Are We Ready for Cell Therapy to Treat Stroke?

Clinical trials of cell therapies that target stroke started at the beginning of this century and they have experienced a significant boost in recent years as a result of promising data from basic research studies. The increase in the information available has paved the way to carry out more innovative and varied human studies. Efforts have focused on the search for a safe and effective treatment to stimulate neuro-regeneration in the brain and to reduce the sequelae of stroke in patients. Therefore, this review aims to evaluate the clinical trials using cell therapy to treat stroke published to date and assess their limitations. From 2000 to date, most of the published clinical trials have focused on phases I or II, and the vast majority of them demonstrate that stem cells are essentially safe to use when administered by different routes, with transient and mild adverse events that do not generally have severe consequences for health. In general, there is considerable variation in the trials in terms of statistical design, sample size, the cells used, the routes of administration, and the functional assessments (both at baseline and follow-up), making it difficult to compare the studies. From this general description, possibly the experimental protocol is the main element to improve in future studies. Establishing an adequate experimental and statistical design will be essential to obtain favorable and reliable results when conducting phase III clinical trials. Thus, it is necessary to standardize the criteria used in these clinical trials in order to aid comparison. Shortly, cell therapy will be a key approach in the treatment of stroke if adequate and comprehensive levels of recovery are to be achieved.

Neurorestoration Approach by Biomaterials in Ischemic Stroke.

Ischemic stroke (IS) is the leading cause of disability in the western world, assuming a high socio-economic cost. One of the most used strategies in the last decade has been biomaterials, which have been initially used with a structural support function. They have been perfected, different compounds have been combined, and they have been used together with cell therapy or controlled release chemical compounds. This double function has driven them as potential candidates for the chronic treatment of IS. In fact, the most developed are in different phases of clinical trial. In this review, we will show the ischemic scenario and address the most important criteria to achieve a successful neuroreparation from the point of view of biomaterials. The spontaneous processes that are activated and how to enhance them is one of the keys that contribute to the success of the therapeutic approach. In addition, the different routes of administration and how they affect the design of biomaterials are analyzed. Future perspectives show where this broad scientific field is heading, which advances every day with the help of technology and advanced therapies.

Dynamic risk control by human nucleus accumbens.

Real-world decisions about reward often involve a complex counterbalance of risk and value. Although the nucleus accumbens has been implicated in the underlying neural substrate, its criticality to human behaviour remains an open question, best addressed with interventional methodology that probes the behavioural consequences of focal neural modulation. Combining a psychometric index of risky decision-making with transient electrical modulation of the nucleus accumbens, here we reveal profound, highly dynamic alteration of the relation between probability of reward and choice during therapeutic deep brain stimulation in four patients with treatment-resistant psychiatric disease. Short-lived phasic electrical stimulation of the region of the nucleus accumbens dynamically altered risk behaviour, transiently shifting the psychometric function towards more risky decisions only for the duration of stimulation. A critical, on-line role of human nucleus accumbens in dynamic risk control is thereby established.

[Recommendations on the use of 5-amino-levulinic acid in surgery of malignant gliomas. Consensus document. The Neuro-oncology Working Group of the Spanish Neurosurgical Society (SENEC)]. / Recomendaciones sobre el uso de ácido 5-aminolevulínico en la cirugía de los gliomas malignos. Documento de consenso.

Among the prognostic factors when it comes to patients with high-grade gliomas, we find the radicality of the surgery performed. The limitations of this factor are caused by either the extension of the tumour or its location in an eloquent area. To achieve this goal, in the last few years we have developed several methods that allow us to maximise tumour resection, while always trying to cause the least possible co-morbidity. One of these methods includes the use of 5-amino-levulinic acid (5-ALA) and the development of fluorescence guided surgery. However, optimal performance requires knowledge of the product employed, the mode of administration and precautions to consider. Members of the neuro-oncology work group of the Spanish Neurosurgical Society (SENEC) have prepared this guideline or consensus document for anyone who wishes to become familiar with the use of 5-ALA fluorescence-guided surgery in the management of high-grade gliomas. For those who already utilise this technique, this document can be useful for consultation purposes.

Subventricular zone in motor neuron disease with frontotemporal dementia.

Investigate how the subventricular proliferation and organisation is modified in a patient with FTLD-ALS. We studied the subventricular zone (SVZ) of a patient with FTLD-ALS immunohistochemical and histologically. We found an increase of Ki-67 positive cells and neuroblast in the subventricular zone, suggesting an activation of proliferating activity in response to FTD-ALS. This proliferation can act as a compensatory mechanism for rapid neuronal death and its modulation could provide a new therapeutic pathway in ALS. These results suggest a modification of neurogenesis in FTD-ALS.

[Transphenoidal endoscopic approaches for pituitary adenomas: a critical review of our experience]. / Abordajes transesfenoidales endoscópicos de los adenomas hipofisarios: una revisión crítica de nuestra experiencia.

BACKGROUND: The surgical approach to the pituitary fossae has evolved from transcranial to sublabial and transseptal microscopic ones, up to the current transsphenoidal endoscopic approach. OBJECTIVES: To present our experience in the transnasal transsphenoidal approach for pituitary adenomas and the modifications introduced to improve tumoral resection and to lower iatrogenia. MATERIAL AND METHODS: Over nine years, we operated on 37 patients with pituitary adenomas using the transsphenoidal endoscopic approach. We utilised optical lens of 0° (approach) and 30° (adenoma resection), optic navigator, surgical instruments for nasal endoscopic and pituitary surgery. During the neurosurgical step, the endoscope was fixed by an articulated arm. We acceded to the pituitary fossae by a bilateral sphenoidotomy. RESULTS: Sphenoid pneumatisation was sufficient in all the patients. The more common postoperative complications were diabetes insipidus and endocrinology deficiencies. Postoperative rhinoliquorrhea affected only one patient. No alterations of nasal fossae were observed. Mean patient hospitalisation was five days. CONCLUSIONS: Transsphenoidal endoscopic approach guided by navigator gives significant advantages: Shorter operating time and fewer complications, greater safety and preservation of the nasal passages. Resecting the sphenoidal rostrum and a fragment of adjacent nasal septum improves surgical instrument management into the pituitary fossae and therefore adenoma resection. Endoscope fixation stabilises the vision and allows the second surgeon to help more effectively.

Differentiation of postnatal neural stem cells into glia and functional neurons on laminin-coated polymeric substrates.

A series of polymeric biomaterials, including poly(methyl acrylate), chitosan, poly(ethyl acrylate) (PEA), poly(hydroxyethyl acrylate) (PHEA), and a series of random copolymers containing ethyl acrylate, hydroxyethyl acrylate, and methyl acrylate were tested in vitro as culture substrates and compared for their effect on the differentiation of neural stem cells (NSCs) obtained from the subventricular zone of postnatal rats. Immunocytochemical assay for specific markers and scanning electron microscopy techniques were employed to determine the adhesion of the cultured NSCs to the different biomaterials and the respective neuronal differentiation. The functional properties and the membrane excitability of differentiated NSCs were investigated using a patch-clamp. The results show that the substrate's surface chemistry influences cell attachment and neuronal differentiation, probably through its influence on adsorbed laminin, and that copolymers based on PEA and PHEA in a narrow composition window are suitable substrates to promote cell attachment and differentiation of adult NSCs into functional neurons and glia.

Survival and differentiation of embryonic neural explants on different biomaterials.

Biomaterials prepared from polyacrylamide, ethyl acrylate (EA), and hydroxyethyl acrylate (HEA) in various blend ratios, methyl acrylate and chitosan, were tested in vitro as culture substrates and compared for their ability to be colonized by the cells migrating from embryonic brain explants. Neural explants were isolated from proliferative areas of the medial ganglionic eminence and the cortical ventricular zone of embryonic rat brains and cultured in vitro on the different biomaterials. Chitosan, poly(methyl acrylate), and the 50% wt copolymer of EA and HEA were the most suitable substrates to promote cell attachment and differentiation of the neural cells among those tested. Immunofluorescence microscopy analysis showed that progenitor cells had undergone differentiation and that the resulting glial and neuronal cells expressed their intrinsic morphological characteristics in culture.