Analysis of White Matter Damage in Patients with Multiple Sclerosis via a Novel In Vivo MR Method for Measuring Myelin, Axons, and G-Ratio

BACKGROUND AND PURPOSE

Myelin and axon volume fractions can now be estimated via MR imaging in vivo, as can the g-ratio, which equals the ratio of the inner to the outer diameter of a nerve fiber. The purpose of this study was to evaluate WM damage in patients with MS via this novel MR imaging technique.

MATERIALS AND METHODS

Twenty patients with relapsing-remitting MS with a combined total of 149 chronic plaques were analyzed. Myelin volume fraction was calculated based on simultaneous tissue relaxometry. Intracellular and CSF compartment volume fractions were quantified via neurite orientation dispersion and density imaging. Axon volume fraction and g-ratio were calculated by combining these measurements. Myelin and axon volume fractions and g-ratio were measured in plaques, periplaque WM, and normal-appearing WM.

RESULTS

All metrics differed significantly across the 3 groups (P < .001, except P = .027 for g-ratio between periplaque WM and normal-appearing WM). Those in plaques differed most from those in normal-appearing WM. The percentage changes in plaque and periplaque WM metrics relative to normal-appearing WM were significantly larger in absolute value for myelin volume fraction than for axon volume fraction and g-ratio (P < .001, except P = .033 in periplaque WM relative to normal-appearing WM for comparison between myelin and axon volume fraction).

CONCLUSIONS

In this in vivo MR imaging study, the myelin of WM was more damaged than axons in plaques and periplaque WM of patients with MS. Myelin and axon volume fractions and g-ratio may potentially be useful for evaluating WM damage in patients with MS.

Temporal mapping of photochemical reactions and molecular excited states with carbon specificity

Photochemical reactions are essential to a large number of important industrial and biological processes. A method for monitoring photochemical reaction kinetics and the dynamics of molecular excitations with spatial resolution within the active molecule would allow a rigorous exploration of the pathway and mechanism of photophysical and photochemical processes. Here we demonstrate that laser-excited muon pump-probe spin spectroscopy (photo-μSR) can temporally and spatially map these processes with a spatial resolution at the single-carbon level in a molecule with a pentacene backbone. The observed time-dependent light-induced changes of an avoided level crossing resonance demonstrate that the photochemical reactivity of a specific carbon atom is modified as a result of the presence of the excited state wavefunction. This demonstrates the sensitivity and potential of this technique in probing molecular excitations and photochemistry.

Abstract P2-04-13: Difference of immune microenvironment between primary and recurrent tumours in breast cancer patients

Background

Immune checkpoint therapy only benefits a fraction of patients, thus huge efforts have been made to develop predictive biomarkers to identify those patients. Immune biomarkers like PD-L1 expression are extremely dynamic and the timing of evaluation, on primary or metastatic disease, may be critical. We have already shown that tumour-infiltrating lymphocytes (TILs) decrease during metastatic progression in triple-negative (TN) and human epidermal growth factor-2 positive (HER2+) breast cancers (Ogiya R, ASCO 2015), suggesting that mechanisms of immune escape contribute and favour the metastatic progression. In this work we aimed to characterize the modulation and changes of specific immune markers during the metastatic spread comparing paired samples from primary and recurrent breast cancers.

Methods

We retrospectively identified 25 patients with HER2+ (n = 14) and TN (n = 11) early breast cancer diagnosed between 1990 and 2009 at Tokai University Hospital, and who subsequently experienced a first regional or distant recurrence confirmed by tumour biopsy/resection. Haematoxylin and eosin-stained slides of these paired samples were evaluated for stromal TILs. Immunohistochemical staining was performed using primary antibodies against CD4, CD8, Foxp3, PD-L1, PD-L2, and HLA-class I.

Results

The sites of first recurrence was the skin (n = 7), brain (n = 6), lymph node (n = 4), lung (n = 3), bone (n = 2), and one of each of bone marrow, liver and muscle. Immunohistochemical evaluations could not be performed in 5 primary tumours and 2 recurrent tumours because of the small quantity of the specimens. The percentage of CD8+ T cells staining in the primary tumours was significantly higher (median 16%) than that in recurrent tumours (median 10%) (paired t-test, p = 0.008) Similarly, the percentage of CD4+ T cells staining in the primary tumours was significantly higher (median 40%) than that in recurrent tumours (median 25%) (p = 0.026). The percentage of Foxp3+ T cells was low (&lt;10%) and similar in both primary and recurrent tumours (p = 0.16). PD-L1, PD-L2, and HLA class I antibody expression was not statistically different between primary and recurrent tumours, but conversions from positive to negative and vice versa were observed. PD-L1+ staining (≥1%) was 90% and 85% in primary and metastatic tumours, respectively.

Comparison of positivity rate between primary and recurrent tumours for each antibody Primary tumourRecurrent tumourPTotal breast tumours (N)2023 TILs positivity rate, median (%)   CD440%25%.03CD816%10%.01Foxp3&lt;10%&lt;10%.16Expression in tumour cells (N)   PD-L1   Strong85.46Weak1015 Negative23 PD-L2   Strong69.78Weak1011 Negative43 HLA   Strong46.89Weak1415 Negative22 

Conclusions

Tumours at first metastatic recurrence in HER2+ and TN breast cancers have a lower percentage of both CD8+ and CD4+ T cells compared to primary tumours, confirming a potential role of immune escape in tumour progression. Other immune markers, including PD-L1, were not found to change significantly, but negative/positive conversions were observed. This suggest that an evaluation of disease at the time of immunotherapy administration might be more informative. These findings warrant larger confirmation studies.

Citation Format: Ogiya R, Niikura N, Kumaki N, Bianchini G, Kitano S, Iwamoto T, Hayashi N, Yokoyama K, Oshitanai R, Terao M, Morioka T, Tsuda B, Okamura T, Saito Y, Suzuki Y, Tokuda Y. Difference of immune microenvironment between primary and recurrent tumours in breast cancer patients [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 P2-04-13.

Abstract P3-13-11: Utility of LigaSureTM vessel-sealing device in axillary dissection for breast cancer surgery: A randomized single center study

Introduction

Axillary lymph node dissection is standard therapy for patients with positive-node breast cancer, and can be performed with an electrocautery scalpel and suture ligation in most cases. However, knot slipping can occur during suture ligation and this can spread thermal damage to peripheral tissues. The LigaSureTM Small Jaw vessel-sealing system was developed as an alternative to suture ligatures, staplers, and other energy-dependent devices for sealing blood and lymphatic vessels, but its use in axillary dissection for breast cancer is limited. We prospectively compared the duration until drain removal after surgery, total lymph fluid drainage volume, intraoperative blood loss, and incidence of complications after axillary dissections, between this device and conventional methods.

Methods

This prospective randomized study was conducted at the Department of Breast and Endocrine Surgery at Tokai University School of Medicine, Kanagawa, Japan, between October 2011 and March 2015. Major eligibility criteria included (1) pathologically confirmed breast cancer diagnosis, (2) age ≥20 and ≤80 years, and (3) a signed informed consent form. The primary endpoint was duration until drain removal after surgery. The secondary endpoints were total lymph fluid drainage volume, intraoperative blood loss, and incidence of postoperative surgical complications. We defined the criterion for drain removal as a lymph fluid drainage volume of &lt;40 mL/day for two consecutive days.The target accrual was 100 patients, with a two-sided error rate of 5%, and 90% power. The assumed duration until drain removal after surgery was 7.2 days in the control group (conventional use of an electrocautery scalpel and suture ligation) and 5.8 days in the study group (use of the LigaSureTM Small Jaw). This clinical study was approved by the Institutional Review Board of the Tokai University School of Medicine and is registered with UMIN (No. 000013034).

Results

Initially, 100 patients were assigned as eligible; however, two patients were later excluded because of the exclusion criteria. Of 98 patients, 49 were randomized to the study group, and 49 to the control group. The mean duration until drain removal after surgery was 5.2 days in the study group and 5.0 days in the control group (p=0.573). The mean total lymph fluid drainage volumes were 260.3 and 233.5 mL (p=0.502), and the mean intraoperative blood loss volumes were 17.8 and 18.0 mL (p=0.949), for the study and control groups, respectively. No significant differences were found between the two groups regarding drain removal duration, total drainage volume, and intraoperative blood loss volume. Both groups had low incidence rates of postoperative hematoma, wound infection, lymphedema, and pain, and had similar incidence rates of seroma formation after drain removal.

Conclusion

Our study results indicated that the use of the LigaSureTM Small Jaw in axillary dissection for breast cancer was as safe as conventional methods. However, using the LigaSureTM Small Jaw did not improve surgical outcomes such as duration until drain removal and total lymph fluid drainage volume compared with conventional methods.

Citation Format: Okamura T, Niikura N, Yokoyama K, Ogiya R, Oshitanai R, Terao M, Morioka T, Tsuda B, Saito Y, Suzuki Y, Tokuda Y. Utility of LigaSureTM vessel-sealing device in axillary dissection for breast cancer surgery: A randomized single center study [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 P3-13-11.

Synthetic MRI in the Detection of Multiple Sclerosis Plaques

BACKGROUND AND PURPOSE

Synthetic MR imaging enables the creation of various contrast-weighted images including double inversion recovery and phase-sensitive inversion recovery from a single MR imaging quantification scan. Here, we assessed whether synthetic MR imaging is suitable for detecting MS plaques.

MATERIALS AND METHODS

Quantitative and conventional MR imaging data on 12 patients with MS were retrospectively analyzed. Synthetic T2-weighted, FLAIR, double inversion recovery, and phase-sensitive inversion recovery images were produced after quantification of T1 and T2 values and proton density. Double inversion recovery images were optimized for each patient by adjusting the TI. The number of visible plaques was determined by a radiologist for a set of these 4 types of synthetic MR images and a set of conventional T1-weighted inversion recovery, T2-weighted, and FLAIR images. Conventional 3D double inversion recovery and other available images were used as the criterion standard. The total acquisition time of synthetic MR imaging was 7 minutes 12 seconds and that of conventional MR imaging was 6 minutes 29 seconds The lesion-to-WM contrast and lesion-to-WM contrast-to-noise ratio were calculated and compared between synthetic and conventional double inversion recovery images.

RESULTS

The total plaques detected by synthetic and conventional MR images were 157 and 139, respectively (P = .014). The lesion-to-WM contrast and contrast-to-noise ratio on synthetic double inversion recovery images were superior to those on conventional double inversion recovery images (P = .001 and < 0.001, respectively).

CONCLUSIONS

Synthetic MR imaging enabled detection of more MS plaques than conventional MR imaging in a comparable acquisition time. The contrast for MS plaques on synthetic double inversion recovery images was better than on conventional double inversion recovery images.

The new high field photoexcitation muon spectrometer at the ISIS pulsed neutron and muon source

A high power pulsed laser system has been installed on the high magnetic field muon spectrometer (HiFi) at the International Science Information Service pulsed neutron and muon source, situated at the STFC Rutherford Appleton Laboratory in the UK. The upgrade enables one to perform light-pump muon-probe experiments under a high magnetic field, which opens new applications of muon spin spectroscopy. In this report we give an overview of the principle of the HiFi laser system and describe the newly developed techniques and devices that enable precisely controlled photoexcitation of samples in the muon instrument. A demonstration experiment illustrates the potential of this unique combination of the photoexcited system and avoided level crossing technique.

Utility of a Multiparametric Quantitative MRI Model That Assesses Myelin and Edema for Evaluating Plaques, Periplaque White Matter, and Normal-Appearing White Matter in Patients with Multiple Sclerosis: A Feasibility Study

BACKGROUND AND PURPOSE

T1 and T2 values and proton density can now be quantified on the basis of a single MR acquisition. The myelin and edema in a voxel can also be estimated from these values. The purpose of this study was to evaluate a multiparametric quantitative MR imaging model that assesses myelin and edema for characterizing plaques, periplaque white matter, and normal-appearing white matter in patients with MS.

MATERIALS AND METHODS

We examined 3T quantitative MR imaging data from 21 patients with MS. The myelin partial volume, excess parenchymal water partial volume, the inverse of T1 and transverse T2 relaxation times (R1, R2), and proton density were compared among plaques, periplaque white matter, and normal-appearing white matter.

RESULTS

All metrics differed significantly across the 3 groups (P < .001). Those in plaques differed most from those in normal-appearing white matter. The percentage changes of the metrics in plaques and periplaque white matter relative to normal-appearing white matter were significantly more different from zero for myelin partial volume (mean, -61.59 ± 20.28% [plaque relative to normal-appearing white matter], and mean, -10.51 ± 11.41% [periplaque white matter relative to normal-appearing white matter]), and excess parenchymal water partial volume (13.82 × 10³ ± 49.47 × 10³% and 51.33 × 10² ± 155.31 × 10²%) than for R1 (-35.23 ± 13.93% and -6.08 ± 8.66%), R2 (-21.06 ± 11.39% and -4.79 ± 6.79%), and proton density (23.37 ± 10.30% and 3.37 ± 4.24%).

CONCLUSIONS

Multiparametric quantitative MR imaging captures white matter damage in MS. Myelin partial volume and excess parenchymal water partial volume are more sensitive to the MS disease process than R1, R2, and proton density.

Validity and reliability of the Family Empowerment Scale for caregivers of adults with mental health issues

WHAT IS KNOWN ON THE SUBJECT?: Empowerment of family caregivers of adults with mental health issues has received increasing attention among mental health nurses in Japan and has been recognized as a new goal of family interventions. The Family Empowerment Scale (FES) was originally developed to measure the empowerment status of parents of children with emotional disorders. However, it was later applied to broader health issues. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: We developed a Japanese version of the FES for family caregivers of adults with mental health issues (FES-AMJ) and examined the validity and reliability among parents. Results showed that the FES-AMJ had acceptable concurrent validity and reliability; however, insufficient construct validity was found, especially for the subscale regarding the service system. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Further studies need to modify the scale. Clarification of ideal family empowerment status in the service system through discussion with mental health nurses and family caregivers may be important.

ABSTRACT

Introduction The Family Empowerment Scale (FES) was originally developed for parents of children with emotional disorders. In Japan, family empowerment is gaining increasing attention and may be one goal of nursing interventions. Aim To develop a Japanese version of the FES for family caregivers of adults with mental health issues and to study the validity and reliability of this scale among parents. Method We translated the FES into Japanese and administered this self-report questionnaire to 275 parents. Results The multitrait scaling analysis revealed acceptable convergent validity and insufficient discriminant validity among all subscales. In particular, all items of the Service system subscale had insufficient discriminant and/or convergent validity. Each subscale significantly correlated with the indicator of empowerment. The intraclass correlation coefficients of each subscale were .855-.917. Cronbach's alpha of each factor ranged from .867 to .895. Discussion The Service system subscale may not linearly reflect family empowerment, and instead may depend on unclear roles of family caregivers of adults, disorder severity or insufficient services. Implications for practice Further studies need to modify the scale. Clarification of ideal family empowerment status in the service system through discussion with mental health nurses and family caregivers may be important.

Resilient help to switch and overlap hierarchical subsystems in a small human group

Groups of social organisms in nature are resilient systems that can overcome unpredicted threats by helping its members. These social organisms are assumed to behave both autonomously and cooperatively as individuals, the helper, the helped and other part of a group depending on the context such as emergencies. However, the structure and function of these resilient actions, such as how helpers help colleagues and how the helper’s action is effective at multiple subsystem scales remain unclear. Here we investigated the behaviour of organised and efficient small human groups in a ballgame defence, and identified three principles of hierarchical resilient help when under attack. First, at a present high emergency level, the helper simply switched the local roles in the attacked subsystem with the helped. Second, at an intermediate emergency level, the helpers effectively acted in overlapping subsystems. Third, for the most critical emergency, the helpers globally switched the action on the overall system. These resilient actions to the benefit of the system were assumed to be observed in only humans, which help colleagues at flexibly switched and overlapped hierarchical subsystem. We suggest that these multi-layered helping behaviours can help to understand resilient cooperation in social organisms and human groups.

X-ray topography using the forward transmitted beam under multiple-beam diffraction conditions

X-ray topographs are taken for a sapphire wafer with the [0001] surface normal, as an example, by forward transmitted synchrotron x-ray beams combined with two-dimensional electronic arrays in the x-ray detector having a spatial resolution of 1 μm. They exhibit no shape deformation and no position shift of the dislocation lines on the topographs. Since the topography is performed under multiple-beam diffraction conditions, the topographic images of a single diffraction (two-wave approximation condition) or plural diffractions (six-wave approximation condition) can be recorded without large specimen position changes. As usual Lang topographs, it is possible to determine the Burgers vector of each dislocation line. Because of high parallelism of the incoming x-rays and linear sensitivity of the electronic arrays to the incident x-rays, the present technique can be used to visualize individual dislocations in single crystals of the dislocation density as high as 1 × 10(5) cm(-2).

Effects of mineralocorticoid receptor antagonists in patients with hypertension and diabetes mellitus: a systematic review and meta-analysis

Blood pressure (BP) control is important to ameliorate cardiovascular events in patients with diabetes mellitus (DM). However, achieving the target BP with a single drug is often difficult. The objective of this study was to evaluate the antihypertensive effects of mineralocorticoid receptor antagonists (MRAs) as add-on therapy to renin–angiotensin system (RAS) inhibitor(s) in patients with hypertension and DM. Studies were searched through October 2014 in MEDLINE, Embase and the Cochrane Central Register of Controlled Trials. Randomized, controlled trials or prospective, observational studies regarding concomitant administration of MRA and RAS inhibitor(s) in patients with DM were included. Articles were excluded if the mean systolic BP (SBP) was <130 mm Hg before randomization for interventional studies or at baseline for prospective cohort studies. We identified nine eligible studies (486 patients): five randomized placebo-controlled trials; three randomized active drug-controlled trials; and one single-arm observational study. The mean differences in office SBP and diastolic BP (DBP) between the MRA and placebo groups were −9.4 (95% confidence interval (CI) −12.9 to −5.9) and −3.8 (95% CI, −5.5 to −2.2) mm Hg, respectively. Subgroup analysis results for study type, age, baseline office SBP and follow-up duration were similar to those of the main analysis. MRA mildly increased serum potassium (0.4 mEq l⁻¹; 95% CI, 0.3–0.5 mEq l⁻¹). A consistent reduction of albuminuria across these studies was also demonstrated. MRA further reduced SBP and DBP in patients with hypertension and DM already taking RAS inhibitors. Serum potassium levels should be monitored to prevent hyperkalemia.