The HSP90 inhibitor HVH-2930 exhibits potent efficacy against trastuzumab-resistant HER2-positive breast cancer

Rationale: Resistance to targeted therapies like trastuzumab remains a critical challenge for HER2-positive breast cancer patients. Despite the progress of several N-terminal HSP90 inhibitors in clinical trials, none have achieved approval for clinical use, primarily due to issues such as induction of the heat shock response (HSR), off-target effects, and unfavorable toxicity profiles. We sought to examine the effects of HVH-2930, a novel C-terminal HSP90 inhibitor, in overcoming trastuzumab resistance. Methods: The effect of HVH-2930 on trastuzumab-sensitive and -resistant cell lines in vitro was evaluated in terms of cell viability, expression of HSP90 client proteins, and impact on cancer stem cells. An in vivo model with trastuzumab-resistant JIMT-1 cells was used to examine the efficacy and toxicity of HVH-2930. Results: HVH-2930 was rationally designed to fit into the ATP-binding pocket interface cavity of the hHSP90 homodimer in the C-terminal domain of HSP90, stabilizing its open conformation and hindering ATP binding. HVH-2930 induces apoptosis without inducing the HSR but by specifically suppressing the HER2 signaling pathway. This occurs with the downregulation of HER2/p95HER2 and disruption of HER2 family member heterodimerization. Attenuation of cancer stem cell (CSC)-like properties was associated with the downregulation of stemness factors such as ALDH1, CD44, Nanog and Oct4. Furthermore, HVH-2930 administration inhibited angiogenesis and tumor growth in trastuzumab-resistant xenograft mice. A synergistic effect was observed when combining HVH-2930 and paclitaxel in JIMT-1 xenografts. Conclusion: Our findings highlight the potent efficacy of HVH-2930 in overcoming trastuzumab resistance in HER2-positive breast cancer. Further investigation is warranted to fully establish its therapeutic potential.

Transient myocardial thickening after routine ovariohysterectomy in a 15-month-old Ragdoll cat

A 15-month-old female Ragdoll cat was evaluated for progressive lethargy, tachypnoea and increased respiratory effort for 1 week after routine ovariohysterectomy. Thoracic radiographs and an echocardiogram showed evidence of congestive heart failure and a hypertrophic cardiomyopathy phenotype, respectively. The maximum left ventricular wall thickness in end diastole was 6.2 mm. The serum cardiac troponin I concentration was 20.86 ng/mL. The cat was treated with furosemide and clopidogrel and discharged after 3 days. A repeat echocardiogram 2 weeks later showed complete resolution of the hypertrophic cardiomyopathy phenotype (maximum left ventricular wall thickness: 5.0 mm). A repeat cardiac troponin I concentration was 0.041 ng/mL. All cardiac medications were discontinued. A final recheck 4 weeks later revealed stable normal echocardiogram and further reduction in cardiac troponin I concentration to 0.004 ng/mL. This case report demonstrates that resolution of transient myocardial thickening can take 2 weeks after the echocardiographic diagnosis of left ventricular thickening.

Suppression of TNBC metastasis by doxazosin, a novel dual inhibitor of c-MET/EGFR

BACKGROUND

Triple-negative breast cancer (TNBC) is characterized by aggressive growth and a high propensity for recurrence and metastasis. Simultaneous overexpression of c-MET and EGFR in TNBC is associated with worse clinicopathological features and unfavorable outcomes. Although the development of new c-MET inhibitors and the emergence of 3rd-generation EGFR inhibitors represent promising treatment options, the high costs involved limit the accessibility of these drugs. In the present study, we sought to investigate the therapeutic potential of doxazosin (DOXA), a generic drug for benign prostate hyperplasia, in targeting TNBC.

METHODS

The effect of DOXA on TNBC cell lines in vitro was evaluated in terms of cell viability, apoptosis, c-MET/EGFR signaling pathway, molecular docking studies and impact on cancer stem cell (CSC)-like properties. An in vivo metastatic model with CSCs was used to evaluate the efficacy of DOXA.

RESULTS

DOXA exhibits notable anti-proliferative effects on TNBC cells by inducing apoptosis via caspase activation. Molecular docking studies revealed the direct interaction of DOXA with the tyrosine kinase domains of c-MET and EGFR. Consequently, DOXA disrupts important survival pathways including AKT, MEK/ERK, and JAK/STAT3, while suppressing CSC-like characteristics including CD44high/CD24low subpopulations, aldehyde dehydrogenase 1 (ALDH1) activity and formation of mammospheres. DOXA administration was found to suppress tumor growth, intra- and peri-tumoral angiogenesis and distant metastasis in an orthotopic allograft model with CSC-enriched populations. Furthermore, no toxic effects of DOXA were observed in hepatic or renal function.

CONCLUSIONS

Our findings highlight the potential of DOXA as a therapeutic option for metastatic TNBC, warranting further investigation.

Passivation effect on Cd0.95Mn0.05Te0.98Se0.02 radiation detection performance

CdTe-based detectors have the problem of Te-rich surface layers caused by Br etching, which is one of fabrication steps. Te-rich layer acts as a trapping center and serves as an additional source of charge carriers, thereby degrading transport property of charge carriers and enriching leakage current on surface of detector. To solve this problem, we introduced sodium hypochlorite (NaOCl) as a passivant, and investigated its effect on Cd0.95Mn0.05Te0.98Se0.02 (CMTS), by analyzing chemical state of surface and its performance. After passivation with NaOCl, the results of X-ray photoelectron spectroscopy (XPS) shows the formation of tellurium oxide and elimination of water on CMTS surface, and CMTS presented enhanced performance with Am-241 radioisotope. Consequently, it is demonstrated that the passivation with NaOCl reduces leakage current, compensates defect, and elevates transport of charge carriers, thereby decreasing charge loss of carriers and improving performance of CMTS detector.

Deep compression network for enhancing numerical reconstruction quality of full-complex holograms

The field of digital holography has been significant developed in recent decades, however, the commercialization of digital holograms is still hindered by the issue of large data sizes. Due to the complex signal characteristics of digital holograms, which are of interferometric nature, traditional codecs are not able to provide satisfactory coding efficiency. Furthermore, in a typical coding scenario, the hologram is encoded and then decoded, leading to a numerical reconstruction via a light wave propagation model. While previous researches have mainly focused on the quality of the decoded hologram, it is the numerical reconstruction that is visible to the viewer, and thus, its quality must also be taken into consideration when designing a coding solution. In this study, the coding performances of existing compression standards, JPEG2000 and HEVC-Intra, are evaluated on a set of digital holograms, then the limitations of these standards are analyzed. Subsequently, we propose a deep learning-based compression network for full-complex holograms that demonstrates superior coding performance when compared to the latest standard codecs such as VVC and JPEG-XL, in addition to JPEG2000 and HEVC. The proposed network incorporates not only the quality of the decoded hologram, but also the quality of the numerical reconstruction as distortion costs for network training. The experimental results validate that the proposed network provides superior objective coding efficiency and better visual quality compared to the existing methods.

Ebastine impairs metastatic spread in triple-negative breast cancer by targeting focal adhesion kinase

We sought to investigate the utility of ebastine (EBA), a second-generation antihistamine with potent anti-metastatic properties, in the context of breast cancer stem cell (BCSC)-suppression in triple-negative breast cancer (TNBC). EBA binds to the tyrosine kinase domain of focal adhesion kinase (FAK), blocking phosphorylation at the Y397 and Y576/577 residues. FAK-mediated JAK2/STAT3 and MEK/ERK signaling was attenuated after EBA challenge in vitro and in vivo. EBA treatment induced apoptosis and a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f, suggesting that EBA targets BCSC-like cell populations while reducing tumor bulk. EBA administration significantly impeded BCSC-enriched tumor burden, angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Our findings suggest that EBA may represent an effective therapeutic for the simultaneous targeting of JAK2/STAT3 and MEK/ERK for the treatment of molecularly heterogeneous TNBC with divergent profiles. Further investigation of EBA as an anti-metastatic agent for the treatment of TNBC is warranted.

Abstract 4037: Doxazosin exerts anti-metastatic potential in triple-negative breast cancer via impairment of cancer stem-like features

Background and Purpose: Triple-negative breast cancer (TNBC) tumors typically harbor a high cancer stem-like population leading to chemo-resistance, recurrence, and metastasis. Tumor metastasis is associated with 90% of cancer-related deaths, highlighting the urgent clinical unmet need. Doxazosin is known to inhibit cell migration and invasion in several cancer cell types; however, the precise mechanisms underlying doxazosin’s anticancer effects in TNBC have not been fully elucidated. In the present study, we sought to investigate the mechanism of action of doxazosin responsible for its effects on apoptosis, cancer stem cell (CSC)-like properties, cell migration, and metastasis in TNBC.

Experimental designs: Doxazosin on TNBC cell lines [MDA-MB-231, BT549, and 4T1] in vitro was evaluated in cell viability, apoptosis, cell migration, CD44/CD24 staining, ALDH1 activity, and mammosphere formation. The effect of doxazosin on tumor growth, angiogenesis, and metastasis was evaluated in an orthotopic allograft mice model with CSC-enriched population.

Results: Doxazosin significantly reduced cell viability and induced apoptosis in MDA-MB-231 and BT549 cells via activation of caspase-3/-7 and cleavage of PARP. Doxazosin significantly suppressed cell migratory capability, concomitant with disrupting cytoskeletal proteins, including vimentin and F-actin expression in TNBC cells. An impairment of BCSC-like properties was associated with reduction of ALDH1 activity and the CD44+/CD24- population, concomitant with suppression of mammosphere-forming ability. Doxazosin administration reduced tumor growth and lung metastasis, as evidenced by a sharp decline in bioluminescence signal intensity. Inhibitory effect of tumor growth was accompanied by a significant decrease of Ki-67 and enhancement of apoptosis with DNA fragmentation and increased cleaved-caspase-3 expression. The latter phenomenon was associated with the impediment of JAK2/STAT3 signaling pathway and CSC-like properties. Furthermore, no toxic effects of doxazosin were found in liver and kidney function in animals.

Conclusion: Taken together, our findings highlight doxazosin as a promising candidate for drug repurposing in suppressing metastatic TNBC.

Citation Format: Seongjae Kim, Dongmi Ko, Juyeon Seo, Soeun Park, Minsu Park, Kee Dal Nam, Yong koo Kang, So Ra Seock, Jaeyoun Park, Eunhye Oh, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. Doxazosin exerts anti-metastatic potential in triple-negative breast cancer via impairment of cancer stem-like features. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4037.

Abstract 423: β-Escin eradicates cancer stem-like population in HER2-positive breast cancer with trastuzumab resistance

Purpose: Trastuzumab resistance is a multifactorial phenomenon arising from the steric effects of p95HER2, activation of HER2 downstream signaling pathways, and the existence of cancer stem cells. We sought to examine the capacity of β-escin, an anti-inflammatory drug, to address trastuzumab resistance in HER2-positive breast cancer cells.

Experimental designs: The effects of β-escin in trastuzumab-sensitive and -resistant cell lines were evaluated for apoptosis, HER2 expression, calpain activation and CSC-like properties. In vivo trastuzumab-resistant xenograft mice model was used to examine tumor growth, angiogenesis and organ toxicity of β-escin.

Results: β-escin induced mitochondrial-mediated apoptosis accompanied by reactive oxygen species (ROS) production and increased active p18Bax fragmentation, leading to caspase-3/-7 activation. β-escin downregulated p95HER2, HER2 and HER3 as well as their phosphorylation. β-escin-induced HER2 degradation appears to be mediated by calpain activation. We observed that treatment with β-escin induced cleavage of HER2 and p95HER2 (at 75, 50 and 42 kDa fragments) in HER2 overexpressing MDA-MB-231 cells. Attenuation of CSC-related features by β-escin challenge was accompanied by marked reductions in CD44high/CD24low stem-like cells and aldehyde dehydrogenase 1 (ALDH1) activity as well as hindrance of mammosphere formation. β-escin administration also significantly retarded tumor growth and angiogenesis in a trastuzumab-resistant JIMT-1 xenograft model via downregulation of CSC-associated markers and intracellular domain HER2. Importantly, β-escin selectively inhibited malignant cells and was less toxic to normal mammary cells, and no toxic effects were found in liver and kidney function in animals.

Conclusion: Herein, for the first time, we report the potent efficacy of β-escin, a drug repurposing candidate with an exceptional safety profile in addressing trastuzumab-resistant HER2-positive breast cancer.

Citation Format: Soeun Park, Minsu Park, Dongmi Ko, Seongjae Kim, Juyeon Seo, Kee Dal Nam, Eunsun Jung, Yong koo Kang, Seojin Jang, So Ra Seock, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo, Jaeyoun Park. β-Escin eradicates cancer stem-like population in HER2-positive breast cancer with trastuzumab resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 423.

Abstract 5805: Ebastine targets cancer stem cell-like properties and metastasis in triple-negative breast cancer by binding focal adhesion kinase

Triple-negative breast cancer (TNBC) exhibits an aggressive behavior associated with poor prognosis due to the absence of established molecular targets. Focal adhesion kinase (FAK) is a major determinant and participates in the acquisition of migration and invasion, as well as the maintenance of breast cancer stem cell (BCSC)-like traits in TNBC. We sought to investigate the effect of ebastine, a second-generation antihistamine on apoptosis, FAK activation, BCSC subpopulations and metastasis in TNBC in vitro and in vivo. TCGA dataset analysis revealed that mRNA levels of FAK were highly expressed in TNBC compared to other breast cancer subtypes. We found that ebastine binds to the tyrosine kinase domain of FAK, which blocks phosphorylation at the Y397 and Y576/577 residues and subsequent inactivation of SRC. Ebastine-induced apoptosis was associated with attenuation of JAK2/STAT3 and MEK/ERK signaling in TNBC cells. Kinetic analysis revealed a concentration-dependent impairment of cell migration in the presence of ebastine in MDA-MB-231 and 4T1 cells in vitro. Ebastine targets BCSC-like cell populations as evidenced by a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f and suppression of mammosphere-forming capacity. Ebastine administration led to a significant reduction in the growth ebastine of BCSC-enriched 4T1 mammospheres orthotopically injected into the mammary glands of Balb/c mice. Ebastine administration significantly impeded angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Importantly, biochemical analysis in mice serum showed that ebastine had no effect on liver and kidney function. Our findings suggest that EBA may be an effective therapeutic repositioning candidate for the simultaneous targeting of multiple survival signaling pathways for the treatment of molecularly heterogeneous TNBC. Further investigation of ebastine as an anti-metastatic agent for the treatment of TNBC is warranted.

Citation Format: Juyeon Seo, Minsu Park, Dongmi Ko, Seongjae Kim, Soeun Park, Kee Dal Nam, Yong Koo Kang, So Ra Seuk, Jaeyoun Park, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. Ebastine targets cancer stem cell-like properties and metastasis in triple-negative breast cancer by binding focal adhesion kinase. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5805.

Abstract 5800: Anti-metastatic potential of pitavastatin in triple-negative breast cancer via targeting breast cancer stem-like properties and STAT3 signaling

Triple-negative breast cancer (TNBC) is the most deadly and aggressive phenotype, with a higher rate of metastatic recurrence. TNBC does yet have a suitable treatment option other than cytotoxic anticancer drugs. Although pitavastatin has been shown to exert anti-proliferative effects and cytotoxicity in various types of cancer cells, the precise mechanisms underlying pitavastatin’s anti-cancer effects in TNBC have not been fully elucidated. We sought to investigate the mechanism of pitavastatin-induced apoptosis and its effects on cancer stem cell (CSC)-like characteristics in TNBC. Exposure to pitavastatin induced mitochondria-mediated apoptotic cell death in BT549 and 4T1 cells. Mitochondrial dysfunction was accompanied with a robust production of reactive oxygen species (ROS) and collapse of mitochondrial membrane potential (MMP), resulting in subsequent activation of caspase-3/-7 and PARP cleavage. Pitavastatin effectively suppressed CSC-like properties in TNBC via targeting CD44+/CD24- and CD49f+/CD24- phenotypes, as well as impediment of mammosphere formation in vitro. This phenomenon was accompanied with dysregulation of STAT3 survival pathway, concomitant with significant downregulation of cyclin D1, survivin and vimentin. Pitavastatin effectively targets both the proliferating TNBC tumor cells and CSCs via the dysregulation of STAT3 and suppression of CSC-like properties, markedly reducing angiogenesis and tumor growth, coinciding with decreased Ki-67 expression. It is noteworthy that pitavastatin considerably suppressed metastasis, coinciding with significant reduction of MMP-2, MMP-9 and VEGF in the circulating blood of mice. Our findings highlight that pitavastatin may be potentially effective for the treatment of metastatic TNBC.

Citation Format: Dongmi Ko, Juyeon Seo, Seongjae Kim, Soeun Park, Minsu Park, Kee Dal Nam, Yong koo Kang, Sora Seock, Eunsun Jung, Yoon-Jae Kim, Jaeyoun Park, Ji Young Kim, Jae Hong Seo. Anti-metastatic potential of pitavastatin in triple-negative breast cancer via targeting breast cancer stem-like properties and STAT3 signaling. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5800.

Abstract 6121: UCP2 inhibitor eradicates cancer stem-like population in trastuzumab-resistant HER2-positive breast cancer

Purpose: Uncoupling protein 2 (UCP2) is a member of the mitochondrial anion carrier protein family that plays an important role in stabilizing the inner mitochondrial membrane potential (MMP, ΔΨm) and controlling reactive oxygen species (ROS) production. A selective UCP2 inhibitor, genipin is known to elicit cytotoxicity in several cancers, however, its effects on cancer stem cells (CSCs)-like properties and trastuzumab resistance in HER2-positive breast cancer cells have not been fully elucidated. In the present study, we sought to investigate the mechanism of action of genipin responsible for the induction of apoptosis and its effects on CSC-like features, expression of HER family member and trastuzumab resistance in HER2-positive breast cancer cells in vitro and in vivo.

Experimental Designs: The effects of genipin on trastuzuamb-sensitive [BT474 and SKBR3] and trastuzumab-resistant [JIMT-1 and MDA-MB-453] HER2-positive breast cancer cell lines in vitro were evaluated for cell viability, Sub-G1, ROS, MMP, ALDH1 activity, CD44+/CD24- subpopulation and mammosphere formation. To confirm the physiological relevance of our in vitro observations, we explored the impact of genipin on tumor growth and angiogenesis and expression of p95HER2 and ALDH1A1 in trastuzumab-resistant xenograft model in vivo.

Results: HER2-positive breast cancer cells harbored a higher level of UCP2, when compared to their counterparts. Genipin significantly downregulated UCP2 and mitochondrial dysfunction coinciding with increased ROS generation and disruption of MMP. These phenomena were accompanied with upregulation of the Bax/Bcl-2 ratio and activation of caspase-3 and caspase-7. Genipin treatment led to significant reduction in levels of truncated p95HER2, p-HER2, p-HER3 and p-Akt levels in both trastuzumab-sensitive and -resistant lines. Marked decline of CD44 and ALDH1A1 expression by genipin treatment was associated with attenuation of mammosphere-forming ability. UCP2 level is predominantly upregulated in CSC-enriched populations, while its knockdown significantly suppressed CSC-like characteristics concomitant with decreased ALDH1A1 and CD44 expression as well as impairment of ALDH1 activity. Genipin administration significantly retarded tumor growth and angiogenesis in trastuzumab-resistant JIMT-1 xenograft tumors. The antitumor effect occurred concomitantly with a decrease in Ki-67 proliferating index and enhancement of apoptosis. Furthermore, individuals receiving genipin exhibited markedly lower levels of p95HER2, full-length p185HER2, CD44 and ALDH1A1 expression compared to their control counterparts.

Conclusion: To our knowledge, our findings are the first reported instance of genipin-induced suppression of CSC-like properties and HER2/HER3/Akt axis, implying that genipin treatment may have application in addressing trastuzumab resistance.

Citation Format: Minsu Park, Soeun Park, Juyeon Seo, Dongmi Ko, Seongjae Kim, Yong Koo Kang, Kee Dal Nam, So Ra Seuk, Tae-Min Cho, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. UCP2 inhibitor eradicates cancer stem-like population in trastuzumab-resistant HER2-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6121.

Development and evaluation of photon-counting Cd0.875Zn0.125Te0.98Se0.02 detector for measuring bone mineral density

Cadmium zinc telluride (CZT) has been actively researched and developed by researchers in various fields. In medical applications, especially photon-counting, CZT enables improved image quality, multi-material decomposition, and improved dose efficiency. Moreover, band gap engineering and selenium addition on CZT improved electrical, spectroscopic and structural properties, thereby supporting performance of CZT as a photon-counting detector. In this study, it is shown that Cd_0.875Zn_0.125Te_0.98Se_0.02 (CZTS) shows sufficient performance without loss of detection efficiency. We carried out a study involving the application of this CZTS on calculating bone mineral density (BMD) values, because this application has a novelty of new material for BMD sensor which follows the CdTe- or CdZnTe- based BMD detector. Anatomical images from different energy bins contained different information of attenuation although the images were taken in the same region at the same time. Moreover, calculated BMD values had a proper tendency depending on the amount of bone in that region. The final BMD value was 1.1972 g/cm², which is close to the real value of 1.2 g/cm². The introduction with a bone filter and a smaller pixel size will improve the accuracy and precision of photon-counting CZTS detectors for measuring BMD values. However, in this study the CZTS showed the feasibility that a photon-counting CZTS detector can help the measurement of BMD values and the diagnosis of osteoporosis.

Thin and hypokinetic myocardial segments in cats with cardiomyopathy

INTRODUCTION/OBJECTIVES

Thin and hypokinetic myocardial segments (THyMS) represent adverse ventricular (LV) remodeling in human hypertrophic cardiomyopathy. We describe the echocardiographic features and outcome in cats with THyMS, and in a subpopulation, the echocardiographic phenotype before LV wall thinning was detected (pre-THyMS).

ANIMALS

Eighty client-owned cats.

MATERIALS AND METHODS

Retrospective multicenter study. Clinical records were searched for cats with THyMS, defined as LV segment(s) with end-diastolic wall thickness (LVWT) <3 mm and hypokinesis in the presence of ≥one LV segment(s) with LVWT >4 mm and normal wall motion. When available, echocardiograms pre-THyMS were assessed. Survival time was defined as time from first presentation with THyMS to death.

RESULTS

Mean thickest LV wall segment (MaxLVWT) was 6.1 mm (95% CI 5.8-6.4 mm) and thinnest (MinLVWT) was 1.7 mm (95% CI 1.6-1.9 mm). The LV free wall was affected in 74%, apex in 13% and septum in 5%. Most cats (85%) presented with heart failure and/or arterial thromboembolism. Median circulating troponin I concentration was 1.4 ng/mL ([range 0.07-180 ng/mL]). Prior echocardiography results were available for 13/80 cats, a mean of 2.5 years pre-THyMS. In segments subsequently undergoing thinning, initial MaxLVWT measured 6.7 mm (95% CI 5.8-7.7 mm) vs. 1.9 mm (95% CI 1.5-2.4 mm) at last echocardiogram (P<0.0001). Survival data were available for 56/80 cats, median survival time after diagnosing THyMS was 153 days (95% CI 83-223 days). Cardiac histopathology in one cat revealed that THyMS was associated with severe transmural scarring.

CONCLUSIONS

Cats with THyMS had advanced cardiomyopathy and a poor prognosis.

Living Lab: Design a digital health intervention for healthy diet of ethnic minority adolescents

 

Eating habits cultivated during adolescence continue through adulthood, and can widen the health gap in adulthood for vulnerable ethnic minority adolescents (EMA). Living Lab is a methodological approach through which stakeholders co-create innovations as citizen scientists in real-life settings. This study aimed to design a digital health intervention (DHI) for enhancing the heathy diet of EMA using the Living Lab approach. The DHI’s content and strategies were derived through literature reviews and focus group interviews. The Living Lab was structured by using 5 principles: real-life setting, user engagement, multi-stakeholder participation, multi-method, and co-creation. It has four activity phases of discovering problems, exploring solutions, solving problems, and disseminating solutions putting more emphasis on the use of digital device and multiple stakeholders such as peers and teachers in co-ideation. DHI participants were grouped into equal proportions of EMA and Korean-ethnic peers. The DHI operates for 2 hours once a week for 4 weeks, with orientation and wrap-up sessions before and after the DHI. Each activity of the co-working process is designed by applying behavior change techniques such as prompts/cues, framing/reframing, and credible sources in a digital educational environment: creating content using Google Jamboard and Padlet, and working on the metaverse platform ZEP. The responses and feedback from the participants are received through an online reflection diary weekly. Usability and acceptability of digital technology are assessed by an online survey on completion of the DHI. The efficacy of DHI is assessed through the change in dietary behavior and food literacy. This study was designed to enable EMA recognize the harmful effects of an unhealthy diet and co-create solutions through dynamic activities in a digital environment. Further, it may serve to change the cultural sensitivity of native peers that influence the health choices of EMA.

Key messages

• Digital-based intervention would be an effective way for vulnerable ethnic minority adolescents to engage in healthy diet.

• The Living Lab approach was used as an essential strategy to develop a digital health intervention to improve the healthy diet of ethnic minority adolescents.

Diverse perspectives on social determinants of multicultural adolescents: A focus group study

Background

As Korea transforms into a multicultural society, social vulnerability of the multicultural adolescents (MAs) puts them at risk for poor health and health disparities. However, there is shortage of evidence on social determinants of health (SDH), which refers to the circumstances of people from birth to death, which affects their health outcomes, for MAs. Thus, this study aims to explore the SDH of MAs from diverse stakeholders’ perspectives.

Methods

This qualitative study comprised 17 focus group interviews with 99 participants (MAs, peers, parents, teachers, neighbors, and community leaders), conducted from June to September 2020. The directed content analysis was conducted using the Minority Health and Health Disparities Research Framework with a high rigor level based on the four criteria of Lincoln and Guba’s trustworthiness.

Results

The participants addressed SDH of MAs in five domains: biological (vulnerability and mechanism); behavioral (health behavior, family/school/peer functioning, and policies and laws); physical/built environment (school/community environment); sociocultural environment (MAs'/parental sociodemographic, language proficiency, MAs'/parental acculturation, social network, and response to/interpersonal/local/societal structural discrimination); and health care system (insurance coverage, MAs'/parental health literacy, availability of services, and health care policies). However, limited SDH in biological and physical/built environment domains were identified.

Conclusions

SDH in sociocultural environment domain and interpersonal influence level were the most commonly addressed. Interpersonal discrimination of both MAs and parents were found to be the most important SDH. These findings suggest that future programs to enhance MAs’ health may be targeted toward reducing discrimination and involving their parents.

Key messages

• Sociocultural environment was found to be the most salient SDH domain to affect MAs’ health.

• SDH of MAs are linked to discrimination and their parents’ sociocultural aspects such as acculturation.

Assessment of aortic valve area on cardiac computed tomography and doppler echocardiography: differences and clinical significance in symptomatic bicuspid aortic stenosis

Backgrounds

This study aimed to investigate the differences and clinical significance of effective orifice area (EOA) on Doppler echocardiography and geometric orifice area (GOA) on cardiac computed tomography (CT) in bicuspid aortic stenosis (AS).

Methods

One-hundred sixty-three consecutive patients (age 64±10 years, 56.4% men) with symptomatic bicuspid AS who were referred for surgery and underwent both cardiac CT and echocardiography within 3 months were studied. For the aortic valve area, GOACT was measured by multiplanar CT planimetry, and EOAEcho was calculated by continuity equation with Doppler echocardiography. The associations of GOACT and EOAEcho with the patients' symptom scale, biomarkers, and left ventricular (LV) functional variables were comprehensively analyzed.

Results

There was a significant but modest correlation between EOAEcho and GOACT (r=0.604, p&lt;0.001). Both EOAEcho and GOACT revealed significant correlations with mean pressure gradient and peak transaortic velocity and the coefficients were higher in EOAEcho than GOACT. EOAEcho of 1.05 cm2 and GOACT of 1.25 cm2 correspond to the hemodynamic cut-off values for diagnosing severe AS. EOAEcho was well correlated with patients' symptom scale and log NT-pro BNP, but GOACT was not. In addition, EOAEcho showed higher correlation coefficient with estimated LV filling pressure and LV global longitudinal strain than GOACT.

Conclusions

Both EOAEcho and GOACT can be used to evaluate the severity of bicuspid AS, however, the threshold for GOACT for diagnosing severe AS should be applied higher than that for EOAEcho. EOAEcho tends to be more correlated with the patients' symptom degree, biomarkers, and LV functional variables than GOACT.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Korean Cardiac Research Foundation

Characteristics and clinical implications of premature summation of early and late diastolic filling in patients without tachycardia

Backgrounds

The summation of early (E) and late diastolic filling (A) on mitral inflow Doppler even in the absence of tachycardia is often found during assessments of left ventricular (LV) diastolic function. We evaluated the echocardiographic characteristics and clinical implications of premature E-A summation.

Methods

We identified 1,014 subjects who showed E-A summation and normal LV ejection fraction between January 2019 and June 2021 in two tertiary hospitals. Among these, 105 (10.4%) subjects showed premature E-A summation at heart rates less than 100 beats per minute (bpm). The conventional echocardiographic parameters and LV global longitudinal strain (GLS) were compared with 1:1 age, sex, and heart rate matched controls without E-A summation.

Results

The premature E-A summation group had a heart rate of 96.4±3.7 bpm. Only 4 (3.8%) subjects were classified as having LV diastolic dysfunction according to the current guidelines. That group showed prolonged isovolumic relaxation time (107.2±25.3 vs. 61.6±15.6 msec, p&lt;0.001), increased Tei index (0.76±0.19 vs. 0.48±0.10, p&lt;0.001), lower LVEF (63.8±7.0 vs. 67.3±5.6%, p&lt;0.001) and lower absolute LV GLS (|LV GLS|) (17.0±4.2 vs. 19.7±3.3%, p&lt;0.001) than controls. As the E-A summation occurred at lower heart rate, the |LV GLS| was also lower (p for trend=0.002).

Conclusions

The premature E-A summation at heart rates less than 100 bpm is associated with subclinical LV dysfunction. Time-based indices and LV GLS are helpful for evaluating this easily overlooked population.

Funding Acknowledgement

Type of funding sources: None.

Entropic comparison of Landau-Zener and Demkov interactions in the phase space of a quadrupole billiard

We investigate two types of avoided crossings in a chaotic billiard within the framework of information theory. The Shannon entropy in the phase space for the Landau-Zener interaction increases as the center of the avoided crossing is approached, whereas for the Demkov interaction, the Shannon entropy decreases as the center of avoided crossing is passed by with an increase in the deformation parameter. This feature can provide a new indicator for scar formation. In addition, it is found that the Fisher information of the Landau-Zener interaction is significantly larger than that of the Demkov interaction.

β-Escin overcomes trastuzumab resistance in HER2-positive breast cancer by targeting cancer stem-like features

Background

The emergence of de novo or intrinsic trastuzumab resistance is exceedingly high in breast cancer that is HER2 positive and correlates with an abundant cancer stem cell (CSC)-like population. We sought to examine the capacity of β-escin, an anti-inflammatory drug, to address trastuzumab resistance in HER2-positive breast cancer cells.

Methods

The effect of β-escin on trastuzumab-resistant and -sensitive cell lines in vitro was evaluated for apoptosis, expression of HER2 family members, and impact on CSC-like properties. An in vivo model of trastuzumab-resistant JIMT-1 was used to examine the efficacy and toxicity of β-escin.

Results

β-escin induced mitochondrial-mediated apoptosis accompanied by reactive oxygen species (ROS) production and increased active p18Bax fragmentation, leading to caspase-3/-7 activation. Attenuation of CSC-related features by β-escin challenge was accompanied by marked reductions in CD44^high/CD24^low stem-like cells and aldehyde dehydrogenase 1 (ALDH1) activity as well as hindrance of mammosphere formation. β-escin administration also significantly retarded tumor growth and angiogenesis in a trastuzumab-resistant JIMT-1 xenograft model via downregulation of CSC-associated markers and intracellular domain HER2. Importantly, β-escin selectively inhibited malignant cells and was less toxic to normal mammary cells, and no toxic effects were found in liver and kidney function in animals.

Conclusions

Taken together, our findings highlight β-escin as a promising candidate for the treatment of trastuzumab-resistant HER2-positive breast cancers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02713-9.

Abstract 896: An antifungal, Itraconazole, induces cell death by targeting HER2 signaling and stem-like properties in trastuzumab-resistant HER2-positive breast cancer

Trastuzumab resistance in HER2-positive breast cancer leads to a poorer prognosis and shorter overall survival. Identifying existing drugs for another purpose of use may be considered as a part of new approaches to overcome resistance in cancer biology. Itraconazole is a FDA-approved drug, which is one of anti-fungal drugs. This drug has been reported to exploit as a cancer therapeutic agent in several cancer types. We sought to investigate the anti-cancer effects of itraconazole on cell proliferation, apoptosis, autophagy and breast cancer stem cell-like properties in terms of challenging trastuzumab resistance in HER2-positive breast cancer. The effect of itraconazole on trastuzumab-resistant cell line, JIMT-1, in vitro was examined in aspects of cell viability, apoptosis, autophagy, and impact on cancer stem cells. As in vivo experimental model, trastuzumab-resistant JIMT-1 cells were implanted to generate xenografts to study anti-tumor efficacy of itraconazole. Treatment of itraconazole significantly suppressed the growth of JIMT-1 cells with marked induction of apoptosis. Itraconazole downregulated p185HER2 and truncated-p95HER2, and their phosphorylation levels in JIMT-1 cells. In addition, the outcome of the decrease in the levels of Beclin-1 and p62 and the increase of LC3 I/II after the exposure to itraconazole supported that itraconazole induced autophagy as well. Importantly, itraconazole not only killed proliferating tumor cells but also effectively eradicated cancer stem-like populations. To elucidate eradication of cancer stem-like population by itraconazole, ALDH1 activity assay and FACS analysis of CD44+/CD24- stem-like phenotype in JIMT-1 cells were carried out. As a result, stem-cell like populations were impaired as evidenced by a significant decrease in ALDH1 activity and CD44+/CD24- stem-like populations. Through in vivo mouse model, the physiological relevance of in vitro observations was confirmed. Evident inhibition of tumor burden and growth in trastuzumab-resistant xenografts was shown in consequence of itraconazole administration, accompanying by substantial downregulation of HER2, ALDH1 and microvessel density as well as dramatic decrease of p62 in vivo. No injury to liver or kidneys by itraconazol was found based on no statistically significant difference in serum levels of ALT, AST and BUN between vehicle- and itraconazole-administrated groups. We have demonstrated that itraconazole, which is FDA-approved drug as an anti-fungal drug, exerts anti-tumor activity in trastuzumab-resistant HER2-positive breast cancer by targeting cancer stem-like properties, suppression of the HER2 signaling as well as induction of autophagy. These findings support the notion that itraconazole might be a new strategic approach as a treatment for trastuzumab-resistant HER2-positive breast cancers.

Citation Format: Jung Min Park, Soeun Park, Minsu Park, Seongjae Kim, Juyeon Seo, Dongmi Ko, Kee Dal Nam, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. An antifungal, Itraconazole, induces cell death by targeting HER2 signaling and stem-like properties in trastuzumab-resistant HER2-positive breast cancer [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 896.

Abstract 1009: A novel C-terminal HSP90 inhibitor NCT-58 targets cancer stem-like properties and suppresses migratory ability in triple-negative breast cancer cells

Background: Although several N-terminal HSP90 inhibitors have been investigated in clinical trials, none have yet been approved for clinical use due to issues including induction of the heat shock response (HSR), off-target effects and toxicity. A major issue for N-terminal inhibitors is induction of the heat shock response (HSR) which triggers cell survival. In the present study, we investigated the effects of NCT-58, a rationally-designed novel HSP90 inhibitor that instead targets the C-terminal domain, and evaluated its capacity to induce apoptosis and target cancer stem-like properties in triple-negative breast cancer.

Materials and Methods: The effect of NCT-58 on TNBC cell lines in vitro was evaluated with cell viability, apoptosis, heat shock response and cell migration. Cancer stem-like properties were examined by Aldefluor positivity, CD44+/CD24- stem-like population and mammosphere formation assays.

Results: NCT-58 induces apoptosis in TNBC cells without triggering the heat shock response (HSR) due to its targeting of the C-terminal region. This is accompanied by potent and simultaneous degradation of AKT, MEK and STAT3. Importantly, NCT-58 kills not only the rapidly proliferating tumor cells and but also effectively eradicates the breast cancer stem-like population (BCSCs). The latter phenomena are accompanied by reductions in the activity of stem/progenitor marker ALDH1 and the CD44+/CD24- stem-like population and as well as impairment of mammosphere formation. Furthermore, NCT-58 markedly impairs cell migratory ability, coinciding with collapse of HSP90 client cytoskeletal proteins including vimentin and F-actin in TNBC cells in vitro. It is noteworthy that NCT-58 exhibits more cytotoxic to tumor cells but minimally cytotoxicity to non-malignant cells.

Conclusion: These findings suggest that NCT-58 may represent an effective therapeutic approach for the simultaneous targeting of HSP90 and its client oncoproteins for the treatment of molecularly heterogeneous TNBC.

Citation Format: Soeun Park, Jung Min Park, Minsu Park, Dongmi Ko, Seongjae Kim, Juyeon Seo, Kee Dal Nam, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. A novel C-terminal HSP90 inhibitor NCT-58 targets cancer stem-like properties and suppresses migratory ability in triple-negative breast cancer cells [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 1009.

Abstract 3712: The C-terminal HSP90 inhibitor, a novel deguelin derivative, exerts anti-metastatic effects in triple-negative breast cancer by targeting cancer stem-like properties

Purpose: Triple-negative breast cancer (TNBC) still relies on non-selective cytotoxic anticancer agents due to the absence of established molecular targets for the phenotype. The heat shock protein 90 (HSP90) is a promising therapeutic target because it affects the overall progression of cancer, including cell proliferation, angiogenesis and metastasis. A variety of N-terminal HSP90 inhibitors have been tried several times in clinical trials, but none have been approved for clinical use to date due to issues including heat shock response (HSR) induction, undesirable effects, and clinical toxicity. In this study, we sought to investigate whether a novel C-terminal HSP90 inhibitor SL-145 could resolve metastasis in TNBC through inhibition of cancer stem-like properties.

Experimental Design: The effects of SL-145 on TNBC cell lines in vitro were evaluated in terms of cell proliferation, apoptosis, caspase-3 activity, breast cancer stem cell (BCSC)-like properties and heat shock response. An orthotopic allograft model with 4T1 mammospheres was used to examine the effect of SL-145 on tumor growth and metastasis in vivo.

Results: SL-145 induces apoptosis without triggering the HSR and simultaneously inhibits several oncogenic signaling pathways including AKT, MEK/ERK and JAK2/STAT3. SL-145 effectively targets BCSC-like properties with significant reductions in CD44, CD49f and ALDH1 expression as well as impairment of mammosphere-forming ability. To confirm the physiological relevance of our in vitro observations, we investigated the effects of SL-145 on tumor growth, angiogenesis and metastasis in mammosphere-derived allograft tumors with self-renewal capacity. SL-145 administration reduced tumor burden and angiogenesis, which were enriched in BCSCs, and it resulted in significant reductions in lung and liver metastases. In addition, no toxic effects of inhibitors on markers of liver or renal function were observed.

Conclusion: Our findings suggest that SL-145 may represent an effective therapeutic approach for targeting cancer stem cells and simultaneous inhibition of the HSP90 client oncoprotein to treat TNBC with a heterogeneous and aggressive nature.

Citation Format: Minsu Park, Tae-Min Cho, Soeun Park, Jung Min Park, Juyeon Seo, Dongmi Ko, Seongjae Kim, So Ra Seuk, Yong Gu Kang, Kee Dal Nam, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. The C-terminal HSP90 inhibitor, a novel deguelin derivative, exerts anti-metastatic effects in triple-negative breast cancer by targeting cancer stem-like properties [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 3712.

Nanoscale pattern formation on silicon surfaces bombarded with a krypton ion beam: experiments and simulations

The nanoscale patterns produced by bombardment of the (100) surface of silicon with a 2 keV Kr ion beam are investigated both experimentally and theoretically. In our experiments, we find that the patterns observed at high ion fluences depend sensitively on the angle of incidence Θ. For Θ values between 74° and 85°, we observe five decidedly different kinds of morphologies, including triangular nanostructures traversed by parallel-mode ripples, long parallel ridges decorated by short-wavelength ripples, and a remarkable mesh-like morphology. In contrast, only parallel-mode ripples are present for low ion fluences except for Θ = 85°. Our simulations show that triangular nanostructures that closely resemble those in our experiments emerge if a linearly dispersive term and a conserved Kuramoto-Sivashinsky nonlinearity are appended to the usual equation of motion. We find ridges traversed by ripples, on the other hand, in simulations of the Harrison-Pearson-Bradley equation (Harrisonet al2017Phys. Rev.E96032804). For Θ = 85°, the solid surface is apparently stable and simulations of an anisotropic Edwards-Wilkinson equation yield surfaces similar to those seen in our experiments. Explaining the other two kinds of patterns we find in our experiments remains a challenge for future theoretical work.

Visualizing Line Defects in non-van der Waals Bi2O2Se Using Raman Spectroscopy

Atomic-layered materials, such as high-quality bismuth oxychalcogenides, which are composed of oppositely charged alternate layers grown using chemical vapor deposition, have attracted considerable attention. Their physical properties are well-suited for high-speed, low-power-consumption optoelectronic devices, and the rapid determination of their crystallographic characteristics is crucial for scalability and integration. In this study, we introduce how the crystallographic structure and quality of such materials can be projected through Raman spectroscopy analysis. Frequency modes at ∼55, ∼78, ∼360, and ∼434 cm^-1 were detected, bearing out theoretical calculations from the literature. The low-frequency modes positioned at 55 and 78 cm^-1 were activated by structural defects, such as grain boundaries and O-rich edges in the Bi₂O₂Se crystals, accompanied by sensitivity to the excitation energy. Furthermore, the line defects at ∼55 cm^-1 exhibited a strong 2-fold polarization dependence, similar to graphene/graphite edges. Our results can help illuminate the mechanism for activating the Raman-active mode from the infrared active mode by defects, as well as the electronic structures of these two-dimensional layered materials. We also suggest that the nanoscale width line defects in Bi₂O₂Se can be visualized using Raman spectroscopy.

Gate-controlled gas sensor utilizing 1D-2D hybrid nanowires network

Novel gas sensors that work at room temperature are attracting attention due to their low energy consumption and stability in the presence of toxic gases. However, the development of sensing characteristics at room temperature is still a primary challenge. Diverse reaction pathways and low adsorption energy for gas molecules are required to fabricate a gas sensor that works at room temperature with high sensitivity, selectivity, and efficiency. Therefore, we enhanced the gas sensing performance at room temperature by constructing hybridized nanostructure of 1D-2D hybrid of SnSe2 layers and SnO2 nanowire networks and by controlling the back-gate bias (Vg = 1.5 V). The response time was dramatically reduced by lowering the energy barrier for the adsorption on the reactive sites, which are controlled by the back gate. Consequently, we believe that this research could contribute to improving the performance of gas sensors that work at room temperature.

Anterior mitral valve leaflet length in cats with hypertrophic cardiomyopathy

INTRODUCTION

Anterior mitral valve leaflet (AMVL) elongation is a recognised feature of hypertrophic cardiomyopathy (HCM). However, whether AMVL elongation precedes left ventricular hypertrophy in cats is currently unknown. The aim of this study was to explore the risk of developing an HCM phenotype in cats with an elongated AMVL.

ANIMALS

FIFTY-FIVE APPARENTLY HEALTHY CATS WITH A NORMAL BASELINE ECHOCARDIOGRAM AND A FOLLOW-UP ECHOCARDIOGRAM AT >ONE YEAR.

MATERIALS AND METHODS

This was a retrospective longitudinal study. Cats at the baseline were grouped based on whether or not they developed an HCM phenotype at follow-up. AMVL length and left atrial and left ventricular dimensions were measured from two-dimensional images.

RESULTS

The median follow-up period of the study population was 5.4 years (25th and 75th quartile, 2.7-6.7 years). During this time, 17 cats (30.9%) developed an HCM phenotype. At the baseline, cats that subsequently developed an HCM phenotype had greater AMVL length (9.4 mm [25th and 75th quartile, 9.0-10.6 mm] vs. 8.5 mm [25th and 75th quartile, 7.6-9.1 mm], P < 0.0001) and maximal left ventricular wall thickness (4.5 mm [25th and 75th quartile, 4.1-4.7 mm] vs. 4.0 mm [25th and 75th quartile, 3.7-4.6 mm], P = 0.007) than those that did not. Multiple logistic regression analysis confirmed that both baseline variables were independent predictors for development of an HCM phenotype.

CONCLUSIONS

The AMVL length was greater in cats that subsequently developed left ventricular hypertrophy. Further studies investigating the clinical application of AMVL in the natural history of feline HCM are warranted.

Differences in the clinical characteristics and long-term outcome of peripartum tako-tsubo cardiomyopathy and peripartum cardiomyopathy

Background

Some peripartum-associated cardiomyopathy patients present similarly to those of tako-tsubo cardiomyopathy (TCM), little is known about the clinical course of peripartum TCM.

Purpose

To know clinicial characteristics and outcomes of peripartum TCM, in comparison with peripartum cardiomyopathy (PPCM)

Methods and results

Of 31 pregnancy-associated cardiomyopathy patients in a tertiary hospital, 10 cases of peripartum TCM and 21 cases of PPCM were found. Maternal near-missed death was significantly more common in the peripartum TCM group than in the PPCM group (100.0% vs. 76.2%, p=0.030). Complete recovery was observed with all peripartum TCM cases, while 23.8% of the PPCM cases had residual left ventricle (LV) dysfunction. LV ejection fraction greater than 30% on the initial echocardiogram independently predicted early echocardiographic recovery of left ventricular systolic function (odds ratio 331.33, 95% confidence interval 3.87–28402.60, p=0.011). There was no difference between the two groups in terms of the rate of adverse clinical events at 3 years of follow-up (PPCM group: 26.3% [5/19] vs. TCM group: 33.3% [3/9], p=0.750).

Conclusions

One-third of pregnancy-associated cardiomyopathy patients had peripartum TCM. With contemporary supportive care, both PPCM and peripartum TCM patients had a low mortality rate and excellent long-term outcomes.

Kaplan-Meier survival curves for death,

Funding Acknowledgement

Type of funding source: None

Layer-engineered large-area exfoliation of graphene

The competition between quality and productivity has been a major issue for large-scale applications of two-dimensional materials (2DMs). Until now, the top-down mechanical cleavage method has guaranteed pure perfect 2DMs, but it has been considered a poor option in terms of manufacturing. Here, we present a layer-engineered exfoliation technique for graphene that not only allows us to obtain large-size graphene, up to a millimeter size, but also allows selective thickness control. A thin metal film evaporated on graphite induces tensile stress such that spalling occurs, resulting in exfoliation of graphene, where the number of exfoliated layers is adjusted by using different metal films. Detailed spectroscopy and electron transport measurement analysis greatly support our proposed spalling mechanism and fine quality of exfoliated graphene. Our layer-engineered exfoliation technique can pave the way for the development of a manufacturing-scale process for graphene and other 2DMs in electronics and optoelectronics.

1067 Replicative and Non-Replicative Nightmares in the Development of Posttraumatic Stress Disorder

Introduction

Nightmares are a frequent and disturbing symptom of posttraumatic stress disorder (PTSD). They are associated with sleep disruption and increased psychopathology. There is growing evidence that different types of nightmares may differ in their effects on psychopathology. Previous findings suggest that nightmares that are close replications of the experienced traumatic event might be especially important in the development of PTSD. This study investigated trauma-related (replicative) and non-trauma-related (non-replicative) nightmares as predictors of PTSD in a civilian sample.

Methods

Participants were recruited from the general public of the greater Boston area. The sample consisted of 108 participants who had experienced a psychological trauma in the past 2 years (e.g. sexual or physical assaults and accidents). The criteria for PTSD were met by 49% of participants. PTSD diagnosis was assessed using the Structured Clinical Interview for DSM-IV-TR Axis I Disorders-Non-Patient Edition. Participants received an Actiwatch 2 (Philips Respironics, Bend, OR) and a sleep diary for sleep measurements over an average of 14 consecutive nights. The diary included a prospective nightmare assessment and an item assessing the relatedness of each nightmare to traumatic events. Logistic regression analyses were performed with PTSD as the categorical outcome variable.

Results

Our analyses showed that replicative nightmares were the only statistically significant predictor of PTSD (OR = 1.2, p = .027), while controlling for age, sex, time since the traumatic event, and actigraphy total sleep time and minutes awake after sleep onset. All of these variables, including non-replicative nightmares, did not significantly predict PTSD in our analyses.

Conclusion

This study confirms and adds to the existing knowledge of nightmares and the importance of the degree to which they replicate the trauma in the development of PTSD. These findings underline the potential role of specific nightmare treatments after traumatic events, with a special focus on replicative nightmares.

Support

R01MH109638

0065 Initial Findings on Associations Between Sleep and Clinical Measures with Neural Activations Accompanying Fear Conditioning and Extinction in Trauma-Exposed Individuals

Introduction

We examined associations of sleep and hyperarousal with neural responses to a fear conditioning and extinction protocol in trauma-exposed individuals. We hypothesized, greater hyperarousal, poorer sleep quality and more nightmares would accompany greater activation of the salience network (associated with fear) and lesser activation of the prefrontal cortex (PFC; associated with fear regulation) throughout this protocol.

Methods

Persons exposed to trauma within the past 2 years (N=119, 43 with Post-traumatic stress disorder; PTSD) completed the PTSD Checklist-5 (PCL-5), two weeks of actigraphy and sleep/nightmare diaries, and a 2-day fear-conditioning and extinction protocol during fMRI. Hyperarousal items from PCL-5, sleep quality, and nightmare frequency were used to predict fMRI contrasts representing (1) initial activations to reinforced conditioned stimuli (CS+) during fear conditioning, (2) change in neural activation to CS+s across extinction learning, and, (3) after 24 hours (extinction recall), selective activation to an extinguished (CS+E) versus an un-extinguished CS+.

Results

During fear conditioning, hyperarousal was positively correlated with activation to the CS+ in the right lateral PFC, whereas nightmare frequency was negatively correlated with activations in bilateral orbitofrontal cortex (OFC). Across extinction learning, sleep onset latency (SOL) was negatively correlated with increased activation to CS+ in bilateral insular and dorsal and middle anterior cingulate cortices (salience regions). At extinction recall, nightmare frequency was negatively correlated with selective activation to the CS+E in the left insular cortex.

Conclusion

Except that fewer nightmares predicted greater OFC activation during fear conditioning, results did not support hypothesized relationships of hyperarousal, poor sleep and nightmares with increased salience network and decreased PFC activation to fear-related stimuli.

Support

Funding: R01MH109638

1081 Associations Among REM Density And Parasympathetic Activity, Nightmares, And Hyperarousal In Trauma-exposed Individuals

Introduction

Individuals with posttraumatic stress disorder (PTSD) exhibit autonomic hyperarousal and nightmares. We hypothesized that REM density (REMD) and REM heart rate variability would predict self-reported hyperarousal, nightmares, and PTSD diagnosis in trauma-exposed individuals.

Methods

Ninety-nine individuals (aged 18-40, 68 females) exposed to a DSM-5 PTSD criterion-A trauma within the past two years (48 meeting PTSD criteria) completed a night of ambulatory polysomnography (PSG) preceded by an acclimation night. REMD in scored sleep recordings were computed using the Matlab program written by Benjamin Yetton. Indices of parasympathetic tone during REM were computed using Kubios software and included Average Root Mean Square of the Successive Differences (RMSSD) and High Frequency power (HFpower). Participants completed two weeks of sleep diaries with nightmare questionnaire and completed the Clinician-Administered PTSD Scale (CAPS-5) and the PTSD Checklist for DSM-5 (PCL-5). Hyperarousal-item scores were computed from the PCL-5 without the sleep item (PCLhyp) and from the CAPS-5 (CAPShyp), and these scores (with their sleep items) were combined into a Composite Hyperarousal Index (CHI). Nightmare rate was the proportion of sleep diaries reporting a nightmare. Simple regressions measured associations among REMD, REM parasympathetic indices, hyperarousal measures, and nightmare rate.

Results

REMD did not significantly predict PTSD diagnosis or hyperarousal scores but did predict decreased parasympathetic activity for both RMSSD (p= 0.002, R= -0.316) and HFpower (p= 0.016 R= -0.250). REMD predicted increased nightmare rate (p= 0.011 R= 0.262). Parasympathetic tone was negatively correlated with CAPShyp, PCLhyp, and CHI for both RMSSD (p= 0.04, 0.011, &lt;0.000, respectively) and HFpower (p= 0.051, 0.021, 0.010, respectively). Lower parasympathetic tone also predicted PTSD diagnosis with both RMSSD (p=0.012, t=2.559) and HFpower (p=0.010, t=2.627), but did not predict nightmare rate.

Conclusion

REMD predicted decreased parasympathetic tone and higher nightmare rate. Parasympathetic tone, but not REMD, predicted hyperarousal and PTSD diagnosis.

Support

R01MH109638

1071 Subjective Measures Of Hyperarousal Predict Subjective Longitudinal And Retrospective Measures Of Sleep Quality In Individuals Exposed To Trauma

Introduction

Hyperarousal and disturbed sleep are intrinsic symptoms of posttraumatic stress disorder (PTSD). We explored whether self-reported indices of hyperarousal predict longitudinally measured objective, subjective, and retrospective evaluations of sleep quality in trauma-exposed individuals.

Methods

Individuals exposed to a DSM-5 PTSD Criterion-A traumatic event within the past two years (N=130, 91 females), aged 18-40 (mean 24.43, SD 5.30), 51.54% of whom met DSM-5 criteria for PTSD, completed 14 days of actigraphy and sleep diaries. Participants also completed the PTSD Checklist for DSM-5 (PCL-5), the Clinician-Administered PTSD Scale (CAPS-5), published Hyperarousal (HAS) and Hypervigilance (HVQ) scales, and the Pittsburgh Sleep Quality Index (PSQI) (N=108-125 for different scales). Mean total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE) and sleep midpoint were calculated from actigraphy and subjective SOL, SE, number of awakenings, and time spent awake from diaries. Simple regressions were used to predict associations of the PCL-5, HAS, and HVQ scores with measures of sleep quality.

Results

Hyperarousal indices predicted diary but not actigraphy measures of sleep quality. Longer diary-reported SOL was predicted by higher scores for: PCL-5 total score (R=0.290, p=0.001), PCL-5 hyperarousal items without the sleep item (R=0.261, p=0.004), and HAS without sleep items (R=0.220, p=0.016). Diary-reported number of awakenings and wake time after sleep onset were predicted by higher HAS scores without the sleep question: (R=0.373, p&lt;0.001; r=0.352, p&lt;0.001). Similarly, all hyperarousal indices significantly predicted PSQI global score (PCL-5: R=0.482, p&lt;0.001; PCL-5 hyperarousal: R=0.389, p&lt;0.001; HVQ: R=0.214, p=0.017; HAS without sleep question: R=0.415, p&lt;0.001).

Conclusion

Self-reported hyperarousal measures predict subjective longitudinal (especially SOL) and retrospective measures, but not objective measurements of sleep quality. Similar discrepancies between self-reported and objective measures of sleep quality have been reported in patients with insomnia disorder. Cognitive-behavioral therapy for insomnia may be especially effective in treating post-traumatic sleep disturbances.

Support

R01MH109638

Long-term biological variability and the generation of a new reference interval for plasma N-terminal pro-B-type natriuretic peptide in Labrador retrievers

OBJECTIVES

First, to investigate the biological variability of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in healthy Labrador retrievers and compare this with current laboratory recommendations for dilated cardiomyopathy screening. Second, to calculate a breed-specific reference interval and validate it in a retrospective cohort.

MATERIALS AND METHODS

Plasma NT-proBNP was measured in 51 clinically healthy Labrador retrievers at 0, 2, 4, 6 and 8 weeks. Coefficient of variation for individual dogs over time, the coefficient of variation for the group at each time point and the index of individuality were calculated. A reference interval was derived and tested on a clinical dataset available from four UK cardiology referral centres.

RESULTS

Median NT-proBNP was 865 pmol/L (315 to 2064 pmol/L). Mean individual coefficient of variation was 19% (95% CI: 16 to 21%) and group coefficient of variation was 43% (95% CI: 41 to 46%), with index of individuality at 0.44. The breed-specific reference interval was 275 to 2100 pmol/L. In the validation group, 93% of NT-proBNP measurements from healthy dogs were within the reference interval. NT-proBNP measurements exceeded the reference interval in 82% of dogs with dilated cardiomyopathy. The upper bound of the reference interval (2100 pmol/L) had a positive predictive value of 90% and a negative predictive value of 87% for identification of dilated cardiomyopathy in this population.

CLINICAL SIGNIFICANCE

Breed-specific reference intervals might improve the diagnostic accuracy of NT-proBNP measurement. Applying the currently recommended general cut-off value to Labradors is likely to result in frequent false positives and diagnosis would be improved by application of the new breed-specific reference interval calculated here.

Automatic matching of computed tomography and stereolithography data

BACKGROUND AND OBJECTIVE

Computed tomography (CT) is one of the most frequently used medical imaging methods. An important application area of CT is dental implants, which require precise inspection and analysis of oral structures. Since CT provides a precise 3D model of the teeth, bones and nerves, it can be used as a surgical guide for dental implants. Along with CT, optical 3D images called stereolithography (STL) have also been widely used. STL images obtained from optical 3D images can be used to show the 3D surfaces of oral structures. Since CT data and STL data deploy different technologies to obtain dental information, we can obtain more accurate dental implants by combining the two datasets. Since the two datasets are acquired by using different sensors, the datasets need to be registered.

METHODS

An automatic matching algorithm is proposed for CT and STL image registration, which is based on depth maps and maximum intensity projection. Then, fine tuning was performed based on volume matching.

RESULTS

When applied to real-world databases, the proposed method provided an average matching error of 2.7 mm for the upper jaw and 2.3 mm for the lower jaw with an average processing time of about 19 s.

CONCLUSIONS

The proposed method performs accurate registration of CT and STL.

Abstract P3-13-01: Application of supine MRI-based 3D printing breast surgical guide for precision breast-conserving surgery

Background

If the size of the tumor is large, neoadjuvant systemic therapy (NST) is performed to reduce the size of the tumor and to conserve the breast. It is known that magnetic resonance imaging is more accurate than mammography (MMG) or ultrasonography (USG) in determining the area of residual cancer in breast-conserving surgery (BSG) after NST. However, there are some problems when performing BCS using MRI. Because the posture of MRI test is different from the posture at surgery, it is difficult to accurately mark the area of the tumor observed in MRI. Neoadjuvant systemic therapy reduces tumor size and often makes it difficult to detect the original tumor area on preoperative MRI. Even if the tumor is not visible in the image, the cancer cells may remain, so it is important to accurately indicate the extent of the initial tumor and remove it. Until now, however, there has been no way to accurately mark past breast tumors in the breast. We have developed a breast surgical guide (BSG) that can mark a range of tumor directly on the breast using three-dimensional printing technology based on supine MRI. This study analyzed the results of patients who underwent BCS using a 3D printing breast surgical guide (3D-BSG) based on supine MRI.

Methods

This trial was designed as a prospective single-institution cohort study. Our study protocol was approved by the Institutional Review Board of Asan Medical Center, Seoul, Korea (IRB No. 2016-1237). Patients who were expected to undergo BCS after NST were enrolled in this study and supine MRI was performed before and after NST. From MRI images, morphological shapes of breasts and tumors were modeled. The prepared digital model was saved in stereolithography file format and then exported to a 3D printer. 3D-BSG is designed to be able to mark the skin and attach the dye injecting column to mark the around the tumor. The breast tissue was removed with blue dye on the basis of the border. To obtain tumor free margin, intraoperative frozen sections were identified in several cavities and re-excision was performed if tumor positive.

Results

Between January 2016 and May 2017, 50 patients were enrolled in the study. BCS was applied to 40 patients, except for those who were rejected or mastectomy. Complete remission was observed in 15 patients after NST. Four patients had tumor positive on resection margins on frozen biopsy during operation, two with IDC and two with DCIS. Re-excision was performed in these patients and tumor negative margin was confirmed in all patients in the final pathology results. The median size of the long axis of the tumor was 1.7 cm (range, 0.5 to 4.5 cm) and the median size of the long axis of the removed breast tissue was 5.1 cm (range, 2.3 to 8.1 cm). The distance between tumor and resection margin was 1.2 cm (range, 0.1 to 4.8 cm)..

Conclusions

In BCS, the application of the supine MRI based 3D-BSG showed low rates of positive margins. Unlike conventional localization techniques, application of 3D-BSG does not cause pain to the patient, has no radiation exposure, and has no time required for the localization procedure, so it will be helpful for patients in BCS in the future.

Citation Format: Ko B, Kim N, Seo J, Kim H, Gong G, Kim S, Son B, Ahn SH. Application of supine MRI-based 3D printing breast surgical guide for precision breast-conserving surgery [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-01.