1,108 research outputs found

    The Role of Osteomacs in Regulating Stem Cell Function and the Hematopoietic Niche

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    Indiana University-Purdue University Indianapolis (IUPUI)Maintenance of hematopoietic stem cell (HSC) function is an orchestrated event requiring the participation of multiple cell types within the hematopoietic niche. Among the key cellular components of the niche are a group of specialized bone-resident macrophages known as osteomacs (OM). Reported here is a detailed characterization of OM and description of discriminating phenotypic and functional properties that clearly distinguish OM from bone marrow-derived macrophages (BM Mφ). Furthermore, it was established that OM support hematopoiesis enhancing activity of osteoblasts and that this activity was augmented by megakaryocytes. Serial transplantation demonstrated that HSC repopulating potential was best maintained by in vitro cultures containing OM, osteoblasts and megakaryocytes. Interestingly, BM Mφ were unable to mediate the same hematopoiesis enhancing activity regardless of whether megakaryocytes were present in co-culture or not. Subsequently, to understand the importance of networking between the residents of the niche, 3D tissue cytometry was performed on fixed and stained unperturbed bone marrow sections. This approach identified the spatial relationships between OM, osteoblasts, megakaryocytes and HSC within the niche and defined parameters, under which these cell types coexist in undamaged bone marrow. In addition, single cell mRNAseq and CyTOF was performed to assess genetic and proteomic expression changes in OM following their interaction with megakaryocytes. These studies revealed the upregulation of CD166 and embigin on OM via osteoblast and megakaryocyte interactions. Clonogenic assays were conducted to examine the impact of these molecules in hematopoietic function. When these assays were initiated with CD166 KO OM or shRNA-mediated embigin knockdown OM, it was established that loss of these surface molecules on OM caused a decline in the normal OM-mediated hematopoietic enhancing activity. Conversely, recombinant CD166 and embigin partially substituted for OM activity thus identifying potential mediators through which OM maintain hematopoietic function. This data, for the first time, reveal intimate spatial interactions between OM, osteoblasts, megakaryocytes and HSC in the hematopoietic niche. They also illustrate the importance of crosstalk between OM, osteoblasts and megakaryocytes and reveal novel mediators such as CD166 and embigin that cooperate with other elements of the niche to support HSC function.2020-09-1

    Alternative Frictional Model for Discontinuous Shear Thickening of Dense Suspensions: Hydrodynamics

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    A consensus has emerged that a constraint to rotational or sliding motion of particles in dense suspensions under flow is the genesis of the discontinuous shear thickening (DST) phenomenon. We show that tangential fluid lubrication interactions due to finite-sized asperities on particle surfaces effectively provide these constraints, changing the dynamics of particle motion. By explicitly resolving for the surface roughness of particles, we show that, while smooth particles exhibit continuous shear thickening, purely hydrodynamic interactions in rough particles result in DST. In contrast to the frictional contact model, the hydrodynamic model predicts negative first and second normal stress differences for dense suspensions in the shear thickened state

    Synergistic Apoptotic Effect of Crocin and Paclitaxel or Crocin and Radiation on MCF-7 Cells, a Type of Breast Cancer Cell Line

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    Background. Chemotherapy, radiotherapy, and surgery are routine treatments of breast cancer. However, these methods could only improve the living survival. Nowadays the combined therapy including herbals such as crocin is to study for improving breast cancer treatment. The purpose of this study was to evaluate the effects of crocin, paclitaxel, and radiation on MCF-7 cell. Methods. To evaluate the effect of crocin, paclitaxel, and radiation on survival rate of MCF-7 cells MTT assay was done. To investigate the apoptotic effect of experimental groups PI-flow cytometry was used and expression of apoptotic proteins (caspase-7, caspase-9, PARP, and p53) was studied by western blot. Results. This study revealed that the combined therapy of 0.01μmol/mL paclitaxel and 2.5 mg/mL crocin after 48 h could cause IC50 for MCF-7 cell line. This study showed that the combined therapy of 2 Gy gamma radiation with crocin could rise apoptosis in MCF-7 cell line from 21 (related to using 2 Gy gamma radiation alone) to 46.6. Conclusion. Crocin and paclitaxel and crocin and gamma radiation had synergistic effect on MCF-7 cell line to get more significant apoptosis. © 2015 Faeze Vali et al

    Merkel cell carcinoma masquerading as cellulitis: A case report and review of the literature

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    © 2018 Multimed Inc. Merkel cell carcinoma (MCC) is an uncommon malignancy of the skin arising from cells located in the deeper layers of the epidermis called Merkel cells. This malignancy rarely presents as a metastatic disease, and the field is therefore deficient in regards to management. We report the case of a 49-year-old woman who presented with a presumptive diagnosis of osteomyelitis of the left fifth digit that was resistant to treatment with antibiotics; she underwent debridement of the digit that revealed MCC and was later to have metastatic disease to her lungs, liver, and musculoskeletal system. The management of MCC, although simple in the early stage of the disease, can become challenging when it is more advanced. Multiple new modalities for its treatment have emerged over the last few years, and more recently, clinical trials are being conducted for the use of immunotherapy agents in the treatment of this malignancy

    Improve Image Security Over wireless Sensor Network

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    The major weaknesses of Wireless Sensor Network is the energy consumption, because the difficult battery replacement or recharge . The energy consume can be regulator by more than one layers. In this paper goals to reduce the energy consume in the physical layer, because the most of the energy consume occurs in the physical layer. This reduce will be achieved via the use of Zigbee transceiver standard at the physical layer with the reduced complexity and lower power consumption than other system used in wireless sensor networks. Furthermore, such use will also enhance energy efficiency and bit error rate of the wireless sensor network. In this paper will apply the chaotic interleaver and chaos encryption to get best encryption (two level encryption) and reducing in time processing and enhancement simulation for bit error rate and peak signal to noise ration by transceiver image cameraman though an AWGN and Rayleigh fadingnbsp channels are displayed

    Alternative Frictional Model for Discontinuous Shear Thickening of Dense Suspensions: Hydrodynamics

    Get PDF
    A consensus has emerged that a constraint to rotational or sliding motion of particles in dense suspensions under flow is the genesis of the discontinuous shear thickening (DST) phenomenon. We show that tangential fluid lubrication interactions due to finite-sized asperities on particle surfaces effectively provide these constraints, changing the dynamics of particle motion. By explicitly resolving for the surface roughness of particles, we show that, while smooth particles exhibit continuous shear thickening, purely hydrodynamic interactions in rough particles result in DST. In contrast to the frictional contact model, the hydrodynamic model predicts negative first and second normal stress differences for dense suspensions in the shear thickened state

    Indole-3-carbinol suppresses NF-κB activity and stimulates the p53 pathway in pre-B acute lymphoblastic leukemia cells

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    B cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most common type of cancer in children. Dramatic improvements in primary therapy for childhood ALL have led to an overall cure rate of 80 , providing opportunities for innovative combined-modality strategies that would increase cure rates while reducing the toxic side effects of current intensive regimens. In this study, we report that indole-3-carbinol (I3C), a natural phytochemical found in cruciferous vegetables, had anti-leukemic properties in BCP-ALL NALM-6 cells. I3C induced cell growth inhibition by G1 cell cycle arrest and triggered apoptosis in a dose- and time-dependent manner. p53, p21, and Bax proteins showed increased expression after I3C treatment. Real-time PCR analysis of pro-apoptotic p53 target genes revealed up-regulation of PUMA, NOXA, and Apaf-1. I3C also suppressed constitutive nuclear factor-κB (NF-κB) activation and inhibited the protein expression of NF-kappa B-regulated antiapoptotic (IAP1, Bcl-xL, Bcl-2, XIAP) and proliferative (c-Myc) gene products. Coadministration of I3C with the topoisomerase II inhibitor, doxorubicin, potentiates cytotoxic effects compared with either agent alone. Apoptosis induction by the drug combination was associated with enhanced caspase-9 activation and PARP cleavage. Furthermore, I3C abolished doxorubicin-induced NF-κB activity as evidenced by decreased nuclear accumulation of p65, inhibition of IκBα phosphorylation and its degradation, and decreased NF-κB DNA-binding activity. Western blot analysis revealed that doxorubicin-induced Bcl-2 protein expression was inhibited by I3C. Overall, our results indicated that using nontoxic agents, such as I3C, in combination with anthracyclines might provide a new insight into the development of novel combination therapies in childhood BCP-ALL. © 2015, International Society of Oncology and BioMarkers (ISOBM)

    Novel Combination for Self-Nanoemulsifying Drug Delivery System of Candesartan Cilexetil

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    Solubility problem of many of effective pharmaceutical molecules are still one of the major obstacle in theformulation of such molecules. Candesartan cilexetil (CC) is angiotensin II receptor antagonist with very low water solubility and this result in low and variable bioavailability. Self- emulsifying drug delivery system (SEDDS) showed promising result in overcoming solubility problem of many drug molecules. CC was prepared as SEDDS by using novel combination of two surfactants (tween 80 and cremophore EL) and tetraglycol as cosurfactant, in addition to the use of triacetin as oil. Different tests were performed in order to confirm the stability of the final product which includes thermodynamic study, determination of self-emulsification time, particle size and zeta potential measurement, and in-vitro drug release. The results showed that the particle size of the best formula was 13.3 nm and zeta potential of -37.45 mV with approximately 100% release after 45 minutes .These results suggest that the preparation of CC. as SEDDS with the use of the above combination of surfactant and cosurfactant is a promising maneuver for oral delivery of CC. in order to improve its bioavailability

    Krüppel-Like Transcription Factor KLF1 Is Required for Optimal γ- and β-Globin Expression in Human Fetal Erythroblasts

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    In human adult erythroid cells, lower than normal levels of Krüppel-like transcription factor 1 (KLF1) are generally associated with decreased adult β- and increased fetal γ-globin gene expression. KLF1 also regulates BCL11A, a known repressor of adult γ-globin expression. In seeming contrast to the findings in adult cells, lower amounts of KLF1 correlate with both reduced embryonic and reduced fetal β-like globin mRNA in mouse embryonic erythroid cells. The role of KLF1 in primary human fetal erythroid cells, which express both γ- and β-globin mRNA, is less well understood. Therefore, we studied the role of KLF1 in ex vivo differentiated CD34+ umbilical cord blood cells (UCB erythroblasts), representing the fetal milieu. In UCB erythroblasts, KLF1 binds to the β-globin locus control region (LCR), and the β-globin promoter. There is very little KLF1 binding detectable at the γ-globin promoter. Correspondingly, when cultured fetal UCB erythroblasts are subjected to lentiviral KLF1 knockdown, the active histone mark H3K4me3 and RNA pol II recruitment are diminished at the β- but not the γ-globin gene. The amount of KLF1 expression strongly positively correlates with β-globin mRNA and weakly positively correlates with BCL11A mRNA. With modest KLF1 knockdown, mimicking haploinsufficiency, γ-globin mRNA is increased in UCB erythroblasts, as is common in adult cells. However, a threshold level of KLF1 is evidently required, or there is no absolute increase in γ-globin mRNA in UCB erythroblasts. Therefore, the role of KLF1 in γ-globin regulation in fetal erythroblasts is complex, with both positive and negative facets. Furthermore, in UCB erythroblasts, diminished BCL11A is not sufficient to induce γ-globin in the absence of KLF1. These findings have implications for the manipulation of BCL11A and/or KLF1 to induce γ-globin for therapy of the β-hemoglobinopathies

    Krüppel-Like Transcription Factor KLF1 Is Required for Optimal γ- and β-Globin Expression in Human Fetal Erythroblasts

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    In human adult erythroid cells, lower than normal levels of Krüppel-like transcription factor 1 (KLF1) are generally associated with decreased adult β- and increased fetal γ-globin gene expression. KLF1 also regulates BCL11A, a known repressor of adult γ-globin expression. In seeming contrast to the findings in adult cells, lower amounts of KLF1 correlate with both reduced embryonic and reduced fetal β-like globin mRNA in mouse embryonic erythroid cells. The role of KLF1 in primary human fetal erythroid cells, which express both γ- and β-globin mRNA, is less well understood. Therefore, we studied the role of KLF1 in ex vivo differentiated CD34+ umbilical cord blood cells (UCB erythroblasts), representing the fetal milieu. In UCB erythroblasts, KLF1 binds to the β-globin locus control region (LCR), and the β-globin promoter. There is very little KLF1 binding detectable at the γ-globin promoter. Correspondingly, when cultured fetal UCB erythroblasts are subjected to lentiviral KLF1 knockdown, the active histone mark H3K4me3 and RNA pol II recruitment are diminished at the β- but not the γ-globin gene. The amount of KLF1 expression strongly positively correlates with β-globin mRNA and weakly positively correlates with BCL11A mRNA. With modest KLF1 knockdown, mimicking haploinsufficiency, γ-globin mRNA is increased in UCB erythroblasts, as is common in adult cells. However, a threshold level of KLF1 is evidently required, or there is no absolute increase in γ-globin mRNA in UCB erythroblasts. Therefore, the role of KLF1 in γ-globin regulation in fetal erythroblasts is complex, with both positive and negative facets. Furthermore, in UCB erythroblasts, diminished BCL11A is not sufficient to induce γ-globin in the absence of KLF1. These findings have implications for the manipulation of BCL11A and/or KLF1 to induce γ-globin for therapy of the β-hemoglobinopathies
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