Effect of Mastication Muscle Activity on Prefrontal Cortex NIRS Measurement: A Pilot Study

Changes in NIRS signals are related to changes in local cerebral blood flow or oxy-Hb concentration. On the other hand, recent studies have revealed the effect of chewing gum on cognitive performance, stress control etc. which accompanied brain activity in the prefrontal cortex (PFC). However, these relationships are still controversial. To evaluate the chewing effect on PFC, NIRS seems to be a suitable method of imaging such results. When measuring NIRS on PFC, blood volume in superficial tissues (scalp, skin, muscle) might have some affect. The aim of the present study was to clarify the effect of the anterior temporal muscle on NIRS signals during gum chewing. Eight healthy volunteers participated. Two-channel NIRS (HOT-1000, NeU, Japan), which can distinguish total-Hb concentrations in deep tissue and superficial tissue layers, was used. In addition to a conventional optode separation distance of 3.0 cm, Hot 1000 has a short distance of 1.0 cm (NEAR channel) to measure NIRS signals that originate exclusively from surface tissues. NIRS probes were placed at Fp1 and Fp2 in the normal probe setting. The headset was displaced to the left in order to allow the left probe to be placed over the left anterior temporal muscle. In the normal setting, the superficial signal curve shows no notable change; however, the neural (calculated and defined in HOT-1000) and deep curves show an increase during the gum chewing task. At the deviated setting, all three signals show marked changes during the task. Total-Hb concentration in the deviated probe setting is significantly large (p < 0.05) than that of in the normal probe setting. When using gum chewing as a task, it would be better to consider a probe position carefully so that the influence of muscle activity on NIRS signal can be distinguished.

Analysis of volume-phase-grating characteristics that a variety of refractive index distributions influence. Part 2: Analysis of spectral bandwidths and angular bandwidths, and the derivation of these equations

To expand the spectral bandwidths with high diffraction efficiency of volume phase (VP) gratings, it is important to know the influence of a variety of refractive index distributions (RIDs) inside the recording material on the bandwidths. The influence of various graded types of RIDs on the full width at half the maximum of the spectral bandwidth (${\lambda _{\rm FWHM}}$λ_FWHM) and the angular bandwidth (${\theta _{\rm FWHM}}$θ_FWHM) is investigated in the Bragg regime. It becomes clear that various graded types of RIDs influence their bandwidths and the characteristics, and the combination of the RIDs and refractive index modulation (${{ n}_m}$n_m) is the most important factor for obtaining the large bandwidths of VP gratings. Theoretically, the ${\lambda _{\rm FWHM}}$λ_FWHM are obtained as the values of 149.7 nm and 257.6 nm (${{ n}_m} = {0.045}$n_m=0.045) for the wavelengths of 900 nm and 1550 nm, respectively. Furthermore, I have succeeded in developing the expression for ${\lambda _{\rm FWHM}}$λ_FWHM and ${\theta _{\rm FWHM}}$θ_FWHM, using the proportional characteristics of VP gratings investigated in this work. The correlative coupling-length coefficients "G-factors" devised as a variety of RID functions in the previous paper are introduced into them. It is apparent that the derived equations of the bandwidths can be adapted to any graded type of RID that changes continuously from a triangular type to a rectangular type of VP grating, which has not been reported yet. The equations have made it easy to design ${\lambda _{\rm FWHM}}$λ_FWHM and ${\theta _{\rm FWHM}}$θ_FWHM of VP gratings.

Analysis of volume-phase-grating characteristics that a variety of refractive index distributions influence. Part 1: derivation of coupling coefficients and grating thickness, and characteristics of the G-factors

The equations for the coupling coefficient and the grating thickness of volume phase gratings are derived from Maxwell's equations in this work. The equations cover all graded types of refractive index distributions (RIDs) which change continuously from a triangular type to a rectangular type. The functions expressed as various graded types of RIDs, which are proposed in this work, are used among them. Furthermore, the new idea, which is the correlative coupling-length coefficient, is devised for the first time as a variety of RID function, "G-factor." The results based on the coupled mode theory in this work show a very close agreement under 0.2% with the results of the rigorous coupled-wave analysis method. The values of the grating thickness and the G-factor are confirmed with validity. By means of this new method, not only can the grating thickness of any graded type of VP grating which is under the Bragg condition be obtained very easily, but the spectral bandwidths and the angular bandwidths which are not under the Bragg condition can be controlled very easily and the configurations of RIDs can be estimated as well.

P5655Efficacy of new-generation atrial antitachycardia pacing for atrial tachyarrhythmias in patients with left ventricular dysfunction

Background

The progression to persistent atrial fibrillation (AF) is associated with a worse clinical outcome in patients with previous atrial tachyarrhythmias. New-generation atrial antitachycardia pacing (ATP) (Reactive ATP) reduced the progression to persistent AF in patients with pacemaker and preserved left ventricular (LV) function. However, little is known about the efficacy of Reactive ATP in patients with cardiac implantable electronic devices (CIED) and LV dysfunction.

Purpose

We aimed to investigate the efficacy of Reactive ATP for atrial tachyarrhythmias in patients with LV dysfunction (LV ejection fraction [LVEF] <40%).

Methods

This study included 423 patients with CIED and previous atrial tachyarrthythmias. Reactive ATP was programmed in 284 patients (ATP group) and 139 were implanted with a dual-chamber device without ATP function (control group). The differences in the success rate of ATP and incidence of progression to persistent AF (≥7 days) between the ATP and control groups were evaluated in 108 patients with LVEF <40% (reduced LVEF) and 315 with LVEF ≥40% (preserved LVEF). Patients with persistent AF were excluded from this study.

Results

During 710±337 days of follow-up period, 16 patients (15%) with reduced LVEF and 51 (16%) with preserved LVEF progressed to persistent AF (p=0.88). The mean ATP success rate was lower in patients with reduced LVEF than in those with preserved LVEF, although not statistically significant (reduced LVEF: 27.2±19.4% and preserved LVEF: 35.1±29.2%, p=0.12). The incidence of progression to persistent AF was significantly lower in the ATP group than in the control group both in patients with reduced and preserved LVEF (log-rank, reduced LVEF: p=0.0070 and preserved LVEF: p<0.0001) (Figure). Multivariate analysis showed that use of Reactive ATP and smaller left atrium were associated with lower incidences of persistent AF, while LVEF was not predictive of progression to persistent AF (Reactive ATP: hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.17–0.46, p<0.0001, left atrium diameter: HR 1.03, 95% CI 1.00–1.07, p=0.030).

Figure 1

Conclusions

Reactive ATP was effective in preventing AF progression in patients with LV dysfunction.

Role of the Immune System in the Development of the Central Nervous System

The central nervous system (CNS) and the immune system are both intricate and highly organized systems that regulate the entire body, with both sharing certain common features in developmental mechanisms and operational modes. It is known that innate immunity-related molecules, such as cytokines, toll-like receptors, the complement family, and acquired immunity-related molecules, such as the major histocompatibility complex and antibody receptors, are also expressed in the brain and play important roles in brain development. Moreover, although the brain has previously been regarded as an immune-privileged site, it is known to contain lymphatic vessels. Not only microglia but also lymphocytes regulate cognition and play a vital role in the formation of neuronal circuits. This review provides an overview of the function of immune cells and immune molecules in the CNS, with particular emphasis on their effect on neural developmental processes.

Systemic administration of quality- and quantity-controlled PBMNCs reduces bisphosphonate-related osteonecrosis of jaw-like lesions in mice

BACKGROUND

Definitive treatment strategies for bisphosphonate-related osteonecrosis of the jaw (BRONJ) have not been developed. Cell-based therapy is an attractive treatment method for intractable diseases in the medical and dental fields; however, approval has been challenging in dentistry. Recently, we developed quality- and quantity (QQ)-controlled peripheral blood mononuclear cells (PBMNCs) that have anti-inflammatory and pro-angiogenesis effects. The aim of this study was to investigate the effects of QQ-controlled PBMNC transplantation on BRONJ-like lesions in mice.

METHODS

To create high-prevalence BRONJ-like lesions, cyclophosphamide (CY) and zoledronate (ZA) were used with tooth extraction. Drug treatment was performed for 5 weeks. QQ-controlled PBMNC transplantation was performed immediately following tooth extraction of both maxillary first molars at 3 weeks after drug administration. Mice were euthanized at 2 weeks post-extraction. Histomorphometric and immunohistochemical analyses, microcomputed tomography assessment, and quantitative polymerase chain reaction evaluation were conducted using maxillae and long bones.

RESULTS

ZA effects on long bones were noted, regardless of CY. Severely inhibited osseous and soft tissue wound healing of tooth extraction sockets was induced by CY/ZA combination therapy, which was diagnosed as BRONJ-like lesions. QQ-controlled PBMNC transplantation reduced BRONJ-like lesions by improving soft tissue healing with increased M1 and M2 macrophages and enhanced neovascularization in the connective tissue of tooth extraction sockets. QQ-controlled PBMNC transplantation also reduced inflammation by decreasing polymorphonuclear cells and TNF-α expression in the tooth extraction sockets. Additionally, QQ-controlled PBMNC transplantation partially improved osseous healing of tooth extraction sockets. Interestingly, only 20,000 QQ-controlled PBMNCs per mouse induced these transplantation effects. QQ-controlled PBMNC transplantation did not affect the systemic microenvironment.

CONCLUSIONS

Our findings suggest that transplantation of a small amount of QQ-controlled PBMNCs may become novel therapeutic or prevention strategies for BRONJ without any adverse side effects.

Coexistence of Ferromagnetic and Stripe-Type Antiferromagnetic Spin Fluctuations in YFe_{2}Ge_{2}

We report neutron scattering measurements of single-crystalline YFe_{2}Ge_{2} in the normal state, which has the same crystal structure as the 122 family of iron pnictide superconductors. YFe_{2}Ge_{2} does not exhibit long-range magnetic order but exhibits strong spin fluctuations. Like the iron pnictides, YFe_{2}Ge_{2} displays anisotropic stripe-type antiferromagnetic spin fluctuations at (π, 0, π). More interesting, however, is the observation of strong spin fluctuations at the in-plane ferromagnetic wave vector (0, 0, π). These ferromagnetic spin fluctuations are isotropic in the (H, K) plane, whose intensity exceeds that of stripe spin fluctuations. Both the ferromagnetic and stripe spin fluctuations remain gapless down to the lowest measured energies. Our results naturally explain the absence of magnetic order in YFe_{2}Ge_{2} and also imply that the ferromagnetic correlations may be a key ingredient for iron-based materials.

Abstract P2-14-09: A novel nipple aleolar complex involvement predictive index (NACPI) for indicating nipple sparing mastectomy in breast cancer patients

Background: While Preservation of NAC is concerned to increase the risk of local recurrences in the retroareolar glandular tissue, nipple sparing mastectomy (NSM) is increasing in patients with breast cancer and has been shown to result in better cosmetic outcome and the benefit for quality-of-life. It is necessary to predict accurately NAC involvement in order to select which patients may be candidates to NSM. The distance from the nipple to the tumor (DNT) is proposed as one of the best criteria to select the patient. The purpose of this study is to identify the predictors of NAC involvement retrospectively and to develop a clinical predictive model to select the patients who can be offered preservation of NAC.Methods: A total of 168 patients with primary operable breast cancer who received subcutaneous mastectomy for breast reconstruction at Saitama Medical Center during July 2013 to December 2017 were selected from the hospital's surgical database. NAC involvement was defined by the presence of invasive carcinoma and/or ductal carcinoma in situ at the subareolar margin.

Results: Of the 148 patients who were preserved NAC, 89.9% (133/148) were NAC involvement negative and 10.1% (15/148) were positive in permanent pathological specimens. Of the 20 patients who were resected NAC, NAC involvement positivity was only 50.0% (10/20). This revealed that NAC involvement with a sensitivity (SN) of 40.0%, a specificity (SP) of 93.0%, a positive predictive value (PPV) of 50.0% and a negative predictive value (NPV) of 89.9% (AUC=0.665, 95%CI: 0.5345-0.796). In 140 patients who were performed intraoperative sub-nipple frozen section biopsy, the findings was significantly associated with NAC involvement (P&lt;0.001), and which predict the NAC involvement with a SN of 93.3%, a SP of 89.6%, a PPV of 51.9%, and a NPV of 99.1% (AUC=0.915, 95%CI: 0.835-0.994). In the concordance rate between frozen section findings and definitive pathologic results, DCIS was 53% (9/17), atypical cell was 50% (2/4) and invasive ductal carcinoma was 100% (3/3). Correlation between NAC involvement and clinicopathological factors, tumor size ≥4cm (P&lt;0.001), DNT &lt;1cm by MMG (P=0.002), DNT &lt;1cm by MRI (P&lt;0.001), nipple contrast findings by MRI (P&lt;0.001), tumor in central portion (P&lt;0.001), multicentirc/focal lesion (P&lt;0.001), c(N) positive (P=0.014) were significant relation with NAC involvement. Each predictors were scored 0 or 1, and the total score of 0-3 points was defined as low risk, 4 points as intermediate risk, and 5-7 points as high risk. Depending on this categorized classification, the NAC involvement rate was 3.5% (5/142) in low risk, 68.7% (11/16) in intermediate risk, 90.0% (9/10) in high risk and there was a significant correlation between the risk group and NAC involvement (P &lt;0.001). Notably, assuming that NAC is preserved for low risk patients and is resected for intermediate and high risk patients, NACPI contributes to improve the accuracy of selecting the surgical procedures (SN 80.0%, SP 95.8%, PPV 76.9%, NPV 96.5% (AUC=0.879, 95%CI: 0.784-0.974)).Conclusion: This study suggests that NACPI can help us indicating subcutaneous mastectomy for the breast cancer patients who request preserve NAC with more oncological safety.

Citation Format: Seki H, Sakurai T, Shimizu K, Mizuno S, Tokuda T, Kaburagi T, Seki M, Karahashi T, Nakajima K. A novel nipple aleolar complex involvement predictive index (NACPI) for indicating nipple sparing mastectomy in 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 P2-14-09.