Stem cell fate is influenced by a number of factors and interactions that require robust control for safe and effective regeneration of functional tissue. Coordinated interactions with soluble factors, other cells, and extracellular matrices define a local biochemical and mechanical niche with complex and dynamic regulation that stem cells sense. Decellularized tissue matrices and synthetic polymer niches are being used in the clinic, and they are also beginning to clarify fundamental aspects of how stem cells contribute to homeostasis and repair, for example, at sites of fibrosis. Multifaceted technologies are increasingly required to produce and interrogate cells ex vivo, to build predictive models, and, ultimately, to enhance stem cell integration in vivo for therapeutic benefit.

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Growth Factors, Matrices, and Forces Combine and Control Stem Cells

Background—The purpose of this statement is to provide an overview of cerebral venous sinus thrombosis and to provide recommendations for its diagnosis, management, and treatment. The intended audi...

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Diagnosis and Management of Cerebral Venous Thrombosis A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

Ageing is the primary risk factor for most neurodegenerative diseases, including Alzheimer disease (AD) and Parkinson disease (PD). One in ten individuals aged ≥65 years has AD and its prevalence continues to increase with increasing age. Few or no effective treatments are available for ageing-related neurodegenerative diseases, which tend to progress in an irreversible manner and are associated with large socioeconomic and personal costs. This Review discusses the pathogenesis of AD, PD and other neurodegenerative diseases, and describes their associations with the nine biological hallmarks of ageing: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, mitochondrial dysfunction, cellular senescence, deregulated nutrient sensing, stem cell exhaustion and altered intercellular communication. The central biological mechanisms of ageing and their potential as targets of novel therapies for neurodegenerative diseases are also discussed, with potential therapies including NAD+ precursors, mitophagy inducers and inhibitors of cellular senescence.

Ageing as a risk factor for neurodegenerative disease.

https://journal.chestnet.org/article/S0012-3692(12)60137-8/pdf

Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

Transplantation of dopaminergic neurons can potentially improve the clinical outcome of Parkinson's disease, a neurological disorder resulting from degeneration of mesencephalic dopaminergic neurons. In particular, transplantation of embryonic-stem-cell-derived dopaminergic neurons has been shown to be efficient in restoring motor symptoms in conditions of dopamine deficiency. However, the use of pluripotent-derived cells might lead to the development of tumours if not properly controlled. Here we identified a minimal set of three transcription factors--Mash1 (also known as Ascl1), Nurr1 (also known as Nr4a2) and Lmx1a--that are able to generate directly functional dopaminergic neurons from mouse and human fibroblasts without reverting to a progenitor cell stage. Induced dopaminergic (iDA) cells release dopamine and show spontaneous electrical activity organized in regular spikes consistent with the pacemaker activity featured by brain dopaminergic neurons. The three factors were able to elicit dopaminergic neuronal conversion in prenatal and adult fibroblasts from healthy donors and Parkinson's disease patients. Direct generation of iDA cells from somatic cells might have significant implications for understanding critical processes for neuronal development, in vitro disease modelling and cell replacement therapies.

Direct generation of functional dopaminergic neurons from mouse and human fibroblasts

Background 
Neural stem cells are currently being investigated as potential therapies for neurodegenerative diseases, stroke, and trauma. However, concerns have been raised over the safety of this experimental therapeutic approach, including, for example, whether there is the potential for tumors to develop from transplanted stem cells.


Methods and Findings 
A boy with ataxia telangiectasia (AT) was treated with intracerebellar and intrathecal injection of human fetal neural stem cells. Four years after the first treatment he was diagnosed with a multifocal brain tumor. The biopsied tumor was diagnosed as a glioneuronal neoplasm. We compared the tumor cells and the patient's peripheral blood cells by fluorescent in situ hybridization using X and Y chromosome probes, by PCR for the amelogenin gene X- and Y-specific alleles, by MassArray for the ATM patient specific mutation and for several SNPs, by PCR for polymorphic microsatellites, and by human leukocyte antigen (HLA) typing. Molecular and cytogenetic studies showed that the tumor was of nonhost origin suggesting it was derived from the transplanted neural stem cells. Microsatellite and HLA analysis demonstrated that the tumor is derived from at least two donors.


Conclusions 
This is the first report of a human brain tumor complicating neural stem cell therapy. The findings here suggest that neuronal stem/progenitor cells may be involved in gliomagenesis and provide the first example of a donor-derived brain tumor. Further work is urgently needed to assess the safety of these therapies.

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Donor-Derived Brain Tumor Following Neural Stem Cell Transplantation in an Ataxia Telangiectasia Patient

The etiology and pathophysiology of cerebral sinus venous thrombosis (CSVT) in the paediatric population is still poorly understood, and the role of thrombophilic risk factors remains to be elucidated. In our multi-center case-controlled study we studied 46 patients with CSVT diagnosed from April 1996 to December 2003, consecutively referred for thrombophilia work-up. The results of thrombophilia screen were compared to 112 healthy paediatric controls. Anticoagulant therapy was applied according to treating physicians’ decisions, and all cases were prospectively followed for a median of 4.1 years. Of 46 children, 8 had CSVT diagnosed in the neonatal period and therefore were analyzed separately. The prevalence of single thrombophilia markers and combinations of thrombophilic risk factors were similar among cases and controls. Among children with CSVT co-morbid systemic illness was present in most patients at diagnosis. Seven out of 8 children with idiopathic CSVT had thrombophilic risk factors as compared to 31/38 patients with co-morbid conditions. Anticoagulation was initiated in most patients, 11/46 patients continued therapy for a total of one year or more post event. Neither clinical presentation nor initial treatment decisions were affected by presence of thrombophilic risk factors in our study group. Thrombophilia prevalence was not increased in children with CSVT as compared to controls, however thrombophilia was more frequent among children with idiopathic CSVT. Thus, those selected patients would benefit most from thrombophilia work-up, required for long-term therapy considerations.

Paediatric cerebral sinus vein thrombosis. A multi-center, case-controlled study.

https://www.pedneur.com/article/S0887-8994(96)00319-0/pdf

Dalia Waldman

Papers

Donor-Derived Brain Tumor Following Neural Stem Cell Transplantation in an Ataxia Telangiectasia Patient

Paediatric cerebral sinus vein thrombosis. A multi-center, case-controlled study.

MRI meningeal enhancement with intracranial hypotension caused by lumbar puncture