, self-esteem and perfectionism. Three hundred fifty-three undergraduates completed surveys about their body dissatisfaction, disordered eating habits, exposure to and influence of mass media, self-esteem and perfectionistic tendencies. As expected, women experienced more symptoms of disordered eating as well as body dissatisfaction than did their male counterparts. There were also gender differences in the risk factors. For women, mass media, self-esteem, and perfectionism related to disordered eating behaviors, whereas for men, only perfectionism and mass media related to disordered eating behaviors. For women, mass media and self-esteem related to body image dissatisfaction, whereas for men, mass media and perfectionism related to body image dissatisfaction. The results of the present study indicate that risk factors for disordered eating and body dissatisfaction for men and women may be different, which has implications for understanding the etiology of body dissatisfaction and disordered eating and for possible treatment interventions.

225. Early ovarian follicle dysgenesis in a disintegrin and metalloproteinase with thrombospondin motifs type 1 (ADAMTS-1) null mice

ADAMTS-1 is a multi-domain, multi-functional matrix metalloproteinase expressed in the mouse ovary during folliculogenesis and ovulation. Adult ADAMTS-1 null female mice are infertile; however, the exact mechanism responsible for their reproductive failure is yet to be explained. ADAMTS-1 null ovaries prior to and following ovulation were examined and a defect in ovarian follicle development was identified. A classification system was devised and used to identify morphological differences between normal and ADAMTS-1 null ovaries. The phenotype indicated a progressive loss of follicle structural integrity ranging from a slight loss of shape, to full structural dysgenesis. As a result, large numbers of oocytes with healthy appearance were found with no surrounding follicle structure. The numbers of preantral follicles was not altered, but type 6 (early antral) follicles in the ADAMTS-1 null ovaries were significantly reduced (P < 0.05) when compared to wild-type ovaries suggesting initiation of follicular degeneration coincident with antrum formation. There was also a significant decrease (P < 0.05) in the number of periovulatory follicles (type 7 and 8) in the ADAMTS-1 null ovaries. This suggests that late folliculogenesis, in the period of rapid growth and expansion is disrupted when ADAMTS-1 is not present and results in fewer follicles available for ovulation. Further, we have demonstrated that the active form of ADAMTS-1 is present in the thecal-granulosa boundary of the ovarian follicle suggesting a role in extracellular matrix remodeling at this boundary during follicle growth. Analyses of the basement membrane at this boundary both in growing and ovulating follicles indicate that ECM remodeling in this region is indeed disrupted. These data demonstrate that remodeling of surrounding structural matrix is crucial to follicle growth and structural integrity. Functional ADAMTS-1 is important for matrix remodeling during the growth of the follicle, particularly during antrum formation.

Dressing size and pain: a prospective trial

BACKGROUND

Pain is a personal, subjective experience. In the postoperative period, pain may be influenced by patient, pharmacological and environmental factors. In surgery the aim is to reduce pain in this period by educating patients and using adequate analgesia. The aim of the present study was to assess the effect of perceived wound size on pain, as indicated by wound dressing, in the immediate postoperative period.

METHODS

Patients undergoing appendicectomy were randomized into a group having a dressing the same size (SSD) as the surgical wound or double the size (DSD) of the wound. Patients' pain perception and analgesic requirements were then recorded and analysed to compare the two groups.

RESULTS

Both groups had similar results when comparing pain perception. The median total pain score for the SSD and DSD groups at 12 and 24 h postoperatively revealed no statistically significant difference (P > 0.05).

CONCLUSION

The data do not support the hypothesis that postoperative pain may be altered by perceived wound dressing size. Dressing size does not appear to be a variable that could easily be altered to reduce postoperative pain in surgical patients.

An altered antioxidant balance occurs in Down syndrome fetal organs: Implications for the “gene dosage effect” hypothesis

Down syndrome (DS) is the congenital birth defect responsible for the greatest number of individuals with mental retardation. It arises due to trisomy of human chromosome 21 (HSA21) or part thereof. To date there have been limited studies of HSA21 gene expression in trisomy 21 conceptuses. In this study we investigate the expression of the HSA21 antioxidant gene, Cu/Zn-superoxide dismutase-1 (SOD1) in various organs of control and DS aborted conceptuses. We show that SOD1 mRNA levels are elevated in DS brain, lung, heart and thymus. DS livers show decreased SOD1 mRNA expression compared with controls. Since non-HSA21 antioxidant genes are reported to be concomitantly upregulated in certain DS tissues, we examined the expression of glutathione peroxidase-1 (GPX1) in control and DS fetal organs. Interestingly, GPX1 expression was unchanged in the majority of DS organs and decreased in DS livers. We examined the SOD1 to GPX1 mRNA ratio in individual organs, as both enzymes form part of the body's defense against oxidative stress, and because a disproportionate increase of SOD1 to GPX1 results in noxious hydroxyl radical damage. All organs investigated show an approximately 2-fold increase in the SOD1 to GPX1 mRNA ratio. We propose that it is the altered antioxidant ratio that contributes to certain aspects of the DS phenotype.

Impact of treatment on the outcome of acute myeloid leukemia with inversion 16: a single institution's experience

To identify treatment factors that may affect the survival of children with inv(16)(p13.1q22), we compared the outcomes of 19 patients with this genetic feature treated at our institution during two treatment eras. Nine patients were treated during era 1 (1980 to 1987), and 10 were treated during era 2 (1988 to 1996). All entered complete remission (CR) with induction therapy. Eight of the nine children treated in era 1 died, seven of relapsed leukemia. In contrast, three of 10 patients treated during era 2 have died, all of non-disease-related causes. Event-free survival (EFS) estimates were significantly higher for patients treated during era 2 than for those treated during era 1 (P = 0.03); the 6-year estimates were 70 +/- 15% (s.e.) and 11 +/- 7%, respectively. Era 2 treatment protocols differed from those of era 1 in their use of higher doses of cytarabine and etoposide during induction and consolidation chemotherapy and in their use of 2-chlorodeoxyadenosine (2-CDA). These results suggest that dose intensification of cytarabine benefits children with AML and inv(16), as is the case in adults. They also suggest that dose intensification of etoposide and addition of 2-CDA may also offer an advantage. This study underscores the dependence of the prognostic impact of cytogenetic features on the efficacy of treatment.

From single site to societal belief: the impact of pediatric oncology nursing research

This review describes the evolution of pediatric oncology nursing research over the past 25 years. It highlights practice-changing contributions from single-site studies and from multisite trials and discusses strategies for interdisciplinary collaboration. Technological advances that will alter the way in which studies are conducted and findings are disseminated will influence the future of nursing research. Studies implemented by pediatric nurse researchers will continue to influence practice and change how we, and others, view the experience of childhood cancer.

Preoxygenation for tracheal suctioning in intubated, ventilated newborn infants

BACKGROUND

Endotracheal suctioning for mechanically ventilated infants is routine practice in neonatal intensive care. However, this practice is associated with serious complications including lobar collapse, pneumothorax, bradycardia and hypoxemia. Increasing the inspired oxygen immediately prior to suction (preoxygenation) has been proposed as an intervention to minimise the risk of complications.

OBJECTIVES

To compare the effects of preoxygenation with no preoxygenation for endotracheal suctioning on ventilated newborn infants. To conduct sub group analyses by i) different populations of newborn infants; by gestational age <30 weeks, <34 weeks and <37 weeks and by disease; infants with chronic lung disease compared to those without and; ii) by different techniques of endotracheal suctioning; with or without disconnection from the ventilator, increased mechanical ventilation, use of manual ventilation and chest wall vibrations or percussion.

SEARCH STRATEGY

The standard search strategy of the Neonatal Review Group was used. This included searches of electronic databases; Oxford Database of Perinatal Trials; Cochrane Controlled Trials Register (Cochrane Library Issue 1 2001); MEDLINE (1966 - April 2001); and CINAHL (1982-2001) using MeSH term infant-newborn and text terms oxygen* and suction*, preoxygenation, pre-oxygenation and premature and also previous reviews including cross references, abstracts in conferences and symposia proceedings, expert informants, journal hand searching in the English language.

SELECTION CRITERIA

Random or quasi random controlled trials of mechanically ventilated neonates in which endotracheal suctioning with preoxygenation was compared to suctioning without preoxygenation.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used, including independent assessment of trial quality and extraction of data by the authors. Data were analysed using relative risk (RR) for dichotomous outcomes and mean difference (MD) for data measured on a continuous scale with the use of 95% confidence intervals. Meta-analysis was conducted using a fixed effects model.

MAIN RESULTS

One cross-over trial involving outcomes for 16 preterm neonates was included in this review. Preoxygenation, prior to an endotracheal suctioning procedure involving two suctions, resulted in a statistically significant reduction in infants with hypoxemia (TcPO2 <40 mmHg) at the end of the first suction (RR 0.18, 95% CI 0.05, 0.69), at the end of the second suction (RR 0.23, 95% CI 0.08, 0.66) and also at 120 seconds after the second suction (RR 0.10, 95% CI 0.01, 0.69). Mean TcPO2 was statistically significantly higher in the preoxygenation group at the end of the first suction (MD 25.00 mmHg, 95%CI 14.20, 35.80), second suction (MD 24.80, 95% CI 14.80, 34.80) and also at 120 seconds after the second suction (MD 29.10, 95% CI 14.96, 43.24). The time taken to return to baseline oxygenation status was shorter than the group not receiving preoxygenation (MD -2.12 minutes, 95% CI -3.82, -0.42).

REVIEWER'S CONCLUSIONS

No recommendations for practice can be confidently made from the results of this review. Although preoxygenation was shown to decrease hypoxemia at the time of suctioning, other clinically important short and longer-term outcomes including adverse effects were unable to be assessed. Further studies are needed to adequately assess the effects of this widely practiced procedure.