Use of transcranial low-intensity focused ultrasound for targeted delivery of stem cell-derived exosomes to the brain.

The blood-brain barrier (BBB) presents a significant challenge for targeted drug delivery. A proposed method to improve drug delivery across the BBB is focused ultrasound (fUS), which delivers ultrasound waves to a targeted location in the brain and is hypothesized to open the BBB. Furthermore, stem cell-derived exosomes have been suggested as a possible anti-inflammatory molecule that may have neural benefits, if able to pass the BBB. In the present study, transcranial low-intensity focused ultrasound (LIFU), without the use of intravenous microbubbles, was assessed for both (1) its ability to influence the BBB, as well as (2) its ability to increase the localization of intravenously administered small molecules to a specific region in the brain. In vivo rat studies were conducted with a rodent-customized 2 MHz LIFU probe (peak pressure = 1.5 MPa), and injection of labeled stem cell-derived exosomes. The results suggested that LIFU (without microbubbles) did not appear to open the BBB after exposure times of 20, 40, or 60 min; instead, there appeared to be an increase in transcytosis of the dextran tracer. Furthermore, the imaging results of the exosome study showed an increase in exosome localization in the right hippocampus following 60 min of targeted LIFU.

Effect of isokinetic training on shoulder impingement.

The aim of this study was to review the literature evaluating the effect of isokinetic training in patients suffering from shoulder impingement syndrome (SIS). Studies published up to March 2011 were located from the Pubmed, Scopus, Lilacs, Physiotherapy Evidence Database, and Cochrane Library databases using "isokinetic", "shoulder", and "impingement" as key words. Referenced studies were also checked. Studies were included if isokinetic training was employed as at least one of the treatments in the therapeutic program to treat shoulder impingement or other shoulder pathologies leading to impingement-related pain. All eligible studies described the level of evidence, patient characteristics, interventions, outcome evaluation, results, complications, and return to work. There were 2 randomized control trials (RCTs) and 4 studies with level 4 evidence that met the inclusion criteria. All of the studies included showed a statistically or clinically significant outcome after isokinetic training. However, most of the studies could not identify the isolated effect of isokinetic training. There was not enough evidence to support or refute the effectiveness of isokinetic training for SIS. This result does not reflect a true lack of effect, but rather a lack of RCTs. A consensus definition of the different types and stages of SIS is urgently needed. More RCTs are also essential to clarify the value of this technique. The homogeneity of treatment interventions, study populations, and outcome measures should be prioritized. Further studies are also needed to clarify the differences in isokinetic data across different types and stages of shoulder impingement.