17 research outputs found

    Co-transplantation of Human Embryonic Stem Cell-derived Neural Progenitors and Schwann Cells in a Rat Spinal Cord Contusion Injury Model Elicits a Distinct Neurogenesis and Functional Recovery

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    Co-transplantation of neural progenitors (NPs) with Schwann cells (SCs) might be a way to overcome low rate of neuronal differentiation of NPs following transplantation in spinal cord injury (SCI) and the improvement of locomotor recovery. In this study, we initially generated NPs from human embryonic stem cells (hESCs) and investigated their potential for neuronal differentiation and functional recovery when co-cultured with SCs in vitro and co-transplanted in a rat acute model of contused SCI. Co-cultivation results revealed that the presence of SCs provided a consistent status for hESC-NPs and recharged their neural differentiation toward a predominantly neuronal fate. Following transplantation, a significant functional recovery was observed in all engrafted groups (NPs, SCs, NPs+SCs) relative to the vehicle and control groups. We also observed that animals receiving co-transplants established a better state as assessed with the BBB functional test. Immunohistofluorescence evaluation five weeks after transplantation showed invigorated neuronal differentiation and limited proliferation in the co-transplanted group when compared to the individual hESC-NPs grafted group. These findings have demonstrated that the co-transplantation of SCs with hESC-NPs could offer a synergistic effect, promoting neuronal differentiation and functional recovery

    Prediction of response to treatment in children with epilepsy

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    Abstract Objective: This study was conducted to predict the response to treatment in patients treated with anti-epilepsy drugs. Material and Methods: This analytical questionnaire-based study was conducted in 2014 among 128 patients with epilepsy admitted to Mofid Children's Hospital, Tehran, Iran. The inclusion criteria were children 2 months to 12 yr of age with epilepsy and patients who experienced fever and seizure attacks at least once were excluded from the study. Patients were followed up for 6 months and the response to their treatment was recorded. The good response to treatment was defined as the absence of seizure with two drugs during follow up. Results: Seventy-two patients (56.3%) were boys. The age of the first seizure was under 2 yr old in 90 patients (70.3%). History of febrile convulsion, family history of epilepsy and history of asphyxia was found in 16 (12.5%), 41 (32%), and 27 (21.1%) patients, respectively. Seizure etiology was idiopathic in 90 patients (70.3%), and the number of seizures was 1-2 in 36 patients (28.1%). Overall, 57 patients (44.5%) had cerebral lesion according to CT scan or MRI, and EEG was abnormal in 101 patients (78.9%). In 6-month follow-up, 40 patients (31.3%) responded well to the treatment and 88 patients (68.8%) responded poorly to the treatment. History of asphyxia (OR = 6.82), neonatal jaundice (OR = 2.81) and abnormal EEG (OR = 0.19) were effective factors in response to treatment. Conclusion: Abnormal EEG is an effective factor in treatment response in the children studied. Key Words: Pediatric, Anti-seizure drug, Response to treatment, Children, Epileps

    The individual-cell-based cryo-chip for the cryopreservation, manipulation and observation of spatially identifiable cells. I: Methodology

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    <p>Abstract</p> <p>Background</p> <p>Cryopreservation is the only widely applicable method of storing vital cells for nearly unlimited periods of time. Successful cryopreservation is essential for reproductive medicine, stem cell research, cord blood storage and related biomedical areas. The methods currently used to retrieve a specific cell or a group of individual cells with specific biological properties after cryopreservation are quite complicated and inefficient.</p> <p>Results</p> <p>The present study suggests a new approach in cryopreservation, utilizing the Individual Cell-based Cryo-Chip (i3C). The i3C is made of materials having appropriate durability for cryopreservation conditions. The core of this approach is an array of picowells, each picowell designed to maintain an individual cell during the severe conditions of the freezing - thawing cycle and accompanying treatments. More than 97% of cells were found to retain their position in the picowells throughout the entire freezing - thawing cycle and medium exchange. Thus the comparison between pre-freezing and post-thawing data can be achieved at an individual cell resolution. The intactness of cells undergoing slow freezing and thawing, while residing in the i3C, was found to be similar to that obtained with micro-vials. However, in a fast freezing protocol, the i3C was found to be far superior.</p> <p>Conclusions</p> <p>The results of the present study offer new opportunities for cryopreservation. Using the present methodology, the cryopreservation of individual identifiable cells, and their observation and retrieval, at an individual cell resolution become possible for the first time. This approach facilitates the correlation between cell characteristics before and after the freezing - thawing cycle. Thus, it is expected to significantly enhance current cryopreservation procedures for successful regenerative and reproductive medicine.</p

    DNA Repair in Human Pluripotent Stem Cells Is Distinct from That in Non-Pluripotent Human Cells

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    The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability. Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use. In this study, a comparison of DNA repair pathways in pluripotent cells, as compared to those in non-pluripotent cells, demonstrated that DNA repair capacities of pluripotent cell lines were more heterogeneous than those of differentiated lines examined and were generally greater. Although pluripotent cells had high DNA repair capacities for nucleotide excision repair, we show that ultraviolet radiation at low fluxes induced an apoptotic response in these cells, while differentiated cells lacked response to this stimulus, and note that pluripotent cells had a similar apoptotic response to alkylating agent damage. This sensitivity of pluripotent cells to damage is notable since viable pluripotent cells exhibit less ultraviolet light-induced DNA damage than do differentiated cells that receive the same flux. In addition, the importance of screening pluripotent cells for DNA repair defects was highlighted by an iPSC line that demonstrated a normal spectral karyotype, but showed both microsatellite instability and reduced DNA repair capacities in three out of four DNA repair pathways examined. Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use

    Prevalence of low birth weight infants and its related factors in Qom delivery units, 2000

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    Background : Infant mortality rate is one of the most important health index in societies for which low birth weight plays the most important role. The present study was carried out in Qom province to determine this index and its related factors. Materials and methods : For this cross sectional study 1927 newborns were selected from different private and public delivery units. A questionnaire was completed and infant's mothers were interviewed and pediatricians examined Infants. Finally, those LBW newborns were entered for analysis. Results : Of 1927 newborns, 11.8 weighed under 2500 grams, of these 47 had mothers aged less than 18 years and 10 had mothers aged more than 35 years. 51 of these infants were female. There was a significant correlation between previous history of abortion and LBW infant delivery, however, we could not find any association between maternal occupation and level of education with LBW infants. Conclusion : The high prevalence of LBW infants in Qom province is noticeable. Further studies are strongly recommended

    Differentiation of human embryonic stem cells into insulin- secreting cells

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    Introduction: Type I diabetes mellitus is caused by autoimmune destruction of the insulin-producing Ξ²-cells. A new potential method for curing the disease is transplantation of differentiated insulin- secreting cells from human embryonic stem cells. Methods: Human embryonic stem cell lines (Royan H1) were used to produce embryoid bodies. Differentiation carried out by growth factor-mediated selection of nestin positive cells. In final stage, these cells were expanded in the presence of bFGF, followed by addition of nicotinamide to promote differentiation of insulin- secreting cells. Cells were assayed by immunocytochemistry, RT-PCR, insulin secreting assay with Radio-immuno assay kit and Transmission Electron Microscopy. The cells were transplanted into immunosuppressed mice. Results: Analysis of differentiation cells immunocytochemistry showed that these cells were insulin, glucagon, somatostatin and pancreatic polypeptide positive. RT-PCR reaction demonstrated the expression of pancreatic endocrine genes. Differentiation cells secreted insulin in response to glucose, but no significance difference in insulin concentration was observed with an increase in concentration of glucose. The implanted cells were vascularized and remained immunoreactive with insulin and glucagon. Transmission Electron microscopy of differentiate cells showed Golgi complexes, rough endoplasmic reticulum and a few granules but no true Ξ² granules. Conclusion: The data showed that human embryonic stem cells can produce insulin secreting cells. However, more studies are needed to generate true beta cells

    Temporal activation of LRH-1 and RAR-gamma in human pluripotent stem cells induces a functional naive-like state

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    Naive pluripotency can be established in human pluripotent stem cells (hPSCs) by manipulation of transcription factors, signaling pathways, or a combination thereof. However, differences exist in the molecular and functional properties of naive hPSCs generated by different protocols, which include varying similarities with pre-implantation human embryos, differentiation potential, and maintenance of genomic integrity. We show here that short treatment with two chemical agonists (2a) of nuclear receptors, liver receptor homologue-1 (LRH-1) and retinoic acid receptor gamma (RAR-gamma), along with 2i/LIF (2a2iL) induces naive-like pluripotency in human cells during reprogramming of fibroblasts, conversion of pre-established hPSCs, and generation of new cell lines from blastocysts. 2a2iL-hPSCs match several defined criteria of naive-like pluripotency and contribute to human-mouse interspecies chimeras. Activation of TGF-beta signaling is instrumental for acquisition of naive-like pluripotency by the 2a2iL induction procedure, and transient activation of TGF-beta signaling substitutes for 2a to generate naive-like hPSCs. We reason that 2a2iL-hPSCs are an easily attainable system to evaluate properties of naive-like hPSCs and for various applications
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