Neural progenitor NT2N cell lines from teratocarcinoma for transplantation therapy in stroke.

This review article discusses recent progress on the use of teratocarcinoma-derived Ntera2/D1 neuron-like cells (NT2N cells, also called hNT cells) as graft source for cell transplantation in stroke. Laboratory evidence has demonstrated the therapeutic potential of NT2N cells in stroke therapy. Phase I and II clinical trials have shown the cells' feasibility, safety and tolerability profiles in stroke patients. Despite these novel features of NT2N cells, the transplantation regimen remains to be optimized. Moreover, determining the mechanisms underlying the grafts' beneficial effects, specifically demonstrating functional synaptic connections between host brain and NT2N cell grafts, warrants further examination. The major limiting factor for initiating a large clinical trial is the cells' highly potent proliferative property due to their cancerous origin, thereby raising the concern that these cells may revert to a neoplastic state over time after transplantation. To this end, we explored a proof-of-concept "retroviral" strategy to further establish the post-mitotic status of NT2N cells by transfecting these cells with the transcription factor Nurr1, in addition to the standard treatment with retinoic acid and mitotic inhibitors. This new cell line NT2N.Nurr1 displays an expedited neuronal commitment and secretes a high level of the neurotrophic factor glial cell line-derived neurotrophic factor (GDNF), and when transplanted into the rodent stroke brain expressed neuronal phenotype and reduced behavioral impairments which are comparable, if not more robust, than those produced by NT2N cells. Such highly potent neuronal lineage commitment and neurotrophic factor secretory function of NT2.Nurr1 cells make them an appealing graft source for transplantation therapy.

Therapeutic targets and limits of minocycline neuroprotection in experimental ischemic stroke.

BACKGROUND: Minocycline, a second-generation tetracycline with anti-inflammatory and anti-apoptotic properties, has been shown to promote therapeutic benefits in experimental stroke. However, equally compelling evidence demonstrates that the drug exerts variable and even detrimental effects in many neurological disease models. Assessment of the mechanism underlying minocycline neuroprotection should clarify the drug's clinical value in acute stroke setting. RESULTS: Here, we demonstrate that minocycline attenuates both in vitro (oxygen glucose deprivation) and in vivo (middle cerebral artery occlusion) experimentally induced ischemic deficits by direct inhibition of apoptotic-like neuronal cell death involving the anti-apoptotic Bcl-2/cytochrome c pathway. Such anti-apoptotic effect of minocycline is seen in neurons, but not apparent in astrocytes. Our data further indicate that the neuroprotection is dose-dependent, in that only low dose minocycline inhibits neuronal cell death cascades at the acute stroke phase, whereas the high dose exacerbates the ischemic injury. CONCLUSION: The present study advises our community to proceed with caution to use the minimally invasive intravenous delivery of low dose minocycline in order to afford neuroprotection that is safe for stroke.

Dietary supplementation exerts neuroprotective effects in ischemic stroke model.

This study examined whether dietary supplementation can be used to protect against ischemic stroke. Two groups of adult male Sprague-Dawley rats initially received NT-020, a proprietary formulation of blueberry, green tea, Vitamin D3, and carnosine (n = 8), or vehicle (n = 7). Dosing for NT-020 and vehicle consisted of daily oral administration (using a gavage) over a 2-week period. On day 14 following the last drug treatment, all animals underwent the stroke surgery using the transient 1-hour suture occlusion of middle cerebral artery (MCAo). To reveal the functional effects of NT-020, animals were subjected to established behavioral tests just prior to stroke surgery and again on day 14 post-stroke. ANOVA revealed significant treatment effects (p < 0.05), characterized by reductions of 11.8% and 24.4% in motor asymmetry and neurologic dysfunction, respectively, in NT-020-treated stroke animals compared to vehicle-treated stroke animals. Evaluation of cerebral infarction revealed a significant 75% decrement in mean glial scar area in the ischemic striatum of NT-020-treated stroke animals compared to that of vehicle-treated stroke animals (p < 0.0005). Quantitative analysis of subventricular zone's cell proliferative activity revealed at least a one-fold increment in the number of BrdU-positive cells in the NT-020-treated stroke brains compared to vehicle-treated stroke brains (p < 0.0005). Similarly, quantitative analysis of BrdU labeling in the ischemic striatal penumbra revealed at least a three-fold increase in the number of BrdU-positive cells in the NT-020-treated stroke brains compared to vehicle-treated stroke brains (p < 0.0001). In addition, widespread double labeling of cells with BrdU and doublecortin was detected in NT-020-treated stroke brains (intact side 17% and ischemic side 75%), which was significantly higher than those seen in vehicle-treated stroke brains (intact side 5% and ischemic side 13%) (p < 0.05). In contrast, only a small number of cells in NT-020-treated stroke brains double labeled with BrdU and GFAP (intact side 1% and ischemic side 2%), which was significantly lower than those vehicle-treated stroke brains (intact side 18% and ischemic side 35%) (p < 0.0001). Endogenous neurogenic factors were also significantly upregulated in the ischemic brains of NT-020-treated stroke animals. These data demonstrate the remarkable neuroprotective effects of NT-020 when given prior to stroke, possibly acting via its neurogenic potential.

Nanotechnology as an adjunct tool for transplanting engineered cells and tissues.

Laboratory and clinical studies have provided evidence of feasibility, safety and efficacy of cell transplantation to treat a wide variety of diseases characterized by tissue and cell dysfunction ranging from diabetes to spinal cord injury. However, major hurdles remain and limit pursuing large clinical trials, including the availability of a universal cell source that can be differentiated into specific cellular phenotypes, methods to protect the transplanted allogeneic or xenogeneic cells from rejection by the host immune system, techniques to enhance cellular integration of the transplant within the host tissue, strategies for in vivo detection and monitoring of the cellular implants, and new techniques to deliver genes to cells without eliciting a host immune response. Finding ways to circumvent these obstacles will benefit considerably from being able to understand, visualize, and control cellular interactions at a sub-micron level. Cutting-edge discoveries in the multidisciplinary field of nanotechnology have provided us a platform to manipulate materials, tissues, cells, and DNA at the level of and within the individual cell. Clearly, the scientific innovations achieved with nanotechnology are a welcome strategy for enhancing the generally encouraging results already achieved in cell transplantation. This review article discusses recent progress in the field of nanotechnology as a tool for tissue engineering, gene therapy, cell immunoisolation, and cell imaging, highlighting its direct applications in cell transplantation therapy.

Transplantation of human neural stem cells exerts neuroprotection in a rat model of Parkinson's disease.

Neural stem cells (NSCs) possess high potencies of self-renewal and neuronal differentiation. We explored here whether transplantation of human NSCs cloned by v-myc gene transfer, HB1.F3 cells, is a feasible therapeutic option for Parkinson's disease. In vivo, green fluorescent protein-labeled HB1.F3 cells (200,000 viable cells in 3 microl of PBS) when stereotaxically transplanted (same-day lesion-transplant paradigm) into the 6-hydroxydopamine-lesioned striatum of rats significantly ameliorated parkinsonian behavioral symptoms compared with controls (vehicle, single bolus, or continuous minipump infusion of trophic factor, or killed cell grafts). Such graft-derived functional effects were accompanied by preservation of tyrosine hydroxylase (TH) immunoreactivity along the nigrostriatal pathway. Grafted HB1.F3 cells survived in the lesioned brain with some labeled with neuronal marker mitogen-activated protein 2 and decorated with synaptophysin-positive terminals. Furthermore, endogenous neurogenesis was activated in the subventricular zone of transplanted rats. To further explore the neuroprotective mechanisms underlying HB1.F3 cell transplantation, we performed cell culture studies and found that a modest number of HB1.F3 cells were TH and dopamine and cAMP-regulated phosphoprotein 32 positive, although most cells were nestin positive, suggesting a mixed population of mature and immature cells. Administration of the HB1.F3 supernatant to human derived dopaminergic SH-SY5Y cells and fetal rat ventral mesencephalic dopaminergic neurons protected against 6-hydroxydopamine neurotoxicity by suppressing apoptosis through Bcl-2 upregulation, which was blocked by anti-stem cell factor antibody alone, the phosphatidylinositol 3-kinase/Akt inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one] alone, or a combination of both. These results suggest that HB1.F3 cell transplantation exerts neuroprotective effects against dopaminergic depletion in vitro and in vivo because of trophic factor secretion and neuronal differentiation.

Transplantation of bone marrow-derived stem cells: a promising therapy for stroke.

Stroke remains a major cause of death in the US and around the world. Over the last decade, stem cell therapy has been introduced as an experimental treatment for stroke. Transplantation of stem cells or progenitors into the injured site to replace the nonfunctional cells, and enhancement of proliferation or differentiation of endogenous stem or progenitor cells stand as the two major cell-based strategies. Potential sources of stem/progenitor cells for stroke include fetal neural stem cells, embryonic stem cells, neuroteratocarcinoma cells, umbilical cord blood-derived nonhematopoietic stem cells, and bone marrow-derived stem cells. The goal of this article is to provide an update on the preclinical use of bone marrow-derived stem cells with major emphasis on mesenchymal stem cells (MSCs) and multipotent adult progenitor cells (MAPCs) because they are currently most widely applied in experimental stroke studies and are now being phased into early clinical trials. The phenotypic features of MSCs and MAPCs, as well as their application in stroke, are described.

Increased 8-OHdG levels in the urine, serum, and substantia nigra of hemiparkinsonian rats.

8-Hydroxy-2'-deoxyguanosine (8-OHdG), the predominant marker of oxidative DNA damage, may be a good biomarker for monitoring the progression of Parkinson's disease (PD). Unfortunately, there are no basic laboratory data examining 8-OHdG levels in animal models of PD. In this study, we demonstrate that rats lesioned with 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle display significantly elevated 8-OHdG levels in urine, serum, and substantia nigra, but not cerebrospinal fluid and striatum, compared to sham controls. These increments in 8-OHdG levels were detected at 2 days, but not at 7 days after the lesion suggesting that oxidative stress is restricted to the acute phase of 6-OHDA neurotoxicity. The present results support 8-OHdG as a biomarker that may aid both in the diagnosis and in the documentation of progression in PD.

Hippocampal CA1 cell loss in a non-human primate model of transient global ischemia: a pilot study.

We exposed adult Rhesus (Macaca mulatta) to a transient global ischemia, which was induced by clipping the innominate and subclavian arteries that originated from the aortic arch. NHP1 received 20-min, while NHP2 and NHP3, were exposed to a 15-min transient global ischemia and were euthanized at day 1 (NHP1), day 5 (NHP2) or day 30 (NHP3) after ischemia, respectively. NHP1 displayed severe paralysis and rigidity, and intermittent convulsions over the next 24 h. Although histological examination of the brain revealed no detectable gross brain damage (i.e., swelling) and only minimal cell loss in the hippocampus, the acute survival time after surgery likely prevented the cerebral ischemia to fully develop and to be morphologically manifested. Nonetheless, the 20-min ischemia might have been too severe and caused a systemic multiple organ collapse that produced the abnormal behavioral symptoms. On the other hand, NHP2 and NHP3 which received 15-min ischemia only exhibited minor hindlimb paralysis. Indeed, by 48 h after ischemia, both animals appeared fully recovered with only fine motor deficits. Immunohistochemical examination revealed that NHP2 and 3, but not NHP1, had a marked neuronal cell loss in the hippocampal region, specifically the cornu Ammonis (CA1) region. The cell loss in these two ischemic NHP hippocampi was further confirmed by direct comparison with a normal Rhesus brain. These findings replicate the brain pathology seen in Japanese macaques exposed to the same ischemia model [T. Tsukada, M. Watanabe, T. Yamashima, Implications of CAD and DNase II in ischemic neuronal necrosis specific for the primate hippocampus, J. Neurochem. 79 (2001) 1196-1206; T. Yamashima, Implication of cysteine proteases calpain, cathepsin and caspase in ischemic neuronal death of primates, Prog. Neurobiol. 62 (2000) 273-295; T. Yamashima, Y. Kohda, K. Tsuchiya, T. Ueno, J. Yamashita, T. Yoshioka, E. Kominami, Inhibition of ischemic hippocampal neuronal death in primates with cathepsin B inhibitor CA-074: a novel strategy for neuroprotection based on calpain-cathepsin hypothesis, Eur. J. Neurosci. 10 (1998) 1723-1733; T. Yamashima, T.C. Saido, M. Takita, A. Miyazawa, J. Yamano, A. Miyakawa, H. Nishijyo, J. Yamashita, S. Kawashima, T. Ono, T. Yoshioka, Transient brain ischemia provokes Ca2+, PIP2 and calpain responses prior to delayed neuronal death in monkeys, Eur. J. Neurosci. 8 (1996) 1932-1944; T. Yamashima, A.B. Tonchey, T. Tsukada, T.C. Saido, S. Imajoh-Ohmi, T. Momoi, E. Kominami, Sustained calpain activation associated with lysosomal rupture executes necrosis of the postischemic CA1 neurons in primates, Hippocampus 13 (2003) 791-800]. The present minimally invasive transient global ischemia model using Rhesus shows many histopathological symptoms seen in human patients who experienced global ischemia, and should allow translational validation of experimental therapeutics for ischemic injury. Additional studies are warranted to reveal behavioral deficits associated with this ischemia model.

Gene therapy, cell transplantation and stroke.

The use of neuroteratocarcinoma cells for transplantation therapy in stroke has emerged as a strategy for cell replacement therapy that has begun its transition from basic science laboratories to a clinical setting. Procurement logistics and novel neuroprotective functions associated with these cells allow neuroteratocarcinoma cells to serve as efficacious alternatives to using fetal cells as donor cell grafts for stroke therapy, although the optimal transplantation regimen must still be determined. In particular, the limitations of current stroke treatments and management reveal an urgent need to examine the efficacy of experimental treatments, such as neural transplantation, in order to develop better treatment therapies. This chapter will discuss the characteristics of NT2N cells, the role of the host brain microenvironment and NT2N cell grafts, laboratory research and clinical trials for the intracerebral transplantation of NT2N cells in stroke, the mechanisms underlying the grafts' effects, and NT2N cell grafts and the need for immunosuppression. This chapter will also highlight some of the most recent findings regarding NT2N cells.

Isolated superficial sylvian vein thrombosis with long cord sign: case report and review of the literature.

Isolated cortical vein thrombosis (ICVT) is extremely rare. Only single case or small series of ICVT have been reported; clinical details are still uncertain. We report a case of isolated superficial sylvian vein thrombosis with exceedingly long cord sign. A 14-year-old female with severe sudden onset headache visited our hospital. Fluid attenuated inversion recovery and echo-planar T2(*) susceptibility-weighted imaging (T2(*)SW) showed a long cord sign on the surface of the sylvian fissure. The patency of dural sinuses and deep cerebral veins were confirmed by magnetic resonance venography (MRV), and diagnosis of ICVT was made. She recovered completely without anticoagulant agents. To clarify the clinical characteristics of ICVT, we reviewed 51 ICVT cases in the literature. In many cases, T2(*)SW was the most useful examination to diagnose ICVT. In contrast with general cerebral venous thrombosis, MRV and conventional angiography were either supporting or useless. Anastomotic cortical veins were involved frequently; symptoms of gyri around the veins were common. It also suggested that ICVTs of the silent area might have been overlooked because of nonspecific symptoms, and more patients with ICVT may exist. In cases involving patients with nonspecific symptoms, the possibility of ICVT should be considered.

A case of intraosseous microcystic meningioma without a mass lesion.

Both intraosseous and microcystic meningiomas are rare tumor types. We report the case of a 66-year-old woman with intraosseous microcystic meningioma without a mass lesion. She presented with a rare intraosseous microcystic meningioma manifesting as pain. Radiological examination revealed an osteolytic lesion in the right parietal bone. Magnetic resonance (MR) images showed iso- to hypointensity on T1-weighted images and hyperintensity on T2-weighted images corresponding to the lesion. T1-weighted MR imaging with gadolinium enhancement better defined the marginal area. The inner table of the skull was disrupted prominently, and both sides of the outer table were eroded. There was fluid leakage during surgery but no obvious tumor mass. Histological examination revealed microcystic meningioma in the inner part of the defective bone. A macroscopic lesion was not found, because most of the tumor comprised microcysts, and their contents leaked out during the surgical procedure. Intraosseous microcystic meningioma may be considered as one of the differential diagnoses when the intraosseous tumor in the skull has fluid leakage and does not have a mass lesion during the surgery.

Endovascular revascularization of external carotid artery occlusion causing tongue infarction: case report.

A 62-year-old man with diabetes and a history of ischemic coronary disease visited the emergency department complaining of acute pain and swelling of the tongue. Physical examination found subtle swelling and pallor of the right side of the tongue, and he was initially diagnosed with glossitis. However, his symptoms were progressive, and the tongue had sustained serious tissue damage before the correct diagnosis was established. Digital subtraction angiography of the cervical vessels revealed occlusion of the right external carotid artery (ECA) and lingual artery without collateral circulation to the right side of the tongue from the contralateral ECA or ipsilateral vertebral artery (VA). Endovascular revascularization was performed to restore blood flow to the tongue using balloon angioplasty of the proximal segment of the right ECA followed by deployment of a self-expanding stent. Tongue pain subsided shortly after the procedure, and configuration of the tongue returned to normal 4 months after intervention. Tongue infarction is rare and usually associated with systemic vasculitides. Tongue infarction due to unilateral occlusion of the ECA is extremely rare because of the rich collateral circulation to the tongue from the ipsilateral VA and contralateral ECA. Atherothrombotic unilateral occlusion of the ECA should be included in the differential diagnosis of tongue infarction. Revascularization of the occluded ECA is worth attempting despite substantial tissue damage because of the viability of the tongue muscles and the minimal risk of complications in experienced hands.

Peri-hemorrhagic degeneration accompanies stereotaxic collagenase-mediated cortical hemorrhage in mouse.

The cortex is a key brain region vulnerable to intracerebral hemorrhage (ICH) associated with stroke and head trauma. Animal models of ICH, via blood or collagenase infusion, have been developed most commonly to target the striatum. Here, we show that stereotaxic injection of collagenase type IV into two sites of the right cortex of adult C57BL6 mice produced hemorrhage to the cortex, subcortical white matter and hippocampus at day 1 post-injury, followed by cortical volume decrement by day 7. Reductions in MAP2- and NeuN-positive neurons were detected at day 1 and 7 post-injury in the core and peri-hemorrhagic cortex, respectively. Fluoro-Jade positive degenerating neurons were observed at day 1 in the peri-hemorrhagic area. An aberrant aggregation of GFAP-positive astrocytes and a significant reduction in RIP-positive oligodendroglial cells were detected at day 7 post-injury in the cortical area. In addition, a significant decrement in retrogradely Cholera Toxin Subunit B-labeled corticospinal neurons was recognized at day 14 post-injury in the ipsilateral cortex. Among the behavioral tests employed, the pole climb movement test robustly detected significant motor dysfunction at day 1, 3, and 7 post-injury that positively but inversely correlated with cortical volume at day 1 and 7 post-injury, respectively. The consistent observation of neuronal cell loss in the hemorrhagic core that subsequently extended to degeneration of neurons in the peri-hemorrhagic area, with accompanying motor abnormalities at least up to the subacute phase, advances this cortical hemorrhage model as a platform for examining the pathophysiology of and experimental treatments for ICH.

Notch-induced rat and human bone marrow stromal cell grafts reduce ischemic cell loss and ameliorate behavioral deficits in chronic stroke animals.

Gene transfection with Notch 1 intracellular domain and subsequent growth factor treatment stimulate neuron-like differentiation of bone marrow stromal cells (BMSCs). Here, we examined the potential of transplanting Notch-induced BMSCs to exert therapeutic effects in a rat model of chronic ischemic stroke. In experiment 1, Notch-induced rat BMSCs were intrastriatally transplanted in rats at 1 month after being subjected to transient occlusion of middle cerebral artery (MCAo). Compared to post-stroke/pretransplantation level, significant improvements in locomotor and neurological function were detected in stroke rats that received 100 k and 200 k BMSCs, but not in those that received 40 k BMSCs. Histological results revealed 9%-15% graft survival, which dose-dependently correlated with behavioral recovery. At 5 weeks post-transplantation, some grafted BMSCs were positive for the glial marker GFAP (about 5%), but only a few cells (2-5 cells per brain) were positive for the neuronal marker NeuN. However, at 12 weeks post-transplantation, where the number of GFAP-positive BMSCs was maintained (5%), there was a dramatic increase in NeuN-positive BMSCs (23%). In experiment 2, Notch-induced human BMSCs were intrastriatally transplanted in rats at 1 month following the same MCAo model. Improvements in both locomotor and neurological function were observed from day 7 to day 28 post-transplantation, with the high dose (180 k) displaying significantly better behavioral recovery than the low dose (90 k) or vehicle. There were no observable adverse behavioral effects during this study period that also involved chronic immunosuppression of all animals. Histological analyses revealed a modest 5%-7% graft survival, with few (<1%) cells expressing an intermediate MAP2 neuronal marker, but not glial or oligodendroglial markers. In addition, striatal peri-infarct cell loss was significantly reduced in transplanted stroke animals compared to vehicle-treated stroke animals. The present study demonstrates the potential of Notch-induced BMSC cell therapy for patients presenting with fixed ischemic stroke.

Anomaly in aortic arch alters pathological outcome of transient global ischemia in Rhesus macaques.

We investigated a non-human primate (NHP) transient global ischemia (TGI) model which was induced by clipping the arteries originating from the aortic arch. Previously we demonstrated that our TGI model in adult Rhesus macaques (Macaca mulatta) results in marked neuronal cell loss in the hippocampal region, specifically the cornu Ammonis (CA1) region. However, we observed varying degrees of hippocampal cell loss among animals. Here, we report for the first time an anomaly of the aortic arch in some Rhesus macaques that appears as a key surgical factor in ensuring the success of the TGI model in this particular NHP. Eleven adult Rhesus macaques underwent the TGI surgery, which involved 10-15-minute clipping of both innominate and subclavian arteries. Animals were allowed to survive between 1 day and 28 days after TGI. Because of our experience and knowledge that Japanese macaques exhibited only innominate and subclavian arteries arising from the aortic arch, macroscopic visualization of these two arteries alone in the Rhesus macaques initially assured us that clipping both arteries was sufficient to produce TGI. During the course of one TGI operation, however, we detected 3 arterial branches arising from the aortic arch, which prompted us to subsequently search for 3 branches in succeeding TGI surgeries. In addition, we performed post-mortem examination of the heart to confirm the number of arterial branches in the aortic arch. Finally, in order to reveal the pathological effect of the aortic arch anomaly, we compared the hippocampal cell loss between animals found to have 3 arterial branches but had all or only two branches clipped during TGI operation. Post-mortem examination revealed that eight NHPs had the typical two arterial aortic branches, but three NHPs displayed an extra arterial aortic branch, indicating that about 30% of Rhesus macaques had 3 arterial branches arising from the aorta. Histological analyses using Nissl staining showed that in NHPs with the aortic arch anomaly clipping only two of three arterial branches led to a partial cell loss and minimal alteration in number of cell layers in the hippocampal region when compared with clipping all three branches, with the hippocampal cell death in the latter resembling the pathological outcome achieved by clipping the two arterial branches in NHPs displaying the typical two-artery aortic arch. The finding that 3 of 11 NHPs exhibited an extra arterial aortic branch recognizes this aortic arch anomaly in Rhesus macaques that warrants a critical surgical maneuver in order to successfully produce consistent TGI-induced hippocampal cell loss.

Intravenous grafts recapitulate the neurorestoration afforded by intracerebrally delivered multipotent adult progenitor cells in neonatal hypoxic-ischemic rats.

Once hypoxic-ischemic (HI) injury ensues in the human neonate at birth, the resulting brain damage lasts throughout the individual's lifetime, as no ameliorative treatments are currently available. We have recently shown that intracerebral transplantation of multipotent adult progenitor cells (MAPCs) results in behavioral improvement and reduction in ischemic cell loss in neonatal rat HI-injury model. In an attempt to advance this cellular therapy to the clinic, we explored the more practical and less invasive intravenous administration of MAPCs. Seven-day-old Sprague-Dawley rats were initially subjected to unilateral HI injury, then 7 days later received intracerebral or intravenous injections of allogeneic rat MAPCs. On post-transplantation days 7 and 14, the animals that received MAPCs via the intracerebral or intravenous route exhibited improved motor and neurologic scores compared with those that received vehicle infusion alone. Immunohistochemical evaluations at day 14 after transplantation revealed that both intracerebrally and intravenously transplanted MAPCs were detected in the ischemic hippocampal area. The degree of hippocampal cell preservation was almost the same in the two treatment groups and greater than that in the vehicle group. These results show that intravenous delivery of MAPCs is a feasible and efficacious cell therapy with potential for clinical use.

Transplantation of post-mitotic human neuroteratocarcinoma-overexpressing Nurr1 cells provides therapeutic benefits in experimental stroke: in vitro evidence of expedited neuronal differentiation and GDNF secretion.

Nurr1 has been implicated as a transcription factor mediating the endogenous neuroprotective mechanism against stroke. We examined the in vivo and in vitro properties of a new human embryonic carcinoma Ntera-2 cell line carrying the human Nurr1 gene (NT2N.Nurr1). Adult Sprague-Dawley rats underwent experimental stroke initially and 14 days later were assigned randomly to receive stereotaxic transplantation of NT2N.Nurr1 cells or infusion of vehicle into their ischemic striatum. Transplantation of NT2N.Nurr1 cells promoted significant attenuation of behavioral impairments over a 56-day period after stroke, characterized by decreased hyperactivity, biased swing activity, and neurologic deficits, as well as significant reduction in ischemic striatal cell loss compared to vehicle-infused stroke animals. Transplanted NT2N.Nurr1 cells survived and expressed neuronal phenotypic markers in the ischemic striatum. In vitro results showed that cultured NT2.Nurr1 cells were already negative for nestin even before retinoic acid treatment, despite strong nestin immunoreactivity in NT2 cells. This indicates Nurr1 triggered a rapid commitment of NT2 cells into a neuronal lineage. Indeed, NT2.Nurr1 cells, at 4 weeks into RA treatment, displayed more abundant tyrosine hydroxylase positive cells than NT2 cells. Parallel ELISA studies showed further that cultured NT2N.Nurr1, but not NT2N cells, secreted glial cell derived neurotrophic factor. The present study shows efficacy of NT2N.Nurr1 cell grafts in ischemic stroke, with in vitro evidence suggesting the cells' excellent neuronal differentiation capability and ability to secrete GDNF as likely mechanisms mediating the observed therapeutic benefits.

MR imaging in endometrial carcinoma as a diagnostic tool for the absence of myometrial invasion.

OBJECTIVE: To evaluate whether magnetic resonance imaging (MRI) is a reliable modality for verifying preoperative diagnosis of stage IA endometrial carcinoma. METHODS: One hundred sixteen patients with endometrial carcinoma underwent preoperative pelvic non-contrast T2-weighted or dynamic MRI. We compared the interpretations of the MRI results with the histological findings of the resected uterus. RESULTS: In assessing the depth of myometrial invasion, the accuracy of MRI was 62.1%. As to the presence of cancerous myometrial invasion, the positive predictive value was 94.4% as high as previously reported by other institutions. However, the negative predictive value, the probability of the absence of myometrial invasion, was only 42.2%. Even when dynamic study was applied to the patient, the value only improved up to 60.0%. CONCLUSION: MRI has a definite advantage in evaluating deep myometrial invasion, but not the absence of invasion. We should take precautions against the risk of under-diagnosis when selecting stage IA endometrial carcinoma with use of MRI to preserve fertility or to eliminate lymphadenectomy.