Light sheet fluorescence microscopy of optically cleared brains for studying the glymphatic system

Fluid transport in the perivascular space by the glia-lymphatic (glymphatic) system is important for the removal of solutes from the brain parenchyma, including peptides such as amyloid-beta which are implicated in the pathogenesis of Alzheimer’s disease. The glymphatic system is highly active in the sleep state and under the influence of certain of anaesthetics, while it is suppressed in the awake state and by other anaesthetics. Here we investigated whether light sheet fluorescence microscopy of whole optically cleared murine brains was capable of detecting glymphatic differences in sleep- and awake-mimicking anaesthesia, respectively. Using light-sheet imaging of whole brains, we found anaesthetic-dependent cerebrospinal fluid (CSF) influx differences, including reduced tracer influx along tertiary branches of the middle cerebral artery and reduced influx along dorsal and anterior penetrating arterioles, in the awake-mimicking anaesthesia. This study establishes that light sheet microscopy of optically cleared brains is feasible for quantitative analyses and can provide images of the entire glymphatic system in whole brains.     

Fatigue failure load of immature anterior teeth: influence of different fiber post-core systems

Odontology - The aim was to explore the fracture-behavior, survival and marginal-microgaps within the root-canal of immature anterior teeth restored with different fiber-reinforced post-core...     

One session of whole body vibration increases voluntary muscle strength transiently in patients with stroke

OBJECTIVE: To determine the effect of whole body vibration on isometric and eccentric torque and electromyography (EMG) variables of knee extensors on the affected side of stroke patients. DESIGN: A randomized controlled study. SETTING: A rehabilitation centre. SUBJECTS: Sixteen patients (age 58.2+/-9.4 years) were enrolled in an inpatient rehabilitation programme 27.2+/-10.4 days after a stroke. INTERVENTIONS: Eight patients were randomly assigned to the vibration group and received 20 Hz vibration (5 mm amplitude) while standing on a vibration platform for 1 minute six times in one session. Patients in the control group also stood on the platform but did not receive vibration. MAIN MEASURES: Maximum isometric and eccentric torque, rate of torque development, root-mean-squared EMG, median frequency of vastus lateralis, and co-activation of knee flexors. RESULTS: Isometric and eccentric knee extension torque increased 36.6% and 22.2%, respectively, after vibration (P<0.05) and 8.4% and 5.3% in the control group. Vibration increased EMG amplitude 44.9% and the median frequency in the vastus lateralis by 13.1% (all P<0.05) without changes in the control group (10.6% and 3.9%). Vibration improved the ability to generate mechanical work during eccentric contraction (17.5%). Vibration reduced biceps femoris co-activation during isometric (8.4%, ns) and eccentric (22.5%, P<0.05) contraction. CONCLUSION: These results suggest that one bout of whole body vibration can transiently increase voluntary force and muscle activation of the quadriceps muscle affected by a stroke.     

Spinal involvement in chronic recurrent multifocal osteomyelitis (CRMO) in childhood and effect of pamidronate

There are only a few studies that address the frequency and type of spinal involvement in patients with chronic recurrent multifocal osteomyelitis (CRMO) as well as the outcome of these patients treated with pamidronate (PAM). We performed a retrospective study on patients with CRMO and analyzed clinical and pain assessments as well as regional and whole body MRI findings and compared with posttreatment findings. Of 102 children and adolescents with CRMO, 27 (26%) had involvement of the spine. Vertebral deformities were seen in 14 of these 27 patients, scoliosis or kyphosis in 6. After routine whole body MRI, 19 complained of back pain, whereas eight were asymptomatic with spinal lesions detected incidentally. A total of 72 spinal lesions were detected, thoracic vertebrae being the most commonly affected. Seven patients were treated with PAM; all of whom had vertebral deformities and ongoing back pain. Pain resolution was achieved within 3 months of PAM treatment in every case. One patient subsequently developed a pain amplification syndrome. Repeat MRI performed at a mean interval of 13 months revealed partial or complete resolution of vertebral hyperintensities in every patient. Improvement of vertebral height was seen in a total of three vertebrae in two patients. Severe side effects were not observed. In conclusion, we demonstrated that spinal involvement and associated vertebral deformities with or without kyphoscoliosis are not rare in CRMO, and PAM appears to be an effective and safe treatment for this condition. Although controlled studies are urgently needed, the use of PAM for refractory CRMO with extended spinal involvement (vertebral deformities, kyphosis, and scoliosis) should be considered, especially after failing of conventional therapy.     

Fatigue performance of endodontically treated premolars restored with direct and indirect cuspal coverage restorations utilizing fiber-reinforced cores

Clinical Oral Investigations - The aim of this in vitro study was to investigate the fatigue survival and fracture behavior of endodontically treated (ET) premolars restored with different types of...     

Achieving brain clearance and preventing neurodegenerative diseases—A glymphatic perspective

Age-related neurodegenerative diseases are a growing burden to society, and many are sporadic, meaning that the environment, diet and lifestyle play significant roles. Cerebrospinal fluid (CSF)-mediated clearing of brain waste products via perivascular pathways, named the glymphatic system, is receiving increasing interest, as it offers unexplored perspectives on understanding neurodegenerative diseases. The glymphatic system is involved in clearance of metabolic by-products such as amyloid-β from the brain, and its function is believed to lower the risk of developing some of the most common neurodegenerative diseases. Here, we present magnetic resonance imaging (MRI) data on the heart cycle’s control of CSF flow in humans which corroborates findings from animal studies. We also review the importance of sleep, diet, vascular health for glymphatic clearance and find that these factors are also known players in brain longevity.     

Flip-flop kinetics of ropivacaine during continuous epidural infusion influences its accumulation rate

Background  

Ropivacaine has an optimal toxicity profile for epidural anesthesia in adults, but there are currently no studies concerning its pharmacokinetics during continuous infusion. The primary objective of this study was to evaluate the pharmacokinetics and safety of ropivacaine in adults during a 48-h continuous epidural infusion.