The Experts below are selected from a list of 72987 Experts worldwide ranked by ideXlab platform
Harry Dolstra - One of the best experts on this subject based on the ideXlab platform.
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high Log Scale expansion of functional human natural killer cells from umbilical cord blood cd34 positive cells for adoptive cancer immunotherapy
PLOS ONE, 2010Co-Authors: Jan Spanholtz, Marleen Tordoir, D N Eissens, F W M B Preijers, Arnold Van Der Meer, Irma Joosten, Nicolaas Schaap, Theo De Witte, Harry DolstraAbstract:Immunotherapy based on natural killer (NK) cell infusions is a potential adjuvant treatment for many cancers. Such therapeutic application in humans requires large numbers of functional NK cells that have been selected and expanded using clinical grade protocols. We established an extremely efficient cytokine-based culture system for ex vivo expansion of NK cells from hematopoietic stem and progenitor cells from umbilical cord blood (UCB). Systematic refinement of this two-step system using a novel clinical grade medium resulted in a therapeutically applicable cell culture protocol. CD56(+)CD3(-) NK cell products could be routinely generated from freshly selected CD34(+) UCB cells with a mean expansion of >15,000 fold and a nearly 100% purity. Moreover, our protocol has the capacity to produce more than 3-Log NK cell expansion from frozen CD34(+) UCB cells. These ex vivo-generated cell products contain NK cell subsets differentially expressing NKG2A and killer immunoglobulin-like receptors. Furthermore, UCB-derived CD56(+) NK cells generated by our protocol uniformly express high levels of activating NKG2D and natural cytotoxicity receptors. Functional analysis showed that these ex vivo-generated NK cells efficiently target myeloid leukemia and melanoma tumor cell lines, and mediate cytolysis of primary leukemia cells at low NK-target ratios. Our culture system exemplifies a major breakthrough in producing pure NK cell products from limited numbers of CD34(+) cells for cancer immunotherapy.
Victor X D Yang - One of the best experts on this subject based on the ideXlab platform.
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differential standard deviation of Log Scale intensity based optical coherence tomography angiography
Journal of Biophotonics, 2017Co-Authors: Weisong Shi, Wanrong Gao, Chaoliang Chen, Victor X D YangAbstract:In this paper, a differential standard deviation of Log-Scale intensity (DSDLI) based optical coherence tomography angiography (OCTA) is presented for calculating microvascular images of human skin. The DSDLI algorithm calculates the variance in difference images of two consecutive Log-Scale intensity based structural images from the same position along depth direction to contrast blood flow. The en face microvascular images were then generated by calculating the standard deviation of the differential Log-Scale intensities within the specific depth range, resulting in an improvement in spatial resolution and SNR in microvascular images compared to speckle variance OCT and power intensity differential method. The performance of DSDLI was testified by both phantom and in vivo experiments. In in vivo experiments, a self-adaptive sub-pixel image registration algorithm was performed to remove the bulk motion noise, where 2D Fourier transform was utilized to generate new images with spatial interval equal to half of the distance between two pixels in both fast-scanning and depth directions. The SNRs of signals of flowing particles are improved by 7.3 dB and 6.8 dB on average in phantom and in vivo experiments, respectively, while the average spatial resolution of images of in vivo blood vessels is increased by 21%.
Yoshikazu Yonemitsu - One of the best experts on this subject based on the ideXlab platform.
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Cytokine-based high Log-Scale expansion of functional human dendritic cells from cord-blood CD34-positive cells
Scientific Reports, 2011Co-Authors: Yui Harada, Yae Okada-nakanishi, Yasuji Ueda, Shunichi Tsujitani, Satoru Saito, Terumi Fuji-ogawa, Akihiro Iida, Mamoru Hasegawa, Tomohiko Ichikawa, Yoshikazu YonemitsuAbstract:Dendritic cells (DCs) play a crucial role in maintaining the immune system. Though DC-based cancer immunotherapy has been suggested as a potential treatment for various kinds of malignancies, its clinical efficacies are still insufficient in many human trials. Issues that limit the clinical efficacy of DC-based immunotherapy, as well as the difficulty of the industrial production of DCs, are largely due to the limited number of autoLogous DCs available from each patient. We here established a possible breakthrough, a simple cytokine-based culture method to expand the Log-Scale order of functional human DCs. Floating cultivation of cord-blood CD34^+ cells under an optimized cytokine cocktail led these progenitor cells to stable Log-Scale proliferation and to DC differentiation. The expanded DCs had typical features of conventional myeloid DCs in vitro . Therefore, the concept of DC expansion should contribute significantly to the progress of DC immunotherapy.
Jerome Mertz - One of the best experts on this subject based on the ideXlab platform.
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Practical Implementation of Log-Scale Active Illumination Microscopy
Ntm, 2011Co-Authors: Jerome MertzAbstract:Active illumination microscopy is a method of redistributing dynamic range in scanning microscopes using feedback for real-time control of illumination power. Images are reconstructed on a Logarithmic Scale to preserve dynamic range benefits.
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practical implementation of Log Scale active illumination microscopy
Biomedical Optics Express, 2010Co-Authors: Kengyeh K Chu, Daryl Lim, Jerome MertzAbstract:Active illumination microscopy (AIM) is a method of redistributing dynamic range in a scanning microscope using real-time feedback to control illumination power on a sub-pixel time Scale. We describe and demonstrate a fully integrated instrument that performs both feedback and image reconstruction. The image is reconstructed on a Logarithmic Scale to accommodate the dynamic range benefits of AIM in a single output channel. A theoretical and computational analysis of the influence of noise on active illumination feedback is presented, along with imaging examples illustrating the benefits of AIM. While AIM is applicable to any type of scanning microscope, we apply it here specifically to two-photon microscopy.
John G Gribben - One of the best experts on this subject based on the ideXlab platform.
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antigen presenting cell mediated expansion of human umbilical cord blood yields Log Scale expansion of natural killer cells with anti myeloma activity
PLOS ONE, 2013Co-Authors: Nina Shah, Beatriz Martinantonio, Hong Yang, Dean A Lee, Laurence J N Cooper, William K Decker, Simon N Robinson, Takuya Sekine, Simrit Parmar, John G GribbenAbstract:Natural killer (NK) cells are important mediators of anti-tumor immunity and are active against several hematoLogic malignancies, including multiple myeloma (MM). Umbilical cord blood (CB) is a promising source of alLogeneic NK cells but large Scale ex vivo expansion is required for generation of clinically relevant CB-derived NK (CB-NK) cell doses. Here we describe a novel strategy for expanding NK cells from cryopreserved CB units using artificial antigen presenting feeder cells (aAPC) in a gas permeable culture system. After 14 days, mean fold expansion of CB-NK cells was 1848-fold from fresh and 2389-fold from cryopreserved CB with >95% purity for NK cells (CD56(+)/CD3(-)) and less than 1% CD3(+) cells. Though surface expression of some cytotoxicity receptors was decreased, aAPC-expanded CB-NK cells exhibited a phenotype similar to CB-NK cells expanded with IL-2 alone with respect to various inhibitory receptors, NKG2C and CD94 and maintained strong expression of transcription factors Eomesodermin and T-bet. Furthermore, CB-NK cells formed functional immune synapses with and demonstrated cytotoxicity against various MM targets. Finally, aAPC-expanded CB-NK cells showed significant in vivo activity against MM in a xenogenic mouse model. Our findings introduce a clinically applicable strategy for the generation of highly functional CB-NK cells which can be used to eradicate MM.
