Although implantation of fetal dopamine (DA) neurons can reduce parkinsonism in patients, current methods are rudimentary, and a reliable donor cell source is lacking. We show that transplanting low doses of undifferentiated mouse embryonic stem (ES) cells into the rat striatum results in a proliferation of ES cells into fully differentiated DA neurons. ES cell-derived DA neurons caused gradual and sustained behavioral restoration of DA-mediated motor asymmetry. Behavioral recovery paralleled in vivo positron emission tomography and functional magnetic resonance imaging data demonstrating DA-mediated hemodynamic changes in the striatum and associated brain circuitry. These results demonstrate that transplanted ES cells can develop spontaneously into DA neurons. Such DA neurons can restore cerebral function and behavior in an animal model of Parkinson's disease. P arkinson's disease (PD) is a degenerative disorder characterized by a loss of midbrain dopamine (DA) neurons with a subsequent reduction in striatal DA (1). Pharmacological treatment with L-DOPA works initially, but reduced efficacy and development of motor complications requires treatment alternatives such as deep brain stimulation and fetal DA neuron transplantation (2). There is evidence both from animal models and clinical investigations showing that fetal DA neurons can produce symptomatic relief (3-6). Technical and ethical difficulties in obtaining sufficient and appropriate donor fetal brain tissue have limited the application of this new therapy.Previous work showed that DA neurons can be produced in vitro from ventral mesencephalic (VM) precursor cells (7). A problem using expanded fetal VM precursors (7) is the low in vivo survival rate of 3-5% of the grafted DA neurons, which eliminates the actual gain by in vitro cell number expansion compared with fresh (unexpanded) fetal day-12 VM (7,8).Embryonic stem (ES) cells have many characteristics required for an optimal cell source for cell-replacement therapy (9, 10). ES cells are self-renewing and multipotent cells derived from the inner cell mass of the preimplantation blastocyst (11). We have shown previously that mouse ES cells transplanted to normal mice or 6-hydroxydopamine (OHDA)-lesioned rats can differentiate spontaneously into tyrosine hydroxylase (TH)-positive and serotonin (5HT)-positive neurons. This differentiation is likely not caused by a specific inductive signal from the host brain, because similar neuronal differentiation occurs after placement in the kidney capsule (11). In our previous study (11), grafts frequently showed heterogeneous morphology and often became very large, disrupting the cytoarchitecture at the implantation site, which prevented the possibility for functional integration. Because neurons develop from ES cells even when implanted outside the central nervous system (11) and ectoderm develops into neural tissue when cellto-cell communication is disrupted by dissociation of the cells (12-14), we hypothesized that dilution of ES cells into single-cell suspension...
Background Population-based cancer survival estimates provide valuable insights into the effectiveness of cancer services and can reflect the prospects of cure. As part of the second phase of the International Cancer Benchmarking Partnership (ICBP), the Cancer Survival in High-Income Countries (SURVMARK-2) project aims to provide a comprehensive overview of cancer survival across seven high-income countries and a comparative assessment of corresponding incidence and mortality trends. Methods In this longitudinal, population-based study, we collected patient-level data on 3•9 million patients with cancer from population-based cancer registries in 21 jurisdictions in seven countries (
Purpose A dramatic improvement in the survival of patients with chronic myeloid leukemia (CML) occurred after the introduction of imatinib mesylate, the first tyrosine kinase inhibitor (TKI). We assessed how these changes affected the life expectancy of patients with CML and life-years lost as a result of CML between 1973 and 2013 in Sweden. Materials and Methods Patients recorded as having CML in the Swedish Cancer Registry from 1973 to 2013 were included in the study and followed until death, censorship, or end of follow-up. The life expectancy and loss in expectation of life were predicted from a flexible parametric relative survival model. Results A total of 2,662 patients with CML were diagnosed between 1973 and 2013. Vast improvements in the life expectancy of these patients were seen over the study period; larger improvements were seen in the youngest ages. The great improvements in life expectancy translated into great reductions in the loss in expectation of life. Patients of all ages diagnosed in 2013 will, on average, lose < 3 life-years as a result of CML. Conclusion Imatinib mesylate and new TKIs along with allogeneic stem cell transplantation and other factors have contributed to the life expectancy in patients with CML approaching that of the general population today. This will be an important message to convey to patients to understand the impact of a CML diagnosis on their life. In addition, the increasing prevalence of patients with CML will have a great effect on future health care costs as long as continuous TKI treatment is required.
Background and AimsMajor depression can be treated by means of cognitive behavior therapy, delivered via the Internet as guided self-help. Individually tailored guided self-help treatments have shown promising results in the treatment of anxiety disorders. This randomized controlled trial tested the efficacy of an Internet-based individually tailored guided self-help treatment which specifically targeted depression with comorbid symptoms. The treatment was compared both to standardized (non-tailored) Internet-based treatment and to an active control group in the form of a monitored online discussion group. Both guided self-help treatments were based on cognitive behavior therapy and lasted for 10 weeks. The discussion group consisted of weekly discussion themes related to depression and the treatment of depression.MethodsA total of 121 participants with diagnosed major depressive disorder and with a range of comorbid symptoms were randomized to three groups. The tailored treatment consisted of a prescribed set of modules targeting depression as well as comorbid problems. The standardized treatment was a previously tested guided self-help program for depression.ResultsFrom pre-treatment to post-treatment, both treatment groups improved on measures of depression, anxiety and quality of life. The results were maintained at a 6-month follow-up. Subgroup analyses showed that the tailored treatment was more effective than the standardized treatment among participants with higher levels of depression at baseline and more comorbidity, both in terms of reduction of depressive symptoms and on recovery rates. In the subgroup with lower baseline scores of depression, few differences were seen between treatments and the discussion group.ConclusionsThis study shows that tailored Internet-based treatment for depression is effective and that addressing comorbidity by tailoring may be one way of making guided self-help treatments more effective than standardized approaches in the treatment of more severe depression.Trial RegistrationClinicaltrials.gov NCT01181583
SummaryAccumulation of Aβ peptide fragments of the APP protein and neurofibrillary tangles of the microtubule-associated protein tau are the cellular hallmarks of Alzheimer’s disease (AD). To investigate the relationship between APP metabolism and tau protein levels and phosphorylation, we studied human-stem-cell-derived forebrain neurons with genetic forms of AD, all of which increase the release of pathogenic Aβ peptides. We identified marked increases in intracellular tau in genetic forms of AD that either mutated APP or increased its dosage, suggesting that APP metabolism is coupled to changes in tau proteostasis. Manipulating APP metabolism by β-secretase and γ-secretase inhibition, as well as γ-secretase modulation, results in specific increases and decreases in tau protein levels. These data demonstrate that APP metabolism regulates tau proteostasis and suggest that the relationship between APP processing and tau is not mediated solely through extracellular Aβ signaling to neurons.
Nurr1 is a transcription factor critical for the development of midbrain dopaminergic (DA) neurons. This study modified mouse embryonic stem (ES) cells to constitutively express Nurr1 under the elongation factor-1alpha promoter. The Nurr1-expression in ES cells lead to up-regulation of all DA neuronal markers tested, resulting in about a 4- to 5-fold increase in the proportion of DA neurons. In contrast, other neuronal and glial markers were not significantly changed by Nurr1 expression. It was also observed that there was an additional 4-fold increase in the number of DA neurons in Nurr1-expressing clones following treatment with Shh, FGF8 and ascorbic acid. Several lines of evidence suggest that these neurons may represent midbrain DA neuronal phenotypes; firstly, they coexpress midbrain DA markers such as aromatic L-amino acid decarboxylase, calretinin, and dopamine transporter, in addition to tyrosine hydroxylase and secondly, they do not coexpress other neurotransmitters such as GABA or serotonin. Finally, consistent with an increased number of DA neurons, the Nurr1 transduction enhanced the ability of these neurons to produce and release DA in response to membrane depolarization. This study demonstrates an efficient genetic manipulation of ES cells that facilitates differentiation to midbrain DA neurons, and it will serve as a framework of genetic engineering of ES cells by key transcription factor to regulate their cell fate.
A useful summary measure for survival data is the expectation of life, which is calculated by obtaining the area under a survival curve. The loss in expectation of life due to a certain type of cancer is the difference between the expectation of life in the general population and the expectation of life among the cancer patients. This measure is used little in practice as its estimation generally requires extrapolation of both the expected and observed survival. A parametric distribution can be used for extrapolation of the observed survival, but it is difficult to find a distribution that captures the underlying shape of the survival function after the end of follow-up. In this paper, we base our extrapolation on relative survival, because it is more stable and reliable. Relative survival is defined as the observed survival divided by the expected survival, and the mortality analogue is excess mortality. Approaches have been suggested for extrapolation of relative survival within life-table data, by assuming that the excess mortality has reached zero (statistical cure) or has stabilized to a constant. We propose the use of flexible parametric survival models for relative survival, which enables estimating the loss in expectation of life on individual level data by making these assumptions or by extrapolating the estimated linear trend at the end of follow-up. We have evaluated the extrapolation from this model using data on four types of cancer, and the results agree well with observed data.
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