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Donald D Davis - One of the best experts on this subject based on the ideXlab platform.

  • intraspecific root grafts and Clonal Growth within ailanthus altissima stands influence verticillium nonalfalfae transmission
    Plant Disease, 2015
    Co-Authors: E S Oneal, Donald D Davis
    Abstract:

    Verticillium nonalfalfae, causal agent of Verticillium wilt, is being considered as a biocontrol for the highly invasive Ailanthus altissima in Pennsylvania. This soilborne fungus is extremely virulent on Ailanthus and rapidly transmitted from diseased to healthy trees within Ailanthus stands. The rapid transmission of the fungus could be facilitated by root grafts, but neither root graft formation in Ailanthus nor Verticillium transmission by root grafts in trees has been reported. Here, V. nonalfalfae transmission between diseased and healthy Ailanthus trees via intraspecific root grafts and Clonal Growth is evaluated. Using air-spade excavation, dye translocation, and root graft inoculations, functional root grafts were detected between Ailanthus trees and transmission of V. nonalfalfae across root grafts demonstrated. Inoculation of one Ailanthus parent stem resulted in 187 root sprouts showing Verticillium wilt symptoms 12 months after inoculation. This study revealed that Clonal Growth and root grafts, normally advantageous Growth habits, leave Ailanthus stands vulnerable to widespread V. nonalfalfae infection. This study also broadens the understanding of the Ailanthus-Verticillium pathosystem, Growth strategies of invasive Ailanthus, and epidemiology of Verticillium wilt within trees.

E S Oneal - One of the best experts on this subject based on the ideXlab platform.

  • intraspecific root grafts and Clonal Growth within ailanthus altissima stands influence verticillium nonalfalfae transmission
    Plant Disease, 2015
    Co-Authors: E S Oneal, Donald D Davis
    Abstract:

    Verticillium nonalfalfae, causal agent of Verticillium wilt, is being considered as a biocontrol for the highly invasive Ailanthus altissima in Pennsylvania. This soilborne fungus is extremely virulent on Ailanthus and rapidly transmitted from diseased to healthy trees within Ailanthus stands. The rapid transmission of the fungus could be facilitated by root grafts, but neither root graft formation in Ailanthus nor Verticillium transmission by root grafts in trees has been reported. Here, V. nonalfalfae transmission between diseased and healthy Ailanthus trees via intraspecific root grafts and Clonal Growth is evaluated. Using air-spade excavation, dye translocation, and root graft inoculations, functional root grafts were detected between Ailanthus trees and transmission of V. nonalfalfae across root grafts demonstrated. Inoculation of one Ailanthus parent stem resulted in 187 root sprouts showing Verticillium wilt symptoms 12 months after inoculation. This study revealed that Clonal Growth and root grafts, normally advantageous Growth habits, leave Ailanthus stands vulnerable to widespread V. nonalfalfae infection. This study also broadens the understanding of the Ailanthus-Verticillium pathosystem, Growth strategies of invasive Ailanthus, and epidemiology of Verticillium wilt within trees.

Timothy C. Thompson - One of the best experts on this subject based on the ideXlab platform.

  • Caveolin-1 mediates testosterone-stimulated survival/Clonal Growth and promotes metastatic activities in prostate cancer cells.
    Cancer research, 2001
    Co-Authors: Guang Yang, Shin Ebara, Takefumi Satoh, Yasutomo Nasu, Terry L. Timme, Chengzhen Ren, Jianxiang Wang, Salahaldin A. Tahir, Timothy C. Thompson
    Abstract:

    Previously, we demonstrated that up-regulation of caveolin-1 (cav-1) was associated with prostate cancer metastasis, biochemical recurrence after radical prostatectomy, and androgen insensitivity. The objective of this study was to characterize the regulation of cav-1 by testosterone (T) and to test the effects of cav-1 on prostate cancer cell survival/Clonal Growth and metastatic activities. Our results demonstrated that T up-regulated cav-1 protein levels in part through transcriptional regulation and significantly enhanced survival of prostate cancer cell lines ABAC3 and LNCaP after serum starvation (>40% and >60% increased viability, respectively) and in an extended clonogenic assay (approximately 4-fold and 6-fold increase in colonies, respectively). Importantly, antisense cav-1 inhibited the survival effects of T in these assay systems. Modest but not high levels of adenoviral vector-mediated cav-1 expression alone also significantly increased viability (>40%) and Clonal Growth (10-fold increase in colonies) after serum starvation. Analysis of spontaneous metastasis in stably transfected antisense cav-1 mouse prostate cancer cell clones demonstrated reduction of spontaneous lymph node metastasis incidence (13%), spontaneous lymph node metastasis volume (46%), and experimental lung metastasis incidence (40%) compared with vector control cell clones. Surgical castration further reduced spontaneous lymph node metastasis incidence and volume (18% and 28%, respectively) in antisense cancer cell clones, but not in vector control clones. Our studies demonstrate that cav-1 is a downstream effector of T-mediated prostate cancer cell survival/Clonal Growth and that modest levels of cav-1 can independently promote prostate cancer cell survival/Clonal Growth and metastatic activities.

  • caveolin 1 mediates testosterone stimulated survival Clonal Growth and promotes metastatic activities in prostate cancer cells
    Cancer Research, 2001
    Co-Authors: Guang Yang, Shin Ebara, Takefumi Satoh, Yasutomo Nasu, Terry L. Timme, Chengzhen Ren, Jianxiang Wang, Salahaldin A. Tahir, Timothy C. Thompson
    Abstract:

    Previously, we demonstrated that up-regulation of caveolin-1 (cav-1) was associated with prostate cancer metastasis, biochemical recurrence after radical prostatectomy, and androgen insensitivity. The objective of this study was to characterize the regulation of cav-1 by testosterone (T) and to test the effects of cav-1 on prostate cancer cell survival/Clonal Growth and metastatic activities. Our results demonstrated that T up-regulated cav-1 protein levels in part through transcriptional regulation and significantly enhanced survival of prostate cancer cell lines ABAC3 and LNCaP after serum starvation (>40% and >60% increased viability, respectively) and in an extended clonogenic assay (approximately 4-fold and 6-fold increase in colonies, respectively). Importantly, antisense cav-1 inhibited the survival effects of T in these assay systems. Modest but not high levels of adenoviral vector-mediated cav-1 expression alone also significantly increased viability (>40%) and Clonal Growth (10-fold increase in colonies) after serum starvation. Analysis of spontaneous metastasis in stably transfected antisense cav-1 mouse prostate cancer cell clones demonstrated reduction of spontaneous lymph node metastasis incidence (13%), spontaneous lymph node metastasis volume (46%), and experimental lung metastasis incidence (40%) compared with vector control cell clones. Surgical castration further reduced spontaneous lymph node metastasis incidence and volume (18% and 28%, respectively) in antisense cancer cell clones, but not in vector control clones. Our studies demonstrate that cav-1 is a downstream effector of T-mediated prostate cancer cell survival/Clonal Growth and that modest levels of cav-1 can independently promote prostate cancer cell survival/Clonal Growth and metastatic activities.

Scheffer C. G. Tseng - One of the best experts on this subject based on the ideXlab platform.

  • integration of bmp wnt signaling to control Clonal Growth of limbal epithelial progenitor cells by niche cells
    Stem Cell Research, 2014
    Co-Authors: Bo Han, Szuyu Chen, Yingting Zhu, Scheffer C. G. Tseng
    Abstract:

    Both BMP and Wnt signaling control stem cells in bulge/dermal papilla, intestinal crypt, and bone marrow. To explore their roles in the limbal niche, which govern corneal epithelial homeostasis, we established an in vitro model of sphere Growth by reunion between single limbal epithelial progenitor cells (LEPCs) and aggregates of limbal niche cells (LNCs) in 3D Matrigel. Compared to LEPCs alone, spheres formed by LEPC+LNC exhibited higher Clonal Growth and less corneal epithelial differentiation. Furthermore, pSmad1/5/8 was in the nucleus of LEPCs, but not LNCs, and correlated with upregulation of BMP1, BMP3, BMP4, all three BMP receptors, and BMP target genes. Inactivation of BMP signaling in LNCs was correlated with upregulation of noggin preferentially expressed by LNCs. Additionally, β-catenin was stabilized in the perinuclear cytoplasm in LEPCs and correlated with upregulation of Wnt7A and FZD5 preferentially expressed by LEPCs. Inactivation of Wnt signaling in LNCs was correlated with upregulation of DKK1/2 by LNCs. Addition of XAV939 that expectedly downregulated perinuclear β-catenin in LEPCs led to significant reduction of epithelial Clonal Growth, but upregulated all three BMP receptors and downregulated LNC-derived noggin, resulting in activation of BMP signaling in LNCs. Addition of noggin that expectedly downregulated nuclear localization of pSmad1/5/8 in LEPCs led to nuclear localization of β-catenin in larger LEPCs but membrane relocation of β-catenin in smaller LEPCs and significant upregulation of DKK1/2. Hence, balancing acts between Wnt signaling and BMP signaling exist not only within LEPCs but also between LEPCs and LNCs to regulate Clonal Growth of LEPCs.

  • Retinoic acid regulates Clonal Growth and differentiation of cultured limbal and peripheral corneal epithelium.
    Investigative ophthalmology & visual science, 1994
    Co-Authors: F. E. Kruse, Scheffer C. G. Tseng
    Abstract:

    PURPOSE To determine if vitamin A could be one of the factors in serum responsible for the previously observed effect of 20% fetal bovine serum on stimulating Clonal Growth of an additional subpopulation in limbal cultures, possibly stem cells, but inhibiting that of transient amplifying cells in peripheral corneal cultures. METHODS A reported serum-free Clonal Growth assay was used. The mitogenic response was measured by colony-forming efficiency (CFE), colony size, and BrdU labeling index; the differentiation was assessed by colony morphology, AE-5 monoClonal antibody staining, and cornified envelope formation. RESULTS HPLC analyses revealed that added retinoic acid (RA) was rapidly taken up by cultured cells. As compared to the control without RA, low concentrations of RA (10(-9) M to 10(-7) M) stimulated the CFE of limbal cultures but did not change that of peripheral corneal cultures. Furthermore, 10(-8) M RA induced the emergence of two new types of colonies, one of which was almost exclusively present in limbal cultures, and allowed continuous Clonal Growth of some colonies in late limbal cultures. RA also dose dependently reduced colony size and BrdU labeling index in both limbal and peripheral corneal cultures. RA in concentrations above 10(-8) M stimulated normal differentiation of both limbal and peripheral corneal epithelial cells, as evidenced by increased AE-5 staining, but inhibited the formation of cornified envelopes, an index for abnormal, squamous metaplasia, in late cultures. CONCLUSION These results suggest that RA has a differential dose-dependent effect on subpopulations of corneal and limbal epithelial cells. Although RA stimulates the conversion of limbal stem cells to transient amplifying cells, it inhibits the amplification of corneal and limbal transient amplifying cells and prevents abnormal terminal differentiation. These data further support the role of vitamin A as a physiological modulator of proliferation and differentiation of the ocular surface epithelium.

  • Clonal Growth and differentiation of rabbit meibomian gland epithelium in serum-free culture: differential modulation by EGF and FGF.
    Investigative ophthalmology & visual science, 1992
    Co-Authors: S. L. Maskin, Scheffer C. G. Tseng
    Abstract:

    We have established a serum-free Clonal culture system to study the Growth and differentiation of individual progenitor epithelial cells of the meibomian gland independent of other cell types and undefined serum factors. Single meibomian gland epithelial cells were obtained by subjecting whole meibomian glands to a brief EDTA treatment, needle aspiration, and nylon mesh filtration. The cells had been isolated by a previously described method using enzymatic and microsurgical techniques. Four to five hundred cells obtained were seeded on a 35 mm or 60 mm dish with serum-free MCDB 151 medium containing insulin, transferrin, selenium, ethanolamine, o-phosphorylethanolamine, dimethyl sulfoxide, and calcium. Control cultures with this basic medium did not show continuous Clonal Growth. Addition of epidermal Growth factor (EGF) from 1 to 5 and 10 ng/ml enhanced Clonal Growth with a decreasing effect as measured by colony forming efficacy and colony size. Clonal Growth was associated with the occurrence of two types of colony morphology and an increase in intracellular lipid production in the BrdU-labelled cells, shown by Nile red fluorescent staining. In contrast, the Clonal Growth stimulated by addition of acidic fibroblast Growth factor (aFGF) from 1 to 100 ng/ml exhibited a pattern of an initial increase followed by a decrease, with the maximum noted at 10 ng/ml. Moreover, the aFGF-stimulated Clonal Growth was associated with a uniform colony morphology and minimal lipid synthesis even in the non-BrdU-labelled cells. These results indicate that Clonal Growth of meibomian gland epithelium can be achieved in a serum-free culture by adding either of these two peptide Growth factors. Furthermore, the Clonal Growth stimulated by EGF was associated with progressive cellular differentiation more so than that of aFGF. Further exploration of such a differential regulation of proliferation and differentiation by EGF and aFGF may provide a better understanding of normal meibomian gland function and pathogenesis of various meibomian gland disorders.

E. S. O'nealandd - One of the best experts on this subject based on the ideXlab platform.

  • Intraspecific Root Grafts and Clonal Growth Within Ailanthus altissima Stands Influence Verticillium nonalfalfae Transmission
    2015
    Co-Authors: E. S. O'nealandd
    Abstract:

    O’Neal, E. S., and Davis, D. D. 2015. Intraspecific root grafts and Clonal Growth within Ailanthus altissima stands influence Verticillium nonalfalfae transmission. Plant Dis. 99:1070-1077. Verticillium nonalfalfae, causal agent of Verticillium wilt, is being considered as a biocontrol for the highly invasive Ailanthus altissima in Pennsylvania. This soilborne fungus is extremely virulent on Ailanthus and rapidly transmitted from diseased to healthy trees within Ailanthus stands. The rapid transmission of the fungus could be facilitated by root grafts, but neitherroot graft formation inAilanthusnorVerticilliumtransmission by root grafts in trees has been reported. Here, V. nonalfalfae transmissionbetween diseasedandhealthyAilanthustreesvia intraspecific root grafts and Clonal Growth is evaluated. Using air-spade excavation, dye translocation, and root graft inoculations, functional root grafts were detected between Ailanthus trees and transmission of V. nonalfalfae across root grafts demonstrated.Inoculation ofoneAilanthus parent stem resulted in 187 root sprouts showing Verticillium wilt symptoms 12 months after inoculation. This study revealed that Clonal Growth and root grafts, normally advantageous Growth habits, leave Ailanthus stands vulnerable to widespread V. nonalfalfae infection. This study also broadens the under