Broken Screw Rotational Symmetry in the Near-Surface Electronic Structure of AB-Stacked Crystals

We investigate the electronic structure of 2H-NbS_{2} and h-BN by angle-resolved photoemission spectroscopy (ARPES) and photoemission intensity calculations. Although in bulk form, these materials are expected to exhibit band degeneracy in the k_{z}=π/c plane due to screw rotation and time-reversal symmetries, we observe gapped band dispersion near the surface. We extract from first-principles calculations the near-surface electronic structure probed by ARPES and find that the calculated photoemission spectra from the near-surface region reproduce the gapped ARPES spectra. Our results show that the near-surface electronic structure can be qualitatively different from the bulk electronic structure due to partially broken nonsymmorphic symmetries.

Jahn-Teller Switching of a Redox-Active Nickel(III) Center in a Homoleptic Thiolato Metalloligand Environment

Treatment of nickel(II) nitrate with the iridium(III) metalloligand fac-[Ir(apt)₃] (apt = 3-aminopropanethiolate) gave the trinuclear complex [Ni{Ir(apt)₃}₂](NO₃)₃ ([1_Ir](NO₃)₃), in which the nickel center has a formal oxidation state of +III. Chemical or electrochemical oxidation and reduction of [1_Ir](NO₃)₃ generated the corresponding trinuclear complexes [Ni{Ir(apt)₃}₂](NO₃)₄ ([1_Ir](NO₃)₄) and [Ni{Ir(apt)₃}₂](NO₃)₂ ([1_Ir](NO₃)₂) with one-electron oxidated and reduced states, respectively. Single-crystal X-ray crystallography revealed that the nickel center in [1_Ir](NO₃)₃ is situated in a highly distorted octahedron due to Jahn-Teller effect, while the nickel center in each of [1_Ir](NO₃)₄ and [1_Ir](NO₃)₂ adopts a normal octahedral geometry. Crystals of [1_Ir](NO₃)₃·2H₂O are dehydrated on heating while retaining their single-crystallinity. The dehydration induces temperature-dependent dynamic disorder of the Jahn-Teller distortion at the nickel(III) center, which is largely quenched upon rehydration of the crystal.

Widely Tunable Berry Curvature in the Magnetic Semimetal Cr1+ δ Te2

Magnetic semimetals have increasingly emerged as lucrative platforms hosting spin-based topological phenomena in real and momentum spaces. Cr_{1+ δ} Te₂ is a self-intercalated magnetic transition metal dichalcogenide (TMD), which exhibits topological magnetism and tunable electron filling. While recent studies have explored real-space Berry curvature effects, similar considerations of momentum-space Berry curvature are lacking. Here, the electronic structure and transport properties of epitaxial Cr_{1+ δ} Te₂ thin films are systematically investigated over a range of doping, δ (0.33 - 0.71). Spectroscopic experiments reveal the presence of a characteristic semi-metallic band region, which shows a rigid like energy shift with δ. Transport experiments show that the intrinsic component of the anomalous Hall effect (AHE) is sizable and undergoes a sign flip across δ. Finally, density functional theory calculations establish a link between the doping evolution of the band structure and AHE: the AHE sign flip is shown to emerge from the sign change of the Berry curvature, as the semi-metallic band region crosses the Fermi energy. These findings underscore the increasing relevance of momentum-space Berry curvature in magnetic TMDs and provide a unique platform for intertwining topological physics in real and momentum spaces.

Layer-Number-Independent Two-Dimensional Ferromagnetism in Cr3Te4

In a conventional magnetic material, a long-range magnetic order develops in three dimensions, and reducing a layer number weakens its magnetism. Here we demonstrate anomalous layer-number-independent ferromagnetism down to the two-dimensional (2D) limit in a metastable phase of Cr₃Te₄. We fabricated Cr₃Te₄ thin films by molecular-beam epitaxy and found that Cr₃Te₄ could host two distinct ferromagnetic phases characterized with different Curie temperatures (T_C). One is the bulk-like "high-T_C phase" showing room-temperature ferromagnetism, which is consistent with previous studies. The other is the metastable "low-T_C phase" with T_C ≈ 160 K, which exhibits a layer-number-independent T_C down to the 2D limit in marked contrast with the conventional high-T_C phase, demonstrating a purely 2D nature of its ferromagnetism. Such significant differences between two distinct phases could be attributed to a small variation in the doping level, making this material attractive for future ultracompact spintronics applications with potential gate-tunable room-temperature 2D ferromagnetism.

The ligand field in low-crystallinity metal-organic frameworks investigated by soft X-ray core-level absorption spectroscopy

The ligand field (LF) of transition metal ions is a crucial factor in realizing the mechanism of novel physical and chemical properties. However, the low-crystallinity state, including the amorphous state, precludes the clarification of the electronic structural relationship of transition metal ions using crystallographic techniques, ultraviolet and infrared optical methods, and magnetometry. Here, we demonstrate that soft X-ray 2p → 3d core-level absorption spectroscopy (L_2,3-edge XAS) systematically revealed the local 3d electronic states, including in the LF, of nitrogen-coordinated transition-metal ions for low-crystallinity cyanide-bridged metal-organic frameworks (MOFs) M[Ni(CN)₄] (MNi; M = Mn, Fe, Co, Ni) and Ni[Pd(CN)₄] (NiPd). In NiNi and NiPd, N-coordinated Ni ions with square-planar symmetry exhibit strong orbital hybridization and ligand-to-metal charge transfer effects. In MnNi, FeNi, and CoNi, the correlation between the crystalline electric field splitting in the LF and the transition metal-nitrogen bonding length is revealed using the multiplet LF theory. Regardless of the different local symmetries, our results indicate that L_2,3-edge XAS is a powerful tool for gaining element-specific knowledge about the transition-metal ion characterizing the functionality of low-crystallinity MOFs and will be the foundation for an attractive platform, such as adsorption/desorption materials.

Hole Dynamics in Photoexcited Hematite Studied with Femtosecond Oxygen K-edge X-ray Absorption Spectroscopy

Hematite (α-Fe₂O₃) is a photoelectrode for the water splitting process because of its relatively narrow bandgap and abundance in the earth's crust. In this study, the photoexcited state of a hematite thin film was investigated with femtosecond oxygen K-edge X-ray absorption spectroscopy (XAS) at the PAL-XFEL in order to follow the dynamics of its photoexcited states. The 200 fs decay time of the hole state in the valence band was observed via its corresponding XAS feature.

Early detection of exacerbation of the severe acute respiratory syndrome coronavirus 2 infection using Fitbit (DEXTERITY pilot study)

 

Some patients with coronavirus disease 2019 (COVID-19) experienced sudden death because of sudden symptom deterioration. Thus, an alarm system that could detect early signs of COVID-19 exacerbation beforehand, to prevent serious illness or death of patients while receiving outpatient treatment at home or in hotels is necessary. Here, we tested whether estimated oxygen variations (EOV), a relative physiological scale that represents users' blood oxygen saturation level during sleep measured by Fitbit, predicted COVID-19 symptom exacerbation. Study period was from August to November 2020. We enrolled 23 COVID-19 patients diagnosed by SARS-CoV-2 polymerase chain reaction-positive (mean age ± standard deviation, 50.9±20 years; 70% female), let each patient wore the Fitbit for 30 days; COVID-19 symptoms were exacerbated in 6 (26%). High EOV signal (a patient's oxygen level exhibits significant dip and recovery within the index period) had 80% sensitivity before symptom exacerbations, whereas resting heart rate signal only had 50% sensitivity. Coincidental obstructive sleep apnea syndrome confirmed by polysomnography was detected in a patient by consistently high EOV signals. This pilot study successfully detected early COVID-19 symptoms exacerbation by measuring EOV and may help to identify early signs of COVID-19 exacerbation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The investigational device used in this study, Fitbit Charge 3, was provided by Fitbit Japan. Summary of high EOV signals and eventsThe clinical course of COVID-19

Femtosecond Charge Density Modulations in Photoexcited CuWO4

Copper tungstate (CuWO4) is an important semiconductor with a sophisticated and debatable electronic structure that has a direct impact on its chemistry. Using the PAL-XFEL source, we study the electronic dynamics of photoexcited CuWO4. The Cu L3 X-ray absorption spectrum shifts to lower energy upon photoexcitation, which implies that the photoexcitation process from the oxygen valence band to the tungsten conduction band effectively increases the charge density on the Cu atoms. The decay time of this spectral change is 400 fs indicating that the increased charge density exists only for a very short time and relaxes electronically. The initial increased charge density gives rise to a structural change on a time scale longer than 200 ps.

Coordination Geometry Changes in Amorphous Cyanide-Bridged Metal-Organic Frameworks upon Water Adsorption

Amorphous coordination polymers and metal-organic frameworks (MOFs) have attracted much attention owing to their various functionalities. Here, we demonstrate the tunable water adsorption behavior of a series of amorphous cyanide-bridged MOFs with different metals (M[Ni(CN)₄]: MNi; M = Mn, Fe, and Co). All three compounds adsorb up to six water molecules at a certain vapor pressure (P_ads) and undergo conversion to crystalline Hofmann-type MOFs, M(H₂O)₂[Ni(CN)₄]·4H₂O (MNi-H₂O; M = Mn, Fe, and Co). The P_ads of MnNi, FeNi, and CoNi for water adsorption is P/P₀ = 0.4, 0.6, and 0.9, respectively. Although the amorphous nature of these materials prevented structural elucidation using X-ray crystallography techniques, the local-scale structure around the N-coordinated M²⁺ centers was analyzed using L_2,3-, K-edge X-ray absorption fine structure, and magnetic measurements. Upon hydration, the coordination geometry of these metal centers changed from tetrahedral to octahedral, resulting in significant reorganization of the MOF local structure. On the other hand, Ni[Ni(CN)₄] (NiNi) containing square-planar Ni²⁺ centers did not undergo significant structural transformation and therefore abruptly adsorbed H₂O in the low-pressure region. We could thus define how changes in the bond lengths and coordination geometry are related to the adsorption properties of amorphous MOF systems.

Transformations of empty CuI4 core to CuI2CuII2O and CuI6S cores via oxide and sulfide insertions

A tetrahedral {CuI4}⁴⁺ core is reversibly transformed to a mixed-valent {CuI2CuII2O}⁴⁺ core via the oxidative insertion and the reductive elimination of an oxide ion.

Direct observation of the electronic states of photoexcited hematite with ultrafast 2p3d X-ray absorption spectroscopy and resonant inelastic X-ray scattering

Ultrafast Fe L₃ XAS and 2p3d RIXS elucidate the photoexcitation process of hematite.

P6199Lipoprotein(a) and risk of chronic kidney disease among 4,235 Japanese hospitalized patients

Background

Lipoprotein (a) [Lp(a)] has been shown to be associated with the development of chronic kidney disease (CKD) among various ethnicities. In addition, recent Mendelian randomization studies have suggested that Lp(a) seems to be causally associated with CKD. However, few data exist regarding this issue among Japanese population.

Purpose

We aimed to investigate the association between serum Lp(a) and the CKD among Japanese population.

Methods

We retrospectively investigated 6,130 subjects whose serum Lp(a) had been measured for any reason (e.g. any operations which needs bed rest for a long duration, risk factors for atherosclerosis such as hypertension or diabetes) at our University Hospital from April 2004 to March 2014. We excluded 1,895 subjects due to the lack clinical data. We assessed their Lp(a), LDL cholesterol, HDL cholesterol, triglycerides, presence of hypertension, diabetes, chronic kidney disease, smoking, body mass index, presence of coronary artery disease (CAD), and presence of CKD (stage 3 or greater).

Results

When the study subjects were divided into 5 groups based on their CKD stage, there was a significant trend among their serum Lp(a) levels (P-trend = 2.7×10–13). Under these conditions, multiple regression analysis showed that Lp(a) was significantly associated with CKD [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.08–1.17; p=1.3×10–7: per 10mg/dL)., independent of other classical risk factors, including age, gender, body mass index, hypertension, diabetes, smoking, LDL cholesterol and triglycerides. Under these conditions, Lp(a) was significantly associated with CAD [OR: 1.11, 95% CI: 1.06–1.16; p=1.7×10–6: per 10mg/dL), independent of the presence of CKD.

Conclusion

Serum Lp(a) was associated with the development of CKD independent of other classical risk factors among Japanese population as well.

Effect of Anisotropic Hybridization in YbAlB_{4} Probed by Linear Dichroism in Core-Level Hard X-Ray Photoemission Spectroscopy

We have probed the crystalline electric-field ground states of pure |J=7/2,J_{z}=±5/2⟩ as well as the anisotropic c-f hybridization in both valence fluctuating systems α- and β-YbAlB_{4} by linear polarization dependence of angle-resolved core level photoemission spectroscopy. Interestingly, the small but distinct difference between α- and β-YbAlB_{4} was found in the polar angle dependence of linear dichroism, indicating the difference in the anisotropy of c-f hybridization, which may be a key to understanding a heavy Fermi liquid state in α-YbAlB_{4} and a quantum critical state in β-YbAlB_{4}.

Abstract P1-11-07: Risk analysis for chemotherapy induced nausea and vomiting (CINV) in patients receiving FEC100 treatment

BACKGROUND:

Anthracycline-containing regimens are standard treatment options in adjuvant and neoadjuvant chemotherapy in breast cancer. Chemotherapy-induced nausea and vomiting (CINV) is experienced frequently in patients receiving these regimens, but the risk factors for CINV are unknown.

OBJECTIVE:

The aim of this study was to investigate risk factors for CINV in anthracycline-containing regimens retrospectively.

METHODS:

Data were collected from the JONIE study, which was conducted in order to estimate the efficacy of zoledronic acid in a neoadjuvant setting from March 2010 to June 2012 (UMIN000003261). A total of 180 patients were recruited, and we used CINV data from the first cycle of FEC100 treatment and patient backgrounds. As the protocol regulation allowed the use of antiemetic drugs,in the first cycle of the FEC100 regimen, patients received various types of antiemetic agents, which we classified into four groups: Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3)+neurokinin-1 receptor antagonist (NK1) (DEX+5-HT3+NK1) group; Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3) (DEX+5HT3) group; Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3)+dopamine receptor antagonist (DRA) (DEX+5HT3+DRA) group; and Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3)+neurokinin-1 receptor antagonist (NK1)+ dopamine receptor antagonist (DRA) (DEX+5-HT3+NK1+DRA) group. Risk factors were selected from patient backgrounds and the combinations of antiemetic drugs. In patient backgrounds, the body mass index (BMI) was stratified into 3 categories: Less than 18.5 (underweight group); equal to or more than 18.5 but less than 25 (standard BMI group); and equal to or more than 25 (overweight group). The risks for CINV were analyzed by univariate and multivariate analyses. P values of less than 0.05 were defined as significant.

RESULTS:

In a univariate analysis of nausea, the body mass index (BMI) was the only significant factor (P<0.05). On the other hand, BMI and the combination of antiemetic drugs were significant factors in vomiting. (P<0.05 and 0.005, respectively). In a multivariate analysis of nausea, the P value for BMI was 0.02. The odds ratio for the underweight group was 7.745 (confidence interval: 2.171 to 27.634) compared with the standard BMI group. In a multivariate analysis of vomiting, BMI and the combination of antiemetic drugs were significant risk factors (P=0.025 and 0.023, respectively). The odds ratio for the underweight group was 3.481 (confidence interval: 1.183 to 10.241)compared with the standard BMI group. Furthermore, the odds ratios in the DEX+5-HT3+DRA and DEX+5HT3 groups were 5.005 (confidence interval: 1.543 to 16.239) and 4.178 (confidence interval: 1.428 to 12.222), respectively, compared with the DEX+5-HT3+NK1 group, which was consistent with the CINV guidelines in 2011.

CONCLUSIONS:

This study revealed that BMI was the most important risk factor for nausea, and that BMI and the combination of antiemetic drugs were risk factors for vomiting. Underweight-patients tend to have CINV in anthracycline-containing regimen. The DEX+5-HT3+NK1 group was the best antiemetic drug combination. These result show that following the CINV guideline treatment is mandatory in order to prevent CINV.

Citation Format: Hayashi M, Nakazawa K, Hasegawa Y, Horiguchi J, Miura D, Ishikawa T, Takao S, Kim SJ, Yamagami K, Miyashita M, Konishi M, Shigeoka Y, Suzuki M, Taguchi T, Kubota T, Tanino Y, Yamada K, Kimura K, Akazawa K, Kohno N. Risk analysis for chemotherapy induced nausea and vomiting (CINV) in patients receiving FEC100 treatment [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 P1-11-07.

Abstract P3-03-21: Usefulness of sentinel lymph node biopsy by indocyanine green fluorescence method for cN0 breast cancer patients

Background. Indocyanine green (ICG) fluorescence method (ICG-f) has been recently widely used in sentinel lymph node (SLN) detection. The advantages of ICG-f are no radiation exposure, no limitation to use in high-volume medical centers without radioactive facility, and to confirm lymph flow as a real-time image from outside the body. ICG-f identified an average of 2.3-3.4 SLNs and the detection rate was 99%, compared to 1.7-2 SLNs by RI methods. Long-term observation after SNB using ICG-f has not been reported, including arm lymphedema as the complication of this method.We evaluate the usefulness of SLN biopsy (SNB) for cN0 breast cancer patients from data of multicenter cohort study on long-term results after negative SNB by ICG-f.

Methods. Eleven hundred and thirty-two women were enrolled who had histologically proved clinical stage T1-4, pN0, M0 primary invasive breast cancer with SNB using ICG-f (ICG alone or combination of RI/blue dye method) sparing axillary lymph node dissection from May 2007 to December 2015. This study is retrospective, multicenter cohort study conducted at 6 centers in Japan. Primary endpoint is axillary recurrence rate. We analyzed the correlation with the axillary recurrence and adjuvant systemic therapy, adjuvant radiotherapy, and the clinicopathological characteristics. Secondary endpoint is lymphedema.

Results and Discussion. The median follow-up time was 41 (range 21-117) months, and axillary recurrence was found in 6 patients (0.53%). Five out of 6 patients were not received standard adjuvant systemic therapy or adjuvant radiation therapy after breast conserving surgerybecause of patient's preference or old age. Lymphedema was identified only 4 patients in 632 patients. It is reported that axillary recurrence after SNB was 0.3-1.65%, which was consistent with our result. Lymphedema was not frequent in patients received SNB using ICG-f, because SLNs are removed along with lymphatic ducts in the limited area of axillary adipose tissue.

Conclusion.Axillary recurrence after negative SNB using ICG-f was comparable to RI or blue dye method. It might be important to perform appropriate adjuvant medication or radiation therapy for preventing axillary recurrence after SNB using ICG-f.

Next, ICG-f after neoadjuvant chemotherapy is to be investigated, because itis reported that removing more than 2 SLNs were associated with a lower likelihood of false negative ratio in patients with clinically node-positive disease converted to clinically node-negative after chemotherapy, and ICG-f might overcome this issue.

Citation Format: Maeshima Y, Takahara S, Yamauchi A, Yamagami K, Sugie T, Yamashiro H, Kato H, Torii M, Takada M, Torii M. Usefulness of sentinel lymph node biopsy by indocyanine green fluorescence method for cN0 breast cancer patients [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 P3-03-21.

Valence Interconversion of Octahedral Nickel(II/III/IV) Centers

Three oxidation states (+2, +3, +4) of an octahedral nickel center were stabilized in a newly prepared RhNiRh trinuclear complex, [Ni{Rh(apt)₃ }₂ ]ⁿ⁺ (apt=3- aminopropanethiolate), in which the nickel center was bound by six thiolato donors sourced from two redox-inert fac-[Rh^III (apt)₃ ] octahedral units. The three oxidation states of the octahedral nickel center were fully characterized by single-crystal X-ray crystallography, as well as spectroscopic, electrochemical, and magnetic measurements; all three were interconvertible, and the conversion was accompanied by changes in color, magnetism, and Jahn-Teller distortion.

Abstract P5-16-10: Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial

BACKGROUND and AIM:

Findings from a randomized phase 2 JONIE1 trial in women with HER2-negative early breast cancer have shown that the addition of zoledronic acid (ZOL) to neoadjuvant chemotherapy (CT) has potential anticancer benefits in postmenopausal and triple-negative breast cancer patients. We report the data for the prespecified secondary endpoint of disease-free survival (DFS).

METHODS:

We enrolled women with HER2-negative early breast cancer and randomly assigned them to receive CT or CT+ZOL (CTZ). All patients received 4 cycles of FEC100 (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2), followed by 12 cycles of paclitaxel at 80 mg/m2 weekly. ZOL (4 mg) was administered 3-4 times weekly for 7 weeks to the CTZ group patients. Definitive surgery was performed 3-4 weeks after the last paclitaxel dose. The primary endpoint was pathological complete response (pCR). The secondary endpoints were the clinical response rates, rate of breast-conserving surgery, safety, and DFS (defined as the time from randomization to disease occurrence or death). The trial is registered as UMIN000003261 (www.umin.ac.jp/english/) with ongoing follow-up.

FINDINGS:

Of the 188 patients enrolled, 95 were assigned to the CT group and 93 to the CTZ group. The mean (95% CI) DFS time of the CT group was 5.15 years (4.83-5.47) and that of the CTZ group was 5.38 years (5.11-5.66). The 3-year DFS rate was 84.6% (95% CI 77.2-92.0) in the CT group and 90.7% (84.6-96.8) in the CTZ group with no significant difference (p = 0.120). The particular benefit from ZOL for the neoadjuvant CT seen as improvement of the pCR rate was indicated in the 3-year DFS period for triple-negative cancer cases (CT vs CTZ: 70.6% vs 94.1%), but not for postmenopausal cases.

CONCLUSIONS:

ZOL slightly improved DFS when combined with CT. Although a significant difference was not found in this study, plans are underway for conducting a combined analysis of 3 neoadjuvant CT trials together with ZOL. The improvement of the pCR rate may be associated with DFS in triple-negative cases. Previous studies have shown that ZOL was more efficacious in an estrogen-suppressed condition. However, the short-term application of ZOL in this study may not be sufficient to improve the outcome in postmenopausal patients.

Citation Format: Ishikawa T, Akazawa K, Hasegawa Y, Tanino H, Horiguchi J, Miura D, Hayashi M, Takao S, Kim SJ, Yamagami K, Miyashita M, Konishi M, Shigeoka Y, Suzuki M, Taguchi T, Kubota T, Kohno N. Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-10.

Heterogeneous catalase-like activity of gold(i)-cobalt(iii) metallosupramolecular ionic crystals

The heterogeneous catalase-like activity of ionic crystals consisting of Au^I₄Co^III₂ complex cations is studied along with their surface morphologies and oxidation states.

Unique heterogeneous catalase-like activity was observed for metallosupramolecular ionic crystals [Au^I₄Co^III₂(dppe)₂(d-pen)₄]X_n ([1]X_n; dppe = 1,2-bis(diphenylphosphino)ethane; d-pen = d-penicillaminate; X_n = (Cl^–)₂, (ClO₄^–)₂, (NO₃^–)₂ or SO₄^2–) consisting of Au^I₄Co^III₂ complex cations, [1]²⁺, and inorganic anions, X^– or X^2–. Treatment of the ionic crystals with an aqueous H₂O₂ solution led to considerable O₂ evolution with a high turnover frequency of 1.4 × 10⁵ h^–1 for the heterogeneous cobalt complexes, which was dependent on their size and shape as well as the arrangement of cationic and anionic species. These dependencies were rationalized by the presence of cobalt(ii) centers on the crystal surface and their efficient exposure on the (111) plane rather than the (100) plane based on morphological and theoretical studies.

Polarized hard X-ray photoemission system with micro-positioning technique for probing ground-state symmetry of strongly correlated materials

An angle-resolved linearly polarized hard X-ray photoemission spectroscopy (HAXPES) system has been developed to study the ground-state symmetry of strongly correlated materials. The linear polarization of the incoming X-ray beam is switched by a transmission-type phase retarder composed of two diamond (100) crystals. The best value of the degree of linear polarization was found to be -0.96, containing a vertical polarization component of 98%. A newly developed low-temperature two-axis manipulator enables easy polar and azimuthal rotations to select the detection direction of photoelectrons. The lowest temperature achieved was 9 K, offering the chance to access the ground state even for strongly correlated electron systems in cubic symmetry. A co-axial sample monitoring system with long-working-distance microscope enables the same region on the sample surface to be measured before and after rotation. Combining this sample monitoring system with a micro-focused X-ray beam by means of an ellipsoidal Kirkpatrick-Baez mirror (25 µm × 25 µm FWHM), polarized valence-band HAXPES has been performed on NiO for voltage application as resistive random access memory to demonstrate the micro-positioning technique and polarization switching.

Abstract P3-07-50: Early and accurate prediction of pathological response by magnetic resonance imaging and ultrasonography in patients undergoing neoadjuvant chemotherapy for operable breast cancer

Background: Neoadjuvant chemotherapy (NAC) reduces tumor size, and increases the frequency of breast-conserving surgery in operable breast cancers. Response predictions to NAC are made based on diagnostic imaging.

Although various studies have reported the optimal timing for diagnostic imaging, this still remains unclear.

Purpose: To identify the optimal timing of diagnostic imaging for the response prediction to NAC, and to evaluate the accuracy of response prediction.

Methods: We evaluated 146 cases enrolled in the JONIE-1 study (a randomized controlled trial comparing zoledronic acid plus chemotherapy with chemotherapy alone as a NAC in patients with HER2-negative primary breast cancer). The chemotherapy regimen was FEC100×4 courses followed by weekly paclitaxel 80×12 courses (± zoledronic acid). Statistical analysis of the association between the tumor reduction ratio and the histopathological response and the prediction of pathological complete response (pCR) was performed using JMP software. The maximum tumor diameter was evaluated using magnetic resonance imaging and ultrasound on each patient 3 times (before NAC, after FEC treatment, after NAC) and tumor reduction ratios were calculated.

Results: The average age of the patients was 49.8 years old. The menopause status was pre-menopause in 84 patients, and post-menopause in 58 patients. Regarding the subtype classification, 116 patients were of the luminal type (Lum) and 26 patients were triple negative (TN), and the Ki-67 labeling index had a median of 25% (1%-93%).

Pathological examination demonstrated that 16 patients had pCR(11.3%, Lum, 9;TN: 7), and 126 patients had non-pCR (88.7%, Lum:107; TN:19). Seven patients had clinical-CR (4.8%, Lum: 4; TN: 3) at post-FEC, and 26 patients (17.8%, Lum: 20; TN: 6) at post-NAC. The prediction of pCR at post-FEC and post-NAC was evaluated by single variable analysis, resulting in an AUC (0.75645) p=0.0017 at post-FEC, and AUC (0.76563) p=0.0001 at post-NAC. The sensitivity / specificity / positive predictive value / negative predictive value were 0.625 / 0.873 / 0.385 / 0.948 at post-FEC, 0.250 / 0.976 / 0.571 / 0.911 at post-NAC, respectively. In TN cases, the values were 0.714 / 0.947 / 0.833 / 0.900 in post-FEC, and 0.429 / 1.000 / 1.000 / 0.826 in post-NAC.

Conclusions: Diagnostic imaging evaluation performed after FEC treatment was useful for the prediction of pCR. Furthermore, the reliability was high in Triple Negative Sub type, but is affected by the existence of residual tumors in Luminal type.

Citation Format: Kaise H, Ishikawa T, Miura D, Hasegawa Y, Horiguchi J, Hayashi M, Takao S, Kim SJ, Tanino H, Miyashita M, Konishi M, Shigeoka Y, Yamagami K, Suzuki M, Taguchi T, Akazawa K, Kohno N. Early and accurate prediction of pathological response by magnetic resonance imaging and ultrasonography in patients undergoing neoadjuvant chemotherapy for operable breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-50.

Immunohistochemical detection of ribonucleotide reductase in human breast-tumors

Ribonucleotide reductase (RNR) consists of two non-identical subunits, R1 and R2 and is one of the key enzymes involved in DNA biosynthesis. RNR activity is considerably higher in malignant tumors than in normal tissues in the rat suggesting that RNR may play an important role in the pathogenesis of human tumors. In order to obtain immunological reagents to study the localization and level of expression of RNR in various human tissues, a synthetic peptide containing sequences corresponding to the COOH-terminal region of the human R2 subunit was used to generate rat monoclonal antibodies. The generated rat monoclonal antibodies (IgG) inhibited RNR enzymatic activity purified from murine P388 leukemia cells. These antibodies were used to immunohistochemically examine the distribution of RNR in a small panel of 8 malignant and 4 benign human breast tumors. Positive immunostaining for RNR was observed in the cytoplasm of human breast carcinoma cells in which a specific 44 kDa specific band of R2 subunit was also detected by Western blot analysis. The immunostaining was blocked by preabsorption of the antibody with an excess amount of the synthetic peptide immunogen. In 8 of 8 breast carcinomas, positive immunostaining for the R2 subunit was observed whereas noninvolved, adjacent breast tissue showed no staining with this antibody. In addition, few of the benign breast lesions exhibited staining with this antibody. These data indicate that these antibodies can immunohistochemically detect RNR in frozen or formalin-fixed, paraffin- embedded tissues and that there is a differential expression of RNR between breast tumors and non-involved breast tissue. Immunohistochemical detection of RNR using these antibodies may therefore be useful for the diagnosis of human breast tumors.

The use of sonication treatment to completely decellularize blood arteries: a pilot study

We have developed a novel sonication decellularization system to prepare completely decellularized bioscaffolds in a short treatment time. The aim of the study is to investigate the sonication decellularization efficiency and its relation with ultrasonic power output and dissolved oxygen (DO) concentration in different detergent solution. In the study, we used aorta samples to evaluate sonication decellularization efficiency, which assessed treatment duration, sonication power and SDS detergent with/without saline. The treated samples were evaluated histologically by Hematoxylin Eosin (HE) staining and scanning electron microscopic (SEM) photographs. The concentration of DO was monitored to identify the effect of sonication on cavitation-related DO concentration in the solution. From histological results, the sonication decellularization efficiency was better than the other preparation methods. Decellularization efficiency was tended to increase significantly when DO value decreasing after 6 hours of treatment. In conclusion, we conclude that sonication treatment can be used to prepare the complete decellularized scaffolds in short treatment time.

Abstract P1-01-12: A Novel Method for Sentinel Lymph Node Biopsy by Indocyanine Green Fluorescence Technique in Breast Cancer

Background: Sentinel lymph node (SLN) biopsy is the standard method to assess the actual axillary lymph node status in breast cancer. Currently dye techniques, radioisotope techniques or combined techniques are usually used for SLN detection. Recently, near infrared fluorescence imaging has been applied clinically in a breast cancer patient to identify SLN. In this study, the feasibility of SLN biopsy using the indocyanine green (ICG) technique were evaluated.

Methods: The study involved four hundreds eleven patients with clinically node negative early breast cancer who underwent SLN in three institutes. A combination of ICG as a fluorescence emitting source and blue dyes were injected in the subareolar area and lymphatic flows were traced with a charge coupled device camera and a real-time image guided surgery enabled to identify the fluorescence image of SLN after meticulous dissection.

Results: The subcutaneous lymphatic channels were detected precisely in all cases. The identification rate of SLN was 99%, (408/411) with a mean number of 2.3±1.2 (range, 1-9) nodes identified per patient. Only one SLN harvested in 30.1% of patients, two in 29.4%, three in 23.9% and four or more in 15.9% of patients. Thirty nine cases (9.5%) had SLNs involved and all of them were ICG positive and 30 of 39 patients (77%) had one SLN involved.

Conclusions: This ICG fluorescence method is simple and achieves a high SLN identification rate. This technique does not require a facility equipped to use radioisotopes. This means that SLN biopsies could even be performed in a small hospital. Orderly and sequential dissection along the lymphatic flow may provide higher sensitivity compared with the conventional radioisotope method. A direct comparison between the radioisotope and ICG fluorescence methods is now required.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-01-12.

Coronary arterial calcification is associated with albuminuria in type 2 diabetic patient

AIM

Although microalbuminuria has been suggested as an independent risk factor for ischemic heart disease, the relationship between diabetic nephropathy and macroangiopathy remains unclear. Previously, we reported that coronary artery calcification detected by electron beam computed tomography (EBCT) could indicate the degree of coronary atherosclerosis in type 2 diabetic patients. In this study, we examine the association between coronary arterial calcification and microalbuminuria and aortic calcification and microalbuminuria.

METHODS

Two hundred and fifty-six patients, including 177 type 2 diabetic patients (106 patients with normoalbuminuria, 71 with microalbuminuria) and 79 non-diabetic patients were evaluated by assessing the urinary albumin excretion rate and using EBCT to determine a coronary calcification score (CCS) and an aortic calcification score (ACS).

RESULTS

No differences were observed regarding age, smoking index or BMI. Diabetic patients exhibited a greater CCS than non-diabetic subjects (non-diabetes 33 +/- 75 vs. diabetes 203 +/- 467, p < 0.05). Diabetic patients with microalbuminuria exhibited the most advanced CCS (253 +/- 491, p < 0.05). In contrast, no difference was observed in ACS among three groups. Multiple regression analysis showed that CCS is significantly associated with urinary albumin excretion rate as well as age, duration of diabetes and serum creatinine (R(2) = 0.31), while ACS is strongly associated with age, smoking, serum creatinine, systolic blood pressure and low-density lipoprotein cholesterol level (R(2) = 0.29).

CONCLUSION

Increased urinary albumin excretion is associated with coronary arterial calcification in diabetic patients.

Effect of exercise training on serum leptin levels in type 2 diabetic patients

To evaluate the effect of exercise training on serum leptin levels 50 sedentary subjects with type 2 diabetes were enrolled in either 6 weeks of aerobic exercise training with diet therapy (n = 23) or diet therapy alone (n = 27). The training program consisted of walking and cycle ergometer exercise for 1 hour at least 5 times per week, with the intensity of exercise maintained at 50% of maximum oxygen uptake. Serum leptin levels decreased significantly in the exercise training (TR) group (7.2 +/- 3.6 to 4.6 +/- 2.5 ng/mL, P <.05), but not in the sedentary (SED) group (6.9 +/- 3.4 to 5.6 +/- 2.9 ng/mL). Leptin levels standardized for percentage body fat (dividing serum leptin level by percentage body fat) after treatment were lower in the TR subjects compared with the SED subjects. Body weight and percentage body fat decreased in all patients; however, no significant changes were observed in either group. Fasting concentrations of plasma insulin and cortisol and the urinary excretion of 17-hydroxycorticosteroid (17-OHCS) did not differ between the groups either before or after treatment. Fasting plasma glucose and hemoglobin A(1c) (HbA(1c)) improved significantly in both groups, although no significant differences were observed between the groups either before or after treatment. Ventilatory threshold increased significantly in the exercise training subjects. This study demonstrates that exercise training in type 2 diabetic subjects reduces serum leptin levels independent of changes in body fat mass, insulin, or glucocorticoids.

Functional expression of cholecystokinin-A receptor on ventromedial hypothalamic neurons in the immature rat brain

Cholecystokinin-8 (CCK-8) dose-dependently increased the cytosolic Ca2+ concentration ([Ca]i) in ventromedial hypothalamic neurons acutely dissociated from the immature rat brain. The CCK-8 response was mimicked by caerulein, but not by CCK(B) agonists, and was often inhibited by CCK(A) receptor antagonists, but rarely by CCK(B) receptor antagonists. The response was dependent on external Ca2+ and Na+, and was inhibited by voltage-dependent Ca2+ channel blockers. The results suggest that CCK-8-induced depolarization via CCK(A) receptors increased Ca2+ influx through a voltage-dependent Ca2+ channel, which in turn increased [Ca]i.

Activation of ATP receptor increases the cytosolic Ca(2+) concentration in nucleus accumbens neurons of rat brain

ATP increased the cytosolic Ca(2+) concentration ([Ca](i)) in nucleus accumbens neurons acutely dissociated from rat brain. The ATP response was dependent on external Ca(2+) and Na(+), and was blocked by voltage-dependent Ca(2+) channel blockers. The results suggest that the ATP-induced depolarization increases Ca(2+) influx resulting in the increase in [Ca](i).

The effect of the antipsychotic drug mosapramine on the expression of Fos protein in the rat brain: comparison with haloperidol, clozapine and risperidone

In this study, we examined the effect of the acute p.o. administration of the antipsychotic drug mosapramine, as well as the antipsychotic drugs clozapine, haloperidol and risperidone, on the expression of Fos protein in the medial prefrontal cortex, nucleus accumbens and dorsolateral striatum of rat brain. The administration of mosapramine (1 or 3 mg/kg) significantly increased the number of Fos protein positive neurons in the medial prefrontal cortex, but not in the dorsolateral striatum. In addition, mosapramine (1, 3 or 10 mg/kg) produced a dose-dependent increase in the number of Fos protein positive neurons in the nucleus accumbens. The acute administration of 10 mg/kg of mosapramine significantly increased the number of Fos protein positive neurons in all brain regions. The acute administration of clozapine (30 mg/kg), similarly to mosapramine at lower doses (1 or 3 mg/kg), significantly increased the number of Fos protein positive neurons in the medial prefrontal cortex and nucleus accumbens, but not dorsolateral striatum. In contrast, haloperidol (0.3 mg/kg) significantly increased the number of Fos protein positive neurons in the nucleus accumbens and dorsolateral striatum, but not medial prefrontal cortex. The acute administration of risperidone (0.3 or 1 mg/kg) did not affect the number of Fos protein positive neurons in the medial prefrontal cortex, nucleus accumbens or dorsolateral striatum of rat brain, whereas a 3 mg/kg dose of risperidone significantly increased the number of Fos protein positive neurons in all brain regions. These results suggest that the ability of mosapramine to enhance expression of Fos protein in the medial prefrontal cortex may contribute to a clozapine-like profile with respect to actions on negative symptoms in schizophrenia. Furthermore, the lack of effect of low doses of mosapramine on Fos protein expression in the dorsolateral striatum, an area believed to play a role in movement, suggests that it may have a lower tendency to induce neurological side effects.

Pharmacological hepatic preconditioning: involvement of 70-kDa heat shock proteins (HSP72 and HSP73) in ischaemic tolerance after intravenous administration of doxorubicin

BACKGROUND

Pharmacological preconditioning may induce a stress response which protects liver against ischaemia-reperfusion injury (IRI). The aim of this study was to determine, in an animal model, whether intravenous administration of doxorubicin induces heat shock proteins (HSPs) in liver tissue and facilitates liver tolerance to subsequent warm IRI.

METHODS

Male Wistar rats were used. Production of HSPs was determined in liver tissue sequentially after the injection of doxorubicin 1 mg/kg body-weight. Acquisition of tolerance for 30 min warm ischaemia and reperfusion of the liver was determined in animals pretreated (48 h beforehand) with doxorubicin, and in controls. Biochemical liver function and liver adenine nucleotide concentration 40 min after reperfusion and survival rate at 7 days after the ischaemic insult were recorded.

RESULTS

Expression of HSP72 and HSP73 in the liver was confirmed 48 h after doxorubicin administration. Biochemical parameters and survival rates were significantly better in pretreated animals than in controls.

CONCLUSION

These results indicate that doxorubicin has the potential to provide the liver with tolerance against IRI. A simultaneous increase of both HSP72 and HSP73 in liver tissue may explain the acquisition of tolerance following the administration of doxorubicin.

Effects of antipsychotic drugs on neurotoxicity, expression of fos-like protein and c-fos mRNA in the retrosplenial cortex after administration of dizocilpine

In this study, we examined the effect of clozapine, olanzapine, risperidone and haloperidol on the neuropathology (i.e. neuronal vacuolization) and the expression of Fos-like protein and c-fos mRNA in the retrosplenial cortex of female Sprague-Dawley rats induced by the NMDA receptor antagonist dizocilpine. Pretreatment (15 min) with clozapine or olanzapine, but not risperidone or haloperidol, blocked the neuronal vacuolization produced by dizocilpine (0.5 mg/kg, s.c.) in the rat retrosplenial cortex in a dose-dependent manner. Furthermore, pretreatment (15 min) with clozapine or olanzapine, but not risperidone or haloperidol, significantly attenuated the expression of Fos-like protein in the retrosplenial cortex induced by dizocilpine (0.5 mg/kg, s.c.) in a dose-dependent manner. The marked expression of c-fos mRNA in the rat retrosplenial cortex induced by the administration of dizocilpine (0.5 mg/kg, s.c.) was significantly attenuated by pretreatment (15 min) with clozapine (10 mg/kg) or olanzapine (10 mg/kg), but not risperidone (10 mg/kg) or haloperidol (10 mg/kg). The present results suggest that pharmacologically relevant doses of clozapine or olanzapine, but not risperidone or haloperidol, block the neuropathological changes and the expression of Fos-like protein and c-fos mRNA in the rat retrosplenial cortex elicited by the administration of dizocilpine. It is possible that the blockade of dizocilpine-induced neuropathological changes by clozapine and olanzapine may be related to the unique antipsychotic actions of these drugs in schizophrenic patients, although this remains to be verified.

Effects of geranyl-geranyl-acetone administration before heat shock preconditioning for conferring tolerance against ischemia-reperfusion injury in rat livers

The effect of geranyl-geranyl-acetone (GGA) administration before heat shock preconditioning on heat shock protein (HSP) 72 induction and on the acquisition of tolerance against ischemia-reperfusion Injury was studied in rat livers. Male Wistar rats were divided into four groups: a control group (group C); a GGA group (group G); a simple heat shock group (group VH); and a heat shock with GGA premedication group (group GH). Five-, 10-, and 15-minute periods of heat shock preconditioning at 42 degrees C were performed in groups VH and GH. Subgroups were determined according to the period of heat shock exposure. After a 48-hour recovery, rats in groups C, VH5, VH15, and GH5 received a 30-minute period of hepatic ischemia. Induction of HSP72, survival rates, and changes in biochemical and histologic parameters were compared among the groups. Five-minute heat shock preconditioning was not enough to Induce HSP72. However, livers in group GH5 expressed approximately the same amount of HSP72 as those in group VH15. The expression of HSP72 in group GH15 was stronger than that found in group VH15. The degree and location of HSP72 expression were not different between groups GH5 and VH15. Seven-day survival was significantly better in groups GH5 (16/16) and VH15 (15/16) than in group C (8/16) or VH5 (9/16). The recovery of adenosine triphosphate in liver tissue was faster, and the release of liver-related enzymes during reperfusion was lower in groups GH5 and VH15 than in group C or VH5. Administration of GGA before heat shock preconditioning augmented the induction of HSP72 by decreasing the threshold for triggering the stress response.

Heat-shock preconditioning reduces oxidative protein denaturation and ameliorates liver injury by carbon tetrachloride in rats

Membrane lipids and cytosolic proteins are major targets of oxidative injury. This study examined the effect of heat-shock preconditioning associated with the induction of heat-shock protein 72 on liver injury, from the aspect of lipid peroxidation and protein denaturation after carbon tetrachloride (CCl4) administration in rats--one of the representative oxidative injuries. Male Wistar rats were divided into two groups, group HS (preconditioned by heat exposure) and group C (not preconditioned). Expression of HSP72 in the liver tissue was confirmed by Western blot analysis. After a 48-h recovery period, all rats were given CCl4 intragastrically. Liver damage was assessed by measuring serum liver-related enzyme levels and adenine nucleotide concentration in the liver tissue. Lipid peroxidation and protein denaturation were evaluated by measuring tiobarbituric acid reactive substances (TBARS) and by immunohistochemical staining of 4-hydroxy-2-nonenal(HNE)-modified proteins in the liver. Survival rates of the rats after CCl4 administration were also compared. Expression of HSP72 was clearly detected in group HS, but not in group C. Heat-shock preconditioning significantly improved the survival rate, suppressed the increase in liver-related enzyme levels and maintained adenosine triphosphate levels (P<0.01 each). HNE-modified proteins--denatured proteins by free radical attack--were significantly less stained in group HS than in group C (P<0.05). However, TBARS levels did not differ between groups. Because heat-shock preconditioning did not alter TBARS levels but reduced HNE-modified proteins in association with the expression of HSP72, it is suggested that HSP72 did not prevent lipid peroxidation but decreased the lipid peroxidation-induced denaturation of proteins. This seemed to be a mechanism of heat-shock preconditioning to ameliorate oxidative liver injury.

The augmentative effect of repeated heat shock preconditioning on the production of heat shock protein 72 and on ischemic tolerance in rat liver tissue

OBJECTIVE

Heat shock pretreatment induces heat shock protein (HSP)72 strongly in rat livers and provides the tolerance against subsequent ischemia-reperfusion injury. In this study, the effects of repeated heat shock pretreatment on the production of HSP72 in rat livers and on subsequent ischemic tolerance were investigated.

METHODS

Rats pretreated with repeated heat shock were compared with those that received a single heat shock pretreatment. The production of HSP72 was analysed using Western-blotting and densitometer. At 48 h after heat shock pretreatment, all rats were subjected to warm liver ischemia for 30 or 45 min and then reperfused. Survival rate of the animals and liver functions during reperfusion were analysed.

RESULTS

The production of HSP72 increased in the repeated heat shock group more than in the single heat shock group. Although there were no significant differences in animal survival or in liver functions after a 30-min ischemia between the single heat shock group and the repeated heat shock group, animal survival and liver functions after a 45-min ischemia were significantly better in the repeated heat shock group.

CONCLUSION

In rats, repetition of heat shock pretreatment augmented the production of HSP72 in liver tissue and protected the liver from ischemia-reperfusion injury.

Dizocilpine-induced neuropathological changes in rat retrosplenial cortex are reversed by subsequent clozapine treatment

In this study, we examined the effect of post-treatment with clozapine on the neuropathological changes in the rat retrosplenial cortex induced by the administration of non-competitive NMDA receptor antagonist dizocilpine ((+)-MK-801). The maximal increase in vacuolized neurons, which are representative of neuropathology, was observed 4 hours after a single injection of dizocilpine (0.5 mg/kg s.c.), with a complete reversal of the neuropathology after 16-24 hours. The administration of clozapine (10 mg/kg, i.p.,) 4 hours after the administration of dizocilpine significantly decreased the number of vacuolized neurons in the retrosplenial cortex 6, 8 or 10 hours after administration of dizocilpine, compared to vehicle-treated animals. Furthermore, the administration of clozapine (5, 10 or 20 mg/kg i.p.) 4 hours after the administration of dizocilpine produced a significant decrease in the number of vacuolized neurons in the retrosplenial cortex in a dose-dependent manner when measure 6 hours post-dizocilpine. These results show that neuropathological changes in the rat retrosplenial cortex produced by dizocilpine can be attenuated by post-treatment with clozapine.