搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Human embryonic stem cells (hESCs) have numerous potential biomedical applications owing to their unique abilities for self-renewal and pluripotency. Successful clinical application of hESCs and derivatives necessitates the culture of these cells in a fully defined environment. We have developed a novel peptide-based surface that uses a high-affinity cyclic RGD peptide for culture of hESCs under chemically defined conditions. View Publication

Because of recent declining malaria transmission in Latin America,some authorities have recommended against chemoprophylaxis for most travelers to this region. However,the predominant parasite species in Latin America,Plasmodium vivax,can form hypnozoites sequestered in the liver,causing malaria relapses. Additionally,new evidence shows the potential severity of vivax infections,warranting continued consideration of prophylaxis for travel to Latin America. Individualized travel risk assessments are recommended and should consider travel locations,type,length,and season,as well as probability of itinerary changes. Travel recommendations might include no precautions,mosquito avoidance only,or mosquito avoidance and chemoprophylaxis. There are a range of good options for chemoprophylaxis in Latin America,including atovaquone-proguanil,doxycycline,mefloquine,and--in selected areas--chloroquine. Primaquine should be strongly considered for nonpregnant,G6PD-nondeficient patients traveling to vivax-endemic areas of Latin America,and it has the added benefit of being the only drug to protect against malaria relapses. View Publication

Anti-obesity medications (AOMs) have become one of the most prescribed drugs in human medicine. While AOMs are known to impact adult neurogenesis in the hypothalamus,their effects on the functional maturation of hypothalamic neurons remain unexplored. Given that AOMs target neurons in the Medial Basal Hypothalamus (MBH),which play a crucial role in regulating energy homeostasis,we hypothesized that AOMs might influence the functional maturation of these neurons,potentially rewiring the MBH. To investigate this,we exposed hypothalamic neurons derived from human induced pluripotent stem cells (hiPSCs) to Semaglutide and lipidized prolactin-releasing peptide (LiPR),two anti-obesity compounds. Contrary to our expectations,treatment with Semaglutide or LiPR during neuronal maturation did not affect the proportion of anorexigenic,Pro-opiomelanocortin-expressing (POMC+) neurons. Additionally,LiPR did not alter the morphology of POMC+ neurons or the expression of selected genes critical for the metabolism or development of anorexigenic neurons. Furthermore,LiPR did not impact the proportion of adult-generated POMC+ neurons in the mouse MBH. Taken together,these results suggest that AOMs do not influence the functional maturation of anorexigenic hypothalamic neurons. View Publication

Three-dimensional (3D) printing is advantageous over conventional technologies for the fabrication of sophisticated structures such as 3D micro-channels for future applications in tissue engineering and drug screening. We aimed to apply this technology to cell-based assays using polydimethylsiloxane (PDMS),the most commonly used material for fabrication of micro-channels used for cell culture experiments. Useful properties of PDMS include biocompatibility,gas permeability and transparency. We developed a simple and robust protocol to generate PDMS-based devices using a soft lithography mold produced by 3D printing. 3D chemical gradients were then generated to stimulate cells confined to a micro-channel. We demonstrate that concentration gradients of growth factors,important regulators of cell/tissue functions in vivo,influence the survival and growth of human embryonic stem cells. Thus,this approach for generation of 3D concentration gradients could have strong implications for tissue engineering and drug screening. View Publication

A defect in cell trafficking and chemotaxis plays an important role in the immune deficiency observed in Wiskott-Aldrich syndrome (WAS). In this report,we show that marrow cells from WAS protein (WASP)-deficient mice also have a defect in chemotaxis. Serial transplantation and competitive reconstitution experiments demonstrated that marrow cells,including hematopoietic progenitors and stem cells (HSCs),have decreased homing capacities that were associated with a defect in adhesion to collagen. During development,HSCs migrate from the liver to the marrow and the spleen,prompting us to ask if a defect in HSC homing during development may explain the skewed X-chromosome inactivation in WAS carriers. Preliminary evidence has shown that,in contrast to marrow progenitor cells,fetal liver progenitor cells from heterozygous females had a random X-chromosome inactivation. When fetal liver cells from WASP-carrier females were injected into irradiated recipients,a nonrandom inactivation of the X-chromosome was found at the level of hematopoietic progenitors and HSCs responsible for the short- and long-term hematopoietic reconstitution. Therefore,the mechanism of the skewed X-chromosomal inactivation observed in WAS carriers may be related to a migration defect of WASP-deficient HSCs. View Publication

We report a system for Cre-regulated expression of RNA interference in vivo. Expression cassettes comprise selectable and FACS-sortable markers in tandem with additional marker genes and shRNAs in the antisense orientation. The cassettes are flanked by tandem LoxP sites arranged so that Cre expression inverts the marker-shRNA construct,allowing its regulated expression (and,at the same time,deletes the original selection/marker genes). The cassettes can be incorporated into retroviral or lentiviral vectors and delivered to cells in culture or used to generate transgenic mice. We describe cassettes incorporating various combinations of reporter genes,miRNA-based RNAi (including two shRNA constructs at once),and oncogenes and demonstrate the delivery of effective RNA interference in cells in culture,efficient transduction into hematopoietic stem cells with cell-type-specific knockdown in their progeny,and rapid generation of regulated shRNA knockdown in transgenic mice. These vector systems allow regulated combinatorial manipulation (both overexpression and loss of function) of gene expression in multiple systems in vitro and in vivo. View Publication

Stem cell therapies hold great promise for repairing tissues damaged due to disease or injury. However,a major obstacle facing this field is the difficulty in identifying cells of a desired phenotype from the heterogeneous population that arises during stem cell differentiation. Conventional fluorescence flow cytometry and magnetic cell purification require exogenous labeling of cell surface markers which can interfere with the performance of the cells of interest. Here,we describe a non-genetic,label-free cell cytometry method based on electrophysiological response to stimulus. As many of the cell types relevant for regenerative medicine are electrically-excitable (e.g. cardiomyocytes,neurons,smooth muscle cells),this technology is well-suited for identifying cells from heterogeneous stem cell progeny without the risk and expense associated with molecular labeling or genetic modification. Our label-free cell cytometer is capable of distinguishing clusters of undifferentiated human induced pluripotent stem cells (iPSC) from iPSC-derived cardiomyocyte (iPSC-CM) clusters. The system utilizes a microfluidic device with integrated electrodes for both electrical stimulation and recording of extracellular field potential (FP) signals from suspended cells in flow. The unique electrode configuration provides excellent rejection of field stimulus artifact while enabling sensitive detection of FPs with a noise floor of 2 $$V(rms). Cells are self-aligned to the recording electrodes via hydrodynamic flow focusing. Based on automated analysis of these extracellular signals,the system distinguishes cardiomyocytes from non-cardiomyocytes. This is an entirely new approach to cell cytometry,in which a cell's functionality is assessed rather than its expression profile or physical characteristics. View Publication

Since the 1960s,the stem cells have been extensively studied including embryonic stem cells,neural stem cells,bone marrow hematopoietic stem cells,and mesenchymal stem cells. In the recent years,several stem cells have been initially used in the treatment of diseases,such as in bone marrow transplant. At the same time,isolation and culture experimental technologies for stem cell research have been widely developed in recent years. In addition,molecular imaging technologies including optical molecular imaging,positron emission tomography,single-photon emission computed tomography,and computed tomography have been developed rapidly in recent the 10 years and have also been used in the research on disease mechanism and evaluation of treatment of disease related with stem cells. This paper will focus on recent typical isolation,culture,and observation techniques of stem cells followed by a concise introduction. Finally,the current challenges and the future applications of the new technologies in stem cells are given according to the understanding of the authors,and the paper is then concluded. View Publication

Mechanisms that maintain cancer stem cells are crucial to tumour progression. The ID2 protein supports cancer hallmarks including the cancer stem cell state. HIFα transcription factors,most notably HIF2α (also known as EPAS1),are expressed in and required for maintenance of cancer stem cells (CSCs). However,the pathways that are engaged by ID2 or drive HIF2α accumulation in CSCs have remained unclear. Here we report that DYRK1A and DYRK1B kinases phosphorylate ID2 on threonine 27 (Thr27). Hypoxia downregulates this phosphorylation via inactivation of DYRK1A and DYRK1B. The activity of these kinases is stimulated in normoxia by the oxygen-sensing prolyl hydroxylase PHD1 (also known as EGLN2). ID2 binds to the VHL ubiquitin ligase complex,displaces VHL-associated Cullin 2,and impairs HIF2α ubiquitylation and degradation. Phosphorylation of Thr27 of ID2 by DYRK1 blocks ID2-VHL interaction and preserves HIF2α ubiquitylation. In glioblastoma,ID2 positively modulates HIF2α activity. Conversely,elevated expression of DYRK1 phosphorylates Thr27 of ID2,leading to HIF2α destabilization,loss of glioma stemness,inhibition of tumour growth,and a more favourable outcome for patients with glioblastoma. View Publication

AIM Bevacizumab has been reported to result in increased tumor invasion when used to treat malignant glioma. We hypothesized that BMP4 would prevent diffuse tumor infiltration induced by bevacizumab for malignant glioma in a xenograft model. METHODS Human glioblastoma (GBM) tumor cells were implanted in the striatum of immunocompromised mice. The animals were treated with bevacizumab and BMP4. Tumor growth and invasion were measured. RESULTS The bevacizumab-treated mice had increased survival compared with control animals (p = 0.02). BMP4 alone did not result in improved survival (p = 1.0). The bevacizumab (p = 0.006) and bevacizumab plus BMP4 (p = 0.006) groups demonstrated significantly decreased total tumor size compared with control. Tumor invasion was significantly decreased in the bevacizumab (p = 0.005),BMP4 (p = 0.04) alone and bevacizumab plus BMP4 (p = 0.002) groups compared with control. No synergistic effect between bevacizumab and BMP4 was observed. CONCLUSION Bevacizumab treatment did not result in diffuse infiltration of human GBM in a mouse xenograft model. BMP4 did have an independent favorable effect on GBM that was not synergistic with bevacizumab treatment. View Publication