Therapeutic efficacy of intravenous infusion of mesenchymal stem cells in rat perinatal brain injury.

BACKGROUND: Perinatal brain injury is multifactorial and primarily associated with brain prematurity, inflammation, and hypoxia-ischemia. Although recent advances in perinatal medicine　have improved the survival rates of preterm infants, neurodevelopmental disorders remain a significant complication. We tested whether the intravenous infusion of mesenchymal stem cells (MSCs) had therapeutic efficacy against perinatal brain injury in rats. METHODS: Pregnant rats at embryonic day (E) 18 received lipopolysaccharide and the pups were born at E21. On postnatal day (PND) 7, the left common carotid artery of each pup was ligated, and they were exposed to 8% oxygen for 2 h. They were randomized on PND10, and MSCs or vehicle were intravenously infused. We performed behavioral assessments, measured brain volume using MRI, and performed histological analyses on PND49. RESULTS: Infused MSCs showed functional improvements in our model. In vivo MRI revealed that MSC infusion increased non-ischemic brain volume compared to the vehicle group. Histological analyses showed that cortical thickness, the number of NeuN+ and GAD67+ cells, and synaptophysin density in the non-ischemic hemisphere in the MSC group were greater than the vehicle group, but less than the control group. CONCLUSIONS: Infused MSCs improve sensorimotor and cognitive functions in perinatal brain injury and enhance neuronal growth. IMPACT: Intravenous infusion of MSCs improved neurological function in rats with perinatal brain injury, including motor, sensorimotor, cognitive, spatial, and learning memory. Infused MSCs increased residual (non-ischemic) tissue volume, number of neuronal cells, GABAergic cells, and cortical synapses in the contralesional (right) hemisphere. Intravenous administration of MSC might be suitable for the treatment of perinatal brain injury.

"Live-Autoradiography" Technique Reveals Genetic Variation in the Rate of Fe Uptake by Barley Cultivars.

Iron (Fe) is an essential trace element in plants; however, the available Fe in soil solution does not always satisfy the demand of plants. Genetic diversity in the rate of Fe uptake by plants has not been broadly surveyed among plant species or genotypes, although plants have developed various Fe acquisition mechanisms. The "live-autoradiography" technique with radioactive 59Fe was adopted to directly evaluate the uptake rate of Fe by barley cultivars from a nutrient solution containing a very low concentration of Fe. The uptake rate of Fe measured by live autoradiography was consistent with the accumulation of Fe-containing proteins on the thylakoid membrane. The results revealed that the ability to acquire Fe from the low-Fe solution was not always the sole determinant of tolerance to Fe deficiency among barley genotypes. The live-autoradiography system visualizes the distribution of ß-ray-emitting nuclides and has flexibility in the shape of the field of view. This technique will strongly support phenotyping with regard to the long-distance transport of nutrient elements in the plant body.

Functional recovery after the systemic administration of mesenchymal stem cells in a rat model of neonatal hypoxia-ischemia.

The authors intravenously infused mesenchymal stem cells (MSCs) into a rat model of neonatal hypoxia-ischemia and found improvements in functional outcome, increased brain volume, and enhanced synaptogenesis. The results of this animal study suggest that the intravenous administration of MSCs should be further explored as a potential treatment for patients suffering from cerebral palsy after hypoxic-ischemic encephalopathy.

Intravenous infusion of mesenchymal stem cells reduces epileptogenesis in a rat model of status epilepticus.

OBJECTIVE: Status epilepticus (SE) causes neuronal cell death, aberrant mossy fiber sprouting (MFS), and cognitive deteriorations. The present study tested the hypothesis that systemically infused mesenchymal stem cells (MSCs) reduce epileptogenesis by inhibiting neuronal cell death and suppressing aberrant MFS, leading to cognitive function preservation in a rat model of epilepsy. METHODS: SE was induced using the lithium-pilocarpine injection model. The seizure frequency was scored using a video-monitoring system and the Morris water maze test was carried out to evaluate cognitive function. Comparisons were made between MSCs- and vehicle-infused rats. Immunohistochemical staining was performed to detect Green fluorescent protein (GFP)+ MSCs and to quantify the number of GAD67+ and NeuN+ neurons in the hippocampus. Manganese-enhanced magnetic resonance imaging (MEMRI) and Timm staining were also performed to assess the MFS. RESULTS: MSC infusion inhibited epileptogenesis and preserved cognitive function after SE. The infused GFP+ MSCs were accumulated in the hippocampus and were associated with the preservation of GAD67+ and NeuN+ hippocampal neurons. Furthermore, the MSC infusion suppressed the aberrant MFS in the hippocampus as evidenced by MEMRI and Timm staining. CONCLUSIONS: This study demonstrated that the intravenous infusion of MSCs mitigated epileptogenesis, thus advancing MSCs as an effective approach for epilepsy in clinical practice.

Association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism.

The aim of this study was to investigate the association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism. A total of 35 university students and staff members participated in this study after providing informed consent. All participants were divided into either a sleep bruxism group (n = 21) or a control group (n = 14), based on the following clinical diagnostic criteria: (1) reports of tooth-grinding sounds for at least two nights a week during the preceding 6 months by their sleep partner; (2) presence of tooth attrition with exposed dentin; (3) reports of morning masticatory muscle fatigue or tenderness; and (4) presence of masseter muscle hypertrophy. Video-polysomnography was performed in the sleep laboratory for two nights. Sleep bruxism episodes were measured using masseter electromyography, visually inspected and then categorized into phasic or tonic episodes. Phasic episodes were categorized further into episodes with or without grinding sounds as evaluated by audio signals. Sleep bruxism subjects with reported grinding sounds had a significantly higher total number of phasic episodes with grinding sounds than subjects without reported grinding sounds or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). Similarly, sleep bruxism subjects with tooth attrition exhibited significantly longer phasic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). Furthermore, sleep bruxism subjects with morning masticatory muscle fatigue or tenderness exhibited significantly longer tonic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). These results suggest that each clinical sign and symptom of sleep bruxism represents different aspects of jaw motor activity during sleep.

Effect of clonazepam and clonidine on primary sleep bruxism: a double-blind, crossover, placebo-controlled trial.

The aim of this study was to assess the acute effects of clonazepam and clonidine on rhythmic masticatory muscle activity in young adults with primary sleep bruxism, as well as accompanying effects on sleep architecture and cardiac activity. This study used a double-blind, crossover, placebo-controlled design. Polysomnography was performed on 19 subjects [nine men and 10 women; mean age (±SE): 25.4 ± 2.7 years] for 5 nights. The first 2 nights were used for the habituation and diagnosis of sleep bruxism. The other 3 nights were randomly assigned for clonazepam (1.0 mg), clonidine (0.15 mg) or placebo (all administered 30 min before bedtime). Sleep, oromotor activity and cardiac activity variables were assessed and compared among the three drug conditions. Clonidine significantly reduced the median percentage of time spent in the rapid eye movement sleep stage compared with placebo and clonazepam. The number of rhythmic masticatory muscle activity episodes was reduced with clonidine by >30% compared with placebo and clonazepam. The reduction of rhythmic masticatory muscle activity index by clonidine was associated with an increase of mean RR intervals (slower heart rate) during quiet sleep periods and during a 70-s period before the onset of rhythmic masticatory muscle activity episodes. However, no changes in cardiac activity variables were observed for clonazepam. In young adults with primary sleep bruxism, clonidine was significantly more effective in suppressing sleep bruxism than clonazepam. The acute effects of clonidine on rhythmic masticatory muscle activity episodes may be mediated by suppression of autonomic nervous system activity and non-rapid eye movement-rapid eye movement sleep processes.

Phasic jaw motor episodes in healthy subjects with or without clinical signs and symptoms of sleep bruxism: a pilot study.

BACKGROUND: To investigate the association between each clinical diagnosis criterion for sleep bruxism (SB) and the frequency of jaw motor events during sleep. METHODS: Video-polysomnography was performed on 17 healthy adult subjects (mean age, 26.7 ± 2.8 years), with at least one of the following clinical signs and symptoms of SB: (1) a report of frequent tooth grinding, (2) tooth attrition with dentine exposure through at least three occlusal surfaces, (3) morning masticatory muscle symptoms, and (4) masseter muscle hypertrophy. Episodes of rhythmic masticatory muscle activity (RMMA) and isolated tonic activity were scored visually. These variables were compared with regards to the presence or absence of each clinical sign and symptom. RESULTS: In 17 subjects, 4.0 ± 2.5/h (0.1-10.2) RMMA and 1.0 ± 0.8/h (0-2.4) isolated tonic episodes were observed (total episodes: 5.0 ± 2.4/h (1.2-11.6)). Subjects with self-reported grinding sounds (n=7) exhibited significantly higher numbers of RMMA episodes (5.7 ± 2.3/h) than those without (n=10; 2.8 ± 1.8/h) (p=0.011). Similarly, subjects with tooth attrition (n=6) showed significantly higher number of RMMA episodes (5.6 ± 3.1/h) than those without (n=11; 3.2 ± 1.6/h) (p=0.049). The occurrence of RMMA did not differ between the presence and absence of morning masticatory muscle symptoms or muscle hypertrophy. CONCLUSIONS: Clinical signs and symptoms frequently used for diagnosing SB can represent different clinical and physiological aspects of jaw motor activity during sleep.

Characteristics of focusing high-energy heavy ion microbeam system at the JAEA AVF cyclotron.

Ion optical analysis was made for a new focusing high-energy heavy ion microbeam system connected to the AVF cyclotron (K=110) at the accelerator facility, TIARA of JAEA Takasaki. The focusing performance of the microbeam system was estimated from both the calculation up to third-order term using TRANSPORT code and the measurement of beam resolution with the secondary electron imaging. As a result, a minimum beam size was evaluated at 0.56 and 0.62 microm in FWHM for the X and Y directions, respectively. The high-energy heavy ion microbeam system seemed to have been established as designed by the calculation with the TRANSPORT code, because it was confirmed that the calculation results was fairly reproduced by the measurement result.

Subcellular changes of essential metal shown by in-air micro-PIXE in oral cadmium-exposed mice.

To clarify the relation of essential metals to cadmium (Cd) toxicity, we evaluated metallothionein expression and analyzed the subcellular distribution of essential metals using in-air micro-Particle-Induced X-ray Emission (PIXE). Four mice were dosed orally with 100 mg/L of Cd in drinking water for 1.5 or 2 years. Frozen samples of organs were used for micro-PIXE analysis and formalin-fixed samples were used for metallothionein staining. Immunohistochemically, metallothionein induction by 1.5y-Cd exposure was higher in the renal cortex than in the liver. Metallothionein expression was reduced after 2y-Cd administration compared to the 1.5y-Cd-exposed mice. Cd-induced tissue damage became marked in the 2y-Cd-exposed mice compared to the 1.5y-Cd-exposed mice, in which nephrotoxicity was more prominent than hepatotoxicity. Cd yield was higher in the renal cortex of the 2y-Cd-exposed mouse than in that of the 1.5y-Cd-exposed mouse, whereas no such increasing tendency was found in the liver. Compared to the control, the Cd-exposed mice markedly accumulated zinc in the liver and renal cortex. In the Cd-exposed mice, iron was mildly accumulated in the renal cortex and was slightly deprived in the liver. Elemental maps showed that a large amount of Cd was spatially combined with zinc in the 1.5y-Cd mouse. Free Cd became abundant in the 2y-Cd-exposed mouse. In addition, a small amount of Cd was colocalized with iron. The data suggest that zinc may contribute to protect against oral-administrated Cd toxicity, and impaired induction of MT may participate in hepato-nephrotoxicity of the 2y-Cd-exposed mouse.

Interferonbeta-induced changes in metallothionein expression and subcellular distribution of zinc in HepG2 cells.

We evaluated the changes of metallothionein induction and cellular zinc distribution in HepG2 cells by interferonbeta treatment. Immunohistochemical staining of metallothionein was observed in the cytoplasm and nuclei of hepatocytes; which was observed predominantly in the cells treated with interferon and zinc compared to those with zinc alone, interferon alone or the no-treated control. The cellular zinc level was higher in order of the interferon- and zinc-treated cells, the zinc-alone-treated cells, and the interferon-alone-treated cells. Flow cytometry showed that S-phase population increased in interferon-alone-treated cells and interferon- and zinc-treated cells, but not in zinc-alone-treated ones. Cellular elemental distribution was analyzed using in-air micro-particle induced X-ray emission. In zinc-alone-treated sample, X-ray spectra showed good consistency between the enhanced cellular zinc distribution and the phosphorous map. Localizations of bromine followed by interferon treatment were found accompanying a spatial correlation with the phosphorous map. The samples treated with interferon and zinc showed the marked accumulation of zinc and bromine. Discrete bromine accumulation sites were clearly visible with a strong spatial correlation followed by zinc accumulation. These findings suggest that interferonbeta in combination with zinc predominantly induces metallothionein expression in HepG2 cells. In addition, interferonbeta may promote the translocation of metallothionein-bound zinc from cytoplasm to S-phase nuclei.