Potential of Fibrin Glue and Mesenchymal Stem Cells (MSCs) to Regenerate Nerve Injuries: A Systematic Review.

Cell-based therapy is a promising treatment to favor tissue healing through less invasive strategies. Mesenchymal stem cells (MSCs) highlighted as potential candidates due to their angiogenic, anti-apoptotic and immunomodulatory properties, in addition to their ability to differentiate into several specialized cell lines. Cells can be carried through a biological delivery system, such as fibrin glue, which acts as a temporary matrix that favors cell-matrix interactions and allows local and paracrine functions of MSCs. Thus, the aim of this systematic review was to evaluate the potential of fibrin glue combined with MSCs in nerve regeneration. The bibliographic search was performed in the PubMed/MEDLINE, Web of Science and Embase databases, using the descriptors ("fibrin sealant" OR "fibrin glue") AND "stem cells" AND "nerve regeneration", considering articles published until 2021. To compose this review, 13 in vivo studies were selected, according to the eligibility criteria. MSCs favored axonal regeneration, remyelination of nerve fibers, as well as promoted an increase in the number of myelinated fibers, myelin sheath thickness, number of axons and expression of growth factors, with significant improvement in motor function recovery. This systematic review showed clear evidence that fibrin glue combined with MSCs has the potential to regenerate nervous system lesions.

Hemichannels in the neurovascular unit and white matter under normal and inflamed conditions.

In the normal brain, cellular types that compose the neurovascular unit, including neurons, astrocytes and endothelial cells express pannexins and connexins, which are protein subunits of two families that form plasma membrane channels. Most available evidence in mammals indicated that endogenously expressed pannexins only form hemichannels, and connexins form both gap junction channels and hemichannels. While gap junction channels connect the cytoplasm of contacting cells and coordinate electrical and metabolic activities, hemichannels communicate intra- and extracellular compartments and serve as diffusional pathways for ions and small molecules. Here, evidence supporting the functional role of hemichannels in the neurovascular unit and white matter under physiological and pathological conditions are reviewed. A sub-threshold acute pathological threatening condition (e.g., stroke and brain infection) leads to glial cell activation, which maintains an active defense and restores the normal function of the neurovascular unit. However, if the stimulus is deleterious, microglia and the endothelium become overactivated, both releasing bioactive molecules (e.g., glutamate, cytokines, prostaglandins and ATP) that increase the activity of astroglial hemichannels, reducing the astrocyte neuroprotective functions, and further reducing neuronal cell viability. Moreover, ATP is known to contribute to myelin degeneration of axons. Consequently, hemichannels might play a relevant role in the excitotoxic response of oligodendrocytes observed in ischemia and encephalomyelitis. Regulated changes in hemichannel permeability in healthy brain cells can have positive consequences in terms of paracrine/autocrine signaling, whereas persistent changes in cells affected by neurological disorders can be detrimental. Therefore, blocking hemichannels expressed by glial cells and/or neurons of the inflamed central nervous system might prevent neurovascular unit dysfunction and neurodegeneration.

El valor de las pruebas de elevación de la pierna con la rodilla extendida y de tensión de la extremidad superior en la evaluación de las disfunciones del movimiento / Value of leg raise test with extended knee and upper limb tension in the assessment of movement disfunctions

El presente trabajo efectúa una revisión de los mecanismos que explican la aplicación terapéutica de 2 maniobras de movilización neural. En extremidad superior, por medio del test de elevación de la pierna con la rodilla extendida, y en la superior a través del test de tensión de la extremidad superior. De esta forma se plantea el empleo de estos procedimientos para evaluar la presencia de alteraciones mecánicas (comprensión neural) o neurofisiológicas (inflamación neurogénica y espasmo muscular reflexógeno). La relación entre estos mecanismos y la aplicación de los procedimientos es discutida en profundidad

Reversal of neuropathic and gastrointestinal complications related to diabetes mellitus in adolescents with improved metabolic control.

Two adolescents with insulin-dependent diabetes mellitus developed unusually severe diabetic neuropathy which responded to intensive measures to achieve improved metabolic control. Employing home blood glucose monitoring and either frequent insulin injections or a portable insulin infusion pump, painful peripheral neuropathy and autonomic gastrointestinal neuropathy improved after five and 12 months of therapy, respectively. During this period of time, abnormal ocular fluorophotometry, an early change in the eye of diabetic patients, also returned to normal. These patients demonstrate the reversibility of unusually severe neuropathy and early ocular changes in adolescents with diabetes when treated with intensive measures designed to improve metabolic control.