Metabolic phenotyping with computed tomography deep learning for metabolic syndrome, osteoporosis and sarcopenia predicts mortality in adults

BACKGROUND

Computed tomography (CT) body compositions reflect age-related metabolic derangements. We aimed to develop a multi-outcome deep learning model using CT multi-level body composition parameters to detect metabolic syndrome (MS), osteoporosis and sarcopenia by identifying metabolic clusters simultaneously. We also investigated the prognostic value of metabolic phenotyping by CT model for long-term mortality.

METHODS

The derivation set (n = 516; 75% train set, 25% internal test set) was constructed using age- and sex-stratified random sampling from two community-based cohorts. Data from participants in the individual health assessment programme (n = 380) were used as the external test set 1. Semi-automatic quantification of body compositions at multiple levels of abdominal CT scans was performed to train a multi-layer perceptron (MLP)-based multi-label classification model. External test set 2 to test the prognostic value of the model output for mortality was built using data from individuals who underwent abdominal CT in a tertiary-level institution (n = 10 141).

RESULTS

The mean ages of the derivation and external sets were 62.8 and 59.7 years, respectively, without difference in sex distribution (women 50%) or body mass index (BMI; 23.9 kg/m2). Skeletal muscle density (SMD) and bone density (BD) showed a more linear decrement across age than skeletal muscle area. Alternatively, an increase in visceral fat area (VFA) was observed in both men and women. Hierarchical clustering based on multi-level CT body composition parameters revealed three distinctive phenotype clusters: normal, MS and osteosarcopenia clusters. The L3 CT-parameter-based model, with or without clinical variables (age, sex and BMI), outperformed clinical model predictions of all outcomes (area under the receiver operating characteristic curve: MS, 0.76 vs. 0.55; osteoporosis, 0.90 vs. 0.79; sarcopenia, 0.85 vs. 0.81 in external test set 1; P < 0.05 for all). VFA contributed the most to the MS predictions, whereas SMD, BD and subcutaneous fat area were features of high importance for detecting osteoporosis and sarcopenia. In external test set 2 (mean age 63.5 years, women 79%; median follow-up 4.9 years), a total of 907 individuals (8.9%) died during follow-up. Among model-predicted metabolic phenotypes, sarcopenia alone (adjusted hazard ratio [aHR] 1.55), MS + sarcopenia (aHR 1.65), osteoporosis + sarcopenia (aHR 1.83) and all three combined (aHR 1.87) remained robust predictors of mortality after adjustment for age, sex and comorbidities.

CONCLUSIONS

A CT body composition-based MLP model detected MS, osteoporosis and sarcopenia simultaneously in community-dwelling and hospitalized adults. Metabolic phenotypes predicted by the CT MLP model were associated with long-term mortality, independent of covariates.

Impact of COVID-19 on the Incidence of Fragility Fracture in South Korea

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic and the consequent social distancing period are thought to have influenced the incidence of osteoporotic fracture in various ways, but the exact changes have not yet been well elucidated. The purpose of this study was to investigate the impact of the COVID-19 pandemic on the incidence of osteoporotic fracture using a nationwide cohort.

METHODS

The monthly incidence rates of vertebral; hip; and non-vertebral, non-hip fractures were collected from a nationwide database of the Korean National Health Insurance Review and Assessment from July 2016 to June 2021. Segmented regression models were used to assess the change in levels and trends in the monthly incidence of osteoporotic fractures.

RESULTS

There was a step decrease in the incidence of vertebral fractures for both males (6.181 per 100,000, P=0.002) and females (19.299 per 100,000, P=0.006). However, there was a negative trend in the incidence of hip fracture among both males (-0.023 per 100,000 per month, P=0.023) and females (-0.032 per 100,000 per month, P=0.019). No impact of COVID-19-related social distancing was noted.

CONCLUSIONS

In conclusion, during the early days of the COVID-19 pandemic, vertebral fracture incidence considerably decreased with the implementation of social distancing measures.

Association of secondhand smoke with fracture risk in community-dwelling nonsmoking adults in Korea

Although the detrimental effects of active smoking on bone health have been widely recognized, the impact of secondhand smoke exposure on fracture risk in non-smokers remains less understood. A total of 4843 nonsmokers aged 40-69 yr, who participated in the Korean Genome and Epidemiology Study from 2001 to 2018, were analyzed. The participants were categorized into two groups based on their exposure status to secondhand smoke: currently exposed and unexposed. The exposure group was subsequently divided into two subgroups based on the median weekly exposure time (high vs low). The incidence of new fractures was determined using self-reported questionnaires. The identified fractures were categorized according to the fracture site: overall, vertebral, hip, non-vertebral, and non-vertebral non-hip fractures. The mean age of the participants was 52.4 yr (84.1% women). Exposure to secondhand smoke was associated with an increased risk of fracture (adjusted hazard ratio [aHR]: 1.27, P = 0.028) after adjusting for multiple covariates including age, sex, BMI, household income, bone density of mid-shaft tibia, C-reactive protein, alcohol consumption, and fracture history. Secondhand smoke remained as a significant risk factor for fracture, independent of the major osteoporotic fracture probabilities estimated using a fracture risk assessment tool (aHR: 1.24, P = 0.038). The high exposure group had higher risk of fracture than that of the unexposed group (aHR: 1.33, P = 0.025), whereas the fracture risk did not differ significantly between low exposure and unexposed groups (aHR: 1.18, P = 0.253), suggesting a potential dose-response relationship. Secondhand smoke showed robust association with increased risk of non-vertebral (aHR: 1.37, P = 0.008) or non-vertebral non-hip fractures (aHR: 1.36, P = 0.013), while its association with vertebral fracture was attenuated (aHR: 1.03, P = 0.908). Secondhand smoke was associated with an elevated risk of fracture in nonsmokers, independent of clinical risk factors.

Two Cases of Frontal Variation of Idiopathic Calvarial Thinning-Therapeutic Effect of Denosumab and Romosozumab

Idiopathic calvarial thinning is a rare condition that causes progressive, painless thinning of the skull bones without systemic disease. We present 2 cases of idiopathic calvarial thinning involving the bifrontal region. Both patients exhibited forehead depression and had normal biochemical tests except for mild vitamin D deficiency. The first patient received treatment with denosumab for 3 years, showing no further progression of the skull thinning. The second patient was treated with denosumab for 3 years, followed by romosozumab for 1 year, resulting in no further progression and even slight recovery of the skull thickness. These cases demonstrate that idiopathic calvarial thinning can involve the bifrontal region and highlight the favorable treatment and prognosis with denosumab or romosozumab.

Assessment of thirty-day readmission rate, timing, causes and predictors after hospitalization with COVID-19

BACKGROUND

There are limited data on the characteristics of 30-day readmission after hospitalization with coronavirus disease 2019 (COVID-19).

OBJECTIVES

To examine the rate, timing, causes, predictors and outcomes of 30-day readmission after COVID-19 hospitalization.

METHODS

From 13 March to 9 April 2020, all patients hospitalized with COVID-19 and discharged alive were included in this retrospective observational study. Multivariable logistic regression was used to identify the predictors of 30-day readmission, and a restricted cubic spline function was utilized to assess the linearity of the association between continuous predictors and 30-day readmission.

RESULTS

A total of 1062 patients were included in the analysis, with a median follow-up time of 62 days. The mean age of patients was 56.5 years, and 40.5% were women. At the end of the study, a total of 48 (4.5%) patients were readmitted within 30 days of discharge, and a median time to readmission was 5 days. The most common primary diagnosis of 30-day readmission was a hypoxic respiratory failure (68.8%) followed by thromboembolism (12.5%) and sepsis (6.3%). The patients with a peak serum creatinine level of ≥1.29 mg/dL during the index hospitalization, compared to those with a creatinine of <1.29 mg/dL, had 2.4 times increased risk of 30-day readmission (adjusted odds ratio: 2.41; 95% CI: 1.23-4.74). The mortality rate during the readmission was 22.9%.

CONCLUSION

With 4.5% of the thirty-day readmission rate, COVID-19 survivors were readmitted early after hospital discharge, mainly due to morbidities of COVID-19. One in five readmitted COVID-19 survivors died during their readmission.

Neuronal Population Responses in the Human Ventral Temporal and Lateral Parietal Cortex during Arithmetic Processing with Digits and Number Words

Past research has identified anatomically specific sites within the posterior inferior temporal gyrus (PITG) and the intraparietal sulcus (IPS) areas that are engaged during arithmetic processing. Although a small region of the PITG (known as the number form area) is selectively engaged in the processing of numerals, its surrounding area is activated during both digit and number word processing. In eight participants with intracranial electrodes, we compared the timing and selectivity of electrophysiological responses in the number form area-surround and IPS regions during arithmetic processing with digits and number words. Our recordings revealed stronger electrophysiological responses in the high-frequency broadband range in both regions to digits than number words, with the difference that number words elicited delayed activity in the IPS but not PITG. Our findings of distinct profiles of responses in the PITG and the IPS to digits compared with number words provide novel information that is relevant to existing theoretical models of mathematical cognition.

A Dual Phosphodiesterase Inhibitor, Zardaverine (Type 3/4), Enhances Motility of Frozen-thawed Boar Sperm

BACKGROUND

Cryopreserved semen is useful for animal breeding via artificial insemination (AI); however, the use of frozen-thawed boar sperm is limited due to cryodamage.

OBJECTIVE

The goal of this study was to improve post-thaw motility of boar semen by supplementing the thawing medium with a phosphodiesterase inhibitor, Zardaverine.

MATERIALS AND METHODS

Thawed boar semen samples were treated with different concentrations of Zardaverine (0, 20, 50, 75, 100 µM) and the motility was evaluated using a computer-assisted sperm analyser. Toxic effects (sperm viability, DNA integrity, mitochondrial activity) were examined by eosin-nigrosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and MitoTracker.

RESULTS

Sperm motility values included curvilinear velocity, rectilinear speed, average value, linearity index, straightness index, and progressive motility. The kinetic values were significantly higher with the 50 uM Zardaverine supplementation compared to non-treated control. Furthermore, there were no toxic effects of the Zardaverine treatment.

CONCLUSION

The dual phosphodiesterase inhibitor (type 3/4) Zardaverine significantly enhanced the motility of thawed spermatozoa without adverse effects.

Generation of embryonic stem-like cells from in vivo-derived porcine blastocysts at a low concentration of basic fibroblast growth factor

Although basic fibroblast growth factor (bFGF) is an essential factor supporting the maintenance of porcine embryonic stem (ES) cell self-renewal and pluripotency, its high cost has limited previous studies, and the development of a low-cost culture system is required. For these systems, in vivo blastocysts were progressively cultured under various conditions consisting of different culture mediums and/or different feeder cell numbers at a low concentration of bFGF. As the results, the sequential culture of in vivo-derived porcine blastocysts on 5.0 × 10⁵ mouse embryonic fibroblast (MEF) feeder cells in alpha minimum essential medium-based medium for primary culture, on 2.5 × 10⁵ MEF feeder cells in Mixture medium for the 1st subpassage, and on 2.5 × 10⁵ MEF feeder cells in DMEM/Ham's F10-based medium for the post-2nd subpassage could support the establishment and maintenance of porcine ES-like cells at the low concentration of bFGF. The established porcine ES-like cells showed ES cell-specific characteristics such as self-renewal and pluripotency. We confirmed that porcine ES-like cells could be generated from in vivo-derived porcine blastocysts at a low concentration of bFGF.

The 100 Most-Cited Articles Focused on Ultrasound Imaging: A Bibliometric Analysis

Purpose The number of citations that an article has received reflects its impact on a particular research area. The aim of this study was to identify the 100 most-cited articles focused on ultrasound (US) imaging and to analyze the characteristics of these articles. Methods We determined the 100 most-cited articles on US imaging via the Web of Science database, using the search term. The following parameters were used to analyze the characteristics of the 100 most-cited articles: publication year, journal, journal impact factor, number of citations and annual citations, authors, department, institution, country, type of article, and topic. Results The number of citations for the 100 most-cited articles ranged from 1849 to 341 (median: 442.0) and the number of annual citations ranged from 108.0 to 8.1 (median: 22.1). The majority of articles were published in 1990 - 1999 (39 %), published in radiology journals (20 %), originated in the United States (45 %), were clinical observation studies (67 %), and dealt with the vessels (35 %). The Department of Internal Medicine at the University of California and the Research Institute of Public Health at the University of Kuopio (n = 4 each) were the leading institutions and Salonen JT and Salonen R (n = 4 each) were the most prolific authors. Conclusion Our study presents a detailed list and analysis of the 100 most-cited US articles, which provides a unique insight into the historical development in this field.

On growth measurements of abdominal aortic aneurysms using maximally inscribed spheres

The maximum diameter, total volume of the abdominal aorta, and its growth rate are usually regarded as key factors for making a decision on the therapeutic operation time for an abdominal aortic aneurysm (AAA) patient. There is, however, a debate on what is the best standard method to measure the diameter. Currently, two dominant methods for measuring the maximum diameter are used. One is measured on the planes perpendicular to the aneurism's central line (orthogonal diameter) and the other one is measured on the axial planes (axial diameter). In this paper, another method called 'inscribed-spherical diameter' is proposed to measure the diameter. The main idea is to find the diameter of the largest sphere that fits within the aorta. An algorithm is employed to establish a centerline for the AAA geometries obtained from a set of longitudinal scans obtained from South Korea. This centerline, besides being the base of the inscribed spherical method, is used for the determination of orthogonal and axial diameter. The growth rate parameters are calculated in different diameters and the total volume and the correlations between them are studied. Furthermore, an exponential growth pattern is sought for the maximum diameters over time to examine a nonlinear growth pattern of AAA expansion both globally and locally. The results present the similarities and discrepancies of these three methods. We report the shortcomings and the advantages of each method and its performance in the quantification of expansion rates. While the orthogonal diameter measurement has an ability of capturing a realistic diameter, it fluctuated. On the other hand, the inscribed sphere diameter method tends to underestimate the diameter measurement but the growth rate can be bounded in a narrow region for aiding prediction capability. Moreover, expansion rate parameters derived from this measurement exhibit good correlation with each other and with growth rate of volume. In conclusion, although the orthogonal method remains the main method of measuring the diameter of an abdominal aorta, employing the idea of maximally inscribed spheres provides both a tool for generation of the centerline, and an additional parameter for quantification of aneurysmal growth rates.

Higher serum uric acid as a protective factor against incident osteoporotic fractures in Korean men: a longitudinal study using the National Claim Registry

In this large longitudinal study of 16,078 Korean men aged 50 years or older, we observed that baseline elevation of serum uric acid level significantly associated with a lower risk of incident fractures at osteoporosis-related sites during an average follow-up period of 3 years.

INTRODUCTION

Male osteoporosis and related fractures are becoming recognized as important public health concerns. Oxidative stress has detrimental effects on bone metabolism, and serum uric acid (UA) is known to be a strong endogenous antioxidant. In the present study, we performed a large longitudinal study with an average follow-up period of 3 years to clarify the role of UA on the risk of incident osteoporotic fractures (OFs).

METHODS

A total of 16,078 Korean men aged 50 years or older who had undergone comprehensive routine health examinations were enrolled. Incident fractures at osteoporosis-related sites (e.g., hip, spine, distal radius, and proximal humerus) that occurred after the baseline examinations were identified from the nationwide claims database of the Health Insurance Review and Assessment Service of Korea by using selected International Classification of Diseases, 10th revision codes.

RESULTS

In total, 158 (1.0 %) men developed incident OFs. The event rate was 33.1 per 10,000 person-years. Subjects without incident OFs had 6.0 % higher serum UA levels than subjects with OFs (P = 0.001). Multivariable-adjusted Cox proportional hazard analyses adjusted for age, body mass index, glomerular filtration rate, lifestyle factors, medical and drug histories, and the presence of baseline radiological vertebral fractures revealed that the hazard ratio per standard deviation increase of baseline UA levels for the development of incident OFs was 0.829 (95 % CI = 0.695-0.989, P = 0.038).

CONCLUSIONS

These data provide the epidemiological evidence that serum UA may act as a protective factor against the development of incident OFs in Korean men.

Abstract P6-06-54: Analysis of treatment and survival of pathologic occult breast cancer with axillary lymph node metastasis: Nationwide retrospective study

Objective

Occult breast cancer (OBC) is a rare presentation which accounts for 0.3-1.0% of all breast cancers. In spite of limited information, there is no consensus regarding the prognostic factors and treatment of OBC. This retrospective study intends to evaluate the overall survival and prognostic factors of occult breast cancer (OBC) in Korea.

Method

This study included 142 pathologic occult breast cancer patients from January 1990 to December 2009, identified from Korean Breast Cancer Society cancer registry. All patients had pathologically positive axillary lymph node (N1-N3) along with pathologically & radiologically negative in-breast lesion (T0/Tx) based on retrospective review of database. Among 142 patients, 32 patients had only axillary lymph node dissection (ALND), 56 patients had breast conserving operation (BCO) with ALND and 54 patients had mastectomy with ALND. 96 patients (96%) had N1 disease, 23 patients (16.2%) had N2 disease and 23 patients (16.2%) had N3 disease.

Results

There was no significant statistical difference in overall survival among different operation method, which is ALND only, BCO with ALND, mastectomy with ALND (p = 0.061), considering that 12 patients (37.5%) among 32 patients who only had ALND had N3 disease comparing that only 7 (12.5%) out of 56 patients and 4 (7.4%) out of 54 patients had N3 disease in BCO with ALND and mastectomy with ALND group separately. Univariate analysis revealed that only nodal status was significant prognostic factor (p = 0.0004), and other factors including radiotherapy (p = 0.696), chemotherapy (p = 0.302), estrogen receptor positivity (p = 0.144), progesterone receptor positivity (p = 0.254), total number of removed lymph node (p = 0.586) didn't show statistical difference in overall survival.

Conclusions

This study suggests that OBC patients who only had ALND showed similar outcomes when comparing with patients who had BCO with ALND or mastectomy with ALND. Also only nodal status might be independent predictors for poor outcomes of occult breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-54.

Healthcare use and prescription patterns associated with adult asthma in Korea: analysis of the NHI claims database

BACKGROUND

National Health Insurance (NHI) claim records could provide valuable data for epidemiological studies of asthma in Korea. The aim of this study is to estimate the prevalence of adult asthma and to investigate asthma-related healthcare use and prescription patterns in Korea over 5 years.

METHODS

National Health Insurance claim records from January 1, 2006 to December 31, 2010 were analyzed in a retrospective, population-based study. Outcome measures included asthma prevalence, healthcare use, and prescription patterns over time, by type of hospital, and by medical specialty. Additionally, we assessed differences in healthcare use between newly diagnosed and previously diagnosed patients in 2009.

RESULTS

Over 5 years, the prevalence of asthma among Korean adults increased from 4944 to 5707 cases per 100,000 population (from 3760 to 4445 in men and from 6108 to 6951 in women). Asthma-related outpatient visits decreased from 4.82 ± 8.02 to 3.44 ± 5.50. Approximately 3% of all patients were hospitalized and 2.4% received asthma-related emergency treatment each year. Pulmonary function tests were performed in 10-11% of patients an average of 1.3 times per year. Newly diagnosed patients experienced fewer asthma-related hospitalizations (1.78% vs 4.35%) and emergency department visits (0.80% vs 2.11%) than the previously diagnosed group. Prescriptions of inhaled corticosteroids-based inhalers were maintained with about 20% of average of all types of hospitals.

CONCLUSIONS

The prevalence of asthma in Korea has increased over a recent 5-year period, and asthma is still suboptimally controlled. Public health strategies are needed to improve the management of asthma in adults.

Effect of Static Pre-stretch Induced Surface Anisotropy on Orientation of Mesenchymal Stem Cells

Mechanical cues in the cellular environment play important roles in guiding various cell behaviors, such as cell alignment, migration, and differentiation. Previous studies investigated mechanical stretch guided cell alignment pre-dominantly with cyclic stretching whereby an external force is applied to stretch the substrate dynamically (i.e., cyclically) while the cells are attached onto the substrate. In contrast, we created a static pre-stretched anisotropic surface in which the cells were seeded subsequent to stretching the substrate. We hypothesized that the cell senses the physical environment through a more active mechanism, namely, even without external forces the cell can actively apply traction and sense an increased stiffness in the stretched direction and align in that direction. To test our hypothesis, we quantified the extent of pre-stretch induced anisotropy by employing the theory of small deformation superimposed on large and predicted the effective stiffness in the stretch direction as well as its perpendicular direction. We showed mesenchymal stem cells (MSC) aligned in the pre-stretched direction, and the cell alignment and morphology were dependent on the pre-stretch magnitude. In addition, the pre-stretched surface demonstrated an ability to promote early myoblast differentiation of the MSC. This study is the first report on MSC alignment on a statically pre-stretched surface. The cell orientation induced by the pre-stretch induced anisotropy could provide insight into tissue engineering applications involving cells that aligned in vivo in the absence of dynamic mechanical stimuli.

The impact of total antioxidant capacity on pulmonary function in asthma patients

BACKGROUND

Oxidative stress, mediated by an imbalance between oxidants and antioxidants, contributes significantly to the pathogenesis of asthma.

OBJECTIVE

To evaluate the impact of serum total antioxidant capacity (TAC) on the pulmonary function of Korean asthma patients.

METHOD

A total of 104 adult asthma patients enrolled from the COREA (Cohort for Reality and Evolution of Adult Asthma in Korea) programme participated in the study. Baseline clinical parameters at enrolment, and the results of pulmonary function tests at baseline and 1 and 2 years after enrolment were collected. TAC at baseline was measured using a Trolox-equivalent antioxidant capacity assay. Patients were divided into two groups based on TAC levels, and various clinical parameters were compared.

RESULT

Serum TAC levels correlated with forced expiratory volume in 1 second (FEV(1)) at baseline (r = 0.22, P = 0.03). The group with higher baseline TAC levels maintained greater mean FEV(1) both 1 and 2 years after enrolment, even after adjusting for sex, age, height, weight, body mass index and smoking status.

CONCLUSION

These results suggest an important link between serum TAC levels and pulmonary function, indicating that higher TAC levels may be a biomarker for favourable prognosis in asthma patients.

Parametric study of effects of collagen turnover on the natural history of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by significant changes in the architecture of the aortic wall, notably, loss of functional elastin and smooth muscle. Because collagen is the principal remaining load-bearing constituent of the aneurysmal wall, its turnover must play a fundamental role in the natural history of the lesion. Nevertheless, detailed investigations of the effects of different aspects of collagen turnover on AAA development are lacking. A finite-element membrane model of the growth and remodelling of idealized AAAs was thus used to investigate parametrically four of the primary aspects of collagen turnover: rates of production, half-life, deposition stretch (prestretch) and material stiffness. The predicted rates of aneurysmal expansion and spatio-temporal changes in wall thickness, biaxial stresses and maximum collagen fibre stretch at the apex of the lesion depended strongly on all four factors, as did the predicted clinical endpoints (i.e. arrest, progressive expansion or rupture). Collagen turnover also affected the axial expansion, largely due to mechanical changes within the shoulder region of the lesion. We submit, therefore, that assessment of rupture risk could be improved by future experiments that delineate and quantify different aspects of patient-specific collagen turnover and that such understanding could lead to new targeted therapeutics.

Importance of initial aortic properties on the evolving regional anisotropy, stiffness and wall thickness of human abdominal aortic aneurysms

Complementary advances in medical imaging, vascular biology and biomechanics promise to enable computational modelling of abdominal aortic aneurysms to play increasingly important roles in clinical decision processes. Using a finite-element-based growth and remodelling model of evolving aneurysm geometry and material properties, we show that regional variations in material anisotropy, stiffness and wall thickness should be expected to arise naturally and thus should be included in analyses of aneurysmal enlargement or wall stress. In addition, by initiating the model from best-fit material parameters estimated for non-aneurysmal aortas from different subjects, we show that the initial state of the aorta may influence strongly the subsequent rate of enlargement, wall thickness, mechanical behaviour and thus stress in the lesion. We submit, therefore, that clinically reliable modelling of the enlargement and overall rupture-potential of aneurysms may require both a better understanding of the mechanobiological processes that govern the evolution of these lesions and new methods of determining the patient-specific state of the pre-aneurysmal aorta (or correlation to currently unaffected portions thereof) through knowledge of demographics, comorbidities, lifestyle, genetics and future non-invasive or minimally invasive tests.

Patterns of missing mini mental status exam (MMSE) in radiation therapy oncology group (RTOG) brain cancer trials

The Mini Mental Status Exam (MMSE) instrument has been commonly used in the Radiation Therapy Oncology Group (RTOG) to assess mental status in brain cancer patients. Evaluating patient factors in relation to patterns of incomplete MMSE assessments can provide insight into predictors of missingness and optimal MMSE collection schedules in brain cancer clinical trials. This study examined eight RTOG brain cancer trials with ten treatment arms and 1,957 eligible patients. Patient data compliance patterns were categorized as: (1) evaluated at all time points (Complete), (2) not evaluated from a given time point or any subsequent time points but evaluated at all the previous time points (Monotone drop-out), (3) not evaluated at any time point (All missing), and (4) all other patterns (Mixed). Patient characteristics and reasons for missingness were summarized and compared among the missing pattern groups. Baseline MMSE scores and change scores after radiation therapy (RT) were compared between these groups, adjusting for differences in other characteristics. There were significant differences in frequency of missing patterns by age, treatment type, education, and Zubrod performance status (ZPS; P < 0.001). Ninety-two percent of patients were evaluated at least once: seven percent of patients were complete pattern, 49% were Monotone pattern, and 36% were mixed pattern. Patients who received RT only regimens were evaluated at a higher rate than patients who received RT + other treatments (49-64% vs. 27-45%). Institutional error and request to not be contacted were the most frequent known reasons for missing data, but most often, reasons for missing MMSE was unspecified. Differences in baseline mean MMSE scores by missing pattern (Complete, Monotone dropout, Mixed) were statistically significant (P < 0.001) but differences were small (<1.5 points) and significance did not persist after adjustment for age, ZPS, and other factors related to missingness. Post-RT change scores did not differ significantly by missing pattern. While baseline and change scores did not differ widely by missing pattern for available measurements, incomplete data was common and of unknown reason, and has potential to substantially bias conclusions. Higher compliance rates may be achievable by addressing institutional compliance with assessment schedules and patient refusal issues, and further exploration of how educational and health status barriers influence compliance with MMSE and other tools used in modern neurocognitive batteries.

Effect of influent nitrogen speciation on organic nitrogen occurrence in activated sludge process effluents

The effect of influent nitrogen composition on organic nitrogen production in a sequencing batch reactor (SBR) activated sludge process was investigated. A laboratory-scale SBR was fed with three different type synthetic wastewaters with varying nitrogen compositions (phase I = nitriloacetic acid + ammonium [NH4-N], phase II = NH(4-)N, and phase III = amino acid mixture + NH(4-)N) was operated. The effluent contained approximately 1 to 2 mg N/L organic nitrogen, even though there was no organic nitrogen in influent. The effluent organic nitrogen increased to approximately 4 mg N/L when the influent composition was changed and then stabilized at <2 mg N/L. The maximum nitrifier growth rate constants (microN) were calculated as 0.91+/-0.10 to 1.14+/-0.08 day-1, 0.82 +/-0.13 day-1, and 0.89+/-0.08 day-1 at 20 degrees C for the three different influent compositions. The effluent colloidal organic nitrogen (CON) was negligible, suggesting that the effluent CON found in full-scale plants may be the result of influent-derived suspended matter.

Intrasac pressure changes and vascular remodeling after endovascular repair of abdominal aortic aneurysms: review and biomechanical model simulation

In this paper, we review existing clinical research data on post-endovascular repair (EVAR) intrasac pressure and relation with abdominal aortic aneurysm (AAA) size changes. Based on the review, we hypothesize that intrasac pressure has a significant impact on post-EVAR AAA size changes, and post-EVAR remodeling depends also on how the pressure has changed over a period of time. The previously developed model of an AAA based on a constrained mixture approach is extended to include vascular adaptation after EVAR using an idealized geometry. Computational simulation shows that the same mechanism of collagen stress-mediated remodeling in AAA expansion induces the aneurysm wall to shrink in a reduced sac-pressure after post-EVAR. Computational simulation suggests that the intrasac pressure of 60 mm Hg is a critical value. At this value, the AAA remains stable, while values above cause the AAA to expand and values below cause the AAA to shrink. There are, however, variations between individuals due to different cellular sensitivities in stress-mediated adaptation. Computer simulation also indicates that an initial decrease in intrasac pressure helps the AAA shrink even if the pressure increases after some time. The presented study suggests that biomechanics has a major effect on initial adaptation after EVAR and also illustrates the utility of a computational model of vascular growth and remodeling in predicting diameter changes during the progression and after the treatment of AAAs.

Direct detection of lower hybrid wave using a reflectometer on Alcator C-Mod

The possibility of directly detecting a density perturbation produced by lower hybrid (LH) waves using a reflectometer is presented. We investigate the microwave scattering of reflectometer probe beams by a model density fluctuation produced by short wavelength LH waves in an Alcator C-Mod experimental condition. In the O-mode case, the maximum response of phase measurement is found to occur when the density perturbation is approximately centimeters in front of the antenna, where Bragg scattering condition is satisfied. In the X-mode case, the phase measurement is predicted to be more sensitive to the density fluctuation close to the cut-off layer. A feasibility test was carried out using a 50 GHz O-mode reflectometer on the Alcator C-Mod tokamak, and positive results including the detection of 4.6 GHz pump wave and parametric decay instabilities were obtained.

Complementary vasoactivity and matrix remodelling in arterial adaptations to altered flow and pressure

Arteries exhibit a remarkable ability to adapt to sustained alterations in biomechanical loading, probably via mechanisms that are similarly involved in many arterial pathologies and responses to treatment. Of particular note, diverse data suggest that cell and matrix turnover within vasoaltered states enables arteries to adapt to sustained changes in blood flow and pressure. The goal herein is to show explicitly how altered smooth muscle contractility and matrix growth and remodelling work together to adapt the geometry, structure, stiffness and function of a representative basilar artery. Towards this end, we employ a continuum theory of constrained mixtures to model evolving changes in the wall, which depend on both wall shear stress-induced changes in vasoactive molecules (which alter smooth muscle proliferation and synthesis of matrix) and intramural stress-induced changes in growth factors (which alter cell and matrix turnover). Simulations show, for example, that such considerations help explain the different rates of experimentally observed adaptations to increased versus decreased flows as well as differences in rates of change in response to increased flows or pressures.

The antitumorgenic actions of estrogen receptor beta in breast cancer cells

Abstract #3056

Recent studies have suggested that ERβ may oppose actions of ERα in breast cancer cells and clinical studies indicate that loss of ERβ expression in ERα positive tumors is associated with a poor prognosis and perhaps resistance to tamoxifen therapy. Clinical evidence indicates that in post menopausal women hormone replacement therapy significantly decreased incidence of colon cancer, suggesting that estrogens have a protective role . We have recently found that in SW 480 colon cancer cells, (ER negative) stable expression of ERβ decreased SKP2, c-myc but not p27kip1 mRNA measured by real time PCR. These results were confirmed for c-myc and SKP2 at the protein level. However, ERβ expression increased only p27 protein levels. Addition of E2 did not regulate effects of ERβ expression.&#x2028; Similar results have been observed with T47D (ER positive breast cancer cells) stably over expressing ERβ. In the latter cells and MCF7 (ER alpha positive) cells over expressing ERβ, E2 induced β catenin protein expression was blocked by ERβ. The latter also blocked AKT and ERK activation by E2 and induced apoptosis, in an E2 independent fashion. ERβ expression also blocked E2 induced growth in MCF 7 cells. Antibody array analysis showed that ERβ regulated &gt;100 proteins at or above the 2 fold level in T47D breast cancer cells,where as 2D PAGE/MS showed that over 60 proteins changed significantly, both types of analysis and Western blots indicate that ERβ regulates Sp1,HSP70,β catenin, c-Jun, JNK,c-Jun ,BAD among other proteins. Antibody arrays and MS have therefore revealed unsuspected targets of ERβ action. Thus, ERβ appears to oppose several actions of ERα in breast cancer cells and block colon cancer cell growth, independently of E2. Design of selective ERβ activating agents or delivery of ERβ using gene therapy may be of substantial utility in the treatment of breast and colon cancer. Category27.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3056.

Thermal characteristics of an end-pumped high-power ytterbium-sensitized erbium-doped fiber laser under natural convection

We investigate the thermal characteristics of a polymer-clad fiber laser under natural convection when it is strongly pumped up to the damage point of the fiber. For this, we utilize a temperature sensing technique based on a fiber Bragg grating sensor array. We have measured the longitudinal temperature distribution of a 2.4-m length ytterbium-sensitized erbium-doped fiber laser that was end-pumped at approximately 975 nm. The measured temperature distribution decreases exponentially, approximately, decaying away from the pump-launch end. We attribute this to the heat dissipation of absorbed pump power. The maximum temperature difference between the fiber ends was approximately 190 K at the maximum pump power of 60.8 W. From this, we estimate that the core temperature reached approximately 236 degrees C.