Fluorine-19 Magnetic Resonance Imaging for Detection of Amyloid ß Oligomers Using a Keto Form of Curcumin Derivative in a Mouse Model of Alzheimer's Disease.

Recent evidence suggests that the formation of soluble amyloid ß (Aß) aggregates with high toxicity, such as oligomers and protofibrils, is a key event that causes Alzheimer's disease (AD). However, understanding the pathophysiological role of such soluble Aß aggregates in the brain in vivo could be difficult due to the lack of a clinically available method to detect, visualize, and quantify soluble Aß aggregates in the brain. We had synthesized a novel fluorinated curcumin derivative with a fixed keto form, named as Shiga-Y51, which exhibited high selectivity to Aß oligomers in vitro. In this study, we investigated the in vivo detection of Aß oligomers by fluorine-19 (19F) magnetic resonance imaging (MRI) using Shiga-Y51 in an APP/PS1 double transgenic mouse model of AD. Significantly high levels of 19F signals were detected in the upper forebrain region of APP/PS1 mice compared with wild-type mice. Moreover, the highest levels of Aß oligomers were detected in the upper forebrain region of APP/PS1 mice in enzyme-linked immunosorbent assay. These findings suggested that 19F-MRI using Shiga-Y51 detected Aß oligomers in the in vivo brain. Therefore, 19F-MRI using Shiga-Y51 with a 7 T MR scanner could be a powerful tool for imaging Aß oligomers in the brain.

Effects of wearing supportive underwear versus pelvic floor muscle training or no treatment in women with symptoms of stress urinary incontinence: an assessor-blinded randomized control trial.

INTRODUCTION AND HYPOTHESIS: In our previous single-arm pilot study, we reported that ready-made supportive underwear (shaper) was effective in elevating the bladder neck and reducing urinary incontinence (UI) symptoms. The aim of this study was to determine the effects of wearing a shaper compared with pelvic floor muscle training (PFMT) at home using a training compact disc with music, or no treatment, in an assessor-blinded randomized control trial, on reducing UI symptoms. METHODS: Participants aged 30-59 years with symptoms of stress urinary incontinence were randomly assigned to three groups: the shaper group, PFMT group, and no treatment group. The UI episodes/week and the Japanese version of the International Consultation on Incontinence Questionnaire Short-Form were compared between the baseline and the 6th or 12th week of the intervention period. RESULTS: Eighty-nine women who completed the 12-week intervention period were analyzed. After the 12-week intervention period, the improvement rate in UI symptoms (ratio of the case number in which the UI episodes/week decreased at least 50% from the baseline) was 73.3% (22/30 women) in the shaper group, 74.2% (23/31 women) in the PFMT group, and 25.0% (7/28 women) in the no treatment group. The improvement rate in UI symptoms in the shaper and PFMT groups was significantly higher than that in the no treatment group (both P < 0.001). CONCLUSIONS: Wearing supportive underwear (shaper) was almost as effective as PFMT at home in reducing UI symptoms.

Relationship Between Cervical, Thoracic, and Lumbar Spinal Alignments in Automotive Seated Posture.

The purpose of this study was to investigate the relationship between cervical, thoracic, and lumbar spinal alignments in one automotive occupant seated posture. An image dataset of the spinal column in the automotive seated posture, previously acquired by an upright open magnetic resonance imaging (MRI) system, was re-analyzed in this study. Spinal alignments were presented by the geometrical centers of the vertebral bodies extracted from the image data. Cervical, thoracic, and lumbar spinal alignments were analyzed separately with multidimensional scaling (MDS). Based on distribution maps of cervical, thoracic, and lumbar spinal alignments created by MDS, representative spinal alignment patterns of the cervical, thoracic, and lumbar spines and the relationship between cervical, thoracic, and lumbar spinal alignments were investigated. As a result, this study found a correlation between cervical and thoracic spinal alignments in an automotive occupant seated posture. According to representative spinal alignment patterns illustrated by the distribution map of spinal alignments, subjects who had kyphotic cervical spinal alignment tended to have less kyphotic thoracic spinal alignment, while subjects who had lordotic cervical spinal alignment tended to have more kyphotic thoracic spinal alignment. For lumbar spinal alignments, no prominent relationship was found between cervical and thoracic spinal alignment in the seated condition of this study.

Fluorine-19 magnetic resonance imaging probe for the detection of tau pathology in female rTg4510 mice.

Aggregation of tau into neurofibrillary tangles (NFTs) is characteristic of tauopathies, including Alzheimer's disease. Recent advances in tau imaging have attracted much attention because of its potential contributions to early diagnosis and monitoring of disease progress. Fluorine-19 magnetic resonance imaging (19 F-MRI) may be extremely useful for tau imaging once a high-quality probe has been formulated. In this investigation, a novel fluorine-19-labeling compound has been developed as a probe for tau imaging using 19 F-MRI. This compound is a buta-1,3-diene derivative with a polyethylene glycol side chain bearing a CF3 group and is known as Shiga-X35. Female rTg4510 mice (a mouse model of tauopathy) and wild-type mice were intravenously injected with Shiga-X35, and magnetic resonance imaging of each mouse's head was conducted in a 7.0-T horizontal-bore magnetic resonance scanner. The 19 F-MRI in rTg4510 mice showed an intense signal in the forebrain region. Analysis of the signal intensity in the forebrain region revealed a significant accumulation of fluorine-19 magnetic resonance signal in the rTg4510 mice compared with the wild-type mice. Histological analysis showed fluorescent signals of Shiga-X35 binding to the NFTs in the brain sections of rTg4510 mice. Data collected as part of this investigation indicate that 19 F-MRI using Shiga-X35 could be a promising tool to evaluate tau pathology in the brain.

Fluorodopa is a Promising Fluorine-19 MRI Probe for Evaluating Striatal Dopaminergic Function in a Rat Model of Parkinson's Disease.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra projecting to the striatum. It has been estimated that approximately 80% of the striatal dopamine and 50% of nigral dopaminergic neurons are lost before the onset of typical motor symptoms, indicating that early diagnosis of PD using noninvasive imaging is feasible. Fluorine-19 (19 F) magnetic resonance imaging (MRI) represents a highly sensitive, easily available, low-background, and cost-effective approach to evaluate dopaminergic function using non-radioactive fluorine-containing dopaminergic agents. The aim of this study was to find a potent 19 F MRI probe to evaluate dopaminergic presynaptic function in the striatum. To select candidates for 19 F MRI probes, we investigated the following eight non-radioactive fluorine-containing dopaminergic agents: fluorodopa (F-DOPA), F-tyrosine, haloperidol, GBR13069 duhydrochloride, GBR12909 duhydrochloride, 3-bis-(4-fluorophenyl) methoxytropane hydrochloride, flupenthixol, and fenfluramine. In 19 F nuclear magnetic resonance measurements, F-tyrosine and F-DOPA displayed a relatively higher signal-to-noise ratio value in brain homogenates than in others. F-DOPA, but not F-tyrosine, induced the rotational behavior in a 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rat model. In addition, a significantly high amount of F-DOPA accumulated in the ipsilateral striatum of hemiparkinsonian rats after the injection. We performed 19 F MRI in PC12 cells and isolated rat brain using a 7T MR scanner. Our findings suggest that F-DOPA is a promising 19 F MRI probe for evaluating dopaminergic presynaptic function in the striatum of hemiparkinsonian rats. © 2016 Wiley Periodicals, Inc.

Initial experiences with MR Image-guided laparoscopic microwave coagulation therapy for hepatic tumors.

PURPOSE: Percutaneous thermal ablation is used for treating hepatic tumors. Recent advances in laparoscopy and imaging modalities have led to the development of a novel image-guided minimally invasive loco-regional treatment. The aim of this trial was to apply laparoscopic assistance to magnetic resonance (MR) image-guided thermoablation instead of ultrasonography, because of its various advantages. METHODS: Patients with hepatic tumors and liver cirrhosis underwent magnetic resonance (MR) image-guided laparoscopic microwave coagulation therapy using a borescope and endoscopic forceps. Six cases of laparoscopic microwave coagulation treatment using MR image guidance were successfully performed between January 2000 and December 2008. Tumors were detected, punctured, and ablated in an open-configured MR scanner. A total of nine hepatocellular carcinoma nodules were preoperatively identified in S3, S5 and S6 (mean diameter = 20.8 ± 5.4 mm). RESULTS: MR-guided microwave coagulation was laparoscopically achieved in all patients without any significant complications that required invasive treatment. The mean length of the operation was 275.3 ± 60.5 min, and the mean postsurgical hospital stay was 10.0 ± 2.3 days. Postoperative confirmation scanning was performed without moving the patients. CONCLUSION: MR-guided laparoscopic microwave coagulation therapy is an effective treatment for hepatic tumors adjacent to other organs, as it allows for more accurate detection of lesions and for tumors to be treated safely while avoiding adjacent organs. It is less invasive than conventional procedures, because the MR real-time guidance enabled continuous monitoring throughout the procedure.

Laparoscopic surgery simulator using first person view and guidance force.

In general, minimally invasive surgery is seen as the most difficult surgery because there is limited field of view with an endoscope and force sensation from surgical instruments such as forceps is poor. Especially in early clinical education for medical students, a virtual reality surgical simulator would be an effective tool. In this paper, we propose a visuohaptic surgery training system for laparoscopical techniques. We recorded a video from a first person point of view of the instructor (expert). And we also recorded operation information (i.e. trajectory) of surgical instruments of the instructor. Then, we displayed the recorded video and the guidance force to trainees. We constructed a prototype surgery training system and the effectiveness of our approach was confirmed.

Development of primary design guidelines for supportive underwear to elevate the bladder neck in women based on finite element analysis of the pelvis.

The use of supportive underwear has been applied for preventing stress urinary incontinence (SUI) which is caused by descent of the bladder neck due to weakness in the pelvic floor muscles, because it is known that SUI can be improved by elevating the descended bladder neck. However, appropriate approaches to the underwear design are still being explored. In order to establish an appropriate first-order design strategy for supportive underwear, clarifying the relationship between the pressure from the underwear and the amount of elevation of the bladder neck is necessary. We constructed a finite element model of the pelvis based on magnetic resonance images of a subject in an upright position, experimentally explored Young's modulus of the soft tissue and analyzed the amount of elevation of the bladder neck when changing the combination of applied pressures from the underwear. The position of the bladder neck relatively elevated when the pressure in the region from the abdomen to the pubis decreased and when the pressure in the region from the perineum to the coccyx increased, suggesting an appropriate design for the supportive underwear.

An MR comparison study of cardiogenic and noncardiogenic pulmonary edema in animal models.

PURPOSE: To apply magnetic resonance (MR) imaging to differential diagnosis of cardiogenic pulmonary edema (CPE) and noncardiogenic pulmonary edema (NCPE). MATERIALS AND METHODS: In the CPE group, MR measurements were performed on 5 rats just before and 3 h after administration of 21 ± 2% body weight of normal saline. In the NCPE group, measurements were similarly performed on 5 animals just before and 48 h after 0.75 mg/body of lipopolysaccharide intratracheal administration. Animals were killed for bronchoalveolar lavage fluid (BALF) or pathological analysis after MR measurements. RESULTS: The relation between signal intensity and the T(2)* value of MR imaging was different in the two groups. The T(2)* in the NCPE group was significantly longer than that in the CPE group at the same signal intensity level. The lactate levels measured by in vivo MR spectroscopy did not show a difference between the CPE and NCPE groups, although the lactate BALF levels of the two groups were significantly different. CONCLUSION: The relation between signal intensity and T(2)* value was useful for the differentiation between these two pulmonary diseases. The measurable lactate level in pulmonary lesions suggests the applicability of MR spectroscopy to pulmonary disease.

Needle insertion simulation by arbitrary Lagrangian-Eulerian method.

In this paper, we performed needle insertion simulation considering needle tip shape by Arbitrary Lagrangian-Eulerian (ALE) method. ALE method is suitable for the large deformation and a fracture. To evaluate developed model, we compared the needle deflection between experimental results and simulation results. As a result, errors in each needle between both results were less than 3 mm.

Histologic Distribution and Characteristics on MR Imaging of Ultrasmall Superparamagnetic Iron Oxide in Ethyl-nitrosourea-induced Endogenous Rat Glioma.

PURPOSE: (1) To evaluate the enhancement patterns of an ultrasmall superparamagnetic iron oxide contrast agent (USPIO-CA) compared with those of a gadolinium-based contrast agent (Gd-BCA). (2) To compare the histologic distribution of USPIO-related iron particles (USPIO-IPs) with the USPIO-enhancement area in the early vascular and in the cellular imaging phase (E- and L-phase, respectively) after intravenous CA administration. METHODS: We performed USPIO-enhanced MRI of N-ethyl-N-nitrosourea (ENU)-induced endogenous rat glioma, including spin-echo (SE) T1-weighted images (T1WIs) and gradient-recalled-echo (GRE) T2-weighted images (T2WIs), before and at 3-6 h after USPIO-CA administration for E-phase images. For L-phase images, MRI was performed at 16-19 and 62-69 h after administration. Two observers determined the USPIO-enhancement area on E-phase images and Gd-enhancement areas. We compared the USPIO-enhancement size (USPIO-ES) and Gd-ES on SE T1WIs, and the hypo-intense USPIO-ES on GRE T2WIs and Gd-ES using the Wilcoxon signed-rank test. In addition, two raters visually evaluated the correspondence between the histologic distribution of USPIO-IPs and the USPIO-enhancement area on corresponding GRE T2WIs at each phase using a 3-rating scale. RESULTS: Significantly smaller hyper-intense, hypo-intense and combined hyper-/hypo-intense areas were observed on USPIO-enhanced SE T1WIs compared with Gd-enhanced images (all P < 0.001). The hypo-intense USPIO-ES on GRE T2WIs was significantly smaller than the Gd-ES (P = 0.001). The distribution of USPIO-IPs on histopathological specimen and USPIO-enhancement on GRE T2WIs exhibited poor agreement in 5 of 9 tumors with enhancement from rats sacrificed early. The distribution of microglia containing USPIO-IPs corresponded with the pattern of USPIO-enhancement in the 2 tumors with late enhancement. CONCLUSION: The enhancement pattern and size of USPIO-CA in a rat glioma model were statistically different from those of Gd-BCA. Our histological data suggests that USPIO-enhanced MRI offers vascular bed imaging in E-phase and might depict the intra-tumoral distribution of immune effector cells in L-phase.

The Effect of Seat Back Inclination on Spinal Alignment in Automotive Seating Postures.

Experimental studies have demonstrated a relationship between spinal injury severity and vertebral kinematics, influenced by the initial spinal alignment of automotive occupants. Spinal alignment has been considered one of the possible causes of gender differences in the risk of sustaining spinal injuries. To predict vertebral kinematics and investigate spinal injury mechanisms, including gender-related mechanisms, under different seat back inclinations, it is needed to investigate the effect of the seat back inclination on initial spinal alignment in automotive seating postures for both men and women. The purpose of this study was to investigate the effect of the seat back inclination on spinal alignments, comparing spinal alignments of automotive seating postures in the 20° and 25° seat back angle and standing and supine postures. The spinal columns of 11 female and 12 male volunteers in automotive seating, standing, and supine postures were scanned in an upright open magnetic resonance imaging system. Patterns of their spinal alignments were analyzed using Multidimensional Scaling presented in a distribution map. Spinal segmental angles (cervical curvature, T1 slope, total thoracic kyphosis, upper thoracic kyphosis, lower thoracic kyphosis, lumbar lordosis, and sacral slope) were also measured using the imaging data. In the maximum individual variances in spinal alignment, a relationship between the cervical and thoracic spinal alignment was found in multidimensional scaling analyses. Subjects with a more lordotic cervical spine had a pronounced kyphotic thoracic spine, whereas subjects with a straighter to kyphotic cervical spine had a less kyphotic thoracic spine. When categorizing spinal alignments into two groups based on the spinal segmental angle of cervical curvature, spinal alignments with a lordotic cervical spine showed significantly greater absolute average values of T1 slope, total thoracic kyphosis, and lower thoracic kyphosis for both the 20° and 25° seat back angles. For automotive seating postures, the gender difference in spinal alignment was almost straight cervical and less-kyphotic thoracic spine for the female subjects and lordotic cervical and more pronounced kyphotic thoracic spine for the male subjects. The most prominent influence of seatback inclination appeared in Total thoracic kyphosis, with increased angles for 25° seat back, 8.0° greater in spinal alignments with a lordotic cervical spine, 3.2° greater in spinal alignments with a kyphotic cervical spine. The difference in total thoracic kyphosis between the two seatback angles and between the seating posture with the 20° seat back angle and the standing posture was greater for spinal alignments with a lordotic cervical spine than for spinal alignments with a kyphotic cervical spine. The female subjects in this study had a tendency toward the kyphotic cervical spine. Some of the differences between average gender-specific spinal alignments may be explained by the findings observed in the differences between spinal alignments with a lordotic and kyphotic cervical spine.

Clinical features of myocardial triglyceride in different types of cardiomyopathy assessed by proton magnetic resonance spectroscopy: comparison with myocardial creatine.

BACKGROUND: Myocardial lipid overstorage may produce cardiomyopathy, leading to dysfunction, but advanced heart failure may cause lipolysis via sympathetic nerve activation. In the failing heart, the creatine kinase system may also be impaired. The aims of this study were to assess myocardial triglyceride (TG) and creatine (CR) in different types of cardiomyopathy and to investigate whether they are related to the severity of cardiac dysfunction. METHODS AND RESULTS: In patients with hypertrophic cardiomyopathy (HCM, n = 8), dilated cardiomyopathy (DCM, n = 12) or ischemic cardiomyopathy (ICM, n = 10), and normal subjects (NML, n = 22), myocardial TG and CR were evaluated using proton magnetic resonance spectroscopy. To assess cardiac sympathetic nerve activity, myocardial MIBG (a radioactive guanethidine analog) uptake was measured in DCM. Myocardial TG was significantly lower in hypertrophic cardiomyopathy (HCM) (1.92 ± 0.99 µmol/g), but higher in ICM (7.59 ± 4.36 µmol/g) than in NML hearts (4.05 ± 1.94 µmol/g). There was no significant difference in TG between DCM (4.84 ± 6.45 µmol/g) and NML. Myocardial CR in HCM (20.4 ± 8.4 µmol/g), DCM (14.8 ± 4.8 µmol/g), and ICM (19.4 ± 6.3 µmol/g) was significantly lower than that in NML hearts (27.1 ± 4.3 µmol/g). Overall, myocardial CR correlated positively with the severity of heart failure estimated by ejection fraction or myocardial BMIPP (a radioactive fatty acid analog) uptake, but TG did not. In DCM, myocardial TG correlated with body mass index, but not with MIBG uptake. CONCLUSIONS: Myocardial TG may be related to the specific cause of disease rather than the severity of cardiac dysfunction. In contrast, myocardial CR reflects the severity of heart failure despite different pathoetiologic mechanisms of dysfunction. In DCM, myocardial TG may be affected by an overweight state rather than cardiac sympathetic nerve dysfunction. Thus, myocardial CR has a closer relationship to heart failure severity than does myocardial TG.

Real-time magnetic resonance-guided microwave coagulation therapy for pelvic recurrence of rectal cancer: initial clinical experience using a 0.5 T open magnetic resonance system.

PURPOSE: This study aims to evaluate consecutive cases of recurrent rectal cancer in the pelvic cavity treated with microwave coagulation therapy using real-time navigation by an open magnetic resonance system. METHODS: Nine recurrent pelvic lesions in 8 patients after curative resection of rectal cancer were treated with real-time magnetic resonance-guided microwave coagulation therapy as a palliative local therapy to reduce tumor volume and/or local pain. Clinical and pathological data were collected retrospectively by reviewing medical records and clinical imaging results. RESULTS: Seven patients received other treatments before real-time magnetic resonance-guided microwave coagulation. Six patients had distant synchronous metastases. Three patients underwent surgery under lumbar anesthesia. Microwave coagulation was performed percutaneously in 5 lesions and under laparotomy in 4 lesions. Although adverse events related to microwave coagulation (skin necrosis and nerve injury) were observed, no fatal complications occurred. Local re-recurrence was observed in 2 of 9 ablated lesions. Except for 1 patient who died of chronic renal failure, the remaining 7 patients died of cancer. Median overall survival after microwave coagulation for all patients was 10 months (range, 4-37 mo). Median overall survival after discovery of pelvic recurrence in all patients was 22 months (range, 9-42 mo). CONCLUSIONS: The benefits of using an open magnetic resonance system in the pelvic cavity include the abilities to treat tumors that cannot be visualized by other modalities, to demonstrate internal architectural changes during treatment, to differentiate treated vs untreated areas, and to allow adjustments to the treatment plan during the procedure. Additional studies are required to clarify the efficacy of tumor coagulation for local control.

Neuroprotective Effects of Casein-Derived Peptide Met-Lys-Pro (MKP) in a Hypertensive Model.

We have previously reported that casein hydrolysate, CH-3, from bovine milk and casein-derived tripeptide Met-Lys-Pro (MKP) has ACE inhibitory activity and reduces blood pressure. In this study, we investigated the therapeutic effects of MKP in a hypertensive rat model (7-week-old male SHRSP/Izm rats). For long term evaluation, rats were fed either a diet containing CH-3 or normal diet. The survival rate of SHRSP rats was significantly improved by intake of CH-3 for 181 days. For short term evaluation, rats were orally administered synthetic tripeptide MKP or distilled water for 4 weeks. MRI study demonstrated that hemorrhagic lesions were observed in two of five rats in the control group, while no hemorrhagic lesions were observed in the MKP group. Volumetric analysis using MRI revealed that MKP administration inhibited atrophy of diencephalic regions. Histological examinations revealed that hemorrhage areas and astrogliosis in the hippocampus and cerebral cortex were lower in the MKP group than in the control group. Gene expression analysis indicated that MKP administration reduced expression of genes related to cerebral circulation insufficiency such as immune responses (Cd74 and Prkcd), response to hypoxia (Ddit4, Apold1, and Prkcd), reactive oxygen species metabolic process (Ddit4 and Pdk4), and apoptotic process (Ddit4, Prkcd, and Sgk1), suggesting that MKP administration prevented cerebral ischemia associated with hypertension. In addition, some genes encoding responses to hormone stimulus (Fos, Dusp1, and Sik1) were also downregulated. Serum aldosterone and corticosterone levels were also significantly decreased following MKP administration. The present study indicates that MKP shows neuroprotective effects in SHRSP rats by regulating cerebral circulation insufficiency and corticoid levels. MKP administration may therefore be a potential therapeutic strategy for hypertensive brain diseases such as cerebrovascular disease.

Magnetic resonance and ultrasound image-guided navigation system using a needle manipulator.

PURPOSE: Image guidance is crucial for percutaneous tumor ablations, enabling accurate needle-like applicator placement into target tumors while avoiding tissues that are sensitive to injury and/or correcting needle deflection. Although ultrasound (US) is widely used for image guidance, magnetic resonance (MR) is preferable due to its superior soft tissue contrast. The objective of this study was to develop and evaluate an MR and US multi-modal image-guided navigation system with a needle manipulator to enable US-guided applicator placement during MR imaging (MRI)-guided percutaneous tumor ablation. METHODS: The MRI-compatible needle manipulator with US probe was installed adjacent to a 3 Tesla MRI scanner patient table. Coordinate systems for the MR image, patient table, manipulator, and US probe were all registered using an optical tracking sensor. The patient was initially scanned in the MRI scanner bore for planning and then moved outside the bore for treatment. Needle insertion was guided by real-time US imaging fused with the reformatted static MR image to enhance soft tissue contrast. Feasibility, targeting accuracy, and MR compatibility of the system were evaluated using a bovine liver and agar phantoms. RESULTS: Targeting error for 50 needle insertions was 1.6 ± 0.6 mm (mean ± standard deviation). The experiment confirmed that fused MR and US images provided real-time needle localization against static MR images with soft tissue contrast. CONCLUSIONS: The proposed MR and US multi-modal image-guided navigation system using a needle manipulator enabled accurate needle insertion by taking advantage of static MR and real-time US images simultaneously. Real-time visualization helped determine needle depth, tissue monitoring surrounding the needle path, target organ shifts, and needle deviation from the path.

Correlation between musculoskeletal structure of the hand and primate locomotion: Morphometric and mechanical analysis in prehension using the cross- and triple-ratios.

Biometric ratios of the relative length of the rays in the hand have been analyzed between primate species in the light of their hand function or phylogeny. However, how relative lengths among phalanges are mechanically linked to the grasping function of primates with different locomotor behaviors remains unclear. To clarify this, we calculated cross and triple-ratios, which are related to the torque distribution, and the torque generation mode at different joint angles using the lengths of the phalanges and metacarpal bones in 52 primates belonging to 25 species. The torque exerted on the finger joint and traction force of the flexor tendons necessary for a cylindrical grip and a suspensory hand posture were calculated using the moment arm of flexor tendons measured on magnetic resonance images, and were compared among Hylobates spp., Ateles sp., and Papio hamadryas. Finally, the torques calculated from the model were validated by a mechanical study detecting the force exerted on the phalanx by pulling the digital flexor muscles during suspension in these three species. Canonical discriminant analysis of cross and triple-ratios classified primates almost in accordance with their current classification based on locomotor behavior. The traction force was markedly reduced with flexion of the MCP joint parallel to the torque in brachiating primates; this was notably lower in the terrestrial quadrupedal primates than in the arboreal primates at mild flexion. Our mechanical study supported these features in the torque and traction force generation efficiencies. Our results suggest that suspensory or terrestrial quadrupedal primates have hand structures that can exert more torque at a suspensory posture, or palmigrade and digitigrade locomotion, respectively. Furthermore, our study suggests availability of the cross and triple-ratios as one of the indicators to estimate the hand function from the skeletal structure.

Trifluoromethoxy-benzylated ligands improve amyloid detection in the brain using (19)F magnetic resonance imaging.

The chemical properties of probes that improve amyloid detection by non-invasive (19)F magnetic resonance imaging (MRI) are of interest. We synthesized benzoxazole compounds with trifluoromethoxy groups, and found that these compounds displayed sharp (19)F nuclear magnetic resonance (NMR) signals in an assay buffer. However, the intensities of the (19)F NMR signals were dramatically reduced in mouse brain lysates. Our results indicate that the inhibitory effect of brain tissue on the (19)F NMR signals from these probes can be attributed to the hydrophobicity of the tissue. These results highlight the importance of using hydrophilic (19)F-MRI agents to avoid the inhibitory effects of brain tissues on (19)F NMR signals.

[The measurement of fractional anisotropy values at the corpus callosum in an irradiated-rat model by 7T-MRI: comparison with quantitative histological evaluation].

Radiation-induced white matter injury has recently been evaluated by fractional anisotropy (FA) values using diffusion tensor image (DTI) data on magnetic resonance (MR) imaging. However, controversy remains as to which histological components affect anisotropy. FA values were compared with histological findings in rat irradiated brains. Forty Gy whole brain radiation was performed on 9 rats, with another 9 rats not subjected to irradiation prepared as the control group. DTI data for the corpus callosum were obtained using a 7.0 Tesla MR scanner at post radiation 18+2 to 48 +/- 2 weeks (p18w-p48w), and the mean FA value (mFA) was calculated. Histological parameters were assessed at p24w, p36w, and p48w in hematoxylin-eosin stained and immunohistochemically processed sections. Numbers of dilated vessels, hypertrophic glial fibrillary acidic protein (GFAP)-positive cells and Olig2-positive cells were quantitatively evaluated. Qualitative assessment of change in neurofilament (NF)-and myelin basic protein (MBP)-positive structures at each time point was also performed. The mFA decreased from p30w to p42w, significantly decreasing at p42w compared to the control group. However, It recovered to control levels at p48w. Histological examination showed that hypertrophic GFAP-positive cells and dilated vessels had increased at p48w. Olig2-positive cells decreased significantly at p48w compared to p24w and p36w (p<0.05). Although NF-positive structures continued to decrease over time, MBP-positive structures recovered at p48w in agreement with the change in mFA. In the subacute/chronic stage, rat irradiated brain FA value in the corpus callosum appears to mainly reflect the change in myelin structure.

DJ-1 protects against neurodegeneration caused by focal cerebral ischemia and reperfusion in rats.

Reactive oxygen species (ROS) is massively produced in the brain after cerebral ischemia and reperfusion. It reacts strongly with cellular components, which has detrimental effects and leads to neuronal cell death. DJ-1, which was found to be the causative gene of familial Parkinson's disease PARK7, is a multifunction protein, which plays a key role in transcriptional regulation, and a molecular chaperone. In this study, we investigated the neuroprotective effect of DJ-1 against neurodegeneration caused by ischemia/reperfusion injury. Cerebral ischemia was induced in rats by 120 mins of middle cerebral artery occlusion (MCAO) using an intraluminal introduction method. The intrastriatal injection of recombinant glutathione S-transferase-tagged human DJ-1 (GST-DJ-1) markedly reduced infarct size in 2,3,5-triphenyltetrazolium chloride staining at 3 days after MCAO. In addition, we performed a noninvasive evaluation of ischemic size using magnetic resonance imaging and found a significant reduction of infarct size with the administration of GST-DJ-1. In GST-DJ-1-treated rats, behavioral dysfunction and nitrotyrosine formation were significantly inhibited. Furthermore, GST-DJ-1 markedly inhibited H(2)O(2)-mediated ROS production in SH-SY5Y cells. These results indicate that GST-DJ-1 exerts a neuroprotective effect by reducing ROS-mediated neuronal injury, suggesting that DJ-1 may be a useful therapeutic target for ischemic neurodegeneration.