Dynamics of magnetization at infinite temperature in a Heisenberg spin chain

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.

Stable quantum-correlated many-body states through engineered dissipation

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

Measurement-induced entanglement and teleportation on a noisy quantum processor

Measurement has a special role in quantum theory1: by collapsing the wavefunction, it can enable phenomena such as teleportation2 and thereby alter the 'arrow of time' that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time3-10 that go beyond the established paradigms for characterizing phases, either in or out of equilibrium11-13. For present-day noisy intermediate-scale quantum (NISQ) processors14, the experimental realization of such physics can be problematic because of hardware limitations and the stochastic nature of quantum measurement. Here we address these experimental challenges and study measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping9,15-17 to avoid mid-circuit measurement and access different manifestations of the underlying phases, from entanglement scaling3,4 to measurement-induced teleportation18. We obtain finite-sized signatures of a phase transition with a decoding protocol that correlates the experimental measurement with classical simulation data. The phases display remarkably different sensitivity to noise, and we use this disparity to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realizing measurement-induced physics at scales that are at the limits of current NISQ processors.

Multiple Prior Live Births Are Associated With Cardiac Remodeling and Heart Failure Risk in Women

OBJECTIVE

Greater parity has been associated with cardiovascular disease risk. We sought to find whether the effects on cardiac remodeling and heart failure risk are clear.

METHODS

We examined the association of number of live births with echocardiographic measures of cardiac structure and function in participants of the Framingham Heart Study (FHS) using multivariable linear regression. We next examined the association of parity with incident heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction using a Fine-Gray subdistribution hazards model in a pooled analysis of n = 12,635 participants in the FHS, the Cardiovascular Health Study, the Multi-Ethnic Study of Atherosclerosis, and Prevention of Renal and Vascular Endstage Disease. Secondary analyses included major cardiovascular disease, myocardia infarction and stroke.

RESULTS

Among n = 3931 FHS participants (mean age 48 ± 13 years), higher numbers of live births were associated with worse left ventricular fractional shortening (multivariable β -1.11 (0.31); P = 0.0005 in ≥ 5 live births vs nulliparous women) and worse cardiac mechanics, including global circumferential strain and longitudinal and radial dyssynchrony (P < 0.01 for all comparing ≥ 5 live births vs nulliparity). When examining HF subtypes, women with ≥ 5 live births were at higher risk of developing future HFrEF compared with nulliparous women (HR 1.93, 95% CI 1.19-3.12; P = 0.008); by contrast, a lower risk of HFpEF was observed (HR 0.58, 95% CI 0.37-0.91; P = 0.02).

CONCLUSIONS

Greater numbers of live births are associated with worse cardiac structure and function. There was no association with overall HF, but a higher number of live births was associated with greater risk for incident HFrEF.

Circulating Androgen Concentrations and Risk of Incident Heart Failure in Older Men: The Cardiovascular Health Study

Background

Circulating androgen concentrations in men decline with age and have been linked to diabetes and atherosclerotic cardiovascular disease (ASCVD). A similar relationship has been reported for low total testosterone and incident heart failure (HF) but remains unstudied for free testosterone or the more potent androgen dihydrotestosterone (DHT). We hypothesized that total/free testosterone are inversely related, sex hormone–binding globulin is positively related, and total/free DHT bear a U‐shaped relationship with incident HF.

Methods and Results

In a sample of men from the CHS (Cardiovascular Health Study) without atherosclerotic cardiovascular disease or HF, serum testosterone and DHT concentrations were measured by liquid chromatography–tandem mass spectrometry, and sex hormone–binding globulin by immunoassay. Free testosterone or DHT was calculated from total testosterone or total DHT, sex hormone–binding globulin, and albumin. We used Cox regression to estimate relative risks of HF after adjustment for potential confounders. In 1061 men (aged 76±5 years) followed for a median of 9.6 years, there were 368 HF events. After adjustment, lower calculated free testosterone was significantly associated with higher risk of HF (hazard ratio [HR], 1.14 [95% CI, 1.01–1.28]). Risk estimates for total testosterone (HR, 1.12 [95% CI, 0.99–1.26]), total DHT (HR, 1.10 [95% CI, 0.97–1.24]), calculated free dihydrotestosterone (HR, 1.09 [95% CI, 0.97–1.23]), and sex hormone–binding globulin (HR, 1.07 [95% CI, 0.95–1.21]) were directionally similar but not statistically significant.

Conclusions

Calculated free testosterone was inversely associated with incident HF, suggesting a contribution of testosterone deficiency to HF incidence among older men. Additional research is necessary to determine whether testosterone replacement therapy might be an effective strategy to lower HF risk in older men.

Report of Prolonged Neonatal Hypoglycemia in Three Infants of Mothers With Variants in HNF1A

Background/Objective

Genetic variants in hepatic nuclear factor 1α (HNF1A) cause maturity-onset diabetes of the young (MODY). We sought to examine whether HNF1A MODY variants also cause neonatal hypoglycemia.

Case Report

We present 3 infants with variants in HNF1A shared with their mothers. The infants experienced neonatal hypoglycemia, 2 extending beyond 1 year and the third resolving by 28 days, and all were large for gestational age (birth weights of >99th percentile). In 2 cases, genetic testing for neonatal hypoglycemia revealed pathogenic variants in HNF1A; 1 mother was previously diagnosed with HNF1A MODY, and the other's genetic testing and ultimate MODY diagnosis were prompted by her child's hypoglycemia workup. In the third case, the infant's persistent hypoglycemia prompted genetic testing, revealing an HNF1A variant of uncertain significance, which was then identified in the mother.

Discussion

Genetic variants causing HNF1A MODY have not been definitively linked to neonatal hypoglycemia or fetal overgrowth in utero. MODY caused by HNF1A is clinically similar to that caused by HNF4A, for which a causal relationship with neonatal hypoglycemia is more certain. Case reports have previously implicated variants in HNF1A in congenital hyperinsulinism; however, these cases have generally not been in families with MODY. The cases presented here suggest that HNF1A variants causing MODY may also cause neonatal hypoglycemia.

Conclusion

Although confounding factors make the assessment of neonatal hypoglycemia challenging, these cases offer potential support for single genetic variants in HNF1A causing both MODY and neonatal hypoglycemia, with associated fetal overgrowth in utero.

A digitally enhanced home-based physical activity intervention for high-risk middle school youth during COVID-19

COVID-19 significantly impacted physical activity among high-risk youth. Camp from Home, a digitally enhanced home-based intervention, was developed to address physical activity disparities among middle school youth during COVID-19. Camp from Home enrolled 62 youth in 54 families from five schools in Philadelphia during the summer of 2020. The 6-week intervention comprised of (1) three home deliveries of "activity kits" including exercise equipment and activity booklets, (2) asynchronous sport and exercise videos posted to a private YouTube channel, and (3) supportive text-messages from health coaches. YouTube analytics and self-report surveys completed by parents and youth at baseline and at the end of programming were used to assess engagement, acceptability, and preliminary efficacy. Youth participants were 12.4 (1.2) years, 38.7% female and 90.3% Black/African American. At follow-up, 41 parents (75.9%) and 34 youth (54.8%) completed measures. Youth self-reported increases in self-efficacy (ΔM(sd) = 0.4(1.0), p = .03) and physical activity (ΔM(sd) = 4.2(7.9), p = .004), despite suboptimal engagement in digital program components. Overall, participants highly rated the program. Activity kits and text-messages from health coaches were rated as most helpful. Most parents (95.1%) and youth (83.8%) expressed interested in participating again in the future. A 6-week digitally enhanced, home-based physical activity intervention was acceptable and feasible among parents and youth during the summer of 2020, with youth reporting improvements in self-efficacy and physical activity. Summer programs are critical for reducing disparities in physical activity and hold potential for addressing key barriers for high-risk youth even outside the context of COVID-19.

Continuous monitoring of advanced hemodynamic parameters shows early cardiovascular changes in a cohort of 492 COVID-19 hospitalized patients

Background

COVID-19 exerts deleterious cardiopulmonary effects, leading to worse prognosis in the most effected.

Purpose

The aim of this retrospective multi-center observational cohort study was to analyze the trajectories of key advanced hemodynamic parameters amongst hospitalized COVID-19 patients according to different risk populations using a chest-patch wearable providing continuous remote patient monitoring.

Methods

The study was conducted in five COVID-19 isolation units. Patients admitted to the units were connected to a photoplethysmography based noninvasive remote advanced hemodynamic monitor after completing a basic risk factor survey. Physiological parameters were measured every 15 minutes during the hospitalization, including cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), heart rate, blood pressure (BP), respiratory rate, blood oxygen saturation (SpO2), and body temperature.

Results

492 COVID-19 patients (179 females, average age 58.7 years) were included in the final analysis, with more than 3 million measurements collected during an average of 75.3 hours. Overall, within the first five days of hospitalizations we found a significant increase in SVR, and a significant decrease in SpO2, DBP, CO and CI (p&lt;0.01 for all). The changes were more prominent in high risk populations- males, older age and obesity and had a temporal correspondence to changes in respiratory parameters.

Conclusions

This is the first comprehensive continuous advanced hemodynamic profiling of COVID-19 patients. Worse hemodynamic status was prominent in high risk populations.

Funding Acknowledgement

Type of funding sources: None.

Ultrasound-assisted magnetic solid-phase extraction of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons from water samples with a magnetic polyaniline modified graphene oxide nanocomposite

A novel magnetic graphene oxide nanocomposite modified with polyaniline (Fe₃O₄@GO-PANI) was synthesized and applied for the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) (i.e. fluorene, phenanthrene and pyrene) and nitrated polycyclic aromatic hydrocarbons (N-PAHs) (i.e. 2-nitrofluorene, 9-nitroanthracene, 1-nitropyrene and 3-nitrofluoranthene) prior to their determination by gas chromatography-mass spectrometry. The prepared nanomaterial was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform-infrared spectroscopy. The main experimental parameters affecting the extraction and desorption steps of the MSPE procedure were investigated and optimized. Under optimum conditions, coefficients of determination (r²) ranged between 0.9970 and 0.9995, limits of detection (LODs, S/N = 3) ranged between 0.04-0.05 ng mL^-1 for PAHs and 0.01-0.11 ng mL^-1 for N-PAHs, while the relative standard deviation for intra-day and inter-day repeatability were lower than 10.0% for PAHs and N-PAHs. The method was successfully applied to the analysis of tap, mineral and river water samples. Relative recoveries in spiked water samples ranged between from 91.6 to 114% and from 92.3 to 110% for PAHs and N-PAHs, respectively. The proposed method is simple, rapid, sensitive and the Fe₃O₄@GO-PANI sorbent can be reused for at least 15 times without significant decrease in extraction recovery.

Gonadotrophin stimulation and risk of relapse in breast cancer

STUDY QUESTION

Is gonadotrophin stimulation as part of IVF associated with an increased risk of relapse in breast cancer?

SUMMARY ANSWER

Controlled ovarian stimulation (COS) in connection with IVF in women with previous breast cancer was not associated with an increased risk of breast cancer relapse.

WHAT IS KNOWN ALREADY

Breast cancer is the most common malignancy among women worldwide and the leading cause of cancer death among females. The use of COS with gonadotrophins with subsequent cryopreservation of oocytes or embryos in order to enhance the chances of pregnancy after cancer treatment is the current most established fertility preservation method for women with breast cancer. To date, there are only a few small retrospective hospital-based controlled studies evaluating the risk of breast cancer relapse in patients undergoing fertility preservation with or without COS, showing no evident risk of relapse in breast cancer after the use of gonadotoxic agents.

STUDY DESIGN, SIZE, DURATION

This was a retrospective, population-based cohort study comprising 5857 women with previous breast cancer of whom 337 were exposed to COS. Exposure (COS) and outcomes (relapse and death) were identified for all patients from 2005 to 2014 by assessing the National Quality Register for Assisted Reproduction, the Swedish Medical Birth Register, the National Patient Register, the Swedish Prescribed Drug Register, the Swedish Cause of Death Register, the National Breast Cancer Register and the Swedish Cancer Register. Matching according to set criteria was possible for 334 women, who constituted the control group. A total of 274 women had undergone IVF after completing breast cancer treatment and 63 women had undergone COS for fertility preservation at the time of breast cancer diagnosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 20–44 years previously diagnosed with breast cancer and exposed to COS were matched for age at breast cancer diagnosis ±5 years, tumour size and lymph node involvement with a non-exposed control group, including women with known T- and N-stages. In a subsequent analysis, the matched cohort was assessed by also including women with unknown T- and N-stages. A secondary analysis comprised the entire non-matched cohort, including all women with known T- and N-stages. Also here, a subsequent analysis included women with missing data for T- and N-stages. The risk of relapse in breast cancer was estimated as crude hazard ratios (HRs) and 95% CI using Cox proportional hazards models in the primary and secondary analyses where T- and N-stages were known: otherwise the risks of relapse were only given descriptively.

MAIN RESULTS AND THE ROLE OF CHANCE

In the primary matched analysis, relapse occurred in 20 of 126 women exposed to COS (15.9%) compared with 39 of 126 (31.0%) in the control cohort (HR = 0.70; 95% CI 0.39–1.45; P = 0.22). In the subsequent analysis, also including women with unknown T- and N-stages, relapse occurred in 27 of 337 (8.0%) women having undergone COS compared with 71/334 (21.3%) among the non-exposed. In the secondary adjusted analysis, relapse occurred in 20 of 126 (15.9%) exposed women and in 918 of 3729 (24.6%) non-exposed women (HR = 0.81; 95% CI 0.49–1.33; P = 0.70). In the subsequent analysis, including unknown T- and N-stages, relapse occurred in 27 of 337 (8.0%) women in the exposed group and 1176 of 5520 (21.3%) in the non-exposed cohort.

LIMITATIONS, REASONS FOR CAUTION

A substantial degree of missing data on important prognostic variables was a limitation, particularly when analysing the total cohort. Furthermore, data on confounding factors, such as BMI, were not completely covered. Another limitation was that a pre-specified variable for relapse was not in use for the majority of the National Breast Cancer Register. Furthermore, the follow-up time from available register data (2005–2014) is rather short. Finally, we cannot be sure whether the prognostic information from receptor status, showing a lower incidence in the exposed group, is representative. Information on T- and N-stages was missing in more than half of the patients.

WIDER IMPLICATIONS OF THE FINDINGS

In this large, retrospective, matched cohort study, we found no increased risk of relapse in breast cancer among women who had been exposed to gonadotrophins as part of IVF. This is reassuring but might be confounded by the selection of a group of women with a more favourable prognosis than those not undergoing IVF. The present study strengthens previous findings by being large, national and register based. Its results are applicable to women undergoing fertility preservation as well as to those undergoing regular IVF treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Supported in part by grants from the Swedish state under the agreement between the Swedish government and the county councils the ALF-agreement (ALFGBG-720291), The Assar Gabrielsson Fund (FB 15-20), The Breast Cancer Fund and the Swedish Association of Local authorities and Regions, SKR. There are no conflicts of interest to declare.

TRIAL REGISTRATION

N/A

0404 Jewish-Arab Disparities in Sleep Behaviors and Differential Ethnic Impact on Daytime Functioning, Driving Safety, and Health in Israel

Introduction

In Israel, those with Arabic as compared to Jewish ethnicity, exhibit poorer health and motor vehicle safety behaviors. Their ethnic differences in sleep duration and quality may modulate their vulnerabilities to these behaviors.

Methods

7,230 Israeli individuals (N=5,880 Jewish and N=1350 Arabic) responded to the 2017 Israeli Bureau of Statistics population-based survey of households. Variables were self-reported. Outcomes included sleepiness, sleep medications, functional impairment, drowsy driving, overall health, 1-year health change, and obesity. Predictors included categorical sleep duration (&lt;=5, 6, 7, 8 [reference], or &gt;=9 hours) and sleep disturbance in the past month (none [reference], mild [1/week], moderate [2-3/week], or severe [&gt;3/week]). Covariates included age, sex, and financial status. Ethnicity (Jewish/Arabic) was treated as a predictor of sleep and behavioral outcomes.

Results

When compared to normal (8-hour) sleepers, Jewish as compared to Arabic individuals were more likely to to sleep &lt;=5h (RRR=3.99, p&lt;0.0005), 6h (RRR=4.65, p&lt;0.0005), and 7h (RRR=3.34, p&lt;0.0005), and were more likely to report severe sleep difficulties (RRR=1.49, p&lt;0.0005) and sleepiness (oOR=1.52, p&lt; 0.0005). Yet, they were less likely to report functional impairment (oOR=0.65, p&lt;0.0005), drowsy driving (OR=0.58, p&lt;0.0005), worse health (oOR=0.51, p&lt;0005), worsening health (oOR=0.70, p&lt;0.0005), or obesity (OR=0.64, p&lt;0.0005). Significant ethnicity by sleep duration interactions (p&lt;0.05) characterized sleepiness, sleep medications, functional impairment, health, and health change. Moreover, significant ethnicity by sleep disturbance interactions (p&lt;0.05) characterized the same outcomes, in addition to drowsy driving. Overall, the impact of sleep duration and sleep difficulties was generally greater among Arabs for all variables.

Conclusion

Despite Jewish individuals endorsing relatively shorter sleep and more severe sleep difficulties, Arabs seem to be more vulnerable to the health and functional outcomes. This finding may explain some of the discrepancies in the health and safety outcomes between these ethnic groups.

Support

Dr. Grandner is supported by R01MD011600

1187 What Types Of Organizations Provide Sleep-focused Workplace Health Promotion Programs For Their Employees? An Analysis Of The 2017 CDC Workplace Health In America Survey

Introduction

There has been a rise in workplace health promotion programs (WHPP)’s in the U.S., designed to improve a variety of employee health behaviors such as exercise and nutrition. Yet, relatively few focus on the third pillar of health: Sleep.

Methods

The CDC collected data from a nationally-representative cohort of companies in 2017. Participants in this Workplace Health in America study completed online surveys reporting the type of WHPP offerings at their worksite and characteristics of their worksite, including occupational field (e.g., agriculture, management, wholesale/retail), workforce size (i.e., small: &lt;100; moderate: 100-499; and large: 500+) and company type (e.g., non-profit, profit-private, profit-public, government). We identified factors associated with an increased likelihood of sleep-focused WHPP using logistic regression adjusted for company size and type. Analyses were weighted for nationally-representative estimates.

Results

Of the N=2,843 companies that provided information, N=261 (11.74%) reported having a sleep program. Worksites with large workforces (OR=4.8, p&lt;0.0005), for-profit public companies (OR=9.0, p&lt;0.0005), in wholesale/retail (OR=3.8, p&lt;0.0005), and those with employer-subsidized full health insurance (OR=12.7, p&lt;0.0005) were more likely to have a sleep-focused WHPP. Other predictors included more long-standing WHPP programs (6 years, OR=4.4, p&lt;0.0005), the presence of employee health in the company’s mission (OR=4.5, p&lt;0.0005), leadership buy-in (OR=3.5, p=0.007), and an annual health promotion budget &gt;$50,000 (OR=11.3, p&lt;0.0005).

Conclusion

In general, workplaces with higher budgets, more well-established health promotion programs, and a mission to promote workplace health are more likely to include a sleep program. Also, publicly-traded companies and government were more likely than private companies to have a sleep program. Future research may consider defining barriers among small business and non-profit organizations for implementing sleep-focused workplace health programs.

Support

T32HL007901

0405 Sleep Duration and Sleep Disturbance Related to Obesity, Health, Motor Vehicle Safety, and Daytime Functioning in Israel: Data From the 2017 Israel Social Survey

Introduction

Previous studies suggest the Israeli population exhibits relatively short sleep duration and experiences sleep difficulties. This analysis evaluates the relationships between habitual sleep and outcomes of interest in this population.

Methods

Data were obtained from 7,230 Israeli individuals. The sample consisted a 2017 population-based survey of households, conducted by the Israeli Bureau of Statistics. All variables were self-reported. Outcomes of interest included drowsy driving, sleep medication use, functional impairment, sleepiness, overall health, 1-year health change, and obesity. Predictors included categories of sleep duration (&lt;=5, 6, 7, 8 [reference], or &gt;=9 hours) and sleep disturbance in the past month (none [reference], mild [1/week], moderate [2-3/week], or severe [&gt;3/week]). Covariates included age, sex, ethnic group, and financial status. Binary and ordinal logistic regressions were employed to evaluate the relationship between them and post-hoc analyses evaluated the relationships between subgroups.

Results

Drowsy driving was associated with &lt;=5h, 6h, and 7h sleep duration categories, and severe sleep disturbance. The use of sleep medication use was associated with &lt;=5h and &gt;=9h, and all levels of sleep disturbance. Functional impairment and sleepiness were both associated with &lt;=5h, 6h, 7h, and &gt;=9h, and all levels of sleep disturbance. Their reported overall health was linked to sleep duration of &lt;=5h and &gt;=9h, and all levels of sleep disturbance. Worsening health was associated with &lt;=5h and all levels of sleep disturbance. Obesity was associated with &lt;=5h and severe sleep disturbance. In post-hoc analyses restricted to individuals with no sleep disturbance, habitual sleep duration was still statistically significantly related to drowsy driving, sleep medications, sleepiness, and health change.

Conclusion

Short sleep duration and sleep disturbance are associated with worse motor vehicle safety, health, and functioning in the Israeli population. Effects of sleep duration were generally maintained even for those without sleep disturbance. These results may help focus public health efforts on improving sleep health.

Support

Dr. Grandner is supported by R01MD011600

No increased risk of relapse of breast cancer for women who give birth after assisted conception

STUDY QUESTION

Is childbirth after IVF associated with a risk of relapse in breast cancer?

SUMMARY ANSWER

Women who had been diagnosed with breast cancer and completed treatment had no increased risk of relapse if they gave birth after conceiving with IVF.

WHAT IS KNOWN ALREADY

Pregnancy and childbirth have not been shown to increase the risk of relapse in breast cancer. Ovarian stimulation during IVF increases the oestrogen levels and could theoretically increase the risk of relapse in breast cancer.

STUDY DESIGN, SIZE, DURATION

This is a retrospective register study, using national Swedish register data from the National Patient Register, the Medical Birth Register, the Swedish National Cancer Register, the National Breast Cancer Register, the National Quality Registry of Assisted Reproduction (Q-IVF), the National IVF Dataset, the Swedish Prescribed Drug Register and the Cause of Death Register. All women diagnosed with breast cancer who were between 20 and 44 years of age during the years 1982 to 2014 and identified in the cancer registries were assessed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women, previously diagnosed with breast cancer, who had given birth after IVF (29 after completed breast cancer treatment and 8 after fertility preservation) were compared with a matched control group who had given birth after spontaneous conception. Matching was done in a ratio 1:4, based on T-stage (size of the tumour) and year of diagnosis +/−5 years.

MAIN RESULTS AND THE ROLE OF CHANCE

We found 26 114 women that had been diagnosed with breast cancer when 20–44 years old and of those 860 had subsequently given birth, 823 after spontaneous and 37 after IVF conception. Follow-up time was similar between the groups, ranging from 2.6 to 24.0 years, with a mean follow-up time of 10.3 (SD 4.2) years in the IVF group and 10.7 (SD 4.4) years in the control group. There were no relapses (0/37) in the IVF group. The relapse rate for the matched controls was 36/148 (24.8%). Ten women who suffered relapse died due to breast cancer.

LIMITATIONS, REASONS FOR CAUTION

This is reassuring data; however, the result is based on a few cases. The poor coverage of important prognostic variables in the register resulted in uncertain comparability of the groups. The main limitation in this study is the extent of missing data on tumour-related variables, due to poor coverage from the early years of the National Breast Cancer Register. It is possible that the women accepted for IVF had a less aggressive breast cancer and were generally healthier than women delivering after conceiving spontaneously and therefore had a lower risk of relapse. Other limitations are the lack of information on the anticancer therapies used and type of disease relapse, plus the older of the two IVF registers did not hold information on unsuccessful IVF cycles, leaving only cycles leading to birth, to be analysed.

WIDER IMPLICATIONS OF THE FINDINGS

We found no indication that women who had been diagnosed with breast cancer had an increased risk of relapse if they gave birth after conceiving with IVF. Based on our findings, there is no evidence to advise against IVF treatment in this group of women. More detailed registry data would be valuable for future studies, enabling proper matching of tumour characteristics between groups.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-720291), The Assar Gabrielsson Fund (FB 15-20), The Breast Cancer Fund and the Swedish Association of Local Authorities and Regions, SKL. There are no conflicts of interest to declare.

Cervical Spine pain as a presenting complaint in metastatic pancreatic cancer: a case report

A 48 year-old female presented to her primary care physician with a two-month history of neck pain with negative cervical spine x-rays. During that office visit, the patient was noted to be tachycardic with EKG revealing ST depressions, which led to hospital admission. Acute coronary syndrome was ruled out, however, persistent neck pain warranted inpatient MRI of the cervical spine, which revealed a cervical spine lesion. Extensive investigation and biopsy ultimately confirmed stage IV pancreatic adenocarcinoma with metastases to the bone, liver, and likely lung. In the literature, the findings of a primary metastatic site being bone is rare with only a few case reports showing vertebral or sternal metastasis as the first clinical manifestation of pancreatic cancer. The uniqueness of this case lies in the only presenting complaint being cervical spine pain in the setting of extensive metastases to the liver, bone, and likely lung.

A phase 2 study of MK-5442, a calcium-sensing receptor antagonist, in postmenopausal women with osteoporosis after long-term use of oral bisphosphonates

In women with osteoporosis treated with alendronate for >12 months and oral bisphosphonates for >3 of the last 4 years, switching to MK-5442, a calcium receptor antagonist, stimulated endogenous parathyroid hormone (PTH) secretion and increased bone turnover marker levels, but produced a decline in bone mineral density (BMD) at all sites.

INTRODUCTION

This study assessed the effects of switching from long-term oral bisphosphonate therapy to the calcium-sensing receptor antagonist MK-5442 on BMD and bone turnover markers (BTMs) in post-menopausal women with osteoporosis.

METHODS

This randomized, active and placebo-controlled, dose-ranging study enrolled 526 postmenopausal women, who had taken alendronate (ALN) for ≥12 months preceding the trial and any oral bisphosphonate for ≥3 of the preceding 4 years and had spine or hip BMD T-scores ≤-2.5 or ≤-1.5 with ≥1 prior fragility fracture. Women were randomized to continue ALN 70 mg weekly or switch to MK-5442 (5, 7.5, 10, or 15 mg daily) or placebo.

RESULTS

Switching from ALN to MK-5442 produced a dose-dependent parathyroid hormone (PTH) pulse of threefold to sixfold above baseline at 1 h, with PTH levels that remained twofold to threefold above baseline at 4 h and returned to baseline by 24 h. Switching to MK-5442 or placebo increased BTM levels compared to baseline within 3 months and MK-5442 10 mg increased BTM levels compared to placebo by 6 months. With all MK-5442 doses and placebo, spine and hip BMD declined from baseline, and at 12 months, BMD levels were below those who continued ALN (all groups P < 0.05 vs ALN). There was also a dose-dependent increase in the incidence of hypercalcemia with MK-5442.

CONCLUSION

Switching from ALN to MK-5442 resulted in a pulsatile increase in PTH and increases in BTMs, but a decline in BMD compared with continued ALN. MK-5442 is not a viable option for the treatment of osteoporosis.

Effect of the cathepsin K inhibitor odanacatib administered once weekly on bone mineral density in Japanese patients with osteoporosis--a double-blind, randomized, dose-finding study

The efficacy and safety of oral placebo or odanacatib 10, 25, or 50 mg once weekly for 52 weeks were evaluated in a double-blind, randomized, multi-center study in Japanese female and male patients with osteoporosis.

INTRODUCTION

Odanacatib is a selective and reversible cathepsin K inhibitor that decreases bone resorption and increases bone mineral density (BMD).

METHODS

The primary efficacy endpoint was percent change from baseline to week 52 in lumbar spine BMD. Secondary endpoints included percent change in total hip, femoral neck, and trochanter BMD and in bone biomarkers after treatment for 52 weeks.

RESULTS

In this study, 286 patients [94% female, mean age (SD) 68.2 (7.1) years] were included in the analysis. The least-squares mean percent changes from baseline to week 52 in the groups receiving placebo, 10, 25 and 50 mg of odanacatib for lumbar spine (L1~L4) BMD were 0.5, 4.1, 5.7, and 5.9% and for total hip BMD were -0.4, 1.3, 1.8, and 2.7%, respectively. The changes in femoral neck and trochanter BMD were similar to those at the total hip. Bone turnover markers were reduced in a dose-dependent manner. However, the effects of odanacatib on bone formation markers were less compared with the effects on bone resorption markers. Tolerability and safety profiles were similar among all treatment groups with no dose-related trends in any adverse events.

CONCLUSIONS

Weekly odanacatib treatment for 52 weeks increased BMD at the lumbar spine and at all hip sites in a dose-dependent manner and was well tolerated in Japanese patients with osteoporosis.

Horner's syndrome in patients admitted to the paediatric intensive care unit: epidemiology, diagnosis and clinical practice

Horner's syndrome appears when the three-neuron sympathetic pathway is interrupted anywhere from the posterior-lateral nuclei of the hypothalamus through the spinal cord to the eye. In children, Horner's syndrome can be either congenital or acquired, but overall it is a rare finding. There are several causes of Horner's syndrome, some of iatrogenic. Although uncommon in the paediatric population, prompt recognition of the syndrome and immediate treatment may prevent permanent damage to the neuronal pathway. Awareness of the risk of developing iatrogenic Horner's syndrome and early detection of signs are recommended to minimise future disability.

Storage stability studies for tributyltin determination in human urine samples using headspace solid-phase microextraction and gas chromatography mass spectrometry

A headspace solid-phase micro-extraction (HS-SPME) method was employed in order to study the effect of storage conditions of human urine samples spiked with tributyltin (TBT) using gas chromatography and mass spectrometry. To render the analyte more volatile, the derivatization (ethylation) was made in situ by sodium tetraethylborate (NaBEt(4) ), which was added directly to dilute unpreserved urine samples and in buffers of similar acidity. The stability of TBT in human urine matrix was compared with the stability of TBT in buffer solutions of similar pH value. Critical parameters of storage conditions such as temperature and time, which affect the stability of TBT in this kind of matrix, were examined extensively. The tests showed that the stability of TBT remains practically satisfactory for a maximum of 2 days of storage either at +4 or 20°C. Greater variations were observed in the concentration of TBT in human urine samples at +4°C and lower ones at -20°C over a month's storage. The freeze-thaw cycles have negative effect on the stability and should be kept to a minimum. The results from spiked urine samples are also discussed in comparison to those acquired from buffer solutions of equal TBT concentration.

Randomized controlled trial of atorvastatin in clinically isolated syndrome: the STAyCIS study

OBJECTIVE

To test efficacy and safety of atorvastatin in subjects with clinically isolated syndrome (CIS).

METHODS

Subjects with CIS were enrolled in a phase II, double-blind, placebo-controlled, 14-center randomized trial testing 80 mg atorvastatin on clinical and brain MRI activity. Brain MRIs were performed quarterly. The primary endpoint (PEP) was development of ≥ 3 new T2 lesions, or one clinical relapse within 12 months. Subjects meeting the PEP were offered additional weekly interferon β-1a (IFNβ-1a).

RESULTS

Due to slow recruitment, enrollment was discontinued after 81 of 152 planned subjects with CIS were randomized and initiated study drug. Median (interquartile range) numbers of T2 and gadolinium-enhancing (Gd) lesions were 15.0 (22.0) and 0.0 (0.0) at baseline. A total of 53.1% of atorvastatin recipients (n = 26/49) met PEP compared to 56.3% of placebo recipients (n = 18/32) (p = 0.82). Eleven atorvastatin subjects (22.4%) and 7 placebo subjects (21.9%) met the PEP by clinical criteria. Proportion of subjects who did not develop new T2 lesions up to month 12 or to starting IFNβ-1a was 55.3% in the atorvastatin and 27.6% in the placebo group (p = 0.03). Likelihood of remaining free of new T2 lesions was significantly greater in the atorvastatin group compared with placebo (odds ratio [OR] = 4.34, p = 0.01). Likelihood of remaining free of Gd lesions tended to be higher in the atorvastatin group (OR = 2.72, p = 0.11). Overall, atorvastatin was well tolerated. No clear antagonistic effect of atorvastatin plus IFNβ-1a was observed on MRI measures.

CONCLUSION

Atorvastatin treatment significantly decreased development of new brain MRI T2 lesion activity, although it did not achieve the composite clinical and imaging PEP.

CLASSIFICATION OF EVIDENCE

This study provided Class II evidence that atorvastatin did not reduce the proportion of patients with CIS meeting imaging and clinical criteria for starting immunomodulating therapy after 12 months, compared to placebo. In an analysis of a secondary endpoint (Class III), atorvastatin was associated with a reduced risk for developing new T2 lesions.

From computed microtomography images to resistivity index calculations of heterogeneous carbonates using a dual-porosity pore-network approach: influence of percolation on the electrical transport properties

Standard reservoir evaluations are based on Archie's law relating the average water saturation to the average electrical resistivity by R(ind) = S(w)(-2). However, especially in the case of complex heterogeneous carbonates, deviation from Archie's law is observed and generally attributed to factors affecting the percolation or disconnectedness of the different phases (wetting films, microporosity, macropores) assuring electrical conductance. Pore-network models (PNM's) in combination with high-resolution computed microtomography (μ-CT) constitute a very effective tool to investigate the influence of the geometry and topology of the porous media on the spatial distribution of the conductive phase, and therefore on the shape of the resistivity index curve. An extended version of the classical PNM applicable to dual-porosity systems is presented. It combines the classical pore-network modeling applied on the macroporous space with the macroscopic properties of the microporous phase, supposing that the two pore systems act in parallel. Three-dimensional images provide information on the connectedness of the microporous phase, which is then included in the simulations. Electrical behavior of sandstone and two carbonates presenting distinct resistivity index curves were simulated and compared to measurements. Both Archie and "non-Archie" behavior were correctly reproduced, and the curve shape was explained considering percolation of the different phases.

Role of Thin Fimbriae in Adherence and Growth of Acinetobacter calcoaceticus RAG-1 on Hexadecane

Acinetobacter calcoaceticus RAG-1, a hydrocarbon-degrading bacterium which adheres avidly to hydrocarbons and other hydrophobic surfaces, possesses numerous thin fimbriae (ca. 3.5-nm diameter) on the cell surface. MR-481, a nonadherent mutant of RAG-1 which is unable to grow on hexadecane under conditions of limited emulsification and low initial cell density, lacks these fimbriae. Prolonged incubation of MR-481 in hexadecane medium enriched for partial adherence revertants. The reappearance of thin fimbriae was observed in all such revertant strains. RAG-1 cells and partial revertant strains were agglutinated in the presence of antibody, whereas MR-481 cells were not. Another mutant, AB15, which was previously isolated on the basis of its nonagglutinability in the presence of antibody, also lacked thin fimbriae and was conditionally nonadherent. Furthermore, strain AB15 was unable to grow on hexadecane medium. Adherence of RAG-1 cells to hexadecane was considerably reduced after shearing treatment. The material removed from the cell surface by shearing of RAG-1 and the partial revertant strains yielded a single antigenic band in RAG-1 and partial revertant strains, as observed by crossed immunoelectrophoresis. This band was absent in both fimbriae-less mutants, MR-481 and AB15. The data demonstrate that the thin fimbriae of RAG-1 (i) are a major factor in adherence to polystyrene and hydrocarbon, (ii) may be crucial in enabling growth of cells on hexadecane, and (iii) constitute the major cell surface agglutinogen.

Emulsan in Acinetobacter calcoaceticus RAG-1: Distribution of Cell-Free and Cell-Associated Cross-Reacting Material

Emulsan is an extracellular polymeric bioemulsifier produced by Acinetobacter calcoaceticus RAG-1. Antibodies prepared against purified emulsan inhibited the activity of the polymer in a standard emulsification test. These antibodies were used to develop a sensitive enzyme-linked immunosorbent assay to monitor changes in cell-free emulsan throughout the growth cycle. This assay was also used to detect emulsan associated with the cell surface and to monitor changes in the distribution of cell-free and cell-associated emulsan throughout the growth cycle. Cells in the early exponential phase exhibited relatively large amounts of cell-associated emulsan which decreased rapidly between the midexponential and early stationary phases. This drop in cell-associated material was accompanied by a rise in the concentration of extracellular polymer. Moreover, in agreement with previous results (C. Rubinovitz, D. L. Gutnick, and E. Rosenberg, manuscript in press), production of cell-free emulsan was enhanced in the presence of chloramphenicol. The release of this material from the cell surface in the presence of chloramphenicol apparently involved the synthesis of cell-associated cross-reacting material since the relative amount of such cell-bound polymer remained constant during the treatment with the drug.

Uranium binding by emulsan and emulsanosols

Emulsan, the extracellular bioemulsifier of Acinetobacter RAG-1, bound up to 0.9 microm of uranium per 1 mg emulsan. The dissociation constant for the emulsan-uranium complex, K(app) (I) was 1.2 x 10(-4)M. Much larger amounts of uranium were bound to emulsan when the biopolymer occurred on hexadecane-water interfaces. Under these conditions, more than 3.5 microm uranium were bound per 1 mg emulsan and the dissociation constant K(app) (II) was 5.1 x 10(-5)M. At pH 2, more than 90% of the uranium bound to emulsan on the hexadecane-water interface was desorbed, while less than 10% bioemulsifier was released from the interface. The different binding parameters of emulsan when free in solution and while adsorbed onto the hexadecane water interface are discussed in view of potential applications and as a model system for studying the properties of an extracellular amphipathic polymer bound to a hydrophobic surface.

Deviation from Archie's law in partially saturated porous media: Wetting film versus disconnectedness of the conducting phase

We experimentally study the electrical transport in partially water-saturated pore network. The porous medium under investigation is a Fontainebleau sandstone, characterized by x-ray tomography. We show the existence of two electrical conductivity regimes. At high water saturation, the electric resistivity follows a well-known Archie law. Below a water saturation S_{w} approximately 0.2 , a strong negative deviation from this Archie law is observed. We attribute this transition to the existence of "a thick liquid film," assuring the ionic conduction in the low saturation regime. A numerical simulation is proposed to confirm this scenario. Two possible protocols are used to distribute the brine phase in the pore network of a three-dimensional microtomography image. The first one is based on a minimization of the interfacial energy. The second takes into account a quasistatic capillary displacement. The classical random-walk algorithm is used to compute the electric conductivity at various water saturations. Without the "thick film," both of the two fluid-placing protocols show a disconnectedness transition of the brine phase when S_{w}<0.2 . Adding this "film" to solid surface, the electrical continuity is maintained. The bending down trend is correctly reproduced, showing that in this range, the electric response cannot be described by a power law as usual.

Medical student psychiatry examination performance at VA and non-VA Clerkship Sites

OBJECTIVE

The authors examined the effects of medical student assignment to U.S. Department of Veterans Affairs (VA) Medical Center inpatient and outpatient psychiatry clerkship sites versus other university and community sites on the performance outcome measure of National Board of Medical Examiners (NBME) subject examination scores.

METHODS

NBME psychiatry scores were compared for stratified random samples of 70 students each for inpatient and outpatient VA and non-VA sites, controlling for baseline clinical knowledge as reflected by second year Human Behavior course scores.

RESULTS

No significant differences were demonstrated in NBME scores between VA and non-VA sites for either inpatient or outpatient programs.

CONCLUSION

Assessed students rotating through several VA clinical sites were as well prepared for NBME subject examinations as those assigned to other sites. Additional measures of educational outcome for VA sites are recommended to assess and enhance clinical education provided by the VA and to strengthen collaboration with university-based medical student teaching programs.

Healthy Israel 2020: a visionary national health targeting initiative

This article describes the development of a national health targeting initiative entitled 'Healthy Israel 2020' which was created to enhance the health and wellbeing of Israelis through a variety of health promotion and disease prevention interventions. This initiative builds upon the experience of two major worldwide targeting efforts, "Health People 2010" of the US and the World Health Organization's Health21', as well as lessons learned from other countries. Important philosophical underpinnings are highlighted, particularly the evidence-based nature of the process. Real-world organizational and policy challenges and creative solutions are presented. It is hoped that this report will be of value to others in Israel and elsewhere who are interested in improving the health of their nations.

21. Optimal care in rheumatoid arthritis: Preliminary findings from a focus group study

The objective of our work was to identify facilitators of optimal care, as well as potential barriers, for patients with rheumatoid arthritis (RA). The design was a focus group study. Individuals with established RA were identified through invitation letters sent using a random sample of the Quebec Arthritis Society mailing list. Patients were eligible for participation if they had a diagnosis of RA confirmed by a rheumatologist and if they had sought care within the McGill Réseau Universitaire Intégré de Santé network. We planned a series of focus group meetings (90 minutes each) to obtain sufficient data in terms of spectrum of ideas. In each moderator-led group, participants were asked to discuss five questions related to quality care. A co-moderator was available to document non-verbal communication, with audio-taping of all sessions and professional transcription for data analysis. Qualitative content analysis, based on grounded theory, was the chosen means of identifying recurring themes and categories. Two focus group sessions have been completed with two more scheduled. Preliminary findings indicate the importance of good communication between family physicians, specialists, and allied health care workers. Final coding of transcripts and computer-assisted content analysis is being completed. However it appears that focus group may be useful in studying optimal care for chronic diseases such as RA. Our preliminary findings emphasize the necessity of good communication among health care providers. Ultimately we hope to generate knowledge that can be transformed into better health for Canadians with arthritis and other chronic diseases.

Cracked and broken teeth--definitions, differential diagnosis and treatment

Cracked and broken teeth present a diagnostic dilemma to the dentist and the sooner a correct diagnosis is made the greater are the chances to save the tooth. As the location, direction and size of the crack or fracture dictates the choice of treatment, it is important to first define the types of cracks and fractures in the coronal and radicular tooth structure. Cracks and fractures can be classified as follows: 1. craze lines 2. fractured cusps 3. cracked teeth 4. split teeth 5. vertical root fractures. The vertical root fracture has been described recently in two articles in this publication, and therefore will not be discussed here. Diagnosis of a cracked tooth is not always initially obvious. The patient's response to clinical testing is the primary diagnostic tool along with the dental history provided by the patient. Radiographs are secondary in making a diagnosis. Clinical aids for reproducing the patient's symptoms such as occlusal bite devices, observing occlusal wear facets and the application of cold water to one tooth at a time may isolate the offending tooth. In situations where an irreversible pulpitis is diagnosed, endodontic treatment is indicated. In the case of a questionable diagnosis, or one in which a potential reversible pulpitis is made, a provisional restoration can be placed for an unspecified time as a diagnostic aid. If endodontic therapy were indicated, consultation with the patient as to the compromised prognosis and the alternatives to endodontic treatment is essential.