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.

Identification and characterization of thermostable glucose dehydrogenases from thermophilic filamentous fungi

FAD-dependent glucose dehydrogenase (FAD-GDH), which contains FAD as a cofactor, catalyzes the oxidation of D-glucose to D-glucono-1,5-lactone, and plays an important role in biosensors measuring blood glucose levels. In order to obtain a novel FAD-GDH gene homolog, we performed degenerate PCR screening of genomic DNAs from 17 species of thermophilic filamentous fungi. Two FAD-GDH gene homologs were identified and cloned from Talaromyces emersonii NBRC 31232 and Thermoascus crustaceus NBRC 9129. We then prepared the recombinant enzymes produced by Escherichia coli and Pichia pastoris. Absorption spectra and enzymatic assays revealed that the resulting enzymes contained oxidized FAD as a cofactor and exhibited glucose dehydrogenase activity. The transition midpoint temperatures (T _m) were 66.4 and 62.5 °C for glycosylated FAD-GDHs of T. emersonii and T. crustaceus prepared by using P. pastoris as a host, respectively. Therefore, both FAD-GDHs exhibited high thermostability. In conclusion, we propose that these thermostable FAD-GDHs could be ideal enzymes for use as thermotolerant glucose sensors with high accuracy.

Aspirin for Stroke Prevention in Elderly Patients With Vascular Risk Factors: Japanese Primary Prevention Project

BACKGROUND AND PURPOSE

The effect of aspirin in primary prevention of stroke is controversial among clinical trials conducted in Western countries, and no data are available for Asian populations with a high risk of intracranial hemorrhage. The objective of this study was to evaluate the effect of aspirin on the risk of stroke and intracranial hemorrhage in the Japanese Primary Prevention Project (JPPP).

METHODS

A total of 14 464 patients (age, 60-85 years) with hypertension, dyslipidemia, and diabetes mellitus participated and were randomized into 2 treatment groups: 100 mg of aspirin or no aspirin. The median follow-up period was 5.02 years.

RESULTS

The cumulative rate of fatal or nonfatal stroke was similar for the aspirin (2.068%; 95% confidence interval [CI], 1.750-2.443) and no aspirin (2.299%; 95% CI, 1.963-2.692) groups at 5 years; the estimated hazard ratio was 0.927 (95% CI, 0.741-1.160; P=0.509). Aspirin nonsignificantly reduced the risk of ischemic stroke or transient ischemic attack (hazard ratio, 0.783; 95% CI, 0.606-1.012; P=0.061) and nonsignificantly increased the risk of intracranial hemorrhage (hazard ratio, 1.463; 95% CI; 0.956-2.237; P=0.078). A Cox regression adjusted by the risk factors for all stroke, which were age >70 years, smoking, and diabetes mellitus, supported the above result.

CONCLUSIONS

Aspirin did not show any net benefit for the primary prevention of stroke in elderly Japanese patients with risk factors for stroke, whereas age >70 years, smoking, and diabetes mellitus were risk factors for stroke regardless of aspirin treatment.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00225849.

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).

IgG4-related Disease with Bone Marrow Involvement

A 61-year-old Japanese woman with anemia, submandibular gland swelling, and enlarged lymph nodes was diagnosed with IgG4-related disease (IgG4-RD) by lymph node biopsy. Bone marrow involvement of IgG4-RD was detected by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and immunohistochemically proven by bone marrow biopsy in this patient. Anemia progressed gradually, and prednisolone treatment was initiated. Anemia and submandibular gland swelling improved soon after prednisolone treatment was initiated. We report a rare case of IgG4-RD involving the bone marrow. FDG-PET/CT and bone marrow biopsy were useful for diagnosis in this case.

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.

Development of Functional Fluorescent Molecular Probes for the Detection of Biological Substances

This review is confined to sensors that use fluorescence to transmit biochemical information. Fluorescence is, by far, the most frequently exploited phenomenon for chemical sensors and biosensors. Parameters that define the application of such sensors include intensity, decay time, anisotropy, quenching efficiency, and luminescence energy transfer. To achieve selective (bio)molecular recognition based on these fluorescence phenomena, various fluorescent elements such as small organic molecules, enzymes, antibodies, and oligonucleotides have been designed and synthesized over the past decades. This review describes the immense variety of fluorescent probes that have been designed for the recognitions of ions, small and large molecules, and their biological applications in terms of intracellular fluorescent imaging techniques.