Progress in brain research
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Over the last years, a plethora of genetic findings have completely changed our views on the aetiology of Parkinson's disease (PD). Linkage studies and positional cloning strategies have identified mutations in a growing number of genes which cause monogenic autosomal-dominant or autosomal-recessive forms of the disorder. ⋯ Thus, an increasingly complex network of genes contributing in different ways to disease risk and progression is emerging. These findings provide the 'genetic entry points' to identify molecular targets and readouts necessary to design rational disease-modifying treatments.
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Somatostatin (SS) and SS receptors (ssts) are broadly expressed in the human body where they exert many physiological actions. Moreover, they can be expressed in many pathological tissues. Particularly, a high density of ssts has been described in human neuroendocrine tumors (NETs). ⋯ Indeed, SS-analogues coupled with (111)In are used to perform sst-scintigraphy, which is a very useful first-line imaging technique in the diagnosis and follow-up of GEP-NETs. Moreover, SS-analogues conjugated to (111)In or to other radioisotopes, such as (177)Lu or (90)Y, have promising effects in the treatment of advanced NETs. ssts are expressed in some non-neuroendocrine tumors as well and in some non-tumoral diseases, suggesting that SS-analogues might have a role in the diagnosis and treatment of these pathological conditions as well. The development of novel SS-analogues with new pharmacokinetic and pharmacodynamic characteristics may further improve the clinical applications of such compounds.
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Review Historical Article
Functional neurosurgery for movement disorders: a historical perspective.
Since the 1960s, deep brain stimulation and spinal cord stimulation at low frequency (30 Hz) have been used to treat intractable pain of various origins. For this purpose, specific hardware have been designed, including deep brain electrodes, extensions, and implantable programmable generators (IPGs). In the meantime, movement disorders, and particularly parkinsonian and essential tremors, were treated by electrolytic or mechanic lesions in various targets of the basal ganglia, particularly in the thalamus and in the internal pallidum. ⋯ The recent development of nanotechnologies allows the design of totally new systems expanding the field of deep brain stimulation. These new techniques will make it possible to not only inhibit or excite deep brain structures to alleviate abnormal symptoms but also open the field for the use of recording cortical activities to drive neuroprostheses through brain-computer interfaces. The new field of compensation of deficits will then become part of the field of functional neurosurgery.
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Alzheimer's disease (AD) is the most prevalent form of neurodegeneration; however, therapies to prevent or treat AD are inadequate. Amyloid-beta (Abeta) protein accrues in cortical senile plaques, one of the key neuropathological hallmarks of AD, and is elevated in brains of early onset AD patients in a small number of families that bear certain genetic mutations, further implicating its role in this devastating neurological disease. In addition, soluble Abeta oligomers have been shown to be detrimental to neuronal function. ⋯ Preclinical trials in nonhuman primates, and human clinical trials using similar Abeta immunogens, are now underway. Abeta immunotherapy looks promising but must be made safer and more effective at generating antibody titers in the elderly. It is hoped that these novel immunogens will enhance Abeta antibody generation across a broad population and avoid the adverse events seen in the earlier clinical trial.
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The search for a "magic bullet" drug targeting a single receptor for the treatment of stroke or traumatic brain injury (TBI) has failed thus far for a variety of reasons. The pathophysiology of ischemic brain injury and TBI involves a number of mechanisms leading to neuronal injury, including excitotoxicity, free radical damage, inflammation, necrosis, and apoptosis. Brain injury also triggers auto-protective mechanisms, including the up-regulation of anti-inflammatory cytokines and endogenous antioxidants. ⋯ Laboratories around the world have shown that progesterone and allopregnanolone act through numerous metabolic and physiological pathways that can affect the injury response in many different tissues and organ systems. Furthermore, progesterone is a natural hormone, synthesized in both males and females, that can act as a pro-drug for other metabolites with their own distinct mode of action in CNS repair. These properties make progesterone a unique and compelling natural agent to consider for testing in clinical trial for CNS injuries including TBI and stroke.