Specific nanoprobe design for MRI: Targeting laminin in the blood-brain barrier to follow alteration due to neuroinflammation

Chronic neuroinflammation is characterized by increased blood-brain barrier (BBB) permeability, leading to molecular changes in the central nervous system that can be explored with biomarkers of active neuroinflammatory processes. Magnetic resonance imaging (MRI) has contributed to detecting lesions and permeability of the BBB. Ultra-small superparamagnetic particles of iron oxide (USPIO) are used as contrast agents to improve MRI observations. Therefore, we validate the interaction of peptide-88 with laminin, vectorized on USPIO, to explore BBB molecular alterations occurring during neuroinflammation as a potential tool for use in MRI. The specific labeling of NPS-P88 was verified in endothelial cells (hCMEC/D3) and astrocytes (T98G) under inflammation induced by interleukin 1β (IL-1β) for 3 and 24 hours. IL-1β for 3 hours in hCMEC/D3 cells increased their co-localization with NPS-P88, compared with controls. At 24 hours, no significant differences were observed between groups. In T98G cells, NPS-P88 showed similar nonspecific labeling among treatments. These results indicate that NPS-P88 has a higher affinity towards brain endothelial cells than astrocytes under inflammation. This affinity decreases over time with reduced laminin expression. In vivo results suggest that following a 30-minute post-injection, there is an increased presence of NPS-P88 in the blood and brain, diminishing over time. Lastly, EAE animals displayed a significant accumulation of NPS-P88 in MRI, primarily in the cortex, attributed to inflammation and disruption of the BBB. Altogether, these results revealed NPS-P88 as a biomarker to evaluate changes in the BBB due to neuroinflammation by MRI in biological models targeting laminin.

Preganglionic injury of C8 nerve root secondary to shoulder dislocation: Diagnosis based on MRI findings

INTRODUCTION

Traumatic spinal root injury caused by shoulder dislocation may involve the brachial plexus or, in some cases, a single nerve. The degree of severity of the injury depends on many patient-specific factors as well as the mechanism of injury. It is essential to suspect this type of lesion by means of a thorough physical examination in order to have better patient outcomes.

CASE PRESENTATION

We presented the subtle magnetic resonance imaging (MRI) findings in a 35-year-old male with left shoulder trauma and dislocation after falling off a bicycle. He complained of decreased muscle strength and sensitivity in the C8 dermatome. Atrophy of the hypothenar region and flexion deformity of the 4th and 5th digits were noted. Magnetic resonance imaging findings were consistent with a partial preganglionic C8 motor root lesion. We found T2 increased signal intensity and thinning of the intradural segment of the C8 motor nerve root and low signal in the sequence of a multi-echo gradient recalled echo (GRE).

CONCLUSION

MRI is a noninvasive tool that allows a detailed anatomical characterization of the nerves. In brachial plexus injuries, the use of the GRE sequence is useful to identify the lesions, even if they are subtle; however, some lesions may go unnoticed. It is important to note that these patients require an interdisciplinary group to reach a correct diagnosis, which is vital to establish the appropriate treatment and follow-up.