Toward Precision Perioperative Therapy in GI Malignancies

PURPOSE

The term precision oncology typically refers to molecularly guided therapies against cancer. Less appreciated but also critically important is molecular identification of patients with resectable disease who are most likely to benefit from perioperative drugs, and tailored selection of such drugs. We call this idea precision perioperative therapy. Over the past several years, use of precision perioperative approaches for patients with localized GI cancers has expanded in clinical trials and practice. Here, we summarize the status of the field and highlight areas of future innovation.

METHODS

Using PubMed, we reviewed articles published from 2017 to 2023 in English. We used search terms "adjuvant," "perioperative," "neoadjuvant," and "precision medicine" for various types of GI malignancies. Information about ongoing clinical trials was accessed through ClinicalTrials.gov, accessed January 2023.

RESULTS

Paradigms such as minimal residual disease detection via circulating tumor DNA and perioperative immunotherapy in lieu of chemotherapy for mismatch repair-deficient disease may lead to reduced toxicity and improved long-term outcomes in select populations. Molecularly targeted drugs that have shown activity against metastatic disease may also hold promise in the curable setting.

CONCLUSION

The field is very much in development, but emerging data demonstrate early promise. We are optimistic that ongoing research efforts will increasingly bring precision perioperative therapy to patients with resectable GI malignancies.

Octahedral Distortion and Displacement-Type Ferroelectricity with Switchable Photovoltaic Effect in a 3d^{3}-Electron Perovskite System

Because of the half-filled t_{2g}-electron configuration, the BO_{6} octahedral distortion in a 3d^{3} perovskite system is usually very limited. In this Letter, a perovskitelike oxide Hg_{0.75}Pb_{0.25}MnO_{3} (HPMO) with a 3d^{3} Mn^{4+} state was synthesized by using high pressure and high temperature methods. This compound exhibits an unusually large octahedral distortion enhanced by approximately 2 orders of magnitude compared with that observed in other 3d^{3} perovskite systems like RCr^{3+}O_{3} (R=rare earth). Essentially different from centrosymmetric HgMnO_{3} and PbMnO_{3}, the A-site doped HPMO presents a polar crystal structure with the space group Ama2 and a substantial spontaneous electric polarization (26.5  μC/cm^{2} in theory) arising from the off-center displacements of A- and B-site ions. More interestingly, a prominent net photocurrent and switchable photovoltaic effect with a sustainable photoresponse were observed in the current polycrystalline HPMO. This Letter provides an exceptional d^{3} material system which shows unusually large octahedral distortion and displacement-type ferroelectricity violating the "d^{0}-ness" rule.

[Research progression of gene fusion detection technology based on next generation sequencing in tumor companion diagnostics]

Gene fusion is one of the mechanisms that promote tumor development. It is also an important cause for the poor prognosis of patients. The detection of gene fusion is crucial for the recognition of tumor biomarker, cancer subtype classification, and clinical medication guidance. Appropriate methods can help the early diagnosis and avoid ineffective medication. Traditional tests include fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), reverse transcription of PCR (RT-PCR), and next generation sequencing (NGS). The next generation sequencing (NGS) mainly includes: whole genome sequencing (WGS), whole transcriptome sequencing (WTS) and target sequencing (hybridization capture method/amplicon method). In clinical concomitant diagnostic applications, some factors such as operability, time/money costs, and the level of expertise required for data analysis should be considered. This article concludes with a discussion of the technical principles of different detection methods and advantages/limitations. Meanwhile, it provides reference opinions for the detection methods of gene fusion.

Abstract 4151: Effect of camidanlumab tesirine (Cami) as monotherapy and in combination with pembrolizumab (PEM) on the immune cell profile in patients with selected advanced solid tumors

Background: Cami, an investigational anti-CD25, pyrrolobenzodiazepine-based antibody drug conjugate, imparts cytotoxicity on CD25+ regulatory T cells (Tregs), leading to immunomodulatory effects (eg, modifying effector T cell [Teff]:Treg intratumoral balance).

Objective: Describe the pharmacokinetics (PK) and circulating immune cell profile of Cami monotherapy and in combination with PEM in patients with advanced solid tumors.

Methods: In the dose-escalation phase 1b trial of Cami (NCT03621982) in patients with advanced solid tumors after failure of recommended therapies, we investigated Cami monotherapy (n=44; doses: 20, 30, 45, 60, 80, 100, 125, and 150 µg/kg every 3 weeks [Q3W]) and Cami combination therapy (n=12; doses: 30, 45, and 60 µg/kg with PEM 200 mg Q3W). Serum conjugated antibody (cAb) and total antibody (tAb) were quantified by a validated chemoimmunoluminescence assay. Soluble CD25 was quantified by a qualified enzyme-linked immunoassay. Circulating immune cell absolute counts were assessed by flow cytometry for Tregs (FoxP3+CD25+CD127low) as a fraction of absolute CD4+ cells, Teff (CD8+), and Teff:Treg. Statistical analyses were performed using a linear mixed-effects model (maximum likelihood) for the biomarker effects model with cAb area under the curve (AUC) during cycle 1, therapy (monotherapy vs combination), and treatment cycle as fixed effects and log AUC slope with intercept by subject or visit day as random effects.

Results: PK analysis found Cmax and AUC of cAb and tAb increased during cycles 1 and 2 with Cami monotherapy and combination therapy across the range of doses. Variability of AUCinf for cAb in cycle 1 appeared modest to marked across discrete dose groups (CV=14.7-98.1%). The clearance of cAb ranged from 1.34 to 3.52 L/day in cycle 1 with no apparent differences between monotherapy and combination therapy. Biomarker modeling demonstrated that cAb AUC and cycle were associated with a significant Tregs depletion and a significant positive effect on Teff:Treg ratio but with no relevant effect on Teff. Within cycle, treatment-related modulation of Teff and Tregs was observed for all doses and conditions. Soluble CD25 appears to be significantly positively affected by cycle 2 treatment.

Conclusions: PK exposure of Cami was dose-related with varying degrees of interpatient variability. Circulating Tregs were significantly decreased and Teff:Treg was significantly increased by Cami exposure, demonstrating the intended immunomodulatory effect of Cami in circulation and suggesting that a combination approach with Cami could address an immune-resistance mechanism. Future analyses will consider discrete PEM effect, correlates to tumor biopsy expression and response, and combined Cami+PEM effect in tumor biopsies. Funding: ADC Therapeutics; medical writing: CiTRUS Health Group.

Citation Format: Igor Puzanov, Christopher T. Chen, Patricia LoRusso, Kyriakos P. Papadopoulos, Shivaani Kummar, Erika Hamilton, Yvan LeBruchec, Karin Havenith, Serafino Pantano, Marie Toukam, Jens Wuerthner, Joseph Boni. Effect of camidanlumab tesirine (Cami) as monotherapy and in combination with pembrolizumab (PEM) on the immune cell profile in patients with selected advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4151.

Abstract 1789: Chromatin modifier alterations confer resistance to endocrine deprivation and CDK4/6 inhibitors in ER+ breast cancer and drive convergent evolution in patient autopsy lesions

We studied resistance mechanisms to hormone therapy and CDK4/6 cell cycle inhibitors in ER+ breast cancer by analyzing whole-exome, whole-genome, single-cell, and bulk transcriptomes in 120 autopsy samples from 13 patients obtained by the Massachusetts General Hospital Rapid Autopsy program. For each patient, we inferred the clonal structure of the samples and tracked the metastatic spread of different clones throughout the body. For 7 patients, we also analyzed serial cfDNA samples to identify clones that were selected for during treatment. We identified significantly recurrent and convergent (arising independently in distinct clones) acquired mutations in ESR1, KRAS, and chromatin modifier genes, in particular, mutations in KMT2C, which may represent mechanisms of drug resistance in this clinical setting. To experimentally study the role of KMT2C mutations, we used CRISPR/Cas9 to knock out KMT2C in the ER+ CAMA1 breast cancer cell line that is sensitive to both ER and CDK4/6 inhibition. KMT2C knock-out cells demonstrated significantly increased viability under treatment with fulvestrant (ERi), palbociclib (CDK4/6i), or their combination compared to the control cell lines. We show that this increased drug resistance is driven by downregulation of the ESR1 pathway, suggesting a decreased dependency on ER signaling for cell cycle progression. In addition to the early survival benefit, KMT2C knock-out resulted in a dramatic outgrowth of cells under long-term fulvestrant treatment. The KMT2C KO fulvestrant-resistant outgrown cells were highly resistant to the CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib compared to control cells, as well as to novel ERalpha inhibitors and a range of targeted therapies currently in clinical trials. By testing a panel of compounds on KMT2C KO and control cell lines, we propose potential novel therapeutic strategies that may help overcome the development of resistance in KMT2C-mutant cells. These findings suggest that KMT2C mutations may be a mechanism of acquired resistance to CDK4/6 inhibitor combinations, and subsequent treatment with therapies directed towards ER or CDK4/6 pathways may be ineffective and other treatment avenues need to be developed.

Citation Format: Elizaveta Leshchiner, Ignaty Leshchiner, Elizabeth E. Martin, Christopher T. Chen, Thomas Zhang, Christopher Pinto, Kahn Rhrissorrakrai, Filippo Utro, Chaya Levovitz, Raquel A. Jacobs, Brian P. Danysh, Kara Slowik, Maida Broudo, Laxmi Parida, Dejan Juric, Gad Getz. Chromatin modifier alterations confer resistance to endocrine deprivation and CDK4/6 inhibitors in ER+ breast cancer and drive convergent evolution in patient autopsy lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1789.

[The characteristics of non-alcoholic fatty liver disease and its associated factors in patients with rheumatoid arthritis]

Objective: To investigate the characteristics of non-alcoholic fatty liver disease (NAFLD) and its associated factors in rheumatoid arthritis (RA) patients. Methods: This cross-sectional study recruited 385 RA patients [including 72 (18.7%) male and 313 (81.3%) female] who received abdominal sonographic examination from August 2015 to May 2021 at Department of Rheumatology, Sun Yat-Sen Memorial Hospital. There were 28 RA patients at 16-29 years old and 32, 80, 121, 99, 25 at 30-39, 40-49, 50-59, 60-69, ≥ 70 years old, respectively. Demographic and clinical data were collected including age, gender, history of alcohol consumption, disease duration, body mass index (BMI), waist circumference, blood pressure, RA disease activity indicators and previous medications. Logistic regression analyses were used to identify the associated factors of NAFLD in RA patients. Results: The prevalence of NAFLD was 24.2% (93/385) in RA patients, 26.3% (21/80) in 40-49 age group and 33.1% (40/121) in 50-59 age group. There were 22.1% (85/385) and 3.6% (14/385) RA patients with overweight and obese, in which the prevalence of NAFLD was 45.9% (39/85) and 78.6% (11/14) respectively, which was 2.6 folds and 4.5 folds that of RA patients with normal BMI. Although there was no significant difference of age, gender and RA disease activity indicators between RA patients with or without NAFLD, those with NAFLD had higher proportions of metabolic diseases including obese (11.8% vs. 1.0%), central obesity (47.3% vs. 16.8%), hypertension (45.2% vs. 29.8%) and type 2 diabetes mellitus (24.7% vs. 12.0%), consistent with higher levels of total cholesterol [(5.33±1.31) mmol/L vs. (4.73±1.12) mmol/L], triglyceride [(1.51±1.08) mmol/L vs. (0.98±0.54) mmol/L] and low-density lipoprotein cholesterol [(3.37±0.97) mmol/L vs. (2.97±0.78) mmol/L, all P<0.05]. Multivariate logistic regression analysis showed that BMI (OR=1.314) and triglyceride (OR=1.809) were the independent factors positively associated with NAFLD in RA patients. Conclusion: NAFLD is a common comorbidity in RA patients, especially in those with middle-aged, overweight or obese, which is associated with high BMI or high triglyceride. Screening and management of NAFLD in RA patients especially those with overweight, obese or dyslipidemia should be emphasized.

[Analysis of public appeals for vaccination in Guangzhou's Government Hotline from 2018 to 2020]

This study analyzed the characteristics and change trend of Guangzhou citizens' demands related to vaccination through government hotlines 12345 and 12320 from 2018 to 2020. It understood the hotspots and needs of the public for vaccination work, analyzed the problems existing in vaccination work, and provided reference and suggestions for health departments to improve vaccination services and formulate relevant policies: to timely improve the professional ability and knowledge reserve of hotline personnel; to strengthen the construction of vaccination service system;to optimize the appointment vaccination service application; to scientifically purchase HPV vaccine and ensure the production and supply of vaccine.

[The characteristics and associated factors of functional limitation in patients with rheumatoid arthritis]

Objective: To investigate the characteristics of functional limitation and associated factors in patients with rheumatoid arthritis (RA). Methods: Consecutive patients with RA were recruited from August 2015 to June 2019 at Department of Rheumatology, Sun Yat-Sen Memorial Hospital. Demographic and clinical characteristics including age, gender, erythrocyte sedimentation rate (ESR), visual analogue scale (VAS) of pain, clinical disease activity index (CDAI), modified total Sharp score were collected. Physical function was assessed by the Stanford health assessment questionnaire disability index (HAQ-DI).Ordered logistic regression was used to analyze the related factors of HAQ-DI. Results: A total of 643 RA patients were finally recruited including 114 males and 529 females with mean age (49.7±12.9) years. There were 399 (62.1%) patients having different degrees of functional limitation, who were classified as mild (293, 45.6%), moderate (73, 11.4%) and severe (33, 5.1%). The prevalence of functional limitation was positively correlated with age and disease activity. The most restricted activity was walking [43.5% (280/643)], followed by gripping [36.1% (232/643)], reaching [35.5% (228/643)], daily activities [33.4% (215/643)], hygiene [33.0% (212/643)], dressing and grooming [29.7% (191/643)] and arising [29.1% (187/643)], and the last eating [18.4% (118/643)]. Multivariate ordered logistic regression analysis showed that age (OR=1.019, 95%CI 1.004-1.035),pain VAS (OR=1.820, 95%CI 1.616-2.050), ESR (OR=1.009, 95%CI 1.001-1.017), CDAI (OR=1.080, 95%CI 1.059-1.102) and modified total Sharp score (OR=1.010, 95%CI 1.004-1.015) were associated factors of functional limitation. Conclusion: The majority RA patients have functional limitation. Age, pain and active disease are independent associated factors. Therefore, target treatment and control of pain should be emphasized in RA patients.

Abstract 37: Convergence of resistance patterns in breast cancer after multiple lines of treatment through analysis of rapid autopsy samples

Determining patterns and mechanisms of drug resistance is fundamentally required for improving clinical outcome of cancer treatments. The ability to study multiple samples from different metastatic sites of the same patient is a clinically challenging task, which has become possible with the advent of “rapid” autopsy procedures (&lt;6 hours from death) conducted on the patients deceased from cancer. We have obtained and analyzed whole-exome, whole genome and transcriptome sequencing data from advanced breast cancer samples derived from multiple cancer lesions of the same patient post-treatment through the Massachusetts General Hospital Rapid Autopsy program. We have integrated genomic and transcriptomic data through advanced clonal reconstruction methods (PhylogicNDT) to investigate how the patients developed resistance to multiple lines of anti-cancer therapy. Additionally, we have used previously collected cell-free DNA samples to establish both a spatial and temporal picture of cancer drug resistance and progression. We have examined clonal heterogeneity and resistance to targeted therapies in 10 metastatic ER+ breast cancer patients over 120 distinct metastatic sites. The majority of patients in this cohort were treated with CDK4/6 cell cycle inhibitors in addition to hormone therapy. We discovered that multiple metastatic sites often share similar clonal structure, but overall progeny of several sibling clones spreads throughout the body, creating “families” of more closely related lesions. These distinct lesion populations often develop independent resistance mechanisms to the many lines of treatment that the patents have received. At least 8 out of 10 patients showed multiple known and potentially novel resistance mechanisms in separate branches of the phylogenetic tree, often converging on distinct mutations in the same resistance genes. Notably we have identified ESR1, KRAS and chromatin modifier recurrent and convergent mutations across the cohort. Temporal analysis using cfDNA taken over the course of treatment allows us to identify clones that expanded in response to a given treatment. Using RNA expression and pathway analysis, we identify unique transcriptional programs, differentially expressed genes and ER-signaling changes between distinct clones within one patient, as well as compare genetically similar clones across patents.

Citation Format: Ignaty Leshchiner, Elizabeth E. Martin, Christopher T. Chen, Elizaveta Leshchiner, Thomas Zhang, Christopher Pinto, Filippo Utro, Kahn Rhrissorrakrai, Chaya Levovitz, Brian P. Danysh, Kara Slowik, Raquel A. Jacobs, Laxmi Parida, Gad Getz, Dejan Juric. Convergence of resistance patterns in breast cancer after multiple lines of treatment through analysis of rapid autopsy samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 37.

Cell-free DNA captures tumor heterogeneity and driver alterations in rapid autopsies with pre-treated metastatic cancer

In patients with metastatic cancer, spatial heterogeneity of somatic alterations may lead to incomplete assessment of a cancer's mutational profile when analyzing a single tumor biopsy. In this study, we perform sequencing of cell-free DNA (cfDNA) and distinct metastatic tissue samples from ten rapid autopsy cases with pre-treated metastatic cancer. We show that levels of heterogeneity in genetic biomarkers vary between patients but that gene expression signatures representative of the tumor microenvironment are more consistent. Across nine patients with plasma samples available, we are able to detect 62/62 truncal and 47/121 non-truncal point mutations in cfDNA. We observe that mutation clonality in cfDNA is correlated with the number of metastatic lesions in which the mutation is detected and use this result to derive a clonality threshold to classify truncal and non-truncal driver alterations with reasonable specificity. In contrast, mutation truncality is more often incorrectly assigned when studying single tissue samples. Our results demonstrate the utility of a single cfDNA sample relative to that of single tissue samples when treating patients with metastatic cancer.

A phase 1b, open-label, dose-escalation study to evaluate camidanlumab tesirine (Cami) as monotherapy in patients (pts) with advanced solid tumors

2556

Background: Depletion of tumor-infiltrating CD25+ regulatory T cells (Tregs), which inhibit tumor-specific immune responses, could contribute to tumor eradication. Cami (ADCT-301), an anti-CD25, pyrrolobenzodiazepine-based antibody-drug conjugate, targets CD25+ Tregs. A mouse surrogate has shown potent antitumor activity in solid tumor models. Here we report preliminary data from the monotherapy arm of a phase 1b trial of Cami in pts with selected advanced solid tumors. Methods: The monotherapy dose-escalation part of this open-label study enrolled pts (aged ≥18 years) with selected advanced solid tumors and no suitable existing therapy. The primary objective was to characterize safety and tolerability, and to identify the recommended phase 2 dose of Cami monotherapy. Secondary and exploratory objectives included evaluation of preliminary antitumor activity, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity. Pts received Cami every 3 weeks (1 cycle) with dose escalation per a 3+3 design. Disease control rate (DCR) was assessed (complete and partial responses [CR, PR] and stable disease). Results: At data cut-off (Dec 17, 2020), 44 pts were enrolled, with primary tumor types (stage IVA/B: 27 pts; 61.4%) of colorectal (15 pts; 34.1%), pancreatic (14 pts; 31.8%), head and neck, ovarian/fallopian tube, and renal cell carcinoma (all 3 pts; 6.8%), non-small cell lung cancer (2 pts; 4.5%), gastric, esophageal/GEJ, melanoma, and triple-negative breast cancer (each 1 pt; 2.3%). Median (range) age was 60.5 (33–82) years; median (range) number of prior systemic therapies was 4 (1–9). Pts received a median (range) of 2 (1–6) Cami cycles at doses of 20–150 µg/kg. Median (range) treatment duration was 22 (1–178) days. No dose-limiting toxicities were reported. The maximum tolerated dose (MTD) was not reached. All-grade treatment-emergent adverse events (TEAEs) in ≥20% pts were nausea (18 pts; 40.9%), decreased appetite and fatigue (each 16 pts; 36.4%), constipation (13 pts; 29.5%), abdominal pain (11 pts; 25%), and rash (10 pts; 22.7%). The only Grade ≥3 TEAE in ≥10% pts was anemia (5 pts; 11.4%). Grade 3 autoimmune AEs (colitis, immune-mediated AE, systemic inflammatory response syndrome) and neurologic AEs (dysphagia and asthenia, but not GBS) were reported in 3 (6.8%) and 2 (4.5%) pts, respectively. 1 (2.3%) Cami-related TEAE led to treatment withdrawal; no Cami-related TEAEs were fatal. DCR was 25% (95% CI: 11.1, 34.7); 11/44 pts attained stable disease. No pts had CR or PR. Conclusions: Dose escalation of Cami monotherapy is complete. The safety profile is encouraging and MTD was not reached. PK/PD data will be presented. 150 µg/kg is the highest dose investigated for single-agent Cami and the highest to be investigated combined with pembrolizumab in selected advanced solid tumors in the current protocol. Funding: ADC Therapeutics SA NCT03621982. Clinical trial information: NCT03621982.

[Predictive value of anti-mutated citrullinated vimentin antibody on one-year radiographic progression in patients with rheumatoid arthritis]

Objective: To investigate the value of baseline anti-mutated citrullinated vimentin (MCV) antibody for predicting one-year radiographic progression in patients with rheumatoid arthritis (RA). Methods: Consecutive RA patients were recruited from November 2014 to July 2018 at Department of Rheumatology, Sun Yat-sen Memorial Hospital, Clinical data were collected including disease activity score in 28 joints with four variables including C-reactive protein (CRP).Serum anti-MCV antibody at baseline was detected by enzyme-linked immunosorbent assay. X ray assessment of both hands/wrists was performed and assessed according to the Sharp/van der Heijde modified score (mTSS) at baseline and the 12th month. Univariate and multivariate logistic regression analyses were used to identify the risk factors for one-year radiographic progression. Results: Among 220 RA patients recruited, the positive rate of anti-MCV antibody at baseline was 77.7%. Compared with those with negative anti-MCV antibody, RA patients with positive anti-MCV antibody had higher disease activity score in 28 joints with four variables induding CRP [3.8 (2.4, 5.0) vs. 3.1 (2.1, 4.0), P=0.007], more physical dysfunction (21.6% vs. 8.2%, P=0.033) and higher radiographic indicators including mTSS [11 (2, 27) vs. 4 (1, 10), P=0.003], joint space narrowing [JSN, 4 (0, 14) vs. 2 (0, 6), P=0.024] and joint erosion[JE, 5 (1, 18)vs. 3 (0, 5), P=0.003]. After one-year follow-up, sixty-six RA patients (30.0%) developed radiographic progression, the percentage of whom was significantly higher in positive anti-MCV group than that in negative anti-MCV group (33.9% vs.16.3%, P=0.018). Multivariate logistic regression analysis suggested that positive anti-MCV antibody at baseline was an independent risk factor for one-year radiographic progression (OR=2.341, 95%CI 1.002-5.469). Conclusion: Positive anti-MCV antibody at baseline predicts one-year radiographic progression in RA patients. In the future, anti-MCV antibody can be used not only as a supplementary laboratory marker, but also in disease activity assessment and prognosis prediction for RA.

Anisotropic 2D excitons unveiled in organic-inorganic quantum wells

Two-dimensional (2D) excitons arise from electron-hole confinement along one spatial dimension. Such excitations are often described in terms of Frenkel or Wannier limits according to the degree of exciton spatial localization and the surrounding dielectric environment. In hybrid material systems, such as the 2D perovskites, the complex underlying interactions lead to excitons of an intermediate nature, whose description lies somewhere between the two limits, and a better physical description is needed. Here, we explore the photophysics of a tuneable materials platform where covalently bonded metal-chalcogenide layers are spaced by organic ligands that provide confinement barriers for charge carriers in the inorganic layer. We consider self-assembled, layered bulk silver benzeneselenolate, [AgSePh]_∞, and use a combination of transient absorption spectroscopy and ab initio GW plus Bethe-Salpeter equation calculations. We demonstrate that in this non-polar dielectric environment, strongly anisotropic excitons dominate the optical transitions of [AgSePh]_∞. We find that the transient absorption measurements at room temperature can be understood in terms of low-lying excitons confined to the AgSe planes with in-plane anisotropy, featuring anisotropic absorption and emission. Finally, we present a pathway to control the exciton behaviour by changing the chalcogen in the material lattice. Our studies unveil unexpected excitonic anisotropies in an unexplored class of tuneable, yet air-stable, hybrid quantum wells, offering design principles for the engineering of an ordered, yet complex dielectric environment and its effect on the excitonic phenomena in such emerging materials.

Abstract PD8-08: Characterization of spatial and temporal heterogeneity of ER positive metastatic breast cancer using serial biopsies

Background: Metastatic breast cancer is characterized by a remarkable level of temporal and spatial heterogeneity. Management decisions based on a single tissue biopsy are therefore inherently limited by sampling bias and by dynamic changes in the receptor status and the mutational profile of the tumor. Methods: We characterized 41 serially enrolled patients on the tissue collection protocol DFHCC 13-416, who had ER+/HER2- breast cancer at the time of diagnosis of early stage disease. Results: 36 out of 41 patients (87.8%) had at least one biopsy in the metastatic setting. The number of biopsies in the metastatic setting ranged from one to seven. Two most frequently biopsied sites were liver (24.4%) and recurrent breast lesions (22.0%). Six out of 41 patients (14.6%) developed ER loss over the course of treatment. Estrogen receptor status conversions were noted in both the liver and in the recurrent breast lesions. PR loss was far more common, noted in 24 out of 41 patients (58.5%). Nine of these patients (21.9%) were PR negative at the time of diagnosis and an additional 15 patients (36.6%) lost PR expression during the course of their therapy. Median time to the loss of ER expression was 6.83 years from the initial diagnosis, while the median time to the loss of PR expression was 4.97 years, consistent with sequential decrease in ER dependence, resulting in loss of PR expression and increased dependence on other survival pathways. Genomic and transcriptomic profiling of all serially collected tissues with reconstruction of phylogenetic trees is ongoing and will be presented at the meeting. Conclusions: Compared to previously published reports, high proportion of patients in this cohort had their metastatic disease confirmed and subsequently followed by serial biopsies. In majority of patients, receptor status changes follow a predictable pattern starting with loss of PR expression, followed by complete loss of ER expression. Concomitant changes in the mutation status of both ER and other co-mutated genes, as well as any associated transcriptomic changes may shed light into new interdependencies and vulnerabilities associated with these dynamic receptor status changes.

Citation Format: Read K. Allen, Christopher J. Pinto, Donna M. Fitzgerald, Tiffany G. Huynh, Christopher T. Chen, Dejan Juric. Characterization of spatial and temporal heterogeneity of ER positive metastatic breast cancer using serial biopsies [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD8-08.

How Substitutional Point Defects in Two-Dimensional WS2 Induce Charge Localization, Spin-Orbit Splitting, and Strain

Control of impurity concentrations in semiconducting materials is essential to device technology. Because of their intrinsic confinement, the properties of two-dimensional semiconductors such as transition metal dichalcogenides (TMDs) are more sensitive to defects than traditional bulk materials. The technological adoption of TMDs is dependent on the mitigation of deleterious defects and guided incorporation of functional foreign atoms. The first step toward impurity control is the identification of defects and assessment of their electronic properties. Here, we present a comprehensive study of point defects in monolayer tungsten disulfide (WS₂) grown by chemical vapor deposition using scanning tunneling microscopy/spectroscopy, CO-tip noncontact atomic force microscopy, Kelvin probe force spectroscopy, density functional theory, and tight-binding calculations. We observe four different substitutional defects: chromium (Cr_W) and molybdenum (Mo_W) at a tungsten site, oxygen at sulfur sites in both top and bottom layers (O_S top/bottom), and two negatively charged defects (CD type I and CD type II). Their electronic fingerprints unambiguously corroborate the defect assignment and reveal the presence or absence of in-gap defect states. Cr_W forms three deep unoccupied defect states, two of which arise from spin-orbit splitting. The formation of such localized trap states for Cr_W differs from the Mo_W case and can be explained by their different d shell energetics and local strain, which we directly measured. Utilizing a tight-binding model the electronic spectra of the isolectronic substitutions O_S and Cr_W are mimicked in the limit of a zero hopping term and infinite on-site energy at a S and W site, respectively. The abundant CDs are negatively charged, which leads to a significant band bending around the defect and a local increase of the contact potential difference. In addition, CD-rich domains larger than 100 nm are observed, causing a work function increase of 1.1 V. While most defects are electronically isolated, we also observed hybrid states formed between Cr_W dimers. The important role of charge localization, spin-orbit coupling, and strain for the formation of deep defect states observed at substitutional defects in WS₂ as reported here will guide future efforts of targeted defect engineering and doping of TMDs.

Large Spin-Orbit Splitting of Deep In-Gap Defect States of Engineered Sulfur Vacancies in Monolayer WS_{2}

Structural defects in 2D materials offer an effective way to engineer new material functionalities beyond conventional doping. We report on the direct experimental correlation of the atomic and electronic structure of a sulfur vacancy in monolayer WS_{2} by a combination of CO-tip noncontact atomic force microscopy and scanning tunneling microscopy. Sulfur vacancies, which are absent in as-grown samples, were deliberately created by annealing in vacuum. Two energetically narrow unoccupied defect states followed by vibronic sidebands provide a unique fingerprint of this defect. Direct imaging of the defect orbitals, together with ab initio GW calculations, reveal that the large splitting of 252±4  meV between these defect states is induced by spin-orbit coupling.

Synthesis, characterization, kinetic drug release and anticancer activity of bisphosphonates multi-walled carbon nanotube conjugates

The statistical proof that most forms of cancer metastasize to bone tissue has redirected research focus to the development of efficient secondary bone cancer treatment regimens. Bisphosphonates (BPs) have been earmarked as a drug of choice for bone metastasis. However, they have a shortcoming of being released before reaching targeted sites due to their low molecular weight. In haste to attain increased efficacy, there is a tendency for drug overdose to occur, resulting in systemic toxicity. One way to curb this is by employing drug delivery systems for targeted and controlled release of the drugs. Having been explored as versatile and innovative drug carriers, multi-walled carbon nanotubes (MWCNTs) have emerged as potential drug delivery systems. Hence, in the present study, alendronate, neridronate and pamidronate are three classes of bisphosphonates that were conjugated onto multi-walled carbon nanotubes. Conjugation was confirmed by characterization techniques including SEM, TEM, EDX, FTIR, Raman and TGA. Drug release studies were also conducted at pH 1.2, 5.5 and 7.4 to study the mechanism of release for neridronate. Results obtained were fitted into Zero order (42.6%), Higuchi (26%) and Korsmeyer-Peppas (22%). The best models describing the release of neridronate from MWCNTs were Zero order, Higuchi and Korsmeyer-Peppas at pH 1.2, 5.5 and 7.4, respectively. A tetrazolium cell viability assay was performed to assess the anticancer activity of the MWCNTs conjugated BPs.

Superconductivity in a unique type of copper oxide

The mechanism of superconductivity in cuprates remains one of the big challenges of condensed matter physics. High-T c cuprates crystallize into a layered perovskite structure featuring copper oxygen octahedral coordination. Due to the Jahn Teller effect in combination with the strong static Coulomb interaction, the octahedra in high-T c cuprates are elongated along the c axis, leading to a 3dx 2-y 2 orbital at the top of the band structure wherein the doped holes reside. This scenario gives rise to 2D characteristics in high-T c cuprates that favor d-wave pairing symmetry. Here, we report superconductivity in a cuprate Ba2CuO4-y , wherein the local octahedron is in a very exceptional compressed version. The Ba2CuO4-y compound was synthesized at high pressure at high temperatures and shows bulk superconductivity with critical temperature (T c ) above 70 K at ambient conditions. This superconducting transition temperature is more than 30 K higher than the T c for the isostructural counterparts based on classical La2CuO4 X-ray absorption measurements indicate the heavily doped nature of the Ba2CuO4-y superconductor. In compressed octahedron, the 3d3z 2-r 2 orbital will be lifted above the 3dx 2-y 2 orbital, leading to significant 3D nature in addition to the conventional 3dx 2-y 2 orbital. This work sheds important light on advancing our comprehensive understanding of the superconducting mechanism of high T c in cuprate materials.

Effects of Defects on Band Structure and Excitons in WS2 Revealed by Nanoscale Photoemission Spectroscopy

Two-dimensional materials with engineered composition and structure will provide designer materials beyond conventional semiconductors. However, the potentials of defect engineering remain largely untapped, because it hinges on a precise understanding of electronic structure and excitonic properties, which are not yet predictable by theory alone. Here, we utilize correlative, nanoscale photoemission spectroscopy to visualize how local introduction of defects modifies electronic and excitonic properties of two-dimensional materials at the nanoscale. As a model system, we study chemical vapor deposition grown monolayer WS₂, a prototypical, direct gap, two-dimensional semiconductor. By cross-correlating nanoscale angle-resolved photoemission spectroscopy, core level spectroscopy, and photoluminescence, we unravel how local variations in defect density influence electronic structure, lateral band alignment, and excitonic phenomena in synthetic WS₂ monolayers.

Cancer is not a risk factor for bullous pemphigoid: 10-year population-based cohort study

BACKGROUND

Bullous pemphigoid (BP) is the most common autoimmune bullous disease. Whether there is an increased risk for subsequent BP among patients with cancer is still unclear.

OBJECTIVES

To evaluate the risk for subsequent BP in patients with cancer.

METHODS

This nationwide population-based cohort study was based on data obtained from the Taiwan National Health Insurance Database between 2000 and 2011. A total of 36 838 patients with cancer and 147 352 age-, sex- and index-date-matched controls were recruited. The hazard ratio (HR) of subsequent BP in the patients with cancer was analysed using a Fine-Gray competing risk regression model with mortality as the competing event.

RESULTS

The incidence of BP per 100 000 person-years was 17·2 in the patients with cancer and 19·8 in the controls; therefore, the crude incidence rate ratio was 0·87 [95% confidence interval (CI) 0·53-1·36]. The HR of subsequent BP in the patients with cancer was 0·47 (95% CI 0·23-0·94) using the Fine-Gray competing risk regression model. Age (HR 1·05, 95% CI 1·03-1·07), diabetes mellitus (HR 1·69, 95% CI 1·10-2·59) and cerebrovascular disease (HR 2·14, 95% CI 1·36-3·34) were independent risk factors for BP.

CONCLUSIONS

The incidence of BP in patients with cancer was not higher than in the control group. Cancer is not a risk factor for BP.

Efficacy, Safety, and Regulatory Approval of Food and Drug Administration–Designated Breakthrough and Nonbreakthrough Cancer Medicines

Purpose

The breakthrough therapy program was established in 2012 to expedite the development and review of new medicines. We evaluated the times to approval, efficacy, and safety of breakthrough-designated versus non–breakthrough-designated cancer drugs approved by the US Food and Drug Administration (FDA).

Methods

We studied all new cancer drugs approved by the FDA between January 2012 and December 2017. Regulatory and therapeutic characteristics (time to FDA approval, pivotal trial efficacy end point, novelty of mechanism of action) were compared between breakthrough-designated and non–breakthrough-designated cancer drugs. Random-effects meta-regression was used to assess the association between breakthrough therapy designation and hazard ratios for progression-free survival (PFS), response rates (RRs) for solid tumors, serious adverse events, and deaths not attributed to disease progression.

Results

Between 2012 and 2017, the FDA approved 58 new cancer drugs, 25 (43%) of which received breakthrough therapy designation. The median time to first FDA approval was 5.2 years for breakthrough-designated drugs versus 7.1 years for non–breakthrough-designated drugs (difference, 1.9 years; P = .01). There were no statistically significant differences between breakthrough-designated and non–breakthrough-designated drugs in median PFS gains (8.6 v 4.0 months; P = .11), hazard ratios for PFS (0.43 v 0.51; P = .28), or RRs for solid tumors (37% v 39%; P = .74). Breakthrough therapy–designated drugs were not more likely to act via a novel mechanism of action (36% v 39%; P = 1.00). Rates of deaths (6% v 4%; P = .99) and serious adverse events (38% v 36%; P = 0.93) were also similar in breakthrough-designated and non–breakthrough-designated drugs.

Conclusion

Breakthrough-designated cancer drugs were associated with faster times to approval, but there was no evidence that these drugs provide improvements in safety or novelty; nor was there a statistically significant efficacy advantage when compared with non–breakthrough-designated drugs.

A Biomechanical Analysis of Interference Screw Versus Bone Tunnel Fixation of Flexor Hallucis Longus Tendon Transfers to the Calcaneus

The flexor hallucis longus tendon transfer is commonly used to restore function in chronic Achilles tendon ruptures and chronic Achilles tendinopathy. The tendon is often secured to the calcaneus either through a bone tunnel or by an interference screw. We hypothesized that tenodesis using the bone tunnel method would be mechanically superior to interference screw fixation for flexor hallucis longus transfers. Eight matched pairs of cadaveric specimens were assigned randomly to the bone tunnel or interference screw technique and were loaded to failure. Biomechanical analysis was performed to evaluate the ultimate strength, peak stress, Young's modulus, failure strain, and strain energy. Unpaired comparison, paired comparison, and linear regression analyses were used to determine statistical significance. A slight 22% ± 9% decrease in Young's modulus and a 52% ± 18% increase of strain energy were found in the interference screw group. However, no differences in ultimate strength, peak stress, or failure strain were seen between the 2 groups on paired comparison. Our findings suggest that interference screw fixation provides similar spontaneous biomechanical properties to the use of a bone tunnel for flexor hallucis longus transfer to the calcaneus. The interference screw is a practical option for fixation of the flexor hallucis longus tendon to the calcaneus and can be performed through a single incision approach.

Coulomb Correlations Intertwined with Spin and Orbital Excitations in LaCoO_{3}

We carried out temperature-dependent (20-550 K) measurements of resonant inelastic x-ray scattering on LaCoO_{3} to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantified the renomalized crystal-field excitation energies and spin-state populations. We show that the screening of the effective on-site Coulomb interaction of 3d electrons is orbital selective and coupled to the spin-state crossover in LaCoO_{3}. The results establish that the gradual spin-state crossover is associated with a relative change of Coulomb energy versus bandwidth, leading to a Mott-type insulator-to-metal transition.

Reconstituting Mouse Lungs with Conditionally Reprogrammed Human Bronchial Epithelial Cells

We developed methods for conditionally reprogramming (CR) primary human bronchial epithelial cells (HBECs) to extend their functional lifespan and permit their differentiation into both upper and lower airway lung epithelium. We also developed a bioreactor to support vascular perfusion and rhythmic breathing of decellularized mouse lungs reconstituted with CR HBECs isolated from patients with and without cystic fibrosis (CF). While conditionally reprogrammed cells only differentiate into an upper airway epithelium after 35 days at the air-liquid interface, in reconstituted lungs these cells differentiate into upper airway bronchial epithelium and lower airway alveolar structures after 12 days. Rapid scale-up and the ability to obtain clonal derivatives of primary patient-derived HBECs without the need for genetic manipulation may permit rapid reconstitution of the lung epithelium; facilitating the study of lung disease in tissue-engineered models.

Neuropsychiatric symptoms in Alzheimer's disease: associations with caregiver burden and treatment outcomes

BACKGROUND

Caregivers play a major role in providing care for patients with Alzheimer's disease (AD) and are themselves at higher risk of health comorbidities.

AIM

To address the impact of neuropsychiatric symptoms of patients in different stages of AD on their caregivers' burden.

DESIGN

This prospective study enrolled 260 AD patients with clinical dementia rating (CDR) of 0.5, 1 and 2 at a tertiary medical center.

METHODS

All patients were tested using the mini-mental state examination (MMSE), the cognitive abilities screening instrument (CASI), the neuropsychiatric inventory (NPI) and the CDR scale. Data regarding therapeutic outcomes of anti-Alzheimer's drugs were also collected. Caregivers were tested using NPI.

RESULTS

The mean follow-up interval was 25.0 ± 12.2 months, and two patients died during follow-up. NPI-burden was positively correlated with NPI-sum ( r  = 0.822, P  <   0.001) but negatively correlated with years of education ( r  = -0.140, P  =   0.024), CASI score ( r  = -0.259, P  <   0.001) and MMSE score ( r  = -0.262, P  <0.001). Multiple linear regression analysis showed that only NPI-sum was independently associated with mean NPI-burden. Both higher mean CASI and MMSE scores had better therapeutic outcome of anti-Alzheimer's drugs ( P  =   0.001 and P =   0.005, respectively).

CONCLUSIONS

The severity of neuropsychiatric symptoms in patients with AD was positively associated with caregiver's stress, and patients with better cognitive functions, under treatment with anti-Alzheimer's drugs, had better therapeutic outcomes. To reduce the impact of neuropsychiatric symptoms, it is crucial to detect dementia in its early phases and provide early intervention with anti-Alzheimer's drugs, which might help decrease the caregiver burden, thereby improving their quality of life.

Medicare Spending for Breast, Prostate, Lung, and Colorectal Cancer Patients in the Year of Diagnosis and Year of Death

OBJECTIVE

To characterize spending patterns for Medicare patients with incident breast, prostate, lung, and colorectal cancer.

DATA SOURCES/STUDY SETTING/STUDY DESIGN

2007-2012 data from the Surveillance, Epidemiology, and End Results Program linked with Medicare fee-for-service claims.

DATA COLLECTION/EXTRACTION METHODS

We calculate per-patient monthly and yearly mean and median expenditures, by cancer type, stage at diagnosis, and spending category, over the years of diagnosis and death.

PRINCIPAL FINDINGS

Over the year of diagnosis, mean spending was $35,849, $26,295, $55,597, and $63,063 for breast, prostate, lung, and colorectal cancer, respectively. Over the year of death, spending was similar across different cancer types and stage at diagnosis.

CONCLUSIONS

Characterization of Medicare spending according to clinically meaningful categories may assist development of oncology alternative payment models and cost-effectiveness models.

Fabrication of Single Crystal Gallium Phosphide Thin Films on Glass

Due to its high refractive index and low absorption coefficient, gallium phosphide is an ideal material for photonic structures targeted at the visible wavelengths. However, these properties are only realized with high quality epitaxial growth, which limits substrate choice and thus possible photonic applications. In this work, we report the fabrication of single crystal gallium phosphide thin films on transparent glass substrates via transfer bonding. GaP thin films on Si (001) and (112) grown by MOCVD are bonded to glass, and then the growth substrate is removed with a XeF₂ vapor etch. The resulting GaP films have surface roughnesses below 1 nm RMS and exhibit room temperature band edge photoluminescence. Magnesium doping yielded p-type films with a carrier density of 1.6 × 10¹⁷ cm^-3 that exhibited mobilities as high as 16 cm²V^-1s^-1. Due to their unique optical properties, these films hold much promise for use in advanced optical devices.

Jahn-Teller distortion driven magnetic polarons in magnetite

The first known magnetic mineral, magnetite, has unusual properties, which have fascinated mankind for centuries; it undergoes the Verwey transition around 120 K with an abrupt change in structure and electrical conductivity. The mechanism of the Verwey transition, however, remains contentious. Here we use resonant inelastic X-ray scattering over a wide temperature range across the Verwey transition to identify and separate out the magnetic excitations derived from nominal Fe²⁺ and Fe³⁺ states. Comparison of the experimental results with crystal-field multiplet calculations shows that the spin–orbital dd excitons of the Fe²⁺ sites arise from a tetragonal Jahn-Teller active polaronic distortion of the Fe²⁺O₆ octahedra. These low-energy excitations, which get weakened for temperatures above 350 K but persist at least up to 550 K, are distinct from optical excitations and are best explained as magnetic polarons.

The Verwey transition of magnetite is complex due to the coexistence of strong correlations and electron-phonon coupling. Here, the authors use resonant inelastic X-ray scattering to show evidence for magnetic polarons in magnetite and provide insight into the nature of the transition.

Walk-in clinics versus physician offices and emergency rooms for urgent care and chronic disease management

BACKGROUND

Walk-in clinics are growing in popularity around the world as a substitute for traditional medical care delivered in physician offices and emergency rooms, but their clinical efficacy is unclear.

OBJECTIVES

To assess the quality of care and patient satisfaction of walk-in clinics compared to that of traditional physician offices and emergency rooms for people who present with basic medical complaints for either acute or chronic issues.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, six other databases, and two trials registers on 22 March 2016 together with reference checking, citation searching, and contact with study authors to identify additional studies. We applied no restrictions on language, publication type, or publication year.

SELECTION CRITERIA

Study design: randomized trials, non-randomized trials, and controlled before-after studies.

POPULATION

standalone physical clinics not requiring advance appointments or registration, that provided basic medical care without expectation of follow-up. Comparisons: traditional primary care practices or emergency rooms.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and the Cochrane Effective Practice and Organisation of Care (EPOC) Group.

MAIN RESULTS

The literature search identified 6587 citations, of which we considered 65 to be potentially relevant. We reviewed the abstracts of all 65 potentially relevant studies and retrieved the full texts of 12 articles thought to fit our study criteria. However, following independent author assessment of the full texts, we excluded all 12 articles.

AUTHORS' CONCLUSIONS

Controlled trial evidence about the mortality, morbidity, quality of care, and patient satisfaction of walk-in clinics is currently not available.

Adiponectin alters renal calcium and phosphate excretion through regulation of klotho expression

The kidney controls systemic calcium and phosphate levels and disturbances of its control mechanisms can lead to a variety of diseases. The insulin-sensitizing adipokine adiponectin is renoprotective and accelerates functional recovery following renal injury. However, unlike other adipokines, adiponectin is reduced in obesity. High adiponectin levels are also correlated with bone loss, suggestive of an additional action in mineral metabolism. Using knockout, wild-type, and adiponectin-overexpressing transgenic mice, we sought to identify the mechanistic basis for adiponectin's ability to regulate calcium and phosphate balance at the level of the kidney. Adiponectin knockout mice exhibited lower serum calcium, lower urinary calcium excretion, and markedly lower serum fibroblast growth factor 23 (FGF23) levels, although circulating klotho concentrations were significantly higher than in wild-type littermates. The transgenic mice exhibited lower bone mass and strength, particularly compared to adiponectin knockout mice. The transgenic mice were hyper-responsive to a 2% phosphate-enriched diet, exhibiting 2-fold higher serum FGF23 and concomitantly higher fractional phosphate excretion. These mice also excreted more calcium with calcium-enriched diet and had less renal klotho protein expression. In contrast, the knockout mice exhibited a smaller increase in FGF23 and maintained elevated klotho levels on both mineral challenges. Kidney-specific adiponectin expression in doxycycline-inducible adiponectin mice and adiponectin addition in vitro confirmed adiponectin's ability to reduce tubular epithelial cell klotho secretion. Thus, adiponectin alters calcium and phosphate balance and renal mineral excretion, in part, through klotho. This work highlights the profound effects of adipose tissue on renal function and has identified a new mechanism by which adiponectin may regulate bone mass.

Introduction to Cartilage

Cartilage is a supporting connective tissue that, together with the bone, forms the framework supporting the body as a whole. There are many distinct types of cartilage, which exhibit numerous similarities as well as differences. Among them, articular cartilage is the best known and the most studied type. Articular cartilage is the thin layer of connective tissue that covers the articulating ends of bones in synovial (diarthrodial) joints. It provides a smooth surface for joint movement and acts as a load-bearing medium that protects the bone and distributes stress. The intense interest in articular cartilage is motivated by the critical role its degradation plays in arthritis and related joint diseases, which are the number one cause of disability in humans. This chapter discusses the physical, chemical and cellular properties of cartilage that give the tissue its extraordinary load-bearing characteristics.

Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels

Resonant inelastic x-ray scattering is used to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO_{3}-LaNiO_{3}-3×(LaAlO_{3}), a system with exceptionally large polarization, as a model system. We find that heterostructuring generates only minor changes in the Ni 3d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This provides an explanation for the limited success of theoretical predictions based on tuning orbital energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.

Transforming healthcare delivery: Why and how accountable care organizations must evolve

Accountable care organizations (ACOs) have shown promise in reducing healthcare spending growth, but have proven to be financially unsustainable for many healthcare organizations. Even ACOs with shared savings have experienced overall losses because the shared savings bonuses have not covered the costs of delivering population health. As physicians and former ACO leaders, we believe in the concept of accountable care, but ACOs need to evolve if they are to have a viable future. We propose the novel possibility of allowing ACOs to bill fee-for-service for their population health interventions, a concept we call population health billing. Journal of Hospital Medicine 2016;11:658-661. © 2016 Society of Hospital Medicine.

Raman and fluorescence characteristics of resonant inelastic X-ray scattering from doped superconducting cuprates

Measurements of spin excitations are essential for an understanding of spin-mediated pairing for superconductivity; and resonant inelastic X-ray scattering (RIXS) provides a considerable opportunity to probe high-energy spin excitations. However, whether RIXS correctly measures the collective spin excitations of doped superconducting cuprates remains under debate. Here we demonstrate distinct Raman- and fluorescence-like RIXS excitations of Bi_1.5Pb_0.6Sr_1.54CaCu₂O_8+δ. Combining photon-energy and momentum dependent RIXS measurements with theoretical calculations using exact diagonalization provides conclusive evidence that the Raman-like RIXS excitations correspond to collective spin excitations, which are magnons in the undoped Mott insulators and evolve into paramagnons in doped superconducting compounds. In contrast, the fluorescence-like shifts are due primarily to the continuum of particle-hole excitations in the charge channel. Our results show that under the proper experimental conditions RIXS indeed can be used to probe paramagnons in doped high-T_c cuprate superconductors.

Topographical variations of the strain-dependent zonal properties of tibial articular cartilage by microscopic MRI

The topographical variations of the zonal properties of canine articular cartilage over the medial tibia were evaluated as the function of external loading by microscopic magnetic resonance imaging (µMRI). T2 and T1 relaxation maps and GAG (glycosaminoglycan) images from a total of 70 specimens were obtained with and without the mechanical loading at 17.6 µm depth resolution. In addition, mechanical modulus and water content were measured from the tissue. For the bulk without loading, the means of T2 at magic angle (43.6 ± 8.1 ms), absolute thickness (907.6 ± 187.9 µm) and water content (63.3 ± 9.3%) on the meniscus-covered area were significantly lower than the means of T2 at magic angle (51.1 ± 8.5 ms), absolute thickness (1251.6 ± 218.4 µm) and water content (73.2 ± 5.6%) on the meniscus-uncovered area. However GAG (86.0 ± 15.3 mg/ml) on the covered area was significantly higher than GAG (70.0 ± 8.8 mg/ml) on the uncovered area. Complex relationships were found in the tissue properties as the function of external loading. The tissue parameters in the superficial zone changed more profoundly than the same properties in the radial zone. The tissue parameters in the meniscus-covered areas changed differently when comparing with the same parameters in the uncovered areas. This project confirms that the load-induced changes in the molecular distribution and structure of cartilage are both depth-dependent and topographically distributed. Such detailed knowledge of the tibial layer could improve the early detection of the subtle softening of the cartilage that will eventually lead to the clinical diseases such as osteoarthritis.

Highly efficient beamline and spectrometer for inelastic soft X-ray scattering at high resolution

The design, construction and commissioning of a beamline and spectrometer for inelastic soft X-ray scattering at high resolution in a highly efficient system are presented. Based on the energy-compensation principle of grating dispersion, the design of the monochromator-spectrometer system greatly enhances the efficiency of measurement of inelastic soft X-rays scattering. Comprising two bendable gratings, the set-up effectively diminishes the defocus and coma aberrations. At commissioning, this system showed results of spin-flip, d-d and charge-transfer excitations of NiO. These results are consistent with published results but exhibit improved spectral resolution and increased efficiency of measurement. The best energy resolution of the set-up in terms of full width at half-maximum is 108 meV at an incident photon energy tuned about the Ni L3-edge.

Hypovitaminosis D and Cervical Disk Herniation among Adults Undergoing Spine Surgery

Study Design Single-center, retrospective study. Objective Suboptimal concentrations of vitamin D have been linked to hip and knee osteoarthritis in large, population-based cohort studies. We sought to examine the association of vitamin D levels with intervertebral disk disease. Methods From January 2010 through May 2011, 91 consecutive, eligible adult spine surgery patients who had undergone cervical magnetic resonance imaging (MRI) and preoperative serum 25-hydroxyvitamin D (s25D) measurement were retrospectively included. MRI was read for C2-T1 disk herniation and degeneration (grades I to V). Logistic regressions were performed. Results Compared with the 384 disks of nondeficient patients, 162 disks of vitamin D-deficient (< 20 ng/mL) patients were more frequently herniated (40% versus 27%, p = 0.004); deficiency was not predictive of individual disk grade (unadjusted odds ratio [uOR] = 0.98, p = 0.817). On regression analysis, deficiency was associated with increased number of herniations per patient (uOR = 2.17, 95% confidence interval [CI] = 1.22 to 3.87, p = 0.009; adjusted odds ratio [aOR] = 2.12, 95% CI = 1.11 to 4.03, p = 0.023). When disks were analyzed individually, and levels (e.g., C5 to C6), additionally controlled for, deficiency correlated with greater likelihood of herniation per disk (uOR = 1.81, 95% CI = 1.22 to 2.66, p = 0.003; aOR = 2.06, 95% CI = 1.25 to 3.41, p = 0.005). Conclusion Among adults undergoing spine surgery at our institution, vitamin D deficiency was associated with cervical disk herniation. Considering the current epidemics of vitamin D insufficiency and neck pain, further investigation is warranted, as these data were retrospectively collected and subject to sampling bias.

Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s^-1·MBq^-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging ^99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using ^99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

Development of a Semiselective Medium for Detection of Nalanthamala psidii, Causal Agent of Wilt of Guava

Guava wilt, caused by Nalanthamala psidii, has become an important disease of guava (Psidium guajava) in Taiwan since the 1970s. This study was conducted to develop a semiselective medium for detecting N. psidii in soil and in tissues of diseased guava trees. Among 9 carbon and 21 nitrogen compounds tested in a modified Czapek-Dox medium, the most effective carbon and nitrogen sources for mycelial growth of N. psidii were sucrose and glycine, respectively. Among eight fungicides tested, iprodione at 5 μg ml^-1 and azoxystrobin at 1 μg ml^-1 were the most effective fungicides for detection of N. psidii in artificially infested soil or in naturally infected guava debris. Based on the requirement for carbon and nitrogen sources and response to fungicides, a semiselective medium designated as modified sucrose-glycine semiselective medium (mSGSSM) was developed for isolation of N. psidii, using the modified Czapek-Dox medium containing 3% sucrose, 0.3% glycine, iprodione at 5 μg ml^-1, azoxystrobin at 1 μg ml^-1, streptomycin at 200 μg ml^-1, and neomycin at 200 μg ml^-1. Colonies of N. psidii on mSGSSM at 30°C for 5 to 10 days were white to orange with sparse aerial hyphae. N. psidii was detected more accurately and efficiently on mSGSSM than on other media, including potato dextrose agar, modified Nash-Snyder medium, and modified Czapek-Dox medium. This semiselective medium is effective in detection of N. psidii from various parts of diseased guava trees and in soil; therefore, it would be a useful medium for etiological, ecological, and epidemiological studies of guava wilt.

Flexible, transparent contacts for inorganic nanostructures and thin films

A transparent, flexible contact is developed using Ni nanoparticles and Ag nanowires and demonstrated on free-standing, polymer embedded, Si microwire solar cells. Contact yields of over 99% and a series resistance of 14 Ω cm² are demonstrated.

Ferromagnetic interfacial interaction and the proximity effect in a Co2FeAl/(Ga,Mn)As bilayer

The magnetic properties of a Co2FeAl/(Ga,Mn)As bilayer epitaxied on GaAs (001) are studied both experimentally and theoretically. Unlike the common antiferromagnetic interfacial interaction existing in most ferromagnet-magnetic semiconductor bilayers, a ferromagnetic interfacial interaction in the Co2FeAl/(Ga,Mn)As bilayer is observed from measurements of magnetic hysteresis and x-ray magnetic circular dichroism. The Mn ions in a 1.36 nm thick (Ga,Mn)As layer remain spin polarized up to 400 K due to the magnetic proximity effect. The minor loops of the Co2FeAl/(Ga,Mn)As bilayer shift with a small ferromagnetic interaction field of +24 Oe and -23 Oe at 15 K. The observed ferromagnetic interfacial coupling is supported by ab initio density functional calculations. These findings may provide a viable pathway for designing room-temperature semiconductor spintronic devices through magnetic proximity effect.

Orthorhombic BiFeO3

A new orthorhombic phase of the multiferroic BiFeO3 has been created via strain engineering by growing it on a NdScO(3)(110)(o) substrate. The tensile-strained orthorhombic BiFeO3 phase is ferroelectric and antiferromagnetic at room temperature. A combination of nonlinear optical second harmonic generation and piezoresponse force microscopy revealed that the ferroelectric polarization in the orthorhombic phase is along the in-plane {110}(pc) directions. In addition, the corresponding rotation of the antiferromagnetic axis in this new phase was observed using x-ray linear dichroism.

Differential time dependency of antiproliferative and apoptotic effects of taxol in human prostate tumors

The pharmacodynamics of taxol in human prostate tumors were studied using histocultures of radical prostatectomy specimens from 34 patients. The results showed that taxol inhibited DNA synthesis and induced apoptosis in all tumors. The taxol-induced DNA inhibition and the apoptotic index increased with drug concentration, but reached a maximal plateau level at a concentration between 120 and 1,200 nM. Increasing the concentration by 10- to 100-fold to 12,000 nM did not significantly increase either effect. To address the existing controversy regarding the effect of treatment duration on cytotoxicity, we evaluated two treatment schedules, (i.e., 24 and 96 hours). Prolonging the treatment time from 24 to 96 hours significantly increased the average maximal inhibition of DNA synthesis (E(max)) from 47% to 70% (p < 0.001) and reduced the incidence of relatively resistant tumors (E(max) < 30%) from 31% to 0% (p = 0.04). By contrast, the prolonged treatment time did not increase the apoptotic effect (p = 0.48). The inter-tumor variation in sensitivity to the antiproliferative effect was substantial; the drug concentration required to produce a 30% DNA inhibition (IC(30)) showed a >300,000- and a 14,000-fold range for the 24 and 96 hour treatments, respectively. In conclusion, data of the present study demonstrate (1) antiproliferative and apoptotic effects of taxol in human prostate tumors, (2) that neither effect was significantly enhanced by increasing the drug concentration above 1,200 nM, and (3) that the antiproliferative effect was affected more significantly by drug exposure time than the apoptotic effect.

First imaging result with an ultrahigh resolution stationary MR compatible SPECT system

In this paper, we will present the design and preliminary performance of an ultrahigh resolution stationary MR compatible SPECT (MRC-SPECT) system that is developed in our lab. The MRC-SPECT system is based on the second-generation energy-resolved photon-counting (ERPC) CdTe detectors and there are several key features associated with this system. Firstly, up to a total of twenty ERPC detectors will be assembled as a very compact ring, which provides an adequate angular sampling capability and a relatively high detection efficiency. The detectors are supported on a gantry made of high strength polyamide structure constructed using 3-D printing. This compact system can be directly operated inside an MR scanner. The detector module used in this system offers an intrinsic resolution of 350μm and an excellent energy resolution of around 3~4kev. Each ERPC detector module consists of four pixelated CdTe detectors with a total dimension of 4.5cm×2.25cm. Secondly, a die-cast platinum pinhole inserts and cast lead apertures are developed for this stationary SPECT system. Four 300/500μm diameter pinholes are used for each detector and all pinholes are mounted around a casted cylinder lead aperture tube. The inner diameter of the lead aperture tube is 6cm and the lead tube thickness is 16mm. The opposite detectors are placed 15.6cm apart and the magnification factor of this SPECT system is about 1.2. Thirdly, a comprehensive charge collection model inside strong magnetic field has been developed to account for the magnetic field induced distortion in the SPECT image. This model can accurately predict the detector's energy and spatial response to gamma ray incident events and then help to compensate for the event position recording error due to the strong magnetic field. In this development, we have made an effort to minimize the amount of magnetic materials in the system to alleviate potential interference to magnetic field inhomogeneity.

Failed healing of rotator cuff repair correlates with altered collagenase and gelatinase in supraspinatus and subscapularis tendons

BACKGROUND

Despite improvements in arthroscopic rotator cuff repair technique and technology, a significant rate of failed tendon healing persists. Improving the biology of rotator cuff repairs may be an important focus to decrease this failure rate. The objective of this study was to determine the mRNA biomarkers and histological characteristics of repaired rotator cuffs that healed or developed persistent defects as determined by postoperative ultrasound.

HYPOTHESIS

Increased synovial inflammation and tendon degeneration at the time of surgery are correlated with the failed healing of rotator cuff tendons.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Biopsy specimens from the subscapularis tendon, supraspinatus tendon, glenohumeral synovium, and subacromial bursa of 35 patients undergoing arthroscopic rotator cuff repair were taken at the time of surgery. Expression of proinflammatory cytokines, tissue remodeling genes, and angiogenesis factors was evaluated by quantitative real-time polymerase chain reaction. Histological characteristics of the affected tissue were also assessed. Postoperative (>6 months) ultrasound was used to evaluate the healing of the rotator cuff. General linear modeling with selected mRNA biomarkers was used to predict rotator cuff healing.

RESULTS

Thirty patients completed all analyses, of which 7 patients (23%) had failed healing of the rotator cuff. No differences in demographic data were found between the defect and healed groups. American Shoulder and Elbow Surgeons shoulder scores collected at baseline and follow-up showed improvement in both groups, but there was no significant difference between groups. Increased expression of matrix metalloproteinase 1 (MMP-1) and MMP-9 was found in the supraspinatus tendon in the defect group versus the healed group (P = .006 and .02, respectively). Similar upregulation of MMP-9 was also found in the subscapularis tendon of the defect group (P = .001), which was consistent with the loss of collagen organization as determined by histological examination. From a general linear model, the upregulation of MMP-1 and MMP-9 was highly correlated with failed healing of the rotator cuff (R(2) = .656).

CONCLUSION

The upregulation of tissue remodeling genes in the torn rotator cuff at the time of surgery provides a snapshot of the biological environment surrounding the torn rotator cuff that is closely related to the healing of repaired rotator cuffs.