Observation of edge states derived from topological helix chains

Introducing the concept of topology has revolutionized materials classification, leading to the discovery of topological insulators and Dirac-Weyl semimetals1-3. One of the most fundamental theories underpinning topological materials is the Su-Schrieffer-Heeger (SSH) model4,5, which was developed in 1979-decades before the recognition of topological insulators-to describe conducting polymers. Distinct from the vast majority of known topological insulators with two and three dimensions1-3, the SSH model predicts a one-dimensional analogue of topological insulators, which hosts topological bound states at the endpoints of a chain4-8. To establish this unique and pivotal state, it is crucial to identify the low-energy excitations stemming from bound states, but this has remained unknown in solids because of the absence of suitable platforms. Here we report unusual electronic states that support the emergent bound states in elemental tellurium, the single helix of which was recently proposed to realize an extended version of the SSH chain9,10. Using spin- and angle-resolved photoemission spectroscopy with a micro-focused beam, we have shown spin-polarized in-gap states confined to the edges of the (0001) surface. Our density functional theory calculations indicate that these states are attributed to the interacting bound states originating from the one-dimensional array of SSH tellurium chains. Helices in solids offer a promising experimental platform for investigating exotic properties associated with the SSH chain and exploring topological phases through dimensionality control.

Antiferromagnetic topological insulator with selectively gapped Dirac cones

Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.

Determination of Lycopene Concentration in Fresh Tomatoes by Spectrophotometry: A Collaborative Study

BACKGROUND

Lycopene has been the object of considerable research attention recently, and the effects of the intake of lycopene, or of tomato products, have been studied in various ways. In Japan, interest in the health-promoting function of food components has increased.

OBJECTIVE

Developing a method to determine lycopene contents in tomato that meets the Japanese Agricultural Standard (JAS).

METHOD

In the proposed JAS method, the test sample consists of fresh tomatoes; a hexane-acetone mixture is utilized as the extraction solvent. A collaborative study was conducted to evaluate the interlaboratory performance of the method.

RESULTS

Ten laboratories participated and analyzed six test materials characterized by a lycopene content between 39 and 170 mg/kg as blind duplicates. After removing statistical outliers, RSDr ranged from 1.2 to 3.0% and RSDR ranged from 2.4 to 4.2%. The HorRat values were calculated and found to be in the 0.26-0.49 range.

CONCLUSIONS

The method for determining the lycopene content in tomato was evaluated by means of a collaborative study, and the reproducibility of this method was found to be acceptable.

HIGHLIGHTS

Intended for standardization in Japan, a method to determine lycopene content in tomato has been developed and shown to have acceptable precision in a collaborative study.

Relation of Poor Nutritional Status to Mild Cognitive Impairment in Patients with Coronary Artery Disease

OBJECTIVES

Nutritional status affects cerebral circulation and cognitive function. More attention needs to be paid to nutritional status in coronary artery disease (CAD) patients, yet the relation between nutritional status or dietary intake (DI) and cognitive function or mild cognitive impairment (MCI) in CAD patients remain unclear. Thus, we examined the following relations: 1) that between nutritional status and cognitive function, and MCI and 2) that between DI and cognitive function, and MCI.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a cross-sectional study of 208 patients with CAD but without dementia.

MEASUREMENTS

MCI was estimated with the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Nutritional status was assessed by the Geriatric Nutritional Risk Index (GNRI), and DI was assessed by total energy intake per day. We investigated the relation between nutritional status or DI and cognitive function by Pearson correlation analysis, and that between nutritional status or DI and MCI by multivariable logistic regression analysis.

RESULTS

The GNRI and DI were positively associated with the MoCA-J score (r = 0.23, p < 0.001, and r = 0.24, p < 0.001, respectively), and both were independently associated with MCI in the multivariable logistic regression analysis (odds ratio, 0.96; p = 0.045, and odds ratio, 0.998; p = 0.020, respectively).

CONCLUSIONS

Poor nutritional status and low DI were found to be significantly associated with cognitive function and MCI in CAD patients. Our findings regarding nutritional status and DI might be useful for clinicians to prevent or intervene in the early cognitive decline of inpatients with CAD.

P6491Predictive effect of mitral annular size on persistent mitral valve dysfunction after transcatheter edge-to-edge mitral valve repair for functional mitral regurgitation

Background

In patients with functional mitral regurgitation (FMR), deformation of the mitral valve (MV) apparatus leads to deteriorating coaptation of both leaflets. The MV geometry is essential to predict procedural success of using the MitraClip™ for FMR patients. Persistent such mitral regurgitation (MR) and post-procedural mitral stenosis (MS) are parameters for an increasing mortality rate after MitraClip implantation. The anterior-to-posterior mitral annulus diameter (MAD) is simple to evaluate with a high reproducibility rate. However, the predictive effect has not been determined to date.

Purpose

We evaluated the predictive effect of baseline anterior-to-posterior MAD on persistent MV dysfunctions after MitraClip™ implantation.

Methods

We investigated the prevalence of procedural failure (MR at discharge > grade 2+) and post-procedural MS (mean transmitral gradient (mTMG) at discharge ≥6 mmHg) in a patient cohort with FMR (n=190), who underwent MitraClip™ implantation. We measured the MV apparatus geometry on mid-systole using transoesophageal echocardiography before the index procedure. The MAD was stratified by interquartile ranges (IQR) in the comparison. (≤34 mm, 35 to 37 mm, 38 to 40 mm, and ≥41 mm, respectively)

Results

The mean age was 75±9 years, and 63 patients (33%) were female. The mean left ventricular ejection fraction was 34±14%. Moderate-to-severe (3+) or severe MR (4+) were documented in all patients before the procedure. Transthoracic echocardiography at discharge revealed residual MR (>2+) in 10 patients (5%) and post-procedural MS in 13 patients (7%), in which one patient presented with both residual MR and MS.

After stratification by the IQRs of MAD, there were significant differences in body weight (p<0.001), height (p<0.001), and body surface area (p<0.001), but no significant differences in the other baseline characteristics. Notably, significant differences in the prevalence of procedural failure (p=0.004) and post-procedural MS (p=0.022) were observed among the groups. (Figure) Specifically, in the cohort with the 4th IQR (MAD ≥41 mm, n=44), procedural failure was observed in 7 patients (16%), although the prevalence was only 2% in the other IQR groups. Moreover, the cohorts with the 1st and 2nd IQR presented with higher prevalence of post-procedural MS (6 of 46 patients (13%) in the 1st IQR group, and 6 of 51 (12%) in the 2nd IQR group) than those with the 3rd and 4th IQRs. (1 of 49 patients (2%) in the 3rd IQR, and none of 44 patients in the 4th IQR)

Figure 1

Conclusion

In this analysis we showed that the mitral annulus size affected MV dysfunction after MitraClip™. Anterior-to-posterior MAD was useful to predict the procedural result. For FMR candidates with dilated mitral annulus larger than 40 mm, new-generation MitraClip-XTR™ system or other therapeutic concept such as annuloplasty may be reasonable to obtain satisfactory MV function.

Complete renal response at 12 months after induction therapy is associated with renal relapse-free rate in lupus nephritis: a single-center, retrospective cohort study

Background

Lupus nephritis (LN) is a major risk factor for overall morbidity and mortality in systemic lupus erythematosus (SLE).

Methods

We retrospectively analyzed cases of proliferative and membranous LN patients who underwent a renal biopsy at our hospital in 1993–2016. We analyzed the association between complete renal response (CR) rates at 12 months after induction therapy and predictive factors for CR and their association with renal flares.

Results

Of the 95 cases analyzed, we were able to track the therapeutic responses of 81 patients at 12 months after their induction therapy. The median follow-up duration after renal biopsy was 51 months (interquartile range: 16.5–154.5 months). The Cox proportional hazards model showed that, compared to not attaining CR at 12 months, the attainment of CR at 12 months was correlated with being free from renal flares. The multivariate logistic analysis revealed that the predictive factors for CR at 12 months were the anti-La/SSB antibodies (U/ml) (odds ratio (OR) 1.22, 95% confidence interval (CI) 1.01–1.63, p = 0.0220), blood urea nitrogen (BUN) (OR 0.68, 95% CI 0.44–0.90, p = 0.00048) and serum β2 microglobulin (MG) (OR 0.26, 95% CI 0.06–0.74, p = 0.00098) levels.

Conclusions

Among LN patients, being free from renal flares was associated with attaining CR at 12 months after induction therapy. Anti-La/SSB antibodies were a positive predictive factor, and BUN and serum β2MG levels were negative predictive factors of CR at 12 months.

Factors predictive of long-term mortality in lupus nephritis: a multicenter retrospective study of a Japanese cohort

Background

Lupus nephritis (LN) is a major determinant of mortality in systemic lupus erythematosus (SLE). Here we evaluated the association between complete renal response (CR) and mortality in LN.

Methods

We retrospectively analyzed the cases of 172 of 201 patients with LN for whom data on the therapeutic response at 6 and 12 months after induction therapy were available. The patients underwent a renal biopsy at Nagasaki University Hospital and community hospitals in Nagasaki between the years 1990 and 2016. We determined the CR rates at 6 and 12 months after induction therapy initiation and evaluated the predictive factors for CR and their relationship with mortality. We performed univariate and multivariable competing risks regression analyses to determine the factors predictive of CR. The patients' survival data were analyzed by the Kaplan–Meier method with a log-rank test.

Results

The median follow-up duration after renal biopsy was 120 months (interquartile range: 60.3–191.8 months). The 5-, 10-, 15- and 20-year survival rates of our cohort were 99.3, 94.6, 92.0 and 85.4%, respectively. During follow-up, nine patients (5.2%) died from cardiovascular events, infection, malignancy and other causes. The multivariate analysis revealed that the following factors were predictive of CR. At 6 months: male gender (odds ratio (OR) 0.23, 95% confidence interval (CI) 0.08–0.65, p = 0.0028), proteinuria (g/gCr) (OR 0.83, 95% CI 0.71–0.97, p = 0.0098) and index of activity (0–24) (OR 0.84, 95% CI 0.71–0.99, p = 0.0382). At 12 months: male gender (OR 0.25, 95% CI 0.09–0.67, p = 0.0043) and index of activity (0–24) (OR 0.82, 95% CI 0.69–0.98, p = 0.0236). The Kaplan–Meier analysis showed that compared to not achieving CR at 12 months, achieving CR at 12 months was significantly correlated with the survival rate (OR 0.18, 95% CI 0.04–0.92, p = 0.0339).

Conclusions

Our results suggest that the survival rate of patients with LN is associated with the achievement of CR at 12 months after induction therapy, and that male gender and a higher index of activity (0–24) are the common predictive factors for failure to achieve CR at 6 and 12 months.

Sphingomyelin Phosphodiesterase 3 Enhances Cytodifferentiation of Periodontal Ligament Cells

Sphingomyelin phosphodiesterase 3 ( Smpd3), which encodes neutral sphingomyelinase 2 (nSMase2), is a key molecule for skeletal development as well as for the cytodifferentiation of odontoblasts and alveolar bone. However, the effects of nSMase2 on the cytodifferentiation of periodontal ligament (PDL) cells are still unclear. In this study, the authors analyzed the effects of Smpd3 on the cytodifferentiation of human PDL (HPDL) cells. The authors found that Smpd3 increases the mRNA expression of calcification-related genes, such as alkaline phosphatase (ALPase), type I collagen, osteopontin, Osterix (Osx), and runt-related transcription factor (Runx)-2 in HPDL cells. In contrast, GW4869, an inhibitor of nSMase2, clearly decreased the mRNA expression of ALPase, type I collagen, and osteocalcin in HPDL cells, suggesting that Smpd3 enhances HPDL cytodifferentiation. Next, the authors used exome sequencing to evaluate the genetic variants of Smpd3 in a Japanese population with aggressive periodontitis (AgP). Among 44 unrelated subjects, the authors identified a single nucleotide polymorphism (SNP), rs145616324, in Smpd3 as a putative genetic variant for AgP among Japanese people. Moreover, Smpd3 harboring this SNP did not increase the sphingomyelinase activity or mRNA expression of ALPase, type I collagen, osteopontin, Osx, or Runx2, suggesting that this SNP inhibits Smpd3 such that it has no effect on the cytodifferentiation of HPDL cells. These data suggest that Smpd3 plays a crucial role in maintaining the homeostasis of PDL tissue.

Relationship between Metabolic Syndrome and Number of Teeth in Japan

The 2004 Japanese National Health and Nutrition Survey collected data on several measures, including self-reported dental health. In addition, this was the first nationwide survey to focus on metabolic syndrome (MetS) in Japan. Therefore, the authors used this nationwide data set to assess the relationship between number of teeth present and MetS. Anonymized data were available with permission from the Ministry of Health, Labour and Welfare of Japan. Data from 3,195 men and women aged 35 to 99 y were examined, and logistic regression analyses were used to evaluate the association between number of teeth and MetS. Moreover, the authors performed an analysis of covariance to compare the mean number of teeth between those with and those without MetS, after adjusting for confounders. In comparison with those having ≥28 teeth, those with fewer remaining teeth demonstrated significantly higher odds of having MetS. Specifically, those having 1 to 9 teeth had higher odds of having MetS than those with more teeth and were more than twice as likely to be affected than those with ≥28 teeth. Furthermore, individuals with MetS in the age groups of 45 to 54, 55 to 64, and 65 to 74 y had significantly fewer teeth than those without MetS in the same age groups. These results suggest that the number of teeth present is associated with the prevalence of MetS in the Japanese population. Knowledge Transfer Statement: The results of this study can be used by clinicians when they examine patients with periodontal disease or extensive tooth loss to refer for a general medical examination.

High glucose-induced oxidative stress increases IL-8 production in human gingival epithelial cells

OBJECTIVE

Diabetes is often associated with increased prevalence and severity of periodontal disease. We hypothesized that gingival epithelial cells modify periodontal disease progression and predicted that hyperglycemia would activate an inflammatory response in human gingival epithelial cells (HGECs).

MATERIALS AND METHODS

We tested our hypothesis in immortalized HGECs (epi 4 cells) isolated from periodontal tissue and transfected with the simian virus 40 T antigen. The epi 4 cells were cultured in high (25 mM, HG) and normal (6 mM, NG) glucose conditions.

RESULTS

The epi 4 cells showed increased interleukin-8 (IL-8) protein secretion and mRNA expression when cultured in HG, compared with in NG. These effects were not associated with increased cell proliferation and were not observed in a hyperosmolar control group (normal glucose with 19 mM mannitol). Increased IL-8 secretion in HG was inhibited by pretreatment with an antioxidant, N-acetylcysteine, or a protein kinase C inhibitor, Ro31-8220. Hyperglycemia did not affect IL-8 secretion by gingival fibroblasts or periodontal ligament cells. In epi 4 cells, hyperglycemia also induced expression of toll-like receptor 2 (TLR2) but not TLR4.

CONCLUSION

These findings suggest a potential participation of epithelial cells in periodontal disease during diabetes by evoking an excessive host inflammatory response.