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Sample records for plasma transforming growth

  1. Elevated Transforming Growth Factor β1 in Plasma of Primary Open-Angle Glaucoma Patients

    PubMed Central

    Kuchtey, John; Kunkel, Jessica; Burgess, L. Goodwin; Parks, Megan B.; Brantley, Milam A.; Kuchtey, Rachel W.

    2014-01-01

    Purpose. To test the hypothesis that primary open-angle glaucoma (POAG) patients have a systemic elevation of transforming growth factor β1 (TGFβ1). Methods. Plasma was prepared from blood samples drawn from patients of the Vanderbilt Eye Institute during clinic visits. Concentrations of total TGFβ1 and thrombospondin-1 (TSP1) in plasma were determined by ELISA. Statistical significance of differences between POAG and control samples was evaluated by Mann-Whitney test. Regression analysis was used to evaluate correlations between plasma TGFβ1 and patient age and between plasma TGFβ1 and TSP1. Results. Plasma samples were obtained from 148 POAG patients and 150 controls. Concentration of total TGFβ1 in the plasma of POAG patients (median = 3.25 ng/mL) was significantly higher (P < 0.0001) than in controls (median = 2.46 ng/mL). Plasma TGFβ1 was not correlated with age of patient (P = 0.17). Thrombospondin-1 concentration was also significantly higher (P < 0.0001) in POAG patients (median = 0.774 μg/mL) as compared to controls (median = 0.567 μg/mL). Plasma total TGFβ1 and TSP1 concentrations were linearly correlated (P < 0.0001). Conclusions. Plasma samples from POAG patients display elevated total TGFβ1 compared to controls, consistent with elevated systemic TGFβ1 in POAG patients. PMID:25061114

  2. Plasma Levels of Transforming Growth Factor-β1 Reflect Left Ventricular Remodeling in Aortic Stenosis

    PubMed Central

    Villar, Ana V.; Cobo, Manuel; Llano, Miguel; Montalvo, Cecilia; González-Vílchez, Francisco; Martín-Durán, Rafael; Hurlé, María A.; Nistal, J. Francisco

    2009-01-01

    Background TGF-β1 is involved in cardiac remodeling through an auto/paracrine mechanism. The contribution of TGF-β1 from plasmatic source to pressure overload myocardial remodeling has not been analyzed. We investigated, in patients with valvular aortic stenosis (AS), and in mice subjected to transverse aortic arch constriction (TAC), whether plasma TGF-β1 relates with myocardial remodeling, reflected by LV transcriptional adaptations of genes linked to myocardial hypertrophy and fibrosis, and by heart morphology and function. Methodology/Principal Findings The subjects of the study were: 39 patients operated of AS; 27 healthy volunteers; 12 mice subjected to TAC; and 6 mice sham-operated. Myocardial samples were subjected to quantitative PCR. Plasma TGF-β1 was determined by ELISA. Under pressure overload, TGF-β1 plasma levels were significantly increased both in AS patients and TAC mice. In AS patients, plasma TGF-β1 correlated directly with aortic transvalvular gradients and LV mass surrogate variables, both preoperatively and 1 year after surgery. Plasma TGF-β1 correlated positively with the myocardial expression of genes encoding extracellular matrix (collagens I and III, fibronectin) and sarcomeric (myosin light chain-2, β-myosin heavy chain) remodelling targets of TGF-β1, in TAC mice and in AS patients. Conclusions/Significance A circulating TGF-β1-mediated mechanism is involved, in both mice and humans, in the excessive deposition of ECM elements and hypertrophic growth of cardiomyocytes under pressure overload. The possible value of plasma TGF-β1 as a marker reflecting preoperative myocardial remodeling status in AS patients deserves further analysis in larger patient cohorts. PMID:20041033

  3. Seminal plasma did not influence the presence of transforming growth factor-β1, interleukine-10 and interleukin-6 in porcine follicles shortly after insemination

    PubMed Central

    2013-01-01

    Background The effects of seminal plasma on the presence of the cytokines transforming growth factor (TGF)-β1, interleukin (IL)-10 and IL-6 in ovarian follicles and follicular fluid were studied shortly after insemination in gilts. Ovaries from gilts were sampled 5–6 h after insemination with either seminal plasma (SP), fresh semen in extender (Beltsville thawing solution, BTS), spermatozoa in extender (Spz), or only BTS (control). Results Immunohistochemical (IHC) labeling of TGF-β1, IL-10 and IL-6 was evident in the ovarian oocytes and granulosa cells independent of stage of follicular development (antral follicles). Theca interna cells were labeled to a high degree in mature follicles. No consistent differences between treatment groups could be observed for any of the cytokines. In follicular fluid, high concentrations of TGF-β1 were found while the levels of IL-10 and IL-6 were low. There were no differences between treatment groups. Conclusions Our results show a presence of the cytokines TGF-β1, IL-6 and IL-10 in oocytes, granulosa and theca cells, as well as in the fluid of mature follicles suggesting a role of these cytokines in intra-ovarian cell communication. However, treatment (SP, fresh semen in BTS, spermatozoa in BTS or BTS) did not influence the IHC-labeling pattern or the levels of these cytokines in follicular fluid shortly after insemination. PMID:24020676

  4. Prognostic significance of in situ and plasma levels of transforming growth factor β1, -2 and -3 in cutaneous melanoma.

    PubMed

    Tang, Ming-Rui; Wang, Yu-Xin; Guo, Shu; Han, Si-Yuan; Li, He-Huan; Jin, Shi-Feng

    2015-06-01

    Melanoma is an aggressive type of cutaneous malignancy. Transforming growth factor (TGF)‑β has been demonstrated to be an important mediator of tumor progression. However, to the best of our knowledge, the systemic roles of plasma TGF‑β and TGF‑β in situ have not been investigated in Han Chinese melanoma patients. The results of the present study demonstrated that the in situ and plasma levels of TGF‑β1, TGF‑β2 and TGF‑β3 protein and messenger RNA were significantly elevated in tumor tissues compared with those of normal tissues. The survival rates of the patients which were triple‑positive (TGF‑β1+, TGF‑β2+ and TGF‑β3+) were found to be markedly decreased compared to those which were single‑ (TGF‑β1+, TGF‑β2+ or TGF‑β3+) or double‑positive (TGF‑β1+, TGF‑β2+; TGF‑β2+, TGF‑β3+; or TGF‑β1+, TGF‑β3+). These results may therefore contribute to the use of TGF‑β as a prognostic biomarker, and to the development of novel therapies for melanoma treatment.

  5. Decreased body fat, elevated plasma transforming growth factor-β levels, and impaired BMP4-like signaling in biglycan-deficient mice.

    PubMed

    Tang, Tao; Thompson, Joel C; Wilson, Patricia G; Nelson, Christina; Williams, Kevin Jon; Tannock, Lisa R

    2013-01-01

    Biglycan (BGN), a small leucine-rich proteoglycan, binds the pro-fibrotic cytokine transforming growth factor β (TGFβ) and inhibits its bioactivity in vitro. Nevertheless, it is controversial whether BGN plays an inhibitory role in vivo. Therefore, the purpose of this study was to evaluate the effect of BGN deficiency on TGFβ activity in vivo by studying 1-year-old Bgn null and wild-type (WT) mice on an Ldlr-null background. Phenotypic and metabolic characterization showed that the Bgn null mice had lower body weight, shorter body length, and shorter femur length (all p < 0.05). Surprisingly, the Bgn null mice also exhibited a striking reduction in percent body fat compared to WT mice (p == 0.006), but no changes were observed in plasma triglycerides, total cholesterol, or glycohemoglobin. Both total and bioactive TGFβ1 concentrations in plasma were markedly elevated in Bgn null mice compared to WT mice (4-fold and 11-fold increase, respectively, both p < 0.001), but no changes were found in hepatic levels of mRNA for Tgfβ1 or its receptors. Bgn null mice exhibited elevated expression of hepatic fibronectin protein (p = 0.034) without changes in hepatic or renal histology, and Bgn null mice had decreased urinary albumin/creatinine ratio (p = 0.01). Two key downstream targets of bone morphogenetic protein 4-like signaling, SMAD1/3/5 phosphorylation and Id2 gene expression, were found dramatically reduced in Bgn null livers (p = 0.034). Thus, BGN deficiency decreases body fat in this hyperlipidemic mouse model without changing liver or kidney histology. Overall, we propose that this unexpected phenotype arises from the effects of BGN deficiency in vivo to elevate TGFβ levels while decreasing bone morphogenetic protein 4-like signaling.

  6. Platelet-rich plasma increases transforming growth factor-beta1 expression at graft-host interface following autologous osteochondral transplantation in a rabbit model

    PubMed Central

    Boakye, Lorraine A; Ross, Keir A; Pinski, John M; Smyth, Niall A; Haleem, Amgad M; Hannon, Charles P; Fortier, Lisa A; Kennedy, John G

    2015-01-01

    AIM: To explore the effect of platelet-rich plasma on protein expression patterns of transforming growth factor-beta1 (TGF-β1) in cartilage following autologous osteochondral transplantation (AOT) in a rabbit knee cartilage defect model. METHODS: Twelve New Zealand white rabbits received bilateral AOT. In each rabbit, one knee was randomized to receive an autologous platelet rich plasma (PRP) injection and the contralateral knee received saline injection. Rabbits were euthanized at 3, 6 and 12 wk post-operatively. Articular cartilage sections were stained with TGF-β1 antibody. Histological regions of interest (ROI) (left, right and center of the autologous grafts interfaces) were evaluated using MetaMorph. Percentage of chondrocytes positive for TGF-β1 was then assessed. RESULTS: Percentage of chondrocytes positive for TGF-β1 was higher in PRP treated knees for selected ROIs (left; P = 0.03, center; P = 0.05) compared to control and was also higher in the PRP group at each post-operative time point (P = 6.6 × 10-4, 3.1 × 10-4 and 7.3 × 10-3 for 3, 6 and 12 wk, respectively). TGF-β1 expression was higher in chondrocytes of PRP-treated knees (36% ± 29% vs 15% ± 18%) (P = 1.8 × 10-6) overall for each post-operative time point and ROI. CONCLUSION: Articular cartilage of rabbits treated with AOT and PRP exhibit increased TGF-β1 expression compared to those treated with AOT and saline. Our findings suggest that adjunctive PRP may increase TGF-β1 expression, which may play a role in the chondrogenic effect of PRP in vivo. PMID:26716092

  7. Plasma membrane reorganization induced by chemical transformation in cultura

    SciTech Connect

    Packard, B.S.

    1984-04-01

    Induction of increased rigidity in the plasma membrane paralleling properties associated with a transformed state was suggested by two experiments. Fluorescence recovery after photobleaching (FRAP) indicated the induction of an environment in the plasma membrane where the synthetic fluorescent phospholipid collarein was immobile on the FRAP timescale. The other technique revealed the binding of epidermal growth factor (EGF) to a cryptic class of receptors which become accessible upon chemical transformation. These two lines of evidence are consistent with a reorganization of the plasma membrane induced by tumor promoters. 110 references, 38 figures, 4 tables.

  8. The relationship of seminal transforming growth factor-β1 and interleukin-18 with reproductive success in women exposed to seminal plasma during IVF/ICSI treatment.

    PubMed

    Nikolaeva, Marina A; Babayan, Alina A; Stepanova, Elena O; Smolnikova, Veronika Y; Kalinina, Elena A; Fernández, Nelson; Krechetova, Lubov V; Vanko, Ludmila V; Sukhikh, Gennady T

    2016-09-01

    It has been proposed that the transforming growth factor (TGF)-β1 present in seminal plasma (SP) triggers a female immune response favorable for implantation. We hypothesize that seminal interleukin (IL)-18, a cytokine that can potentially cause implantation failure, interferes with the beneficial effect of TGF-β1. This study aims to determine whether the levels of seminal TGF-β1 and IL-18 are associated with reproductive outcomes in patients exposed to SP during in vitro fertilization (IVF) or IVF with intracytoplasmic sperm injection (ICSI). A prospective study, which included 71 couples undergoing IVF/ICSI was carried out. Female patients were exposed to their partners' SP via timed intercourse before the day of ovum pick-up (OPU) and also subjected to intravaginal SP application just after OPU. Quantitative measurements of total TGF-β1 (active plus latent) as well as IL-18 were determined by FlowCytomix™ technology in the SP to be used for intravaginal applications. Comparison of SP cytokine profiles between pregnant and non-pregnant groups revealed that pregnancy was correlated with a lower concentration of IL-18 (P=0.018) and lower content per ejaculate for both of IL-18 (P=0.0003) and TGF-β1 (P=0.047). The ratio of TGF-β1-to-IL-18 concentration was significantly higher in the pregnant than in the non-pregnant group (P=0.026). This study supports the notion that two key cytokines TGF-β1 and IL-18, both present in SP are associated with reproductive outcomes in female patients exposed to SP during IVF/ICSI treatment. PMID:27423966

  9. The relationship of seminal transforming growth factor-β1 and interleukin-18 with reproductive success in women exposed to seminal plasma during IVF/ICSI treatment.

    PubMed

    Nikolaeva, Marina A; Babayan, Alina A; Stepanova, Elena O; Smolnikova, Veronika Y; Kalinina, Elena A; Fernández, Nelson; Krechetova, Lubov V; Vanko, Ludmila V; Sukhikh, Gennady T

    2016-09-01

    It has been proposed that the transforming growth factor (TGF)-β1 present in seminal plasma (SP) triggers a female immune response favorable for implantation. We hypothesize that seminal interleukin (IL)-18, a cytokine that can potentially cause implantation failure, interferes with the beneficial effect of TGF-β1. This study aims to determine whether the levels of seminal TGF-β1 and IL-18 are associated with reproductive outcomes in patients exposed to SP during in vitro fertilization (IVF) or IVF with intracytoplasmic sperm injection (ICSI). A prospective study, which included 71 couples undergoing IVF/ICSI was carried out. Female patients were exposed to their partners' SP via timed intercourse before the day of ovum pick-up (OPU) and also subjected to intravaginal SP application just after OPU. Quantitative measurements of total TGF-β1 (active plus latent) as well as IL-18 were determined by FlowCytomix™ technology in the SP to be used for intravaginal applications. Comparison of SP cytokine profiles between pregnant and non-pregnant groups revealed that pregnancy was correlated with a lower concentration of IL-18 (P=0.018) and lower content per ejaculate for both of IL-18 (P=0.0003) and TGF-β1 (P=0.047). The ratio of TGF-β1-to-IL-18 concentration was significantly higher in the pregnant than in the non-pregnant group (P=0.026). This study supports the notion that two key cytokines TGF-β1 and IL-18, both present in SP are associated with reproductive outcomes in female patients exposed to SP during IVF/ICSI treatment.

  10. Arterial Stiffening in Western Diet-Fed Mice Is Associated with Increased Vascular Elastin, Transforming Growth Factor-β, and Plasma Neuraminidase

    PubMed Central

    Foote, Christopher A.; Castorena-Gonzalez, Jorge A.; Ramirez-Perez, Francisco I.; Jia, Guanghong; Hill, Michael A.; Reyes-Aldasoro, Constantino C.; Sowers, James R.; Martinez-Lemus, Luis A.

    2016-01-01

    Consumption of excess fat and carbohydrate (Western diet, WD) is associated with alterations in the structural characteristics of blood vessels. This vascular remodeling contributes to the development of cardiovascular disease, particularly as it affects conduit and resistance arteries. Vascular remodeling is often associated with changes in the elastin-rich internal elastic lamina (IEL) and the activation of transforming growth factor (TGF)-β. In addition, obesity and type II diabetes have been associated with increased serum neuraminidase, an enzyme known to increase TGF-β cellular output. Therefore, we hypothesized that WD-feeding would induce structural modifications to the IEL of mesenteric resistance arteries in mice, and that these changes would be associated with increased levels of circulating neuraminidase and the up-regulation of elastin and TGF-β in the arterial wall. To test this hypothesis, a WD, high in fat and sugar, was used to induce obesity in mice, and the effect of this diet on the structure of mesenteric resistance arteries was investigated. 4-week old, Post-weaning mice were fed either a normal diet (ND) or WD for 16 weeks. Mechanically, arteries from WD-fed mice were stiffer and less distensible, with marginally increased wall stress for a given strain, and a significantly increased Young's modulus of elasticity. Structurally, the wall cross-sectional area and the number of fenestrae found in the internal elastic lamina (IEL) of mesenteric arteries from mice fed a WD were significantly smaller than those of arteries from the ND-fed mice. There was also a significant increase in the volume of elastin, but not collagen in arteries from the WD cohort. Plasma levels of neuraminidase and the amount of TGF-β in mesenteric arteries were elevated in mice fed a WD, while ex vivo, cultured vascular smooth muscle cells exposed to neuraminidase secreted greater amounts of tropoelastin and TGF-β than those exposed to vehicle. These data suggest that

  11. Association between Plasma Levels of Transforming Growth Factor-beta1, IL-23 and IL-17 and the Severity of Autism in Egyptian Children

    ERIC Educational Resources Information Center

    Hashim, Haitham; Abdelrahman, Hadeel; Mohammed, Doaa; Karam, Rehab

    2013-01-01

    It has been recently shown that dysregulation of transforming growth factor-beta1 (TGF-beta1), IL-23 and IL-17 has been identified as a major factor involved in autoimmune disorders. Based on the increasing evidence of immune dysfunction in autism the aim of this study was to measure serum levels of TGF-beta1, IL-23 and IL-17 in relation to the…

  12. Dust Growth in Astrophysical Plasmas

    NASA Astrophysics Data System (ADS)

    Bingham, R.; Tsytovich, V. N.

    2002-12-01

    Dust formation in space is important in diverse environments such as dust molecular clouds, proto-planetary nebulae, stellar outbursts, and supernova explosions. The formation of dust proceeds the formation of stellar objects and planets. In all these environments the dust particles interact with both neutral and plasma particles as well as with (ultraviolet) radiation and cosmic rays. The conventional view of grain growth is one based on accretion by the Van der Waals and chemical forces [Watson and Salpeter [14] considered in detail both theoretically and numerically (Kempf at all [6],Meaking [7]( and confirmed recently by micro-gravity experiments Blum et all [2]). The usual point of view is that the dust grow is occurring in dust molecular clouds at very low temperatures ~ (10 - 30)° K and is a slow process - dust grows to a size of about 0.1 μm in 106 - 109 years. This contradicts recent observations of dust growing in winds of C-stars in about 10 years and behind the supernova SN1987A shock in about 500 days. Also recent observation of star formation at the edge of irradiated dust clouds suggests that new plasma mechanism operates in star formation. Dusty plasma mechanisms of agglomeration are analyzed as an explanation of the new astrophysical observation. New micro-gravity experiments are proposed for observing the plasma mechanisms of dust agglomeration at gas pressures substantially higher than used in ([2]. Calculations for the growth rates of dust agglomeration due to plasma mechanisms are presented. It is shown that at large neutral gas densities the dust plasma attraction provides an explanation of dust grow in about 10 days observed in H-star winds. Ionization by cosmic rays and by radioactive dust can provide the dust attraction necessary for forming dust clumping observed in molecular clouds and the fractal plasma clumping can enhance the time to reach the gravitational contraction phase operating at the final stage of star formation. A new

  13. Transforming growth factor beta1 and aldosterone

    PubMed Central

    Matsuki, Kota; Hathaway, Catherine K.; Chang, Albert S.; Smithies, Oliver; Kakoki, Masao

    2016-01-01

    Purpose of review It is well established that blocking renin-angiotensin II-aldosterone system (RAAS) is effective for the treatment of cardiovascular and renal complications in hypertension and diabetes mellitus. Although the induction of transforming growth factor beta1 (TGFbeta1) by components of RAAS mediates the hypertrophic and fibrogenic changes in cardiovascular-renal complications, it is still controversial as to whether TGFbeta1 can be a target to prevent such complications. Here we review recent findings on the role of TGFbeta1 in fluid homeostasis, focusing on the relationship with aldosterone. Recent findings TGFbeta1 suppresses adrenal production of aldosterone and renal tubular sodium reabsorption. We have generated mice with TGFbeta1 mRNA expression graded in five steps from 10% to 300% normal, and found that blood pressure and plasma volume are negatively regulated by TGFbeta1. Notably, the 10 % hypomorph exhibits primary aldosteronism and sodium and water retention due to markedly impaired urinary excretion of water and electrolytes. Summary These results identify TGFbeta signaling as an important counterregulatory system against aldosterone. Understanding the molecular mechanisms for the suppressive effects of TGFbeta1 on adrenocortical and renal function may further our understanding of primary aldosteronism as well as assist in the development of novel therapeutic strategies for hypertension. PMID:25587902

  14. Preoperative administration of polysaccharide Kureha and reduced plasma transforming growth factor-β in patients with advanced gastric cancer: A randomized clinical trial

    PubMed Central

    YAMASHITA, KEISHI; SAKURAMOTO, SHINICHI; MIENO, HIROAKI; NEMOTO, MASAYUKI; SHIBATA, TOMOTAKA; KATADA, NATSUYA; OHTSUKI, SHIGEAKI; SAKAMOTO, YASUTOSHI; HOSHI, KEIKA; WANG, GUOQIN; HEMMI, OSAMU; SATOH, TOSHIHIKO; KIKUCHI, SHIRO; WATANABE, MASAHIKO

    2015-01-01

    Systemic abrogation of TGF-β signaling results in tumor reduction through cytotoxic T lymphocytes activity in a mouse model. The administration of polysaccharide-Kureha (PSK) into tumor-bearing mice also showed tumor regression with reduced TGF-β. However, there have been no studies regarding the PSK administration to cancer patients and the association with plasma TGF-β. PSK (3 g/day) was administered as a neoadjuvant therapy for 2 weeks before surgery. In total, 31 advanced gastric cancer (AGC) patients were randomly assigned to group A (no neoadjuvant PSK; n=14) or B (neoadjuvant PSK therapy; n=17). Plasma TGF-β was measured pre- and postoperatively. The allocation factors were clinical stage (cStage) and gender. Plasma TGF-β ranged from 1.85–43.5 ng/ml (average, 9.50 ng/ml) in AGC, and 12 patients (38.7%) had a high value, >7.0 ng/ml. These patients were largely composed of poorly-differentiated adenocarcinoma with pathological stage III/IV. All the six elevated cases in group B showed a significant reduction of plasma TGF-β (from 21.6 to 4.5 ng/ml, on average), whereas this was not exhibited in group A. The cases within the normal limits of TGF-β remained unchanged irrespective of PSK treatment. Analysis of variance showed a statistically significant reduction in the difference of plasma TGF-β between groups A and B (P=0.019). PSK reduced the plasma TGF-β in AGC patients when the levels were initially high. The clinical advantage of PSK may, however, be restricted to specific histological types of AGC. Perioperative suppression of TGF-β by PSK may antagonize cancer immune evasion and improve patient prognosis in cases of AGC. PMID:26137253

  15. Decreased body fat, elevated plasma transforming growth factor-β levels, and impaired BMP4-like signaling in biglycan-deficient mice

    PubMed Central

    Tang, Tao; Thompson, Joel C.; Wilson, Patricia G.; Nelson, Christina; Williams, Kevin Jon; Tannock, Lisa R.

    2015-01-01

    Biglycan (BGN), a small leucine-rich proteoglycan, binds the pro-fibrotic cytokine TGFβ and inhibits its bioactivity in vitro. Nevertheless, it is controversial whether BGN plays an inhibitory role in vivo. Therefore, the purpose of this study was to evaluate the effect of BGN deficiency on TGFβ activity in vivo by studying one-year-old Bgn null and wildtype mice on an Ldlr-null background. Phenotypic and metabolic characterization showed that the Bgn null mice had lower body weight, shorter body length and shorter femur length (all p<0.05). Surprisingly, the Bgn null mice also exhibited a striking reduction in percent body fat compared to wildtype mice (p=0.006), but no changes were observed in plasma triglycerides, total cholesterol, or glycohemoglobin. Both total and bioactive TGFβ1 concentrations in plasma were markedly elevated in Bgn null mice compared to wildtype mice (4-fold and 11-fold increase, respectively, both p<0.001), but no changes were found in hepatic levels of mRNA for Tgfβ1 or its receptors. Bgn null mice exhibited elevated expression of hepatic fibronectin protein (p=0.034) without changes in hepatic or renal histology, and Bgn null mice had decreased urinary albumin/creatinine ratio (p=0.01). Two key downstream targets of bone morphorgenic protein (BMP) 4 signaling, SMAD1/3/5 phosphorylation and Id2 gene expression, were found dramatically reduced in Bgn null livers (p=0.034). Thus, BGN deficiency decreases body fat in this hyperlipidemic mouse model without changing liver or kidney histology. Overall, we propose that this unexpected phenotype arises from effects of BGN deficiency in vivo to elevate TGFβ levels while decreasing BMP4-like signaling. PMID:22834985

  16. Role of growth factors in the growth of normal and transformed cells

    SciTech Connect

    Lokeshwar, V.B.

    1989-01-01

    Growth factors play an important role in the growth of normal cells. However, their untimely and/or excess production leads to neoplastic transformation. The role of growth factors in the growth of normal cells was studied by investigating the mechanism of transmodulation of the cell surface EGF receptor number by protamine. Protamine increased the EGF stimulated mitogenic response in Swiss mouse 3T3 cells and A431 cells by increasing the number of functionally active EGF receptors. Protamine also increased EGF receptor number in plasma membranes and solubilized membranes. This was evidenced by an increase in both {sup 125}I-EGF-EGF-receptor complex and EGF stimulated phosphorylation of the EGF receptor. The solubilized EGF receptor was retained on a protamine-agarose gel indicating that protamine might increase EGF receptor number by directly activating cryptic EGF receptors in the plasma membranes. The role of growth factors in neoplastic transformation was studied by investigating the role of the oncogene v-sis in the growth of Simian sarcoma virus (SSV) transformed cells. The product of the oncogene v-sis is 94% homologous to the B chain of PDGF. This study found that (i) v-sis gene product is synthesized as a 32 kDa unglycosylated monomer which is glycosylated, dimerized and proteolytically processed into p36, p72, p68, p58, p44 and p27 mol. wt. species respectively. (ii) p36, p72, p68 and p58 are very likely formed in the endoplasmic reticulum and/or Golgi complex. A fraction of newly synthesized p72, p68 and p58 is degraded intracellularly at a fast rate. (iii) p44 is a secretory product which remains tightly associated with the cell surface. p44 is recaptured by the cells through interaction with cell surface PDGF receptors and degraded into p27. (iv) During long term cultures p44 is extracellularly cleaved into a 27 kDa product.

  17. Phase transformation and growth of hygroscopic aerosols

    SciTech Connect

    Tang, I.N.

    1995-09-01

    Ambient aerosols frequently contain large portions of hygroscopic inorganic salts such as chlorides, nitrates, and sulfates in either pure or mixed forms. Such inorganic salt aerosols exhibit the properties of deliquescence and efflorescence in air. The phase transformation from a solid particle to a saline droplet usually occurs spontaneously when the relative humidity of the atmosphere reaches a level specific to the chemical composition of the aerosol particle. Conversely, when the relative humidity decreases and becomes low enough, the saline droplet will evaporate and suddenly crystallize, expelling all its water content. The phase transformation and growth of aerosols play an important role in many atmospheric processes affecting air quality, visibility degradation, and climate changes. In this chapter, an exposition of the underlying thermodynamic principles is given, and recent advances in experimental methods utilizing single-particle levitation are discussed. In addition, pertinent and available thermodynamic data, which are needed for predicting the deliquescence properties of single and multi-component aerosols, are compiled. This chapter is useful to research scientists who are either interested in pursuing further studies of aerosol thermodynamics, or required to model the dynamic behavior of hygroscopic aerosols in a humid environment.

  18. Association between Plasma Endothelin-1, Transforming Growth Factor-β, Fibroblast Growth Factor, and Nitric Oxide Levels and Liver Injury in Hematopoietic Stem Cell Transplantation Recipients with Persistent Iron Overload after Transplantation.

    PubMed

    Akı, Şahika Zeynep; Suyanı, Elif; Cengiz, Mustafa; Özenirler, Seren; Elbeğ, Şehri; Paşaoğlu, Hatice; Sucak, Gülsan Türköz

    2015-05-01

    Graft-versus-host disease, iron overload, and infections are the major causes of liver dysfunction in allogeneic hematopoietic stem cell transplantation (AHSCT) recipients. We investigated the relationship between serum iron parameters and the levels of transforming growth factor-β (TGF-β), fibroblast growth factor (FGF), endothelin-1 (ET-1), and nitric oxide (NO) as predictors of chronic liver injury in 54 AHSCT recipients who survived at least a year after transplantation. Serum samples from patients were obtained for the evaluation of ET-1, TGF-β, FGF, NO, and nontransferrin bound iron at the first year follow-up visit using commercially available ELISA kits. Patients were categorized depending on serum ferritin and transferrin saturation levels. The parameters were compared between the groups, and survival analysis was also performed. Most of the AHSCT recipients (81.5%) were in complete remission during the study. After a median follow-up time of 73 months (range, 13 to 109 months), 72.2% of the patients were alive. Mean serum levels of ET-1, NO, TGF-β, and FGF were 81.54 ± 21.62 μmol/mL, 31.82 ± 26.42 μmol/mL, 2.56 ± 0.77 ng/mL, and 50.31 ± 32.69 pg/mL, respectively. Nineteen patients (35.2% of the cohort) had serum ferritin levels higher than 1000 ng/mL. Mean serum levels of ET-1, NO, TGF-β, and FGF were similar in patients with serum ferritin levels below or above 1000 ng/mL (P > .05). Serum ferritin levels were positively correlated with serum alanine aminotransferase (r = .284, P = .042) and γ-glutamyl transferase (r = .271, P = .05) levels and were negatively correlated with serum albumin levels (r = .295, P = .034). There was a significant positive correlation between serum transferrin saturation and alanine aminotransferase levels (r = .305, P = .03). Serum ET-1 level was positively correlated with alkaline phosphatase levels (r = .304, P = .026). In univariate Cox regression analysis serum levels of iron parameters, ET-1, NO, TGF-β, and

  19. Application of an impedance matching transformer to a plasma focus.

    PubMed

    Bures, B L; James, C; Krishnan, M; Adler, R

    2011-10-01

    A plasma focus was constructed using an impedance matching transformer to improve power transfer between the pulse power and the dynamic plasma load. The system relied on two switches and twelve transformer cores to produce a 100 kA pulse in short circuit on the secondary at 27 kV on the primary with 110 J stored. With the two transformer systems in parallel, the Thevenin equivalent circuit parameters on the secondary side of the driver are: C = 10.9 μF, V(0) = 4.5 kV, L = 17 nH, and R = 5 mΩ. An equivalent direct drive circuit would require a large number of switches in parallel, to achieve the same Thevenin equivalent. The benefits of this approach are replacement of consumable switches with non-consumable transformer cores, reduction of the driver inductance and resistance as viewed by the dynamic load, and reduction of the stored energy to produce a given peak current. The system is designed to operate at 100 Hz, so minimizing the stored energy results in less load on the thermal management system. When operated at 1 Hz, the neutron yield from the transformer matched plasma focus was similar to the neutron yield from a conventional (directly driven) plasma focus at the same peak current.

  20. Transforming growth factor-β and fibrosis

    PubMed Central

    Verrecchia, Franck; Mauviel, Alain

    2007-01-01

    Transforming growth factor-β (TGF-β), a prototype of multifunctional cytokine, is a key regulator of extracellular matrix (ECM) assembly and remodeling. Specifically, TGF-β isoforms have the ability to induce the expression of ECM proteins in mesenchymal cells, and to stimulate the production of protease inhibitors that prevent enzymatic breakdown of the ECM. Elevated TGF-β expression in affected organs, and subsequent deregulation of TGF-β functions, correlates with the abnormal connective tissue deposition observed during the onset of fibrotic diseases. During the last few years, tremendous progress has been made in the understanding of the molecular aspects of intracellular signaling downstream of the TGF-β receptors. In particular, Smad proteins, TGF-β receptor kinase substrates that translocate into the cell nucleus to act as transcription factors, have been studied extensively. The role of Smad3 in the transcriptional regulation of typeIcollagen gene expression and in the development of fibrosis, demonstrated both in vitro and in animal models with a targeted deletion of Smad3, is of critical importance because it may lead to novel therapeutic strategies against these diseases. This review focuses on the mechanisms underlying Smad modulation of fibrillar collagen expression and how it relates to fibrotic processes. PMID:17589920

  1. A Plasma-Based DC-DC Electrical Transformer

    NASA Astrophysics Data System (ADS)

    Nebel, Richard; Finn, John

    2013-10-01

    Previous work has indicated that it may be possible to make DC-DC electrical transformers using plasmas. The mechanism is an MHD electromagnetic relaxation process induced by helical electrodes. This process is now being tested on the Bismark device at Tibbar Technologies.

  2. Transforming growth factor-beta 1 and fibroblast growth factors in rat growth plate.

    PubMed

    Jingushi, S; Scully, S P; Joyce, M E; Sugioka, Y; Bolander, M E

    1995-09-01

    Chondrocytes in the growth plate progress in an orderly fashion from resting through proliferating to hypertrophic cells. In the region of hypertrophic chondrocytes, the cartilage is invaded by capillary loops and endochondral ossification is initiated. It is currently believed that growth factors may regulate the proliferation and maturation of chondrocytes and the synthesis of extracellular matrix in the growth plate. The ordered sequence of proliferation and differentiation observed in the growth plate provides a unique opportunity to study the role of acidic fibroblast growth factor, basic fibroblast growth factor, and transforming growth factor-beta 1 in the regulation of these processes. In this study, expression of the mRNA of these growth factors was examined using total RNA extracted from the physis and epiphysis of rat tibias. Transforming growth factor-beta 1 mRNA was detected by Northern hybridization. Expression of the genes encoding acidic and basic fibroblast growth factors was demonstrated by polymerase chain reaction amplification. In addition, using polyclonal antibodies against these growth factors, we localized them by immunohistochemical analysis. Strong intracellular staining with a predominantly nuclear pattern was observed in chondrocytes from the proliferating and upper hypertrophic zones. In contrast, chondrocytes in the resting zone stained only faintly for the presence of these growth factors. Some chondrocytes in the resting zone adjacent to the proliferating zone stained with these antibodies, and the antibodies also stained cells in the zone of Ranvier, which regulates latitudinal bone growth. Lastly, the location of transforming growth factor-beta 1 was examined further with use of a polyclonal antipeptide antibody specific for its extracellular epitope.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7472755

  3. Model for a transformer-coupled toroidal plasma source

    NASA Astrophysics Data System (ADS)

    Rauf, Shahid; Balakrishna, Ajit; Chen, Zhigang; Collins, Ken

    2012-01-01

    A two-dimensional fluid plasma model for a transformer-coupled toroidal plasma source is described. Ferrites are used in this device to improve the electromagnetic coupling between the primary coils carrying radio frequency (rf) current and a secondary plasma loop. Appropriate components of the Maxwell equations are solved to determine the electromagnetic fields and electron power deposition in the model. The effect of gas flow on species transport is also considered. The model is applied to 1 Torr Ar/NH3 plasma in this article. Rf electric field lines form a loop in the vacuum chamber and generate a plasma ring. Due to rapid dissociation of NH3, NHx+ ions are more prevalent near the gas inlet and Ar+ ions are the dominant ions farther downstream. NH3 and its by-products rapidly dissociate into small fragments as the gas flows through the plasma. With increasing source power, NH3 dissociates more readily and NHx+ ions are more tightly confined near the gas inlet. Gas flow rate significantly influences the plasma characteristics. With increasing gas flow rate, NH3 dissociation occurs farther from the gas inlet in regions with higher electron density. Consequently, more NH4+ ions are produced and dissociation by-products have higher concentrations near the outlet.

  4. Modeling Growth of Nanostructures in Plasmas

    NASA Technical Reports Server (NTRS)

    Hwang, Helen H.; Bose, Deepak; Govindan, T. R.; Meyyappan, M.

    2004-01-01

    As semiconductor circuits shrink to CDs below 0.1 nm, it is becoming increasingly critical to replace and/or enhance existing technology with nanoscale structures, such as nanowires for interconnects. Nanowires grown in plasmas are strongly dependent on processing conditions, such as gas composition and substrate temperature. Growth occurs at specific sites, or step-edges, with the bulk growth rate of the nanowires determined from the equation of motion of the nucleating crystalline steps. Traditional front-tracking algorithms, such as string-based or level set methods, suffer either from numerical complications in higher spatial dimensions, or from difficulties in incorporating surface-intense physical and chemical phenomena. Phase field models have the robustness of the level set method, combined with the ability to implement surface-specific chemistry that is required to model crystal growth, although they do not necessarily directly solve for the advancing front location. We have adopted a phase field approach and will present results of the adatom density and step-growth location in time as a function of processing conditions, such as temperature and plasma gas composition.

  5. Transformer ratio improvement for beam based plasma accelerators

    SciTech Connect

    O'Shea, Brendan; Rosenzweig, James; Barber, Samuel; Fukasawa, Atsushi; Williams, Oliver; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl

    2012-12-21

    Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R {<=} 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab.

  6. Latent transforming growth factor binding protein 4 regulates transforming growth factor beta receptor stability.

    PubMed

    Su, Chi-Ting; Huang, Jenq-Wen; Chiang, Chih-Kang; Lawrence, Elizabeth C; Levine, Kara L; Dabovic, Branka; Jung, Christine; Davis, Elaine C; Madan-Khetarpal, Suneeta; Urban, Zsolt

    2015-07-15

    Mutations in the gene for the latent transforming growth factor beta binding protein 4 (LTBP4) cause autosomal recessive cutis laxa type 1C. To understand the molecular disease mechanisms of this disease, we investigated the impact of LTBP4 loss on transforming growth factor beta (TGFβ) signaling. Despite elevated extracellular TGFβ activity, downstream signaling molecules of the TGFβ pathway, including pSMAD2 and pERK, were down-regulated in LTBP4 mutant human dermal fibroblasts. In addition, TGFβ receptors 1 and 2 (TGFBR1 and TGFBR2) were reduced at the protein but not at the ribonucleic acid level. Treatment with exogenous TGFβ1 led to an initially rapid increase in SMAD2 phosphorylation followed by a sustained depression of phosphorylation and receptor abundance. In mutant cells TGFBR1 was co-localized with lysosomes. Treatment with a TGFBR1 kinase inhibitor, endocytosis inhibitors or a lysosome inhibitor, normalized the levels of TGFBR1 and TGFBR2. Co-immunoprecipitation demonstrated a molecular interaction between LTBP4 and TGFBR2. Knockdown of LTBP4 reduced TGFβ receptor abundance and signaling in normal cells and supplementation of recombinant LTBP4 enhanced these measures in mutant cells. In a mouse model of Ltbp4 deficiency, reduced TGFβ signaling and receptor levels were normalized upon TGFBR1 kinase inhibitor treatment. Our results show that LTBP4 interacts with TGFBR2 and stabilizes TGFβ receptors by preventing their endocytosis and lysosomal degradation in a ligand-dependent and receptor kinase activity-dependent manner. These findings identify LTBP4 as a key molecule required for the stability of the TGFβ receptor complex, and a new mechanism by which the extracellular matrix regulates cytokine receptor signaling.

  7. Latent transforming growth factor binding protein 4 regulates transforming growth factor beta receptor stability

    PubMed Central

    Su, Chi-Ting; Huang, Jenq-Wen; Chiang, Chih-Kang; Lawrence, Elizabeth C.; Levine, Kara L.; Dabovic, Branka; Jung, Christine; Davis, Elaine C.; Madan-Khetarpal, Suneeta; Urban, Zsolt

    2015-01-01

    Mutations in the gene for the latent transforming growth factor beta binding protein 4 (LTBP4) cause autosomal recessive cutis laxa type 1C. To understand the molecular disease mechanisms of this disease, we investigated the impact of LTBP4 loss on transforming growth factor beta (TGFβ) signaling. Despite elevated extracellular TGFβ activity, downstream signaling molecules of the TGFβ pathway, including pSMAD2 and pERK, were down-regulated in LTBP4 mutant human dermal fibroblasts. In addition, TGFβ receptors 1 and 2 (TGFBR1 and TGFBR2) were reduced at the protein but not at the ribonucleic acid level. Treatment with exogenous TGFβ1 led to an initially rapid increase in SMAD2 phosphorylation followed by a sustained depression of phosphorylation and receptor abundance. In mutant cells TGFBR1 was co-localized with lysosomes. Treatment with a TGFBR1 kinase inhibitor, endocytosis inhibitors or a lysosome inhibitor, normalized the levels of TGFBR1 and TGFBR2. Co-immunoprecipitation demonstrated a molecular interaction between LTBP4 and TGFBR2. Knockdown of LTBP4 reduced TGFβ receptor abundance and signaling in normal cells and supplementation of recombinant LTBP4 enhanced these measures in mutant cells. In a mouse model of Ltbp4 deficiency, reduced TGFβ signaling and receptor levels were normalized upon TGFBR1 kinase inhibitor treatment. Our results show that LTBP4 interacts with TGFBR2 and stabilizes TGFβ receptors by preventing their endocytosis and lysosomal degradation in a ligand-dependent and receptor kinase activity-dependent manner. These findings identify LTBP4 as a key molecule required for the stability of the TGFβ receptor complex, and a new mechanism by which the extracellular matrix regulates cytokine receptor signaling. PMID:25882708

  8. Phosphoinositide turnover in cell growth and transformation

    SciTech Connect

    Fleischman, L.F.

    1987-01-01

    Interaction of cells with various stimuli triggers a common signal transduction pathway involving breakdown and resynthesis of the minor membrane lipid phosphatidylinositol-4,5-bisphosphate (PIP/sub 2/). Hydrolysis of PIP/sub 2/ by phospholipase C generates two key catabolites-inositol-1,4,5-trisphosphate (IP/sub 3/) and diacylglycerol (DAG)-which mediate and amplify cellular responses. These studies provide evidence for potential involvement of this pathway in oncogenic transformation and cell cycle progression. Altered levels of PIP/sub 2/ and its breakdown products were found in cells transformed by ras oncogenes, in contrast to untransformed counterparts. Steady-state levels of PIP/sub 2/, DAG and inositol phosphates were measured in NIH 3T3 and NRK cells metabolically labelled with /sup 3/H-glycerol and /sup 3/H-inositol. DAG and inositol phosphate levels were significantly elevated by 2.5-3 fold in the transformed cells while levels of PIP/sub 2/ were decreased. These findings suggest that the ras protein may activate phospholipase C. Elevated DAG content in the transformed cells was also measured by phosphorylation of DAG using a partially purified DAG kinase, indicating that the differences seen could not be attributed to differences in labelling between the cell lines.

  9. Influence of Atmospheric Pressure Torch Plasma Irradiation on Plant Growth

    NASA Astrophysics Data System (ADS)

    Akiyoshi, Yusuke; Hayashi, Nobuya; Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu

    2011-10-01

    Growth stimulation characteristics of plants seeds are investigated by an atmospheric discharge irradiation into plasma seeds. Atmospheric pressure plasma torch is consisted of alumina ceramics tube and the steel mesh electrodes wind inside and outside of the tube. When AC high voltage (8 kHz) is applied to the electrode gap, the barrier discharge plasma is produced inside the alumina ceramics tube. The barrier discharge plasma is blown outside with the gas flow in ceramics tube. Radish sprouts seeds locate at 1 cm from the torch edge. The growth stimulation was observed in the length of a stem and a root after the plasma irradiation. The stem length increases approximately 2.8 times at the cultivation time of 24 h. And the growth stimulation effect is found to be maintained for 40 h, after sowing seeds. The mechanism of the growth stimulation would be the redox reaction inside plant cells induced by oxygen radicals.

  10. Role of hydrogen in evolution of plasma parameters and dust growth in capacitively coupled dusty plasmas

    SciTech Connect

    Chai, K. B.; Choe, Wonho; Seon, C. R.; Chung, C. W.

    2010-11-15

    The temporal behavior of naturally produced dust parameters (radius and density) and plasma parameters (electron temperature and ion flux) was investigated in radio frequency SiH{sub 4}/H{sub 2}/Ar plasmas. As a result, the electron temperature and ion flux were shown to be strongly correlated with the three-step dust growth pattern. In addition, the generation of dust particles was suppressed by mixing more hydrogen gas due to the plasma chemistry, and consequently, the dust growth rate in the molecular accretion growth, which is known to be proportional to the growth rate of thin film deposition, increased.

  11. A study on improvement of discharge characteristic by using a transformer in a capacitively coupled plasma

    SciTech Connect

    Kim, Young-Cheol; Kim, Hyun-Jun; Lee, Hyo-Chang; Chung, Chin-Wook

    2015-12-15

    In a plasma discharge system, the power loss at powered line, matching network, and other transmission line can affect the discharge characteristics such as the power transfer efficiency, voltage and current at powered electrode, and plasma density. In this paper, we propose a method to reduce power loss by using a step down transformer mounted between the matching network and the powered electrode in a capacitively coupled argon plasma. This step down transformer decreases the power loss by reducing the current flowing through the matching network and transmission line. As a result, the power transfer efficiency was increased about 5%–10% by using a step down transformer. However, the plasma density was dramatically increased compared to no transformer. This can be understood by the increase in ohmic heating and the decrease in dc-self bias. By simply mounting a transformer, improvement of discharge efficiency can be achieved in capacitively coupled plasmas.

  12. Kinetic Study of the Solid-State Transformation of Vacuum-Plasma-Sprayed Ti-6Al-4V Alloy

    NASA Astrophysics Data System (ADS)

    Salimijazi, H. R.; Mousavi, Z. A.; Golozar, M. A.; Mostaghimi, J.; Coyle, T.

    2014-01-01

    Because of the nature of the plasma spraying process, the physical and mechanical properties of vacuum-plasma-sprayed structures of Ti-6Al-4V alloy are completely different from those of conventionally manufactured alloys such as bulk materials from casting and forging. To obtain desired mechanical and physical properties, vacancy and internal defects must be reduced, splat boundaries must be eliminated, and optimal phase compositions should be obtained through postdeposition heat treatments. To determine appropriate heat treatment processes, one needs to study the kinetic behavior of the as-sprayed microstructure at elevated temperatures. In the current study, the kinetics of the solid transformations found in Ti-6Al-4V alloys produced during the vacuum plasma spraying process was studied based on the Johnson-Mehl-Avrami theory. For the kinetic behavior of this alloy, the nonconstant temperature dependence of the transformation rate constant exhibits an irregularity at 900 °C, marking a change in the transformation mechanism. For the lower-temperature (<900 °C) curves, the constant gradient indicates a lack of change in the transformation mechanism, including homogeneous nucleation, with growth of α phase. For higher temperatures (>900 °C), a gradient change indicates a change in the transformation mechanism. The first mechanism was the formation of α-phase grain boundary, and the second mechanism was α-plate nucleation and growth from grain boundaries. The value of the transformation rate constant in the kinetics study of as-sprayed Ti-6Al-4V alloy was much higher than for material produced by the casting method. Using the results obtained from the kinetics of the phase transformation at different constant temperatures, a time-temperature-transformation (TTT) diagram for as-sprayed Ti-6Al-4V alloy was developed.

  13. Simulation of the dc Plasma in Carbon Nanotube Growth

    NASA Technical Reports Server (NTRS)

    Hash, David; Bose, Deepak; Govindan, T. R.; Meyyappan, M.; Biegel, Bryan (Technical Monitor)

    2003-01-01

    A model for the dc plasma used in carbon nanotube growth is presented, and one-dimensional simulations of an acetylene/ammonia/argon system are performed. The effect of dc bias is illustrated by examining electron temperature, electron and ion densities, and neutral densities. Introducing a tungsten filament in the dc plasma, as in hot filament chemical vapor deposition with plasma assistance, shows negligible influence on the system characteristics.

  14. Regulation of human amnion cell growth and morphology by sera, plasma, and growth factors.

    PubMed

    Gaffney, E V; Grimaldi, M A

    1981-01-01

    The requirements of human epithelial cells derived from the amnion membrane for serum factors were investigated. The growth promoting effects of human whole blood serum (WBS), platelet-poor defibrinogenated plasma, and plasma-derived serum (PDS) were examined in primary cultures of these ectodermal cells. The numbers of population doublings recorded after 10 days in the presence of 10% WBS, defibrinogenated plasma, or PDS were 2.3, 2.0 or 1.5, respectively. Although dialysis of sera or plasma had little effect on growth promotion, it markedly decreased the capacity of plasma to maintain cells in culture beyond 10 days. The differences in growth activities could not be attributed to the presence of anticoagulant in plasma and PDS or to the presence of excess calcium in PDS. Platelet lysates and purified platelet-derived growth factor had no effect on growth. Amnion cell growth was enhanced by epidermal growth factor (EGF) or hydrocortisone, but the glucocorticoid did not condition cells to respond to growth factors. Insulin and fibroblast growth factor singly or in combination had no effect on cell replication. Giant cell formation accompanied maintenance in hydrocortisone with defibrinogenated plasma and PDS. Discrete regions of dense population appeared in the presence of hydrocortisone, EGF, and undialyzed supplements.

  15. Suppression of vertical instability in elongated current-carrying plasmas by applying stellarator rotational transform

    SciTech Connect

    ArchMiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Knowlton, S. F.; Ma, X.; Maurer, D. A.; Pandya, M. D.; Traverso, P.

    2014-05-15

    The passive stability of vertically elongated current-carrying toroidal plasmas has been investigated in the Compact Toroidal Hybrid, a stellarator/tokamak hybrid device. In this experiment, the fractional transform f, defined as the ratio of the imposed external rotational transform from stellarator coils to the total rotational transform, was varied from 0.04 to 0.50, and the elongation κ was varied from 1.4 to 2.2. Plasmas that were vertically unstable were evidenced by motion of the plasma in the vertical direction. Vertical drifts are measured with a set of poloidal field pickup coils. A three chord horizontally viewing interferometer and a soft X-ray diode array confirmed the drifts. Plasmas with low fractional transform and high elongation are the most susceptible to vertical instability, consistent with analytic predictions that the vertical mode in elongated plasmas can be stabilized by the poloidal field of a relatively weak stellarator equilibrium.

  16. Nanowire growth by an electron beam induced massive phase transformation

    DOE PAGES

    Sood, Shantanu; Kisslinger, Kim; Gouma, Perena

    2014-11-15

    Tungsten trioxide nanowires of a high aspect ratio have been synthesized in-situ in a TEM under an electron beam of current density 14A/cm² due to a massive polymorphic reaction. Sol-gel processed pseudocubic phase nanocrystals of tungsten trioxide were seen to rapidly transform to one dimensional monoclinic phase configurations, and this reaction was independent of the substrate on which the material was deposited. The mechanism of the self-catalyzed polymorphic transition and accompanying radical shape change is a typical characteristic of metastable to stable phase transformations in nanostructured polymorphic metal oxides. A heuristic model is used to confirm the metastable to stablemore » growth mechanism. The findings are important to the control electron beam deposition of nanowires for functional applications starting from colloidal precursors.« less

  17. Nanowire growth by an electron beam induced massive phase transformation

    SciTech Connect

    Sood, Shantanu; Kisslinger, Kim; Gouma, Perena

    2014-11-15

    Tungsten trioxide nanowires of a high aspect ratio have been synthesized in-situ in a TEM under an electron beam of current density 14A/cm² due to a massive polymorphic reaction. Sol-gel processed pseudocubic phase nanocrystals of tungsten trioxide were seen to rapidly transform to one dimensional monoclinic phase configurations, and this reaction was independent of the substrate on which the material was deposited. The mechanism of the self-catalyzed polymorphic transition and accompanying radical shape change is a typical characteristic of metastable to stable phase transformations in nanostructured polymorphic metal oxides. A heuristic model is used to confirm the metastable to stable growth mechanism. The findings are important to the control electron beam deposition of nanowires for functional applications starting from colloidal precursors.

  18. Diamond film growth argon-carbon plasmas

    DOEpatents

    Gruen, Dieter M.; Krauss, Alan R.; Liu, Shengzhong; Pan, Xianzheng; Zuiker, Christopher D.

    1998-01-01

    A method and system for manufacturing diamond film. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrogen and hydrocarbon and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous and deposition of a diamond film on a substrate.

  19. Release kinetics of platelet-derived and plasma-derived growth factors from autologous plasma rich in growth factors.

    PubMed

    Anitua, Eduardo; Zalduendo, Mari Mar; Alkhraisat, Mohammad Hamdan; Orive, Gorka

    2013-10-01

    Many studies have evaluated the biological effects of platelet rich plasma reporting the final outcomes on cell and tissues. However, few studies have dealt with the kinetics of growth factor delivery by plasma rich in growth factors. Venous blood was obtained from three healthy volunteers and processed with PRGF-Endoret technology to prepare autologous plasma rich in growth factors. The gel-like fibrin scaffolds were then incubated in triplicate, in a cell culture medium to monitor the release of PDGF-AB, VEGF, HGF and IGF-I during 8 days of incubation. A leukocyte-platelet rich plasma was prepared employing the same technology and the concentrations of growth factors and interleukin-1β were determined after 24h of incubation. After each period, the medium was collected, fibrin clot was destroyed and the supernatants were stored at -80°C until analysis. The growth factor delivery is diffusion controlled with a rapid initial release by 30% of the bioactive content after 1h of incubation and a steady state release when almost 70% of the growth factor content has been delivered. Autologous fibrin matrix retained almost 30% of the amount of the growth factors after 8 days of incubation. The addition of leukocytes to the formula of platelet rich plasma did not increase the concentration of the growth factors, while it drastically increased the presence of pro-inflammatory IL-1β. Further studies employing an in vitro inflammatory model would be interesting to study the difference in growth factors and pro-inflammatory cytokines between leukocyte-free and leukocyte-rich platelet rich plasma.

  20. Diamond film growth argon-carbon plasmas

    DOEpatents

    Gruen, D.M.; Krauss, A.R.; Liu, S.Z.; Pan, X.Z.; Zuiker, C.D.

    1998-12-15

    A method and system are disclosed for manufacturing diamond film. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrogen and hydrocarbon and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous and deposition of a diamond film on a substrate. 29 figs.

  1. Transforming growth factor (TGF)-. alpha. in human milk

    SciTech Connect

    Okada, Masaki; Wakai, Kae; Shizume, Kazuo ); Iwashita, Mitsutoshi ); Ohmura, Eiji; Kamiya, Yoshinobu; Murakami, Hitomi; Onoda, Noritaka; Tsushima, Toshio

    1991-01-01

    Transforming growth factor (TGF)-{alpha} and epidermal growth factor (EGF) were measured in human milk by means of homologous radioimmunoassay. As previously reported, EGF concentration in the colostrum was approximately 200 ng/ml and decreased to 50 ng/ml by day 7 postpartum. The value of immunoreactive (IR)-TGF-{alpha} was 2.2-7.2 ng/ml, much lower than that of EGF. In contrast to EGF, the concentration of IR-TGF-{alpha} was fairly stable during the 7 postpartum days. There was no relationship between the concentrations of IR-TGF-{alpha} and IR-EGF, suggesting that the regulatory mechanism in the release of the two growth factors is different. On gel-chromatography using a Sephadex G-50 column, IR-EGF appeared in the fraction corresponding to that of authentic human EGF, while 70%-80% of the IR-TGF-{alpha} was eluted as a species with a molecular weight greater than that of authentic human TGF-{alpha}. Although the physiological role of TGF-{alpha} in milk is not known, it is possible that it is involved in the development of the mammary gland and/or the growth of newborn infants.

  2. Direct observation of grain growth from molten silicon formed by micro-thermal-plasma-jet irradiation

    PubMed Central

    Hayashi, Shohei; Fujita, Yuji; Kamikura, Takahiro; Sakaike, Kohei; Akazawa, Muneki; Ikeda, Mitsuhisa; Hanafusa, Hiroaki; Higashi, Seiichiro

    2012-01-01

    Phase transformation of amorphous-silicon during millisecond annealing using micro-thermal-plasma-jet irradiation was directly observed using a high-speed camera with microsecond time resolution. An oval-shaped molten-silicon region adjacent to the solid phase crystallization region was clearly observed, followed by lateral large grain growth perpendicular to a liquid-solid interface. Furthermore, leading wave crystallization (LWC), which showed intermittent explosive crystallization, was discovered in front of the moving molten region. The growth mechanism of LWC has been investigated on the basis of numerical simulation implementing explosive movement of a thin liquid layer driven by released latent heat diffusion in a lateral direction. PMID:23185095

  3. Direct observation of grain growth from molten silicon formed by micro-thermal-plasma-jet irradiation

    SciTech Connect

    Hayashi, Shohei; Fujita, Yuji; Kamikura, Takahiro; Sakaike, Kohei; Akazawa, Muneki; Ikeda, Mitsuhisa; Hanafusa, Hiroaki; Higashi, Seiichiro

    2012-10-22

    Phase transformation of amorphous-silicon during millisecond annealing using micro-thermal-plasma-jet irradiation was directly observed using a high-speed camera with microsecond time resolution. An oval-shaped molten-silicon region adjacent to the solid phase crystallization region was clearly observed, followed by lateral large grain growth perpendicular to a liquid-solid interface. Furthermore, leading wave crystallization (LWC), which showed intermittent explosive crystallization, was discovered in front of the moving molten region. The growth mechanism of LWC has been investigated on the basis of numerical simulation implementing explosive movement of a thin liquid layer driven by released latent heat diffusion in a lateral direction.

  4. Studies on the nature of plasma growth hormone

    NASA Technical Reports Server (NTRS)

    Ellis, S.; Grindeland, R. E.; Reilly, T. J.; Yang, S. H.

    1976-01-01

    The paper presents further evidence for the existence of two discrete forms of growth hormone in human plasma, one which is detectable by both radioimmunoassay and bioassay and is immunoreactive, and the other, termed 'bioactive', which is detected by tibial bioassay but shows little reactivity with currently available antisera to pituitary growth hormone. The same division of immunoactive and bioactive growth hormone occurs in rats, though with less disparity. Tests on rats indicated that the bioactive hormone is preferentially released into jugular vein plasma and that plasma concentrations of the bioactive hormone can be enhanced by insulin administration. The bioactive hormone was detectable by tibial assays in Cohn fractions IV, IV-1, and IV-4, and could be concentrated about 40-fold by fractionation with (NaPO3)6 and (NH4)2SO4.

  5. Equivalent circuit of radio frequency-plasma with the transformer model.

    PubMed

    Nishida, K; Mochizuki, S; Ohta, M; Yasumoto, M; Lettry, J; Mattei, S; Hatayama, A

    2014-02-01

    LINAC4 H(-) source is radio frequency (RF) driven type source. In the RF system, it is required to match the load impedance, which includes H(-) source, to that of final amplifier. We model RF plasma inside the H(-) source as circuit elements using transformer model so that characteristics of the load impedance become calculable. It has been shown that the modeling based on the transformer model works well to predict the resistance and inductance of the plasma.

  6. Incisional wound healing in transforming growth factor-beta1 null mice.

    PubMed

    Koch, R M; Roche, N S; Parks, W T; Ashcroft, G S; Letterio, J J; Roberts, A B

    2000-01-01

    Expression of endogenous transforming growth factor-beta1 is reduced in many animal models of impaired wound healing, and addition of exogenous transforming growth factor-beta has been shown to improve healing. To test the hypothesis that endogenous transforming growth factor-beta1 is essential for normal wound repair, we have studied wound healing in mice in which the transforming growth factor-beta1 gene has been deleted by homologous recombination. No perceptible differences were observed in wounds made in 3-10-day-old neonatal transforming growth factor-beta1 null mice compared to wild-type littermates. To preclude interference from maternally transferred transforming growth factor-beta1, cutaneous wounds were also made on the backs of 30-day-old transforming growth factor-beta1 null and littermate control mice treated with rapamycin, which extends their lifetime and suppresses the inflammatory response characteristic of the transforming growth factor-beta1 null mice. Again, no impairment in healing was seen in transforming growth factor-beta1 null mice. Instead these wounds showed an overall reduction in the amount of granulation tissue and an increased rate of epithelialization compared to littermate controls. Our data suggest that release of transforming growth factor-beta1 from degranulating platelets or secretion by infiltrating macrophages and fibroblasts is not critical to initiation or progression of tissue repair and that endogenous transforming growth factor-beta1 may actually function to increase inflammation and retard wound closure.

  7. Halo Formation And Emittance Growth of Positron Beams in Plasmas

    SciTech Connect

    Muggli, P.; Blue, B.E.; Clayton, C.E.; Decker, F.J.; Hogan, M.J.; Huang, C.; Joshi, C.; Katsouleas, Thomas C.; Lu, W.; Mori, W.B.; O'Connell, C.L.; Siemann, R.H.; Walz, D.; Zhou, M.; /UCLA

    2011-10-25

    An ultrarelativistic 28.5 GeV, 700-{micro}m-long positron bunch is focused near the entrance of a 1.4-m-long plasma with a density n{sub e} between {approx}10{sup 13} and {approx}5 x 10{sup 14} cm{sup -3}. Partial neutralization of the bunch space charge by the mobile plasma electrons results in a reduction in transverse size by a factor of {approx}3 in the high emittance plane of the beam {approx}1 m downstream from the plasma exit. As n{sub e} increases, the formation of a beam halo containing {approx}40% of the total charge is observed, indicating that the plasma focusing force is nonlinear. Numerical simulations confirm these observations. The bunch with an incoming transverse size ratio of {approx}3 and emittance ratio of {approx}5 suffers emittance growth and exits the plasma with approximately equal sizes and emittances.

  8. Simulations of a High-Transformer-Ratio Plasma Wakefield Accelerator Using Multiple Electron Bunches

    SciTech Connect

    Kallos, Efthymios; Muggli, Patric; Katsouleas, Thomas; Yakimenko, Vitaly; Park, Jangho

    2009-01-22

    Particle-in-cell simulations of a plasma wakefield accelerator in the linear regime are presented, consisting of four electron bunches that are fed into a high-density plasma. It is found that a high transformer ratio can be maintained over 43 cm of plasma if the charge in each bunch is increased linearly, the bunches are placed 1.5 plasma wavelengths apart and the bunch emmitances are adjusted to compensate for the nonlinear focusing forces. The generated wakefield is sampled by a test witness bunch whose energy gain after the plasma is six times the energy loss of the drive bunches.

  9. Capsaicin Inhibits Preferentially the NADH Oxidase and Growth of Transformed Cells in Culture

    NASA Astrophysics Data System (ADS)

    Morre, D. James; Chueh, Pin-Ju; Morre, Dorothy M.

    1995-03-01

    A hormone- and growth factor-stimulated NADH oxidase of the mammalian plasma membrane, constitutively activated in transformed cells, was inhibited preferentially in HeLa, ovarian carcinoma, mammary adenocarcinoma, and HL-60 cells, all of human origin, by the naturally occurring quinone analog capsaicin (8-methyl-N-vanillyl-6-noneamide), compared with plasma membranes from human mammary epithelial, rat liver, normal rat kidney cells, or HL-60 cells induced to differentiate with dimethyl sulfoxide. With cells in culture, capsaicin preferentially inhibited growth of HeLa, ovarian carcinoma, mammary adenocarcinoma, and HL-60 cells but was largely without effect on the mammary epithelial cells, rat kidney cells, or HL-60 cells induced to differentiate with dimethyl sulfoxide. Inhibited cells became smaller and cell death was accompanied by a condensed and fragmented appearance of the nuclear DNA, as revealed by fluorescence microscopy with 4',6-diamidino-2-phenylindole, suggestive of apoptosis. The findings correlate capsaicin inhibition of cell surface NADH oxidase activity and inhibition of growth that correlate with capsaicin-induced apoptosis.

  10. Transforming Growth Factor Beta and Excess Burden of Renal Disease

    PubMed Central

    August, Phyllis; Sharma, Vijay; Ding, Ruchuang; Schwartz, Joseph E.; Suthanthiran, Manikkam

    2009-01-01

    End-stage renal disease (ESRD) is more frequent in African Americans (blacks) compared to whites. Because renal fibrosis is a correlate of progressive renal failure and a dominant feature of ESRD, and because transforming growth factor beta 1 (TGF-β1) can induce fibrosis and renal insufficiency, we hypothesized that TGF-β1 hyperexpression is more frequent in blacks compared to whites. We measured circulating levels of TGF-β1 in black and white patients with ESRD, hypertension, and in normal patients. We demonstrated that circulating levels of TGF-β1 are higher in black ESRD patients, hypertensive patients, and normal control patients compared to their white counterparts. Our preliminary genetic analyses suggest that TGF-β1 DNA polymorphisms are different in blacks and whites. Our observations of hyperexpression of TGF-β1 in blacks suggest a mechanism for the increased prevalence of renal failure and hypertensive target organ damage in this population. PMID:19768163

  11. The latent transforming growth factor beta binding protein (LTBP) family.

    PubMed Central

    Oklü, R; Hesketh, R

    2000-01-01

    The transforming growth factor beta (TGFbeta) cytokines are a multi-functional family that exert a wide variety of effects on both normal and transformed mammalian cells. The secretion and activation of TGFbetas is regulated by their association with latency-associated proteins and latent TGFbeta binding proteins (LTBPs). Over the past few years, three members of the LTBP family have been identified, in addition to the protoype LTBP1 first sequenced in 1990. Three of the LTBP family are expressed in a variety of isoforms as a consequence of alternative splicing. This review summarizes the differences between the isoforms in terms of the effects on domain structure and hence possible function. The close identity between LTBPs and members of the fibrillin family, mutations in which have been linked directly to Marfan's syndrome, suggests that anomalous expression of LTBPs may be associated with disease. Recent data indicating that differential expression of LTBP1 isoforms occurs during the development of coronary heart disease is considered, together with evidence that modulation of LTBP function, and hence of TGFbeta activity, is associated with a variety of cancers. PMID:11104663

  12. Nucleation and growth of Nb nanoclusters during plasma gas condensation

    SciTech Connect

    Bray, K. R.; Jiao, C. Q.; DeCerbo, J. N.

    2013-06-21

    Niobium nanoclusters were produced using a plasma gas condensation process. The influence of gas flow rate, aggregation length, and source current on the nanocluster nucleation and growth were analyzed. Nanoclusters with an average diameter from 4 nm to 10 nm were produced. Cluster size and concentration were tuned by controlling the process inputs. The effects of each parameter on the nucleation zone, growth length, and residence time was examined. The parameters do not affect the cluster formation and growth independently; their influence on cluster formation can be either cumulative or competing. Examining the nucleation and growth over a wide combination of parameters provided insight into their interactions and the impact on the growth process. These results provide the opportunity for a broader understanding into the nucleation and growth of nanoclusters and some insights into how process parameters interact during deposition. This knowledge will enhance the ability to create nanoclusters with desired size dispersions.

  13. Flute growth rate of plasma jet in mirror machine

    NASA Astrophysics Data System (ADS)

    Be'ery, I.; Seemann, O.; Goldstein, G.; Fisher, A.; Ron, A.

    2014-02-01

    The evolution of flute instability in a cold, high-density hydrogen plasma jet, injected into a mirror machine, is studied. The experiment was designed to minimize the interaction of the plasma with the walls, thus bringing it close to the ideal magnetic Rayleigh-Taylor instability conditions. The modal growth rate was measured in various settings to demonstrate the effects of the finite Larmor radius, Bohm diffusion, conductive limiter, biased limiter and neutral background gas. In this paper we will demonstrate that lowering the magnetic field increases stability, as does the insertion of a conducting ring. However, if the ring is biased, the stability is reduced due to inhomogeneous coupling between the plasma and the limiter. It was also found that heavy background gas dramatically reduces the flute instability growth rate.

  14. Optical Plasma Control During ARC Carbon Nanotube Growth

    NASA Technical Reports Server (NTRS)

    Hinkov, I.; Farhat, S.; DeLaChapelle, M. Lamy; Fan, S. S.; Han, H. X.; Li, G. H.; Scott, C. D.

    2001-01-01

    To improve nanotube production, we developed a novel optical control technique, based on the shape of the visible plasma zone created between the anode and the cathode in the direct current (DC) arc process. For a given inert gas, we adjust the anode to cathode distance (ACD) in order to obtain strong visible vortices around the cathode. This enhance anode vaporization, which improve nanotubes formation. In light of our experimental results, we focus our discussion on the relationship between plasma parameters and nanotube growth. Plasma temperature control during arc process is achieved using argon, helium, and their mixtures as a buffer gases. The variation of the gas mixture from pure argon to pure helium changes plasma temperature. As a consequence, the microscopic characteristics of nanotubes as diameter distribution is changed moving from smaller values for argon to higher diameters for helium. We also observe a dependence of the macroscopic characteristics of the final products as Brunauer-Emmett-Teller (BET) surface area.

  15. Plasma Position Measurements in a Tokamak with an Iron Core Transformer

    NASA Astrophysics Data System (ADS)

    Kwon, Gi-Chung; Choe, W.; Kim, Jayhyun; Yi, Hyo-Suk; Jeon, Sang-Jean; Huh, Songwhe; Chang, Hong-Young; Choi, Duk-In

    2000-07-01

    Two simple methods of estimating the plasma position in a large-aspect-ratio, low-βp tokamak with an iron core transformer are demonstrated: a magnetic diagnostic method and an optical method. The magnetic diagnostic method utilizes an array of magnetic pickup coils to measure the poloidal magnetic field produced by the plasma current. To include the effects of toroidicity and an iron core transformer, the correction factor was calculated with the magnetic material (or iron core) inside the calculation domain and incorporated in the analysis. The evolution of horizontal and vertical displacement of the plasma center obtained in this way is used to control the KAIST-Tokamak plasmas. To compare the plasma position estimated using the magnetic pickup coils, a simple optical method is also demonstrated on KAIST-TOKAMAK using a composite video signal from a charge-coupled device (CCD) camera. The two results are in good agreement.

  16. Transcriptional modulation of transin gene expression by epidermal growth factor and transforming growth factor beta

    SciTech Connect

    Machida, C.M.; Muldoon, L.L.; Rodland, K.D.; Magun, B.E.

    1988-06-01

    Transin is a transformation-associated gene which is expressed constitutively in rat fibroblasts transformed by a variety of oncogenes and in malignant mouse skin carcinomas but not benign papillomas or normal skin. It has been demonstrated that, in nontransformed Rat-1 cells, transin RNA expression is modulated positively by epidermal growth factor (EGF) and negatively by transforming growth factor beta (TGF-BETA); other peptide growth factors were found to have no effect on transin expression. Results presented here indicate that both protein synthesis and continuous occupancy of the EGF receptor by EGF were required for sustained induction of transin RNA. Treatment with TGF-BETA inhibited the ability of EGF to induce transin, whether assayed at the transcriptional level by nuclear run-on analysis or at the level of transin RNA accumulation by Northern (RNA) blot analysis of cellular RNA. TGF-BETA both blocked initial production of transin transcription by EGF and halted established production of transin transcripts during prolonged treatment. These results suggest that TGF-BETA acts at the transcriptional level to antagonize EGF-mediated induction of transin gene expression.

  17. Correlation between nanoparticle and plasma parameters with particle growth in dusty plasmas

    SciTech Connect

    Chai, Kil Byoung; Seon, C. R.; Choe, Wonho; Chung, C. W.; Yoon, N. S.

    2011-01-01

    Since plasma parameters are altered by dust particles, studying how plasma parameters are related to dust particle growth is an important research issue in dusty plasma. In this paper, the correlation between plasma parameters (electron temperature and ion flux) and particle parameters (particle radius and density) is investigated in silane plasma both experimentally using a floating probe and theoretically by solving balance equations including an additional electron and ion loss to the dust. The results reveal that while the ion flux shows two peak values in the early discharge phase and at the end of coagulation phase, the electron temperature shows a sudden increase in the coagulation step and a gradual decrease in the molecular accretion step. Moreover, the calculated results with the secondary electron emission taken into account produce the best fit with the experimental results. Thus the study confirms that the secondary electron emission plays a crucial role in the coagulation of the dust particles.

  18. Growth of large patterned arrays of neurons using plasma methods

    NASA Astrophysics Data System (ADS)

    Brown, I. G.; Bjornstad, K. A.; Blakely, E. A.; Galvin, J. E.; Monteiro, O. R.; Sangyuenyongpipat, S.

    2003-05-01

    To understand how large systems of neurons communicate, we need to develop, among other things, methods for growing patterned networks of large numbers of neurons. Success with this challenge will be important to our understanding of how the brain works, as well as to the development of novel kinds of computer architecture that may parallel the organization of the brain. We have investigated the use of metal ion implantation using a vacuum-arc ion source, and plasma deposition with a filtered vacuum-arc system, as a means of forming regions of selective neuronal attachment on surfaces. Lithographic patterns created by the treating surface with ion species that enhance or inhibit neuronal cell attachment allow subsequent proliferation and/or differentiation of the neurons to form desired patterned neural arrays. In the work described here, we used glass microscope slides as substrates, and some of the experiments made use of simple masks to form patterns of ion beam or plasma deposition treated regions. PC-12 rat neurons were then cultured on the treated substrates coated with Type I Collagen, and the growth and differentiation was monitored. Particularly good selective growth was obtained using plasma deposition of diamond-like carbon films of about one hundred Angstroms thickness. Neuron proliferation and the elaboration of dendrites and axons after the addition of nerve growth factor both showed excellent contrast, with prolific growth and differentiation on the treated surfaces and very low growth on the untreated surfaces.

  19. Growth hormone and insulin-like growth factor I plasma levels in patients with hypophosphatemic rickets.

    PubMed

    Jasper, H; Cassinelli, H

    1993-01-01

    The cause of the growth retardation present in patients with hypophosphatemic rickets has not been totally elucidated. There has been a previous report of a growth hormone deficit in a group of these patients. To verify this abnormality we studied two groups of patients with hypophosphatemic rickets, one with (n = 6) and the other without (n = 7) treatment with calcitriol and oral phosphates. All patients in both groups showed a normal growth hormone response (> 10 micrograms/l) to standard stimulatory tests and normal IGF-I plasma levels. Mean IGF-I plasma levels were not significantly different (untreated 1.46 +/- 0.80 U/ml, treated 1.25 +/- 0.69 U/ml) and the mean logarithmic deviation of IGF-I plasma levels from both groups did not differ from normal. In summary, we found no abnormalities of the growth hormone-IGF-I axis in our patients with hypophosphatemic rickets.

  20. Transient growth in stable linearized Vlasov-Maxwell plasmas

    SciTech Connect

    Podesta, J. J.

    2010-12-15

    Large amplitude transient growth of kinetic scale perturbations in stable collisionless magnetized plasmas has recently been demonstrated using a linearized Landau fluid model. Initial perturbations with lengthscales of the order of the ion gyroradius were shown to have transient timescales that in some cases were long compared to the ion gyroperiod, {Omega}{sub i}t>>1. Moreover, it was suggested that such perturbations are not rare but instead form a large class within the set of all possible initial conditions. For collisionless plasmas, the Vlasov-Maxwell equations provide a more complete description of kinetic physics and the existence of transient growth of solutions for the linearized Vlasov-Maxwell system is an interesting question. The existence of transient growth of solutions is demonstrated here for a special case of the Vlasov-Maxwell equations, namely, the one dimensional Vlasov-Poisson system. The analysis is different from the standard approach of nonmodal analysis since the initial value problem is described by a Volterra integral equation of the second kind, reflecting the fact that the time evolution of the system depends on the memory of the state from time zero through time t. For the case of a thermal equilibrium plasma, it is shown how initial conditions may be constructed to obtain solutions that grow linearly in time; the duration of this growth is the time required for a thermal electron to traverse the wavelength of the initial perturbation, a timescale that can last for many plasma periods 2{pi}/{omega}{sub pe}, thus demonstrating the existence of transient growth of solutions for the linearized Vlasov-Poisson system. The results suggest that the phenomenon of transient growth may be a common feature of the linearized Vlasov-Maxwell system as well as for Landau fluid models.

  1. Hilbert-Huang Transform in MHD Plasma Diagnostics

    SciTech Connect

    Kakurin, A.M.; Orlovsky, I.I.

    2005-12-15

    A new method for processing experimental data from MHD diagnostics is discussed that provides a more detailed study of the dynamics of large-scale MHD instabilities. The method is based on the Hilbert-Huang transform method and includes an empirical mode decomposition algorithm, which is used to decompose the experimental MHD diagnostic signals into a set of frequency- and amplitude-modulated harmonics in order to construct the time evolutions of the amplitudes and frequencies of these harmonics with the help of the Hilbert transform. The method can also be applied to analyze data from other diagnostics that measure unsteady oscillating signals.

  2. The Role of Transforming Growth Factor β1 in the Regulation of Blood Pressure

    PubMed Central

    Matsuki, Kota; Hathaway, Catherine K.; Lawrence, Marlon G.; Smithies, Oliver; Kakoki, Masao

    2016-01-01

    Although human association studies suggest a link between polymorphisms in the gene encoding transforming growth factor (TGF) β1 and differing blood pressure levels, a causative mechanism for this correlation remains elusive. Recently we have generated a series of mice with graded expression of TGFβ1, ranging from approximately 10% to 300% compared to normal. We have found that blood pressure and plasma volume are negatively regulated by TGFβ1. Of note, the 10% hypomorph exhibits primary aldosteronism and markedly impaired urinary excretion of water and electrolytes. We here review previous literature highlighting the importance of TGFβ signaling as a natriuretic system, which we postulate is a causative mechanism explaining how polymorphisms in TGFβ1 could influence blood pressure levels. PMID:25801626

  3. Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer

    SciTech Connect

    Babij, Michał; Kowalski, Zbigniew W. Nitsch, Karol; Gotszalk, Teodor; Silberring, Jerzy

    2014-05-15

    The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet.

  4. Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer.

    PubMed

    Babij, Michał; Kowalski, Zbigniew W; Nitsch, Karol; Silberring, Jerzy; Gotszalk, Teodor

    2014-05-01

    The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet. PMID:24880391

  5. Tomography of homogenized laser-induced plasma by Radon transform technique

    NASA Astrophysics Data System (ADS)

    Eschlböck-Fuchs, S.; Demidov, A.; Gornushkin, I. B.; Schmid, T.; Rössler, R.; Huber, N.; Panne, U.; Pedarnig, J. D.

    2016-09-01

    Tomography of a laser-induced plasma in air is performed by inverse Radon transform of angle-resolved plasma images. Plasmas were induced by single laser pulses (SP), double pulses (DP) in collinear geometry, and by a combination of single laser pulses with pulsed arc discharges (SP-AD). Images of plasmas on metallurgical steel slags were taken at delay times suitable for calibration-free laser-induced breakdown spectroscopy (CF-LIBS). Delays ranged from few microseconds for SP and DP up to tens of microseconds for SP-AD excitation. The white-light and the spectrally resolved emissivity ε(x,y,z) was reconstructed for the three plasma excitation schemes. The electron number density Ne(x,y,z) and plasma temperature Te(x,y,z) were determined from Mg and Mn emission lines in reconstructed spectra employing the Saha-Boltzmann plot method. The SP plasma revealed strongly inhomogeneous emissivity and plasma temperature. Re-excitation of plasma by a second laser pulse (DP) and by an arc discharge (SP-AD) homogenized the plasma and reduced the spatial variation of ε and Te. The homogenization of a plasma is a promising approach to increase the accuracy of calibration-free LIBS analysis of complex materials.

  6. Transforming Growth Factor-β and the Hallmarks of Cancer

    PubMed Central

    Tian, Maozhen; Neil, Jason R.; Schiemann, William P.

    2010-01-01

    Tumorigenesis is in many respects a process of dysregulated cellular evolution that drives malignant cells to acquire six phenotypic hallmarks of cancer, including their ability to proliferate and replicate autonomously, to resist cytostatic and apoptotic signals, and to induce tissue invasion, metastasis, and angiogenesis. Transforming growth factor-β (TGF-β) is a potent pleiotropic cytokine that functions as a formidable barrier to the development of cancer hallmarks in normal cells and tissues. Paradoxically, tumorigenesis counteracts the tumor suppressing activities of TGF-β, thus enabling TGF-β to stimulate cancer invasion and metastasis. Fundamental gaps exist in our knowledge of how malignant cells overcome the cytostatic actions of TGF-β, and of how TGF-β stimulates the acquisition of cancer hallmarks by developing and progressing human cancers. Here we review the molecular and cellular mechanisms that underlie the ability of TGF-β to mediate tumor suppression in normal cells, and conversely, to facilitate cancer progression and disease dissemination in malignant cells. PMID:20940046

  7. The Neuroprotective Functions of Transforming Growth Factor Beta Proteins

    PubMed Central

    Dobolyi, Arpád; Vincze, Csilla; Pál, Gabriella; Lovas, Gábor

    2012-01-01

    Transforming growth factor beta (TGF-β) proteins are multifunctional cytokines whose neural functions are increasingly recognized. The machinery of TGF-β signaling, including the serine kinase type transmembrane receptors, is present in the central nervous system. However, the 3 mammalian TGF-β subtypes have distinct distributions in the brain suggesting different neural functions. Evidence of their involvement in the development and plasticity of the nervous system as well as their functions in peripheral organs suggested that they also exhibit neuroprotective functions. Indeed, TGF-β expression is induced following a variety of types of brain tissue injury. The neuroprotective function of TGF-βs is most established following brain ischemia. Damage in experimental animal models of global and focal ischemia was shown to be attenuated by TGF-βs. In addition, support for their neuroprotective actions following trauma, sclerosis multiplex, neurodegenerative diseases, infections, and brain tumors is also accumulating. The review will also describe the potential mechanisms of neuroprotection exerted by TGF-βs including anti-inflammatory, -apoptotic, -excitotoxic actions as well as the promotion of scar formation, angiogenesis, and neuroregeneration. The participation of these mechanisms in the neuroprotective effects of TGF-βs during different brain lesions will also be discussed. PMID:22942700

  8. ZnO nanorod growth by plasma-enhanced vapor phase transport with different growth durations

    SciTech Connect

    Kim, Chang-Yong; Oh, Hee-bong; Ryu, Hyukhyun; Yun, Jondo; Lee, Won-Jae

    2014-09-01

    In this study, the structural properties of ZnO nanostructures grown by plasma-enhanced vapor phase transport (PEVPT) were investigated. Plasma-treated oxygen gas was used as the oxygen source for the ZnO growth. The structural properties of ZnO nanostructures grown for different durations were measured by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The authors comprehensively analyzed the growth of the ZnO nanostructures with different growth durations both with and without the use of plasma-treated oxygen gas. It was found that PEVPT has a significant influence on the growth of the ZnO nanorods. PEVPT with plasma-treated oxygen gas facilitated the generation of nucleation sites, and the resulting ZnO nanorod structures were more vertical than those prepared by conventional VPT without plasma-treated oxygen gas. As a result, the ZnO nanostructures grown using PEVPT showed improved structural properties compared to those prepared by the conventional VPT method.

  9. A fluctuation-induced plasma transport diagnostic based upon fast-Fourier transform spectral analysis

    NASA Technical Reports Server (NTRS)

    Powers, E. J.; Kim, Y. C.; Hong, J. Y.; Roth, J. R.; Krawczonek, W. M.

    1978-01-01

    A diagnostic, based on fast Fourier-transform spectral analysis techniques, that provides experimental insight into the relationship between the experimentally observable spectral characteristics of the fluctuations and the fluctuation-induced plasma transport is described. The model upon which the diagnostic technique is based and its experimental implementation is discussed. Some characteristic results obtained during the course of an experimental study of fluctuation-induced transport in the electric field dominated NASA Lewis bumpy torus plasma are presented.

  10. Non-linear plasma wake growth of electron holes

    SciTech Connect

    Hutchinson, I. H.; Haakonsen, C. B.; Zhou, C.

    2015-03-15

    An object's wake in a plasma with small Debye length that drifts across the magnetic field is subject to electrostatic electron instabilities. Such situations include, for example, the moon in the solar wind and probes in magnetized laboratory plasmas. The instability drive mechanism can equivalently be considered drift down the potential-energy gradient or drift up the density-gradient. The gradients arise because the plasma wake has a region of depressed density and electrostatic potential into which ions are attracted along the field. The non-linear consequences of the instability are analysed in this paper. At physical ratios of electron to ion mass, neither linear nor quasilinear treatment can explain the observation of large-amplitude perturbations that disrupt the ion streams well before they become ion-ion unstable. We show here, however, that electron holes, once formed, continue to grow, driven by the drift mechanism, and if they remain in the wake may reach a maximum non-linearly stable size, beyond which their uncontrolled growth disrupts the ions. The hole growth calculations provide a quantitative prediction of hole profile and size evolution. Hole growth appears to explain the observations of recent particle-in-cell simulations.

  11. Role of ion density in growth, transport, and morphology of nanoparticles generated in plasmas

    NASA Astrophysics Data System (ADS)

    Chai, Kil Byoung; Choe, Wonho

    2012-08-01

    Spatial distribution, growth, and morphology of the nanoparticle were investigated in the plasmas with relatively low and high ion densities. Our experimental results reveal that cauliflower-shaped amorphous nanoparticles are dominantly distributed throughout the entire plasma in the low ion density plasma while spherical crystalline particles are spread near the plasma edge in the high ion density plasma. Only agglomeration growth step of the nanoparticles was observed without molecular accretion growth step in the high density plasma. Based on the experimental and numerical results, the role of ion density in the growth mechanism and transport of the nanoparticles is discussed.

  12. Transforming growth factor-betas and vascular disorders.

    PubMed

    Bobik, Alex

    2006-08-01

    Transforming growth factor-beta (TGF-beta) superfamily members, TGF-beta and bone morphogenetic proteins (BMPs), are potent regulatory cytokines with diverse functions on vascular cells. They signal through heteromeric type I and II receptor complexes activating Smad-dependent and Smad-independent signals, which regulate proliferation, differentiation, and survival. They are potent regulators of vascular development and vessel remodeling and play key roles in atherosclerosis and restenosis, regulating endothelial, smooth muscle cell, macrophage, T cell, and probably vascular calcifying cell responses. In atherosclerosis, TGF-beta regulates lesion phenotype by controlling T-cell responses and stimulating smooth muscle cells to produce collagen. It contributes to restenosis by augmenting neointimal cell proliferation and collagen accumulation. Defective TGF-beta signaling in endothelial cells attributable to mutations in endoglin or the type I receptor ALK-1 leads to hereditary hemorrhagic telangiectasia, whereas defective BMP signaling attributable to mutations in the BMP receptor II has been associated with development of primary pulmonary hypertension. The development of mouse models with either cell type-specific or general inactivation of TGF-beta/BMP signaling has started to reveal the importance of the regulatory network of TGF-beta/BMP pathways in vivo and their significance for atherosclerosis, hereditary hemorrhagic telangiectasia, and primary pulmonary hypertension. This review highlights recent findings that have advanced our understanding of the roles of TGF-beta superfamily members in regulating vascular cell responses and provides likely avenues for future research that may lead to novel pharmacological therapies for the treatment or prevention of vascular disorders. PMID:16675726

  13. Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution

    SciTech Connect

    Laroche, G.; Vallade, J.; Bazinette, R.; Hernandez, E.; Hernandez, G.; Massines, F.; Nijnatten, P. van

    2012-10-15

    This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm Multiplication-Sign 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45 Degree-Sign beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

  14. Growth model of binary alloy nanopowders for thermal plasma synthesis

    NASA Astrophysics Data System (ADS)

    Shigeta, Masaya; Watanabe, Takayuki

    2010-08-01

    A new model is developed for numerical analysis of the entire growth process of binary alloy nanopowders in thermal plasma synthesis. The model can express any nanopowder profile in the particle size-composition distribution (PSCD). Moreover, its numerical solution algorithm is arithmetic and straightforward so that the model is easy to use. By virtue of these features, the model effectively simulates the collective and simultaneous combined process of binary homogeneous nucleation, binary heterogeneous cocondensation, and coagulation among nanoparticles. The effect of the freezing point depression due to nanoscale particle diameters is also considered in the model. In this study, the metal-silicon systems are particularly chosen as representative binary systems involving cocondensation processes. In consequence, the numerical calculation with the present model reveals the growth mechanisms of the Mo-Si and Ti-Si nanopowders by exhibiting their PSCD evolutions. The difference of the materials' saturation pressures strongly affects the growth behaviors and mature states of the binary alloy nanopowder.

  15. Growth model of binary alloy nanopowders for thermal plasma synthesis

    SciTech Connect

    Shigeta, Masaya; Watanabe, Takayuki

    2010-08-15

    A new model is developed for numerical analysis of the entire growth process of binary alloy nanopowders in thermal plasma synthesis. The model can express any nanopowder profile in the particle size-composition distribution (PSCD). Moreover, its numerical solution algorithm is arithmetic and straightforward so that the model is easy to use. By virtue of these features, the model effectively simulates the collective and simultaneous combined process of binary homogeneous nucleation, binary heterogeneous cocondensation, and coagulation among nanoparticles. The effect of the freezing point depression due to nanoscale particle diameters is also considered in the model. In this study, the metal-silicon systems are particularly chosen as representative binary systems involving cocondensation processes. In consequence, the numerical calculation with the present model reveals the growth mechanisms of the Mo-Si and Ti-Si nanopowders by exhibiting their PSCD evolutions. The difference of the materials' saturation pressures strongly affects the growth behaviors and mature states of the binary alloy nanopowder.

  16. Modulation of growth and differentiation in normal human keratinocytes by transforming growth factor-beta

    SciTech Connect

    Matsumoto, K.; Hashimoto, K.; Hashiro, M.; Yoshimasa, H.; Yoshikawa, K. )

    1990-10-01

    The effect of transforming growth factor-type beta 1(TGF-beta) on the growth and differentiation of normal human skin keratinocytes cultured in serum-free medium was investigated. TGF-beta markedly inhibited the growth of keratinocytes at the concentrations greater than 2 ng/ml under low Ca2+ conditions (0.1 mM). Growth inhibition was accompanied by changes in cell functions related to proliferation. Remarkable inhibition of DNA synthesis was demonstrated by the decrease of (3H)thymidine incorporation. The decrease of (3H)thymidine incorporation was observed as early as 3 hr after addition of TGF-beta. TGF-beta also decreased c-myc messenger RNA (mRNA) expression 30 min after addition of TGF-beta. This rapid reduction of c-myc mRNA expression by TGF-beta treatment is possibly one of the main factors in the process of TGF-beta-induced growth inhibition of human keratinocytes. Since growth inhibition and induction of differentiation are closely related in human keratinocytes, the growth-inhibitory effect of TGF-beta under high Ca2+ conditions was examined. TGF-beta inhibited the growth of keratinocytes under high Ca2+ conditions in the same manner as under low Ca2+ conditions, suggesting that it is a strong growth inhibitor in both low and high Ca2+ environments. The induction of keratinocyte differentiation was evaluated by measuring involucrin expression and cornified envelope formation: TGF-beta at 20 ng/ml increased involucrin expression from 9.3% to 18.8% under high Ca2+ conditions, while it decreased involucrin expression from 7.0% to 3.3% under low Ca2+ conditions. Cornified envelope formation was modulated in a similar way by addition of TGF-beta: TGF-beta at 20 ng/ml decreased cornified envelope formation by 53% under low Ca2+ conditions, while it enhanced cornified envelope formation by 30.7% under high Ca2+ conditions.

  17. The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk.

    PubMed

    McPherson, R J; Wagner, C L

    2001-01-01

    Transforming growth factor alpha (TGF-alpha) and beta 2 (TGF-beta2) are present in human milk and are involved in growth differentiation and repair of neonatal intestinal epithelia. Heat treatment at 56 degrees C has been shown effective for providing safe banked donor milk, with good retention of other biologically active factors. The purpose of our study was to determine the effect of heat sterilization on TGF-alpha and TGF-beta2 concentrations in human milk. Twenty milk samples were collected from 20 lactating mothers in polypropylene containers and frozen at -20 degrees C for transport or storage. Before heat treatment by holder pasteurization, the frozen milk was thawed and divided into 1-mL aliquots. All samples were heated in an accurately regulated water bath until a holding temperature was achieved, then held for 30 minutes using constant agitation. Holding temperature ranged from 56.5 degrees C to 56.9 degrees C. The milk was then stored at 4 degrees C overnight for analysis the following day. The concentration of TGF-alpha was measured by radioimmunoassay. Mean concentration +/- SD of TGF-alpha in raw milk samples was 119+/-50 pg/mL, range 57 to 234. The mean concentration +/- SD of TGF-alpha in heat treated samples was 113+/-50 pg/mL, range 51 to 227. TGF-alpha concentration was minimally affected by pasteurization, with an overall loss of 6.1%. Of 19 samples, 4 had increased and 15 had decreased concentrations after pasteurization (mean percent SEM: 94%+/-7% of raw milk, range 72%+/-107%). The concentration of acid-activated TGF-beta2 was measured by enzyme-linked immunosorbent assay. Mean concentration +/- SD of TGF-beta2 in raw milk samples was 5624+/-5038 pg/mL, range 195 to 15480. The mean concentration +/- SD of TGF-beta2 in heat-treated samples was 5073+/-4646 pg/mL, range 181 to 15140. TGF-beta2 survived with relatively little loss (0.6%): of 18 samples, 11 had increased and 7 had decreased concentrations after pasteurization (mean percent

  18. The Role of Plasma in Plasma Enhanced Chemical Vapour Deposition of Nanostructure Growth

    NASA Technical Reports Server (NTRS)

    Hash, David B.; Meyyappan, M.; Teo, Kenneth B. K.; Lacerda, Rodrigo G.; Rupesinghe, Nalin L.

    2004-01-01

    Chemical vapour deposition (CVD) has become the preferred process for high yield growth of carbon nanotubes and nanofibres because of its ability to pattern growth through lithographic positioning of transition metal catalysts on substrates. Many potential applications of nanotubes such as field emitters [1] require not only patterned growth but also vertical alignment. Some degree of ali,ment in thermal CVD processes can be obtained when carbon nanotubes are grown closely together as a result of van der Waals interactions. The ali,onment however is marginal, and the van der Waals prerequisite makes growth of freestanding nanofibres with thermal CVD unrealizable. The application of electric fields as a means of ali,onment has been shown to overcome this limitation [2-5], and highly aligned nanostructures can be grown if electric fields on the order of 0.5 V/microns are employed. Plasma enhanced CVD in various configurations including dc, rf, microwave, inductive and electron cyclotron resonance has been pursued as a means of enabling alignment in the CVD process. However, the sheath fields for the non-dc sources are in general not sufficient for a high degree of ali,pment and an additional dc bias is usually applied to the growth substrate. This begs the question as to the actual role of the plasma. It is clear that the plasma itself is not required for aligned growth as references [3] and [4] employed fields through small applied voltages (3-20 V) across very small electrode spacings (10-100 microns) and thus avoided striking a discharge.

  19. Selective inhibition of growth-related gene expression in murine keratinocytes by transforming growth factor beta.

    PubMed Central

    Coffey, R J; Bascom, C C; Sipes, N J; Graves-Deal, R; Weissman, B E; Moses, H L

    1988-01-01

    Transforming growth factor beta (TGF beta) is a potent inhibitor of epithelial cell proliferation. A nontumorigenic epidermal growth factor (EGF)-dependent epithelial cell line, BALB/MK, is reversibly growth arrested by TGF beta. TGF beta will also abrogate EGF-stimulated mitogenesis of quiescent BALB/MK cells. Increased levels of calcium (greater than 1.0 mM) will induce differentiation in BALB/MK cells; in contrast, TGF beta-mediated growth inhibition does not result in induction of terminal differentiation. In the present study, the effects of TGF beta and calcium on growth factor-inducible gene expression were examined. TGF beta markedly decreased c-myc and KC gene expression in rapidly growing BALB/MK cells and reduced the EGF induction of c-myc and KC in a quiescent population of cells. TGF beta exerted its control over c-myc expression at a posttranscriptional level, and this inhibitory effect was dependent on protein synthesis. TGF beta had no effect on c-fos gene expression, whereas 1.5 mM calcium attenuated EGF-induced c-fos expression in quiescent cells. Expression of beta-actin, however, was slightly increased in both rapidly growing and EGF-restimulated quiescent BALB/MK cells treated with TGF beta. Thus, in this system, TGF beta selectively reduced expression of certain genes associated with cell proliferation (c-myc and KC), and at least part of the TGF beta effect was at a posttranscriptional level. Images PMID:2463471

  20. Regulation of intestinal epithelial cell growth by transforming growth factor type. beta

    SciTech Connect

    Barnard, J.A.; Beauchamp, R.D.; Coffey, R.J.; Moses, H.L. )

    1989-03-01

    A nontransformed rat jejunal crypt cell line (IEC-6) expresses transforming growth factor type {beta}1 (TGF-{beta}1) mRNA, secretes latent {sup 125}I-labeled TGF-{beta}1 to specific, high-affinity cell surface receptors. IEC-6 cell growth is markedly inhibited by TGF-{beta}1 and TGF-{beta}2 with half-maximal inhibition occurring between 0.1 and 1.0 ng of TGF-{beta}1 per ml. TGF-{beta}1-mediated growth inhibition is not associated with the appearance of biochemical markers of enterocyte differentiation such as alkaline phosphatase expression and sucrase activity. TGF-{beta}1 increases steady-state levels of its own mRNA expression within 8 hr of treatment of rapidly growing IEC-6 cells. In freshly isolated rat jejunal enterocytes that are sequentially eluted from the crypt villus axis, TGF-{beta}1 mRNA expression is most abundant in terminally differentiated villus tip cells and least abundant in the less differentiated, mitotically active crypt cells. The authors conclude that TGF-{beta}1 is an autoregulated growth inhibitor in IEC-6 cells that potentially functions in an autocrine manner. In the rat jejunal epithelium, TGF-{beta}1 expression is most prominently localized to the villus tip--i.e., the region of the crypt villus unit that is characterized by the terminally differentiated phenotype. These data suggest that TGF-{beta}1 may function in coordination of the rapid cell turnover typical for the intestinal epithelium.

  1. Mechanism of Growth Enhancement of Plants Induced by Active Species in Plasmas

    NASA Astrophysics Data System (ADS)

    Watanabe, Satoshi; Ono, Reoto; Hayashi, Nobuya

    2015-09-01

    Plant growth enhances when seeds are irradiated by plasma. However the mechanism of the growth enhancement by plasma has not been clarified. In this study, growth enhancement of plants using various active species and variation of plant cells are investigated. RF plasma is generated under conditions where pressure is 60 Pa and input electrical power is 60 W. Irradiation period varies from 0 (control) to 75 min. Air plasma shows maximum growth of plants with irradiation period of 60 min on the other hand, oxygen plasma shows the maximum growth with irradiation period of 15 min. From change of gaseous species and pressure dependence, growth enhancing factor is expected to be active oxygen species produced in plasma. According to gene expression analysis of Arabidopsis, there are two speculated mechanism of plant growth enhancement. The first is acceleration of cell cycle by gene expressions of photosynthesis and glycolytic pathway, and the second is increase of cell size via plant hormone production.

  2. TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF)

    EPA Science Inventory

    TITLE:
    TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF). AUTHORS (ALL): Abbott, Barbara D.1; Best, Deborah S.1; Narotsky, Michael G.1. SPONSOR NAME: None INSTITUTIONS (ALL): 1. Repro Tox ...

  3. Flute instability growth on a magnetized plasma column.

    SciTech Connect

    Genoni, Thomas C.; Welch, Dale Robert; Ditmire, T.; Rose, David Vincent; Mehlhorn, Thomas Alan; Porter, John Larry, Jr.

    2006-08-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r{sub i}, where R is the Gaussian characteristic radius and r{sub i} is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation. Keywords: Microinstabilities, Magnetic confinement and equilibrium, Particle-in-cell method.

  4. Flute instability growth on a magnetized plasma column.

    SciTech Connect

    Genoni, Thomas C.; Rose, David Vincent; Ditmire, T.; Mehlhorn, Thomas Alan; Welsh, D. R.; Porter, John Larry, Jr.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r{sub i}, where R is the Gaussian characteristic radius and r{sub i} is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation.

  5. Flute instability growth on a magnetized plasma column

    SciTech Connect

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-09-15

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r{sub i}, where R is the Gaussian characteristic radius and r{sub i} is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation.

  6. Plasma Conductivity and Ionization Growth in Flame Breakdown

    NASA Astrophysics Data System (ADS)

    Robledo-Martinez, Arturo; Hernandez, J. Luis

    2000-10-01

    An investigation into the properties of flame breakdown is reported. A series of DC discharge tests were performed in a set of parallel plane electrodes bridged by flames from a bunsen burner. The experimental setup aims to reproduce the conditions found in waste-disposal reactors where the combined effect of fire and an electrical arc degrade noxious substances. The current was simultaneously monitored in different points of the discharge zone. As the applied voltage is increased, it is found that initially the ionization from the flame controls discharge growth but that in later stages avalanche growth takes over. The slope of the I-V characteristics was used for estimating the Townsend ionization coefficients. The overall plasma conductivity was estimated from both the external circuit measurements and the plasma parameters. The results obtained are compared with previous investigations in which mean discharge resistivity is a relevant parameter, employed for designing applications. The effect of gap separation and height over the burner top were also analyzed. This way it was observed that the temperature profile of the flame dictates the spatial distribution of electrical conductivity and thus of breakdown.

  7. Dust Particle Growth and Application in Low Temperature Plasmas

    SciTech Connect

    Boufendi, L.

    2008-09-23

    Dust particle nucleation and growth has been widely studied these last fifteen years in different chemistries and experimental conditions. This phenomenon is correlated with various electrical changes at electrodes, including self-bias voltage and amplitudes of the various harmonics of current and voltage [1]. Some of these changes, such as the appearance of more resistive plasma impedance, are correctly attributed to loss of electrons in the bulk plasma to form negative molecular ions (e.g. SiH{sub 3}{sup -}) and more precisely charged nanoparticles. These changes were studied and correlated to the different phases on the dust particle formation. It is well known now that, in silane argon gas mixture discharges, in the first step of this particle formation we have formation of nanometer sized crystallites. These small entities accumulate and when their number density reaches a critical value, about 10{sup 11} to 10{sup 12} cm{sup -1}, they start to aggregate to form bigger particles. The different phases are well defined and determined thanks to the time evolution of the different electrical parameter changes. The purpose of this contribution is to compare different chemistries to highlight similarities and/or differences in order to establish possible universal dust particle growth mechanisms. The chemistries we studied concern SiH{sub 4}-Ar, CH{sub 4}, CH{sub 4}-N{sub 2} and Sn(CH{sub 3}){sub 4}[2]. We also refer to works performed in other laboratories in different discharge configurations [3]. Different applications have already developed or are foreseen for these nanoparticles. The first application concerns the inclusion of nanosized dust crystallites in an amorphous matrix in order to modify the optoelectronic and mechanical properties [4-5]. At the present time a very active research programs are devoted towards single electron devises where nanometer sized crystallites play a role of quantum dots. These nanoparticles can be produced in low pressure cold

  8. Scaling of the Longitudinal Electric Field and Transformer Ratio in a Nonlinear Plasma Wakefield Accelerator

    SciTech Connect

    Blumenfeld, I.; Clayton, C.E.; Decker, F.J.; Hogan, M.J.; Huang, C.; Ischebeck, R.; Iverson, R.H.; Joshi, C.; Katsouleas, T.; Kirby, N.; Lu, W.; Marsh, K.A.; Mori, W.B.; Muggli, P.; Oz, E.; Siemann, R.H.; Walz, D.R.; Zhou, M.; /UCLA

    2012-06-12

    The scaling of the two important figures of merit, the transformer ratio T and the longitudinal electric field E{sub z}, with the peak drive-bunch current I{sub p}, in a nonlinear plasma wakefield accelerator is presented for the first time. The longitudinal field scales as I{sub P}{sup 0.623{+-}0.007}, in good agreement with nonlinear wakefield theory ({approx}I{sub P}{sup 0.5}), while the unloaded transformer ratio is shown to be greater than unity and scales weakly with the bunch current. The effect of bunch head erosion on both parameters is also discussed.

  9. Observation of plasma instabilities related to dust particle growth mechanisms in electron cyclotron resonance plasmas

    SciTech Connect

    Drenik, A.; Margot, J.

    2013-10-15

    Instabilities are observed in the self-bias voltage measured on a probe immersed in microwave plasma excited at Electron Cyclotron Resonance (ECR). Observed in the MHz range, they were systematically measured in dust-free or dusty plasmas (obtained for different conditions of applied microwave powers and acetylene flow rates). Two characteristic frequencies, well described as lower hybrid oscillations, can be defined. The first one, in the 60–70 MHz range, appears as a sharp peak in the frequency spectra and is observed in every case. Attributed to ions, its position shift observed with the output power highlights that nucleation process takes place in the dusty plasma. Attributed to lower hybrid oscillation of powders, the second broad peak in the 10–20 MHz range leads to the characterization of dust particles growth mechanisms: in the same way as in capacitively coupled plasmas, accumulation of nucleus confined near the probe in the magnetic field followed by aggregation takes place. Then, the measure of electrical instabilities on the self-bias voltage allows characterizing the discharge as well as the chemical processes that take place in the magnetic field region and their kinetics.

  10. Effects of plasma irradiation using various feeding gases on growth of Raphanus sativus L.

    PubMed

    Sarinont, Thapanut; Amano, Takaaki; Attri, Pankaj; Koga, Kazunori; Hayashi, Nobuya; Shiratani, Masaharu

    2016-09-01

    In this work, we have studied the action of dielectric barrier discharge (DBD) plasma irradiation using various feeding gases on seeds of Raphanus sativus L. and analysis their growth. Our experimental data shows that Air, O2, and NO(10%)+N2 feeding gases plasma irradiation enhanced plant growth, whereas N2, He and Ar feeding gases plasma irradiation had little influence on plant growth. Moreover, humid air plasma irradiation was more effective in growth enhancement than dry one. More than 2.3 times faster growth was observed by 3 min air plasma irradiation with 40-90% relative humidity. The reactive species generated by plasma in gas phase were detected using optical emission spectroscopy and in liquid phase by electron spin resonance (ESR) spectroscopy. We concluded that OH and O radicals were key species for plant growth enhancement. PMID:27021583

  11. A Putatively Functional Haplotype in the Gene Encoding Transforming Growth Factor Beta-1 as a Potential Biomarker for Radiosensitivity

    SciTech Connect

    Schirmer, Markus A.; Brockmoeller, Juergen; Rave-Fraenk, Margret; Virsik, Patricia; Wilken, Barbara; Kuehnle, Elna; Campean, Radu; Hoffmann, Arne O.; Mueller, Katarina; Goetze, Robert G.; Neumann, Michael; Janke, Joerg H.; Nasser, Fatima; Wolff, Hendrik A.; Ghadimi, B. Michael; Schmidberger, Heinz; Hess, Clemens F.; Christiansen, Hans; Hille, Andrea

    2011-03-01

    Purpose: To determine whether genetic variability in TGFB1 is related to circulating transforming growth factor-{beta}1 (TGF-{beta}1) plasma concentrations after radiotherapy and to radiosensitivity of lymphoid cells. Patients and Methods: Transforming growth factor-{beta}1 plasma concentrations (n = 79) were measured in patients 1 year after radiotherapy and chromosomal aberrations (n = 71) ex vivo before therapy start. Furthermore, TGF-{beta}1 secretion and apoptosis were measured in isolated peripheral blood mononuclear cells of 55 healthy volunteers. These phenotypes were analyzed in relation to five germline polymorphisms in the 5' region of the TGFB1 gene. Because of high linkage disequilibrium, these five polymorphisms reflect frequent genetic variation in this region. A presumed impact of TGF-{beta}1 on DNA damage or repair was measured as micronucleus formation in 30 lymphoblastoid cell lines. Results: We identified a hypofunctional genetic haplotype termed H3 tagging the 5' region of the TGFB1 gene encoding TGF-{beta}1. H3 was associated with lower TGF-{beta}1 plasma concentrations in patients (p = 0.01) and reduced TGF-{beta}1 secretion in irradiated peripheral blood mononuclear cells (p = 0.003). Furthermore, cells with H3 were less prone to induction of chromosomal aberrations (p = 0.001) and apoptosis (p = 0.003) by irradiation. The hypothesis that high TGF-{beta}1 could sensitize cells to DNA damage was further supported by increased micronuclei formation in 30 lymphoblastoid cell lines when preincubated with TGF-{beta}1 before irradiation (p = 0.04). Conclusions: On the basis of TGF-{beta}1 plasma levels and radiation sensitivity of lymphoid cells, this study revealed a putatively hypofunctional TGFB1 haplotype. The significance of this haplotype and the suggested link between TGF-{beta}1 function and DNA integrity should be further explored in other cell types, as well as other experimental and clinical conditions.

  12. Role of polypeptide growth factors in phenotypic transformation of normal rat kidney cells

    SciTech Connect

    van Zoelen, E.J.J.; van Oostwaard, T.M.J.; de Laat, S.W.

    1988-01-05

    A serum-free assay has been established for studying the role of polypeptide growth factors in inducing loss of density-dependent inhibition of growth of normal rat kidney (NRK) cells. The process has been characterized by measuring the time course of (/sup 3/H)thymidine incorporation into confluent, quiescent NRK cultures stimulated by defined polypeptide growth factors, in combination with cell counting studies, increases in DNA content, and cell cycle analysis by means of a fluorescence-activated cell sorter. It is shown that none of the growth factors tested is able to induce loss of density-dependent inhibition of growth by itself, but strong synergism was observed when combinations of growth factors were tested. None of the above factors was found to be essential, however, since any combination of three of the above four growth factors strongly induced the process. Strong parallels were observed between the growth factor requirements for inducing loss of density-dependent inhibition of growth under serum-free conditions and the requirements for induction of anchorage-independent proliferation under growth factor-defined assay conditions. This indicates that most likely the same cellular processes underlie these two aspects of phenotypic transformation, although data indicate that anchorage-independent proliferation may be a more restricted property of phenotypic transformation than loss of density dependence of proliferation. It is concluded that phenotypic transformation of NRK cells does not require specific polypeptide growth factors, but reflects the ability of these cells to respond to multiple growth factors.

  13. Effects of plasma power on the growth of carbon nanotubes in the plasma enhanced chemical vapor deposition method

    NASA Astrophysics Data System (ADS)

    Abdi, Y.; Arzi, E.; Mohajerzadeh, S.

    2008-11-01

    Effects of plasma power on the growth of the multi-wall carbon nanotubes (CNTs) are reported. CNTs were grown on the silicon wafers by plasma enhanced chemical vapor deposition (PECVD) method using a mixture of acetylene and hydrogen at the temperature of 650°C. Plasma powers ranging from zero to 35W were applied on the samples and the effects of different magnitudes of the plasma power on the growth direction of the CNTs were investigated. Regular vertically aligned nanotubes were obtained at plasma power of 25W. In order to set on the plasma during the growth, electrical force was applied on the carbon ions. Nickel layer was used as a catalyst, and prior to the nanotubes growth step, it was treated by hydrogen plasma bombardment in order to obtain the Ni nano-islands. In this step, as the plasma power on the Ni layer was increased, the grain size of nickel nano-particles decreased, and hence, nanotubes of smaller diameter were obtained later on. At the last step some anomalous structures of agglomerated CNTs were obtained by controlling the plasma power. Samples were analyzed by scanning tunneling microscopy (STM) and scanning electron microscopy (SEM).

  14. Levels of transforming growth factor beta and transforming growth factor beta receptors in rat liver during growth, regression by apoptosis and neoplasia.

    PubMed

    Grasl-Kraupp, B; Rossmanith, W; Ruttkay-Nedecky, B; Müllauer, L; Kammerer, B; Bursch, W; Schulte-Hermann, R

    1998-09-01

    Transforming growth factor beta1 (TGF-beta1) has been implicated as inhibitor of cell proliferation and a potent inducer of apoptosis in vitro and in vivo after the administration of high doses. To assess the role of endogenous TGF-beta1, we quantitated the cytokine and its receptors in rat liver during regenerative and hyperplastic growth, regression by apoptosis, and in hepatocellular carcinoma (HCC). This was accomplished by Northern blot analysis and by RNase protection assay of the messenger RNA (mRNA) of TGF-beta1 and TGF-beta receptors (TbetaR) types I to III and by an activity bioassay of the TGF-beta proteins. Untreated rat livers were found to contain 15.6 +/- 4.8 ng TGF-beta1 protein/g tissue; TGF-beta2 protein was not detected. To induce toxic cell death and subsequent regenerative DNA synthesis in the liver, rats were treated with a necrogenic dose of carbon tetrachloride (CCl4). After 24 and 48 hours, there was an upregulation of TGF-beta1 (mRNA, up to tenfold; protein, about twofold) and of TbetaRs (mRNA: two- to fourfold); that indicates an overall enhanced production of and sensitivity to TGF-beta1, which may serve to confine the regenerative response. Hyperplastic liver growth and regression of the hyperplasia were induced by treatment with cyproterone acetate (CPA) or nafenopin (NAF) followed by withdrawal; neither mRNAs of TGF-beta1 and TbetaR types I to III nor TGF-beta1 protein exhibited significant changes during the growth phase or during regression by apoptosis. We also studied neoplastic growth. HCC, obtained after long-term treatment with NAF, exhibited high rates of cell replication and apoptosis. The majority of lesions contained mRNA and protein of TGF-beta1 and mRNA of TbetaR types I to III at concentrations similar to those of the surrounding tissue. In conclusion, during liver regeneration there is a pronounced upregulation of expression of both TGF-beta1 and TbetaRs I to III, but not during mitogen-induced liver growth or

  15. Baseline geoenvironmental experiments for in-situ soil transformation by plasma torch

    SciTech Connect

    Beaver, J.R.; Mayne, P.W.

    1995-12-31

    The advent of the nontransferred plasma arc torch has implicated a range of in-situ geoenvironmental applications that can revolutionize methods of ground modification and field remediation of contaminated sites. With reverse polarity nontransferred arc type plasma torches, temperatures of 4,000 C to 7,000 C can be directed at specific targets of contaminated soil or waste. At these extreme temperatures, all organic materials within the soil undergo pyrolysis, while the bulk composition is transformed into a magma that subsequently cools to form a vitrified mass resembling volcanic obsidian or a dense partially crystalline material resembling microcrystalline igneous rock. Simulations of in-situ transformation of soil have been conducted using both 100-kW and 240-kW torches to alter clay, silty sand, and sand in chamber tests. Although these materials are primarily composed of silica and alumina oxides having melting temperatures of 1,100 C to 1,600 C, the formation of a spheroidal magma core occurred within the first five minutes of exposure to the plasma flame. Experiments were conducted to quantify the improved engineering properties that occur after transformation and to demonstrate the relative effects of power level, water content, and soil type on the size and strength of the altered material. The ongoing research also serves as a baseline study for further experimentation that will focus on the in-situ remediation of soils with varied contaminants.

  16. Buckyball microwave plasmas: Fragmentation and diamond-film growth

    SciTech Connect

    Gruen, D.M.; Liu, Shengzhong; Krauss, A.R.; Pan, Xianzheng

    1993-08-01

    Microwave discharges (2.45 GHz) have been generated in C{sub 60}-containing Ar produced by flowing Ar over fullerene-containing soot. Optical spectroscopy shows that the spectrum is dominated by the d{sup 3}{Pi}g-a{sup 3}{Pi}u Swan bands of C{sub 2} and particularly the {Delta}v = {minus}2, {minus}1, 0, +1, and +2 sequences. These results give direct evidence that C{sub 2} is one of the products of C{sub 60} fragmentation brought about, at least in part, by collisionally induced dissociation (CID). C{sub 60} has been used as a precursor in a plasma-enhanced chemical vapor deposition (PECVD) experiment to grow diamond-thin films. The films, grown in an Ar/H{sub 2} gas mixture (0.14% carbon content, 100 Torr, 20 sccm Ar, 4 sccm H{sub 2}, 1500 W, 850{degree}C substrate temperature), were characterized with SEM, XRD, and Raman spectroscopy. Growth rate was found to be {approx} 0.6 {mu}/hr. Assuming a linear dependence on carbon concentration, a growth rate at least six times higher than commonly observed using methane as a precursor, would be predicted at a carbon content of 1% based on C{sub 60}. Energetic and mechanistic arguments are advanced to rationalize this result based on C{sub 2} as the growth species.

  17. Transforming growth factor (TGF)-β levels and unprovoked recurrent venous thromboembolism.

    PubMed

    Memon, Ashfaque A; Sundquist, Kristina; Wang, Xiao; Svensson, Peter J; Sundquist, Jan; Zöller, Bengt

    2014-10-01

    Prediction of recurrence in patients with unprovoked venous thromboembolism (VTE) remains a challenge. Studies of atherosclerosis suggest a protective role of transforming growth factor (TGF)-β. However, the role of TGF-β has not been studied in VTE. The aim of this study was to investigate TGF-β as a predictive marker of recurrent VTE in patients with a first episode of unprovoked VTE. Patients in the Malmö Thrombophilia Study (MATS) were followed after the discontinuation of anticoagulant treatment until the diagnosis of recurrent VTE or the end of the study in December 2008 (mean ± SD 38.5 months ± 27). Among patients with a first episode of unprovoked VTE, we identified 42 patients with recurrent VTE during the follow-up period. Two age- and sex-matched control subjects without recurrent VTE were selected for each patient (n = 84). Plasma levels of the three isoforms of TGF-β (TGF-β1, TGF-β2 and TGF-β3) were quantified simultaneously by TGF-β 3-plex immunoassay. Compared to controls, plasma levels of TGF-β1 and TGF-β2 were significantly lower in patients with recurrent VTE (p < 0.05), whereas no difference was found for TGF-β3. In a multivariate Cox regression analyses, adjusted for inherited thrombophilia, age, sex and BMI, low levels of TGF-β1 [hazard ratio (HR) = 2.2, 95% confidence interval (CI) 1.1-4.3; p = 0.02] and TGF-β2 (HR = 2.4, 95% CI 1.2-4.7; p = 0.01) were independently associated with a higher risk of recurrent VTE. We propose TGF-β1 and TGF-β2 as potential predictive markers for recurrence in patients with unprovoked VTE.

  18. Loss of responsiveness to transforming growth factor beta induces malignant transformation of nontumorigenic rat prostate epithelial cells.

    PubMed

    Tang, B; de Castro, K; Barnes, H E; Parks, W T; Stewart, L; Böttinger, E P; Danielpour, D; Wakefield, L M

    1999-10-01

    Transforming growth factor (TGF)-betas are multifunctional growth factors, the properties of which include the potent inhibition of epithelial cell growth. Expression patterns of TGF-betas and TGF-beta receptors in the normal prostate indicate that these growth regulators play key roles in prostatic development and proliferative homeostasis. Importantly, TGF-beta receptor levels are frequently diminished in malignant human prostate tissue. To test the hypothesis that loss of TGF-beta responsiveness is causally involved in the tumorigenic process, we have used retroviral transduction to introduce a dominant-negative mutant type II TGF-beta receptor (DNR) into the premalignant rat prostatic epithelial cell line, NRP-152. High-level expression of the DNR abolished the ability of TGF-beta to inhibit cell growth, to promote cell differentiation, and to induce apoptosis, and it partially blocked the induction of extracellular matrix gene expression. When injected into nude mice, NRP-152-DNR cells formed carcinomas at 13 of 34 sites, compared with 0 of 30 sites for parental and control cells (P = 0.0001). We conclude that the type II TGF-beta receptor is an important tumor suppressor in the prostate, and furthermore, that loss of TGF-beta responsiveness can contribute early in the tumorigenic process by causing the malignant transformation of preneoplastic cells.

  19. Phase transformation and wear studies of plasma sprayed yttria stabilized zirconia coatings containing various mol% of yttria

    SciTech Connect

    Aruna, S.T. Balaji, N.; Rajam, K.S.

    2011-07-15

    Plasma sprayable grade zirconia powders doped with various mol% of yttria (0, 2, 3, 4, 6, 8 and 12 mol%) were synthesized by a chemical co-precipitation route. The coprecipitation conditions were adjusted such that the powders possessed good flowability in the as calcined condition and thus avoiding the agglomeration step like spray drying. Identical plasma spray parameters were used for plasma spraying all the powders on stainless steel plates. The powders and plasma sprayed coatings were characterized by X-ray diffractometry, Scanning Electron Microscopy and Raman spectroscopy. Zirconia powders are susceptible to phase transformations when subjected to very high temperatures during plasma spraying and XRD is insensitive to the presence of some non crystalline phases and hence Raman spectroscopy was used as an important tool. The microstructure of the plasma sprayed coatings showed a bimodal distribution containing fully melted and unmelted zones. The microhardness and wear resistance of the plasma sprayed coatings were determined. Among the plasma sprayed coatings, 3 mol% yttria stabilized zirconia coating containing pure tetragonal zirconia showed the highest wear resistance. - Research Highlights: {yields} Preparation plasma sprayable YSZ powders without any agglomeration process and plasma spraying {yields} Phase transformation studies of plasma sprayed YSZ coatings by XRD and Raman spectroscopy {yields} Microstructure of the plasma sprayed coatings exhibited bimodal distribution {yields} Plasma sprayed 3 mol% YSZ coating exhibited the highest wear resistance {yields} Higher wear resistance is due to the higher fracture toughness of tetragonal 3 mol% YSZ phase.

  20. Comparison of humoral insulin-like growth factor-1, platelet-derived growth factor-BB, transforming growth factor-β1, and interleukin-1 receptor antagonist concentrations among equine autologous blood-derived preparations.

    PubMed

    Ionita, Christiane R; Troillet, Antonia R; Vahlenkamp, Thomas W; Winter, Karsten; Brehm, Walter; Ionita, Jean-Claude

    2016-08-01

    OBJECTIVE To compare humoral insulin-like growth factor (IGF)-1, platelet-derived growth factor (PDGF)-BB, transforming growth factor (TGF)-β1, and interleukin-1 receptor antagonist (IL-1Ra) concentrations in plasma and 3 types of equine autologous blood-derived preparations (ABPs). SAMPLE Blood and ABP samples from 12 horses. PROCEDURES Blood samples from each horse were processed by use of commercial systems to obtain plasma, platelet concentrate, conditioned serum, and aqueous platelet lysate. Half of the platelet concentrate samples were additionally treated with a detergent to release intracellular mediators. Humoral IGF-1, PDGF-BB, TGF-β1, and IL-1Ra concentrations were measured with ELISAs and compared statistically. RESULTS Median IGF-1 concentration was highest in conditioned serum and detergent-treated platelet concentrate, followed by platelet concentrate and plasma; IGF-1 was not detected in platelet lysate. Mean PDGF-BB concentration was highest in platelet lysate, followed by detergent-treated platelet concentrate and conditioned serum; PDGF-BB was not detected in plasma and platelet concentrate. Median TGF-β1 concentration was highest in detergent-treated platelet concentrate, followed by conditioned serum, platelet lysate, and platelet concentrate; TGF-β1 was not detected in most plasma samples. Median IL-1Ra concentration was highest in platelet lysate, followed by conditioned serum; IL-1Ra was not detected in almost all plasma, detergent-treated platelet concentrate, and platelet concentrate samples. CONCLUSIONS AND CLINICAL RELEVANCE Each ABP had its own cytokine profile, which was determined by the specific processing method. Coagulation and cellular lysis strongly increased humoral concentrations of cell-derived cytokines. No ABP had the highest concentrations for all cytokines. Further studies are needed to assess clinical relevance of these findings. PMID:27463555

  1. Lead (Pb) attenuation of plasma growth hormone output

    SciTech Connect

    Berry, W.D.; Moriarty, C.M.; Lau, Y.S.; Edwards, G.L.

    1996-03-08

    Lead (Pb) induced growth retardation may occur through disruption of the hypothalamic-pituitary-growth hormone (GH) axis. Episodic GH secretion and GH response to exogenous growth hormone releasing hormone (GHRH) were measured in rats chronically exposed to Pb. Male rats received lead nitrate (1000 ppm) in their drinking water from 21 through 49 days of age gained less weight than non-Pb treated controls (242{plus_minus}3 g vs 309{plus_minus}8 g, P{le}0.01). Mean blood Pb was 40 {plus_minus} 5 ug/dl in Pb treated rats vs. nondetectable in controls. Total food intake was increased by Pb treatment (340 vs 260 g/rat). Mean plasma GH levels were significantly reduced by Pb treatment (40.21 {plus_minus} 7 vs 71.53 {plus_minus} 11 ng/mlP= 0.025). However, the temporal pattern of episodic GH release was maintained in the Pb-treated rats. This indicates that Pb does not disrupt the timing of GHRH and somatostatin (SS) release from the hypothalamus but may alter the relative levels of GHRH and SS released. Pb treated rats also retained the ability to secrete GH in response to exogenous GHRH. However, response to GHRH tended to be lower in the Pb treated rats. The greatest effect of Pb was seen at the highest dose of GHRH 5 {mu}g/kg GHRH dose (485.6 {plus_minus} 103 vs. 870.2 {plus_minus} 317 ng/ml; P =0.2). This suggests that Pb disrupts GH synthesis, signal transduction, or secretory mechanisms in the somatotrope.

  2. Regulation of growth and gene expression in human papillomavirus-transformed keratinocytes by transforming growth factor-beta: implications for the control of papillomavirus infection.

    PubMed

    Braun, L; Dürst, M; Mikumo, R; Crowley, A; Robinson, M

    1992-01-01

    Cervical carcinogenesis is a multistep process that appears to be initiated by infection of squamous epithelial cells in the cervix with one of a limited number of human papillomavirus (HPV) types. However, the mechanisms involved in the evolution of benign, HPV-induced lesions to malignancy have not yet been fully elucidated. Transforming growth factor-beta (TGF-beta), a multifunctional growth factor produced by cells in the skin, inhibits the proliferation of foreskin and cervical keratinocytes in vitro. We examined the effects of TGF-beta on growth and virus early-gene expression in cell lines immortalized by two HPV types associated with cervical carcinogenesis as well as the expression of TGF-beta 1 mRNA transcripts in normal and HPV-positive cells in vivo and in vitro. We found that normal and HPV-positive cells expressed similar levels of TGF-beta 1 mRNAs and exhibited similar patterns of responsiveness to three isoforms of TGF-beta in both monolayer and modified organotypic cultures. Of particular interest is our finding that the expression of the E6 and E7 early viral transforming regions of both HPV16 and HPV18 was reversibly and rapidly inhibited by TGF-beta. In one HPV16-positive cell line examined in detail, inhibition of HPV expression required protein synthesis and occurred at the level of transcription. HPV-immortalized cells selected for resistance to in vitro differentiation signals remained sensitive to TGF-beta-mediated growth inhibition. These results, showing that both growth and virus gene expression in HPV-transformed cells were responsive to TGF-beta, suggest that endogenous growth factors produced by different cell types in squamous epithelium may play a role in the progression of cervical neoplasia. PMID:1326988

  3. Substrate flexibility regulates growth and apoptosis of normal but not transformed cells

    NASA Technical Reports Server (NTRS)

    Wang, H. B.; Dembo, M.; Wang, Y. L.

    2000-01-01

    One of the hallmarks of oncogenic transformation is anchorage-independent growth (27). Here we demonstrate that responses to substrate rigidity play a major role in distinguishing the growth behavior of normal cells from that of transformed cells. We cultured normal or H-ras-transformed NIH 3T3 cells on flexible collagen-coated polyacrylamide substrates with similar chemical properties but different rigidity. Compared with cells cultured on stiff substrates, nontransformed cells on flexible substrates showed a decrease in the rate of DNA synthesis and an increase in the rate of apoptosis. These responses on flexible substrates are coupled to decreases in cell spreading area and traction forces. In contrast, transformed cells maintained their growth and apoptotic characteristics regardless of substrate flexibility. The responses in cell spreading area and traction forces to substrate flexibility were similarly diminished. Our results suggest that normal cells are capable of probing substrate rigidity and that proper mechanical feedback is required for regulating cell shape, cell growth, and survival. The loss of this response can explain the unregulated growth of transformed cells.

  4. Growth Enhancement of Radish Sprouts Induced by Low Pressure O2 Radio Frequency Discharge Plasma Irradiation

    NASA Astrophysics Data System (ADS)

    Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu; Hayashi, Nobuya

    2012-01-01

    We studied growth enhancement of radish sprouts (Raphanus sativus L.) induced by low pressure O2 radio frequency (RF) discharge plasma irradiation. The average length of radish sprouts cultivated for 7 days after O2 plasma irradiation is 30-60% greater than that without irradiation. O2 plasma irradiation does not affect seed germination. The experimental results reveal that oxygen related radicals strongly enhance growth, whereas ions and photons do not.

  5. Non-instantaneous growth characteristics of martensitic transformation in high Cr ferritic creep-resistant steel

    NASA Astrophysics Data System (ADS)

    Liu, Chenxi; Shao, Yi; Chen, Jianguo; Liu, Yongchang

    2016-08-01

    Microstructural observation and high-resolution dilatometry were employed to investigate kinetics of martensitic transformation in high Cr ferritic creep-resistant steel upon different quenching/cooling rates. By incorporating the classical athermal nucleation and impingement correction, a non-instantaneous growth model for martensitic transformation has been developed. The developed model describes austenite/martensite interface mobility during martensite growth. The growth rate of martensite is found to be varied from 1 × 10-6 to 3 × 10-6 m/s. The low interface mobility suggests that it is not appropriate to presume the instantaneous growth behavior of martensite. Moreover, based on the proposed model, nucleation rate of martensite under different cooling rates is found to be nearly the same, while the growth rate of martensite is promoted by increasing the cooling rate.

  6. Relation of the slow growth phenotype to neoplastic transformation: possible significance for human cancer.

    PubMed

    Chow, M; Rubin, H

    1999-09-01

    Deletions are widely distributed over the genome in the most frequently occurring human cancers and are the most abundant genetic lesion found there. Deletions are highly correlated with the slow growth phenotype of mutated animal and human cells and result in chromosomal transposition when the retained ends are joined. Transpositions are only a minor source of mutation in rapidly multiplying bacteria but are a major cause of mutations in stationary bacteria. The NIH 3T3 line of mouse cells undergoes neoplastic transformation during prolonged incubation in a stationary state and expresses the slow growth phenotype on serial subculture at low density, suggesting a relation between transformation and chromosomal deletions. To further explore the relation between neoplastic transformation and the slow growth phenotype as a surrogate for deletions, two sublines of the NIH 3T3 cells with differing competence for transformation were serially subcultured in the stationary state at confluence and tested at each subculture for transformation and growth rate. Cell death in a fraction of the population and a heritable slowdown in proliferation of most of the survivors became increasingly pronounced with successive rounds of confluence. The reduction in growth rate was not proportional to the degree of transformation of the cultures, but all of the transformed cultures were slow growers at low density. All of the discrete colonies from cloning transformed cultures developed at a lower initial rate than control colonies under optimal conditions for growth, but they continued to grow at later stages, forming multilayered colonies under conditions that inhibited the further growth of the control colonies. The results suggest that prolonged incubation of NIH 3T3 cells in the stationary state results in growth-impairing deletions over a wide range of sites in the genome, but more restricted subsets of such lesions are responsible for neoplastic transformation. These findings

  7. Cells transformed with a ts viral src mutant are temperature sensitive for in vivo growth.

    PubMed Central

    Chambers, A F; Wilson, S

    1985-01-01

    Studies on ts mutants of avian sarcoma viruses have previously implicated the src gene product (pp60src) kinase function in in vitro transformation. The role of src in vivo, however, has not been clearly defined. Using a sensitive and quantitative assay that was developed in chicken embryos (Chambers et al., Cancer Res. 42:4018-4025, 1982), we tested the in vivo tumorigenic properties of cells transformed with LA23, an avian sarcoma virus that is temperature sensitive for in vitro transformation. We found that the in vivo growth ability of these cells was temperature sensitive and that this in vivo behavior correlated with the in vitro transformation behavior (growth in soft agar and saturation density). PMID:3921824

  8. Plasma Plume Oscillations Monitoring during Laser Welding of Stainless Steel by Discrete Wavelet Transform Application

    PubMed Central

    Sibillano, Teresa; Ancona, Antonio; Rizzi, Domenico; Lupo, Valentina; Tricarico, Luigi; Lugarà, Pietro Mario

    2010-01-01

    The plasma optical radiation emitted during CO2 laser welding of stainless steel samples has been detected with a Si-PIN photodiode and analyzed under different process conditions. The discrete wavelet transform (DWT) has been used to decompose the optical signal into various discrete series of sequences over different frequency bands. The results show that changes of the process settings may yield different signal features in the range of frequencies between 200 Hz and 30 kHz. Potential applications of this method to monitor in real time the laser welding processes are also discussed. PMID:22319311

  9. Data on combination effect of PEG-coated gold nanoparticles and non-thermal plasma inhibit growth of solid tumors.

    PubMed

    Kaushik, Nagendra Kumar; Kaushik, Neha; Yoo, Ki Chun; Uddin, Nizam; Kim, Ju Sung; Lee, Su Jae; Choi, Eun Ha

    2016-12-01

    Highly resistant tumor cells are hard to treat at low doses of plasma. Therefore, researchers have gained more attention to development of enhancers for plasma therapy. Some enhancers could improve the efficacy of plasma towards selectivity of cancer cells damage. In this dataset, we report the application of low doses of PEG-coated gold nanoparticles with addition of plasma treatment. This data consists of the effect of PEG-coated GNP and cold plasma on two solid tumor cell lines T98G glioblastoma and A549 lung adenocarcinoma. Cell proliferation, frequency of cancer stem cell population studies by this co-treatment was reported. Finally, we included in this dataset the effect of co-treatment in vivo, using tumor xenograft nude mice models. The data supplied in this article supports the accompanying publication "Low doses of PEG-coated gold nanoparticles sensitize solid tumors to cold plasma by blocking the PI3K/AKT-driven signaling axis to suppress cellular transformation by inhibiting growth and EMT" (N. K. Kaushik, N. Kaushik, K. C. Yoo, N Uddin, J. S. Kim, S. J. Lee et al., 2016) [1]. PMID:27668278

  10. The growth and transformation of American ego psychology.

    PubMed

    Wallerstein, Robert S

    2002-01-01

    The roots of ego psychology trace back to Sigmund Freud's The Ego and the Id (1923) and "Inhibitions, Symptoms and Anxiety" (1926), works followed by two additional fundaments, Anna Freud's The Ego and the Mechanisms of Defense (1936) and Heinz Hartmann's Ego Psychology and the Problem of Adaptation (1939). It was brought to full flowering in post-World War II America by Hartmann and his many collaborators, and for over two decades it maintained a monolithic hegemony over American psychoanalysis. Within this framework the conceptions of the psychoanalytic psychotherapies evolved as specific modifications of psychoanalytic technique directed to the clinical needs of the spectrum of patients not amenable to psychoanalysis proper. This American consensus on the ego psychology paradigm and its array of technical implementations fragmented several decades ago, with the rise in America of Kohut's self psychology, geared to the narcissistic disorders, and with the importation from Britain of neo-Kleinian and object-relational perspectives, all coinciding with the rapid growth of the varieties of relational psychoanalysis, with its shift in focus to the two-person, interactive, and co-constructed transference-countertransference matrix. Implications of this intermingled theoretical pluralism (as contrasted with the unity of the once dominant ego psychology paradigm) for the evolution of the American ego psychology are spelled out.

  11. Increases in plasma sheet temperature with solar wind driving during substorm growth phases

    PubMed Central

    Forsyth, C; Watt, C E J; Rae, I J; Fazakerley, A N; Kalmoni, N M E; Freeman, M P; Boakes, P D; Nakamura, R; Dandouras, I; Kistler, L M; Jackman, C M; Coxon, J C; Carr, C M

    2014-01-01

    During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase. PMID:26074645

  12. Increases in plasma sheet temperature with solar wind driving during substorm growth phases

    NASA Astrophysics Data System (ADS)

    Forsyth, C.; Watt, C. E. J.; Rae, I. J.; Fazakerley, A. N.; Kalmoni, N. M. E.; Freeman, M. P.; Boakes, P. D.; Nakamura, R.; Dandouras, I.; Kistler, L. M.; Jackman, C. M.; Coxon, J. C.; Carr, C. M.

    2014-12-01

    During substorm growth phases, magnetic reconnection at the magnetopause extracts ~1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.

  13. Platelet-rich plasma preparation for regenerative medicine: optimization and quantification of cytokines and growth factors

    PubMed Central

    2013-01-01

    Introduction Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed. Methods PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure. Results Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 106 to 1.9 × 106 platelets/μl). Platelets were highly purified, because only <0.3% from the initial red blood cells and leukocytes was present in the final PRP preparation. We also quantified growth factors, cytokines and chemokines secreted by the concentrated platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation

  14. The sublimation growth of AlN fibers: transformations in morphology & fiber direction

    NASA Astrophysics Data System (ADS)

    Bao, H. Q.; Chen, X. L.; Li, H.; Wang, G.; Song, B.; Wang, W. J.

    2009-01-01

    The growth of AlN fibers using sublimation method was investigated in the temperature range from 1600 °C to 2000 °C. Large-scale AlN fibers are obtained with diameters from 100 nm to 50 μm and lengths up to several millimeters. The fiber morphology and growth direction are characterized by X-ray diffraction (XRD), field emission scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman scattering. The fibers change from wire-like to prism-like in morphology and increase in diameter as rising temperatures, accompanying a transformation in axial direction from [10 bar{1}0 ] to [0001]. The transformation in the growth direction is discussed in terms of AlN structure and supersaturation of AlN gas species. These results provide useful information for controlling the growth of large-scale AlN fibers.

  15. Time-dependent release of growth factors from implant surfaces treated with plasma rich in growth factors.

    PubMed

    Sánchez-Ilárduya, María Belén; Trouche, Elodie; Tejero, Ricardo; Orive, Gorka; Reviakine, Ilya; Anitua, Eduardo

    2013-05-01

    Plasma rich in growth factors (PRGFs) technology is an autologous platelet-rich plasma approach that provides a pool of growth factors and cytokines that have been shown to increase tissue regeneration and accelerate dental implant osseointegration. In this framework, the spatiotemporal release of growth factors and the establishment of a provisional fibrin matrix are likely to be key aspects governing the stimulation of the early phases of tissue regeneration around implants. We investigated the kinetics of growth factor release at implant surfaces functionalized either with PRGFs or platelet-poor plasma and correlated the results obtained with the morphology of the resulting interfaces. Our main finding is that activation and clot formation favors longer residence times of the growth factors at the interfaces studied, probably due to their retention in the adsorbed fibrin matrix. The concentration of the platelet-derived growth factors above the interfaces becomes negligible after 2-4 days and is significantly higher in the case of activated interfaces than in the case of nonactivated ones, whereas that of the plasmatic hepatocyte growth factor is independent of platelet concentration and activation, and remains significant for up to 9 days. Platelet-rich plasma preparations should be activated to permit growth factor release and thereby facilitate implant surface osseointegration.

  16. Platelet and growth factor concentrations in activated platelet-rich plasma: a comparison of seven commercial separation systems.

    PubMed

    Kushida, Satoshi; Kakudo, Natsuko; Morimoto, Naoki; Hara, Tomoya; Ogawa, Takeshi; Mitsui, Toshihito; Kusumoto, Kenji

    2014-06-01

    Platelet-rich plasma (PRP) is blood plasma that has been enriched with platelets. It holds promise for clinical use in areas such as wound healing and regenerative medicine, including bone regeneration. This study characterized the composition of PRP produced by seven commercially available separation systems (JP200, GLO PRP, Magellan Autologous Platelet Separator System, KYOCERA Medical PRP Kit, SELPHYL, MyCells, and Dr. Shin's System THROMBO KIT) to evaluate the platelet, white blood cell, red blood cell, and growth factor concentrations, as well as platelet-derived growth factor-AB (PDGF-AB), transforming growth factor beta-1 (TGF-β1), and vascular endothelial growth factor (VEGF) concentrations. PRP prepared using the Magellan Autologous Platelet Separator System and the KYOCERA Medical PRP Kit contained the highest platelet concentrations. The mean PDGF-AB concentration of activated PRP was the highest from JP200, followed by the KYOCERA Medical PRP Kit, Magellan Autologous Platelet Separator System, MyCells, and GLO PRP. TGF-β1 and VEGF concentrations varied greatly among individual samples, and there was almost no significant difference among the different systems, unlike for PDGF. The SELPHYL system produced PRP with low concentrations of both platelets and growth factors. Commercial PRP separation systems vary widely, and familiarity with their individual advantages is important to extend their clinical application to a wide variety of conditions.

  17. The evolution of carbon nanotubes during their growth by plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Wang, Hengzhi; Ren, Z. F.

    2011-10-01

    During the growth of carbon nanotubes (CNTs) by plasma enhanced chemical vapor deposition (PECVD), plasma etching is the crucial factor that determines the growth mode and alignment of the CNTs. Focusing on a thin catalyst coating (Ni = 5 nm), this study finds that the CNT growth by PECVD goes through three stages from randomly entangled (I-CNTs) to partially aligned (II-CNTs) to fully aligned (III-CNTs). The I-CNTs and II-CNTs are mostly etched away by the plasma as time goes by ending up with III-CNTs as the only product when growth time is long enough. However, with a thickness of the catalyst coating of 10 nm or more, neither I-CNTs nor II-CNTs are produced, but III-CNTs are the only type of CNTs grown during the whole growth process. During the growth of III-CNTs, the catalyst particles (Ni) stay on the tips of each of the aligned CNTs and act as a 'safety helmet' to protect the CNTs from plasma ion bombardment. On the other hand, it is also the plasma that limits the growth of III-CNTs, since the plasma eventually etches all the catalytic particles out and stops the growth.

  18. The evolution of carbon nanotubes during their growth by plasma enhanced chemical vapor deposition.

    PubMed

    Wang, Hengzhi; Ren, Z F

    2011-10-01

    During the growth of carbon nanotubes (CNTs) by plasma enhanced chemical vapor deposition (PECVD), plasma etching is the crucial factor that determines the growth mode and alignment of the CNTs. Focusing on a thin catalyst coating (Ni = 5 nm), this study finds that the CNT growth by PECVD goes through three stages from randomly entangled (I-CNTs) to partially aligned (II-CNTs) to fully aligned (III-CNTs). The I-CNTs and II-CNTs are mostly etched away by the plasma as time goes by ending up with III-CNTs as the only product when growth time is long enough. However, with a thickness of the catalyst coating of 10 nm or more, neither I-CNTs nor II-CNTs are produced, but III-CNTs are the only type of CNTs grown during the whole growth process. During the growth of III-CNTs, the catalyst particles (Ni) stay on the tips of each of the aligned CNTs and act as a 'safety helmet' to protect the CNTs from plasma ion bombardment. On the other hand, it is also the plasma that limits the growth of III-CNTs, since the plasma eventually etches all the catalytic particles out and stops the growth. PMID:21911923

  19. Temperature dependence of inductively coupled plasma assisted growth of TiN thin films.

    SciTech Connect

    Meng, W. J.; Curtis, T. J.; Rehn, L. E.; Baldo, P. M.; Materials Science Division; Louisiana State Univ.

    1999-11-01

    The use of low pressure high density plasmas to assist the synthesis of ceramic thin film materials is in its infancy. Using an inductively coupled plasma assisted magnetron sputtering system, we examine the dependence of plasma-assisted growth of TiN thin films on growth temperature at different ratios of ion flux to neutral atom flux. Our results indicate that a temperature independent densification of TiN films occurs above a certain ion to neutral atom flux ratio. As an example of this temperature independent densification, we demonstrate the formation of dense B1 TiN crystalline thin films at growth temperatures down to {approx}100 K.

  20. Effect of plasma rich in growth factors on alveolar osteitis

    PubMed Central

    Haraji, Afshin; Lassemi, Eshagh; Motamedi, Mohammad Hosein Kalantar; Alavi, Maryam; Adibnejad, Saman

    2012-01-01

    Introduction: The high prevalence of dry socket or alveolar osteitis (AO) is of concern in surgical removal of third molars. The aim of the present study was to assess the preventive effect of plasma rich in growth factors (PRGF) on AO and also its effect on pain management and healing acceleration in third molar extraction sockets of high-risk patients. Materials and Methods: This split-mouth, double-blind clinical trial included 40 bilateral third molar extractions (80 sockets) with at least one identified risk factor for AO. PRGF was obtained from patient's own blood, based on manufacturer's instruction, and blindly placed in one of the two bilateral sockets (PRGF group; n = 20) of each patient. The contralateral socket was treated with a placebo (control group; n = 20). Samples were evaluated for AO and pain incidence on days 2, 3 and 4 and healing and infection on days 3 and 7. Data were analyzed in SPSS v16 using Wilcoxon test. Results: There was a significant difference in dry socket and pain incidence and healing rate between the two groups. Intensity of pain and occurrence of dry socket in the study group was lower than the controls. Also the healing rate was higher (P < 0.05) for the PRGF group. No sign of infection was seen in either group. Conclusion: The application of PRGF may significantly reduce the incidence of AO or its associated pain and may accelerate healing. The prophylactic use of PRGF following third molar extraction may be suggested especially in the patients at risk of AO. PMID:23251056

  1. Stable Glass Transformation to Supercooled Liquid via Surface-Initiated Growth Front

    SciTech Connect

    Swallen, Stephen F.; Traynor, Katherine; McMahon, Robert J.; Ediger, M. D.; Mates, Thomas E.

    2009-02-13

    Highly stable glasses of tris-naphthylbenzene transform into a liquid when annealed above the glass transition temperature T{sub g}. In contrast to the predictions of standard models, the observed transformation is spatially inhomogeneous. Secondary ion mass spectrometry experiments on isotopically labeled multilayer films show that the liquid grows into the stable glass with sharp growth fronts initiated at the free surface and at the interface with the substrate. For the free surface, the growth velocity is constant in time and has the same temperature dependence as self-diffusion in the equilibrium supercooled liquid. These stable glasses are packed so efficiently that surfaces and interfaces are required to initiate the transformation to the liquid even well above T{sub g}.

  2. Modeling plasma-assisted growth of graphene-carbon nanotube hybrid

    NASA Astrophysics Data System (ADS)

    Tewari, Aarti

    2016-08-01

    A theoretical model describing the growth of graphene-CNT hybrid in a plasma medium is presented. Using the model, the growth of carbon nanotube (CNT) on a catalyst particle and thereafter the growth of the graphene on the CNT is studied under the purview of plasma sheath and number density kinetics of different plasma species. It is found that the plasma parameter such as ion density; gas ratios and process parameter such as source power affect the CNT and graphene dimensions. The variation in growth rates of graphene and CNT under different plasma power, gas ratios, and ion densities is analyzed. Based on the results obtained, it can be concluded that higher hydrocarbon ion densities and gas ratios of hydrocarbon to hydrogen favor the growth of taller CNTs and graphene, respectively. In addition, the CNT tip radius reduces with hydrogen ion density and higher plasma power favors graphene with lesser thickness. The present study can help in better understanding of the graphene-CNT hybrid growth in a plasma medium.

  3. Changes in plasma growth hormone (GH) and secretion patterns of GH and luteinizing hormone in buffaloes (Bubalus bubalis) during growth.

    PubMed

    Mondal, Mohan; Prakash, B S

    2004-08-01

    To assess the changes of plasma growth hormone (GH) and secretion patterns of GH and luteinizing hormone (LH) during growth in buffaloes, six growing female Murrah buffalo calves (mean age 6+/-0.9 months and body weight 66+/-6 kg) were selected. Plasma samples were collected twice a week for 52 weeks for GH and LH assay. To examine for pulsatile secretion samples were collected at 15 minutes interval for 9 hr at weeks 6 and 42 for GH and LH measurements. Plasma progesterone was also estimated in twice-a-week samples to assess whether any of the buffalo had begun ovarian cyclicity. The body weight of all animals was recorded at weekly interval. Plasma GH concentration decreased (P < 0.01) only up to week 29 and showed an increasing trend (P < 0.01) thereafter. The ratio of plasma GH to body weight declined (P < 0.01) throughout the entire experimental period. Plasma GH showed a declining trend only up to when the animals attained 155 kg body weight and thereafter showed an increasing trend (P < 0.01). Plasma GH revealed distinct pulsatile patterns of release, with a mean of 6 and 5 pulses in the 6-week and 42-week samples, respectively. The plasma LH concentrations around the 42-week time period were significantly higher (P < 0.01) than at the 6-week time period, and they exhibited pulsatility. No animal reached puberty until the end of the experiment. In summary, plasma GH levels have a definite pattern of change during growth and patterns of secretion of plasma GH and LH also have a relation with body weight in this species of animal. PMID:15554346

  4. Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

    SciTech Connect

    Demaurex, Bénédicte; Bartlome, Richard; Seif, Johannes P.; Geissbühler, Jonas; Alexander, Duncan T. L.; Jeangros, Quentin; Ballif, Christophe; De Wolf, Stefaan

    2014-08-05

    Low-temperature (≤ 180 °C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-ehanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems not only from the growth conditions but also from unintentional contamination of the reactor. As a result of our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.

  5. Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

    SciTech Connect

    Demaurex, Bénédicte Bartlome, Richard; Seif, Johannes P.; Geissbühler, Jonas; Ballif, Christophe; De Wolf, Stefaan; Alexander, Duncan T. L.; Jeangros, Quentin

    2014-08-07

    Low-temperature (≤200 °C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-enhanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems not only from the growth conditions but also from unintentional contamination of the reactor. Based on our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.

  6. Divergent effects of epidermal growth factor and transforming growth factors on a human endometrial carcinoma cell line.

    PubMed

    Korc, M; Haussler, C A; Trookman, N S

    1987-09-15

    Epidermal growth factor (EGF), at concentrations ranging from 0.83 to 4.98 nM, markedly inhibited the proliferation of RL95-2 cells that were seeded at low plating densities (4.7 X 10(3) cells/cm2). Under the same incubation conditions, 16.6 pM EGF enhanced cell proliferation. At high plating densities (2.5 X 10(4) cells/cm2) 0.83 nM EGF also stimulated cell proliferation. Both the inhibitory and stimulatory effects of EGF were mimicked by transforming growth factor-alpha (TGF-alpha). However, the inhibitory action of TGF-alpha was always greater that of EGF. Binding studies with 125I-labeled TGF-alpha indicated that maximal cell surface binding of TGF-alpha occurred at 15 min, whereas maximal internalization occurred at 45 min. Both cell surface and internalized radioactivity declined sharply thereafter. Analysis of radioactivity released into the incubation medium during pulse-chase experiments indicated that RL95-2 cells extensively degraded both TGF-alpha and EGF. The lysosomotropic compound methylamine arrested the generation of low-molecular-weight degradation products of EGF, but not of TGF-alpha. In contrast to EGF and TGF-alpha, transforming growth factor-beta (TGF-beta) inhibited the proliferation of RL95-2 cells that were seeded at either low or high plating densities. Further, transforming growth factor-beta induced the appearance of large cuboidal cells that were readily distinguished from cells treated with either EGF or TGF-alpha. These findings point to complex regulatory actions of growth factors on the proliferation of RL95-2 cells and suggest that the processing of TGF-alpha following EGF receptor activation is distinct from the processing of EGF. PMID:3497713

  7. A novel collagen/platelet-rich plasma (COL/PRP) scaffold: preparation and growth factor release analysis.

    PubMed

    Zhang, Xiujie; Wang, Jingwei; Ren, Mingguang; Li, Lifeng; Wang, Qingwen; Hou, Xiaohua

    2016-06-01

    Platelet-rich plasma (PRP) has been widely used in clinical practice for more than 20 years because it causes the release of many growth factors. However, the burst release pattern and short release period of PRP have become obstacles to its application. An optimal controllable release system is an urgent need for researchers. This study investigated whether collagen/PRP (COL/PRP) scaffolds can serve as a vehicle for the controllable release of growth factors. We fabricated a novel scaffold that integrates PRP activated by thrombin or collagen into type I collagen. The mechanical properties, cytotoxicity, and transforming growth factor β1 (TGF-β1), platelet derived growth factor (PDGF), fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) content were evaluated. Our results demonstrate that the COL/PRP scaffolds were not cytotoxic to L-929 fibroblasts. The PDGF and FGF content in the thrombin group was at a higher level and lasted for a long period of time. Collagen and thrombin played the same role in the release of TGF-β1 and VEGF. These data suggest that the novel COL/PRP scaffolds provide a carrier for the controllable release of growth factors and may be used in tissue- regenerative therapies.

  8. Insights into gold-catalyzed plasma-assisted CVD growth of silicon nanowires

    NASA Astrophysics Data System (ADS)

    Chen, Wanghua; Roca i Cabarrocas, Pere

    2016-07-01

    Understanding and controlling effectively the behavior of metal catalyst droplets during the Vapor-Liquid-Solid growth of nanowires are crucial for their applications. In this work, silicon nanowires are produced by plasma-assisted Chemical Vapor Deposition using gold as a catalyst. The influence of hydrogen plasma on nanowire growth is investigated experimentally and theoretically. Interestingly, in contrast to conventional chemical vapor deposition, the growth rate of silicon nanowires shows a decrease as a function of their diameters, which is consistent with the incorporation of silicon via sidewall diffusion. We show that Ostwald ripening of catalyst droplets during nanowire growth is inhibited in the presence of a hydrogen plasma. However, when the plasma is off, the diffusion of Au atoms on the nanowire sidewall can take place. Based on this observation, we have developed a convenient method to grow silicon nanotrees.

  9. Plasma membrane proteomics in the maize primary root growth zone: novel insights into root growth adaptation to water stress.

    PubMed

    Voothuluru, Priyamvada; Anderson, Jeffrey C; Sharp, Robert E; Peck, Scott C

    2016-09-01

    Previous work on maize (Zea mays L.) primary root growth under water stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. These responses involve spatially differential and coordinated regulation of osmotic adjustment, modification of cell wall extensibility, and other cellular growth processes that are required for root growth under water-stressed conditions. As the interface between the cytoplasm and the apoplast (including the cell wall), the plasma membrane likely plays critical roles in these responses. Using a simplified method for enrichment of plasma membrane proteins, the developmental distribution of plasma membrane proteins was analysed in the growth zone of well-watered and water-stressed maize primary roots. The results identified 432 proteins with differential abundances in well-watered and water-stressed roots. The majority of changes involved region-specific patterns of response, and the identities of the water stress-responsive proteins suggest involvement in diverse biological processes including modification of sugar and nutrient transport, ion homeostasis, lipid metabolism, and cell wall composition. Integration of the distinct, region-specific plasma membrane protein abundance patterns with results from previous physiological, transcriptomic and cell wall proteomic studies reveals novel insights into root growth adaptation to water stress.

  10. Plasma membrane proteomics in the maize primary root growth zone: novel insights into root growth adaptation to water stress.

    PubMed

    Voothuluru, Priyamvada; Anderson, Jeffrey C; Sharp, Robert E; Peck, Scott C

    2016-09-01

    Previous work on maize (Zea mays L.) primary root growth under water stress showed that cell elongation is maintained in the apical region of the growth zone but progressively inhibited further from the apex. These responses involve spatially differential and coordinated regulation of osmotic adjustment, modification of cell wall extensibility, and other cellular growth processes that are required for root growth under water-stressed conditions. As the interface between the cytoplasm and the apoplast (including the cell wall), the plasma membrane likely plays critical roles in these responses. Using a simplified method for enrichment of plasma membrane proteins, the developmental distribution of plasma membrane proteins was analysed in the growth zone of well-watered and water-stressed maize primary roots. The results identified 432 proteins with differential abundances in well-watered and water-stressed roots. The majority of changes involved region-specific patterns of response, and the identities of the water stress-responsive proteins suggest involvement in diverse biological processes including modification of sugar and nutrient transport, ion homeostasis, lipid metabolism, and cell wall composition. Integration of the distinct, region-specific plasma membrane protein abundance patterns with results from previous physiological, transcriptomic and cell wall proteomic studies reveals novel insights into root growth adaptation to water stress. PMID:27341663

  11. Time-frequency analysis of non-stationary fusion plasma signals using an improved Hilbert-Huang transform

    SciTech Connect

    Liu, Yangqing Tan, Yi; Xie, Huiqiao; Wang, Wenhao; Gao, Zhe

    2014-07-15

    An improved Hilbert-Huang transform method is developed to the time-frequency analysis of non-stationary signals in tokamak plasmas. Maximal overlap discrete wavelet packet transform rather than wavelet packet transform is proposed as a preprocessor to decompose a signal into various narrow-band components. Then, a correlation coefficient based selection method is utilized to eliminate the irrelevant intrinsic mode functions obtained from empirical mode decomposition of those narrow-band components. Subsequently, a time varying vector autoregressive moving average model instead of Hilbert spectral analysis is performed to compute the Hilbert spectrum, i.e., a three-dimensional time-frequency distribution of the signal. The feasibility and effectiveness of the improved Hilbert-Huang transform method is demonstrated by analyzing a non-stationary simulated signal and actual experimental signals in fusion plasmas.

  12. Time-frequency analysis of non-stationary fusion plasma signals using an improved Hilbert-Huang transform

    NASA Astrophysics Data System (ADS)

    Liu, Yangqing; Tan, Yi; Xie, Huiqiao; Wang, Wenhao; Gao, Zhe

    2014-07-01

    An improved Hilbert-Huang transform method is developed to the time-frequency analysis of non-stationary signals in tokamak plasmas. Maximal overlap discrete wavelet packet transform rather than wavelet packet transform is proposed as a preprocessor to decompose a signal into various narrow-band components. Then, a correlation coefficient based selection method is utilized to eliminate the irrelevant intrinsic mode functions obtained from empirical mode decomposition of those narrow-band components. Subsequently, a time varying vector autoregressive moving average model instead of Hilbert spectral analysis is performed to compute the Hilbert spectrum, i.e., a three-dimensional time-frequency distribution of the signal. The feasibility and effectiveness of the improved Hilbert-Huang transform method is demonstrated by analyzing a non-stationary simulated signal and actual experimental signals in fusion plasmas.

  13. x-ray irradiation analysis based on wavelet transform in tokamak plasma.

    PubMed

    Ghanbari, K; Ghoranneviss, M; Elahi, A Salar; Saviz, S

    2014-01-01

    Hard x-ray emission from the Runaway electrons is an important issue in tokamaks. Suggesting methods to reduce the Runaway electrons and therefore the emitted hard x-ray is important for tokamak plasma operation. In this manuscript, we have investigated the effects of external fields on hard x-ray intensity and Magneto-Hydro-Dynamic (MHD) activity. In other words, we have presented the effects of positive biased limiter and Resonant Helical Field (RHF) on the MHD fluctuations and hard x-ray emission from the Runaway electrons. MHD activity and hard x-ray intensity were analyzed using Wavelet transform in the presence of external fields and without them. The results show that the MHD activity and therefore the hard x-ray intensity can be controlled by the external electric and magnetic fields.

  14. TRANSFORMATION

    SciTech Connect

    LACKS,S.A.

    2003-10-09

    Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

  15. The effects of plasma diffusion and viscosity on turbulent instability growth

    SciTech Connect

    Haines, Brian M. Vold, Erik L.; Molvig, Kim; Aldrich, Charles; Rauenzahn, Rick

    2014-09-15

    We perform two-dimensional simulations of strongly–driven compressible Rayleigh–Taylor and Kelvin–Helmholtz instabilities with and without plasma transport phenomena, modeling plasma species diffusion, and plasma viscosity in order to determine their effects on the growth of the hydrodynamic instabilities. Simulations are performed in hydrodynamically similar boxes of varying sizes, ranging from 1 μm to 1 cm in order to determine the scale at which plasma effects become important. Our results suggest that these plasma effects become noticeable when the box size is approximately 100 μm, they become significant in the 10 μm box, and dominate when the box size is 1 μm. Results suggest that plasma transport may be important at scales and conditions relevant to inertial confinement fusion, and that a plasma fluid model is capable of representing some of the kinetic transport effects.

  16. Graphene growth by a metal-catalyzed solid-state transformation of amorphous carbon.

    PubMed

    Rodríguez-Manzo, Julio A; Pham-Huu, Cuong; Banhart, Florian

    2011-02-22

    Single and few-layer graphene is grown by a solid-state transformation of amorphous carbon on a catalytically active metal. The process is carried out and monitored in situ in an electron microscope. It is observed that an amorphous carbon film is taken up by Fe, Co, or Ni crystals at temperatures above 600 °C. The nucleation and growth of graphene layers on the metal surfaces happen after the amorphous carbon film has been dissolved. It is shown that the transformation of the energetically less favorable amorphous carbon to the more favorable phase of graphene occurs by diffusion of carbon atoms through the catalytically active metal.

  17. Handling Arabidopsis plants: growth, preservation of seeds, transformation, and genetic crosses.

    PubMed

    Rivero, Luz; Scholl, Randy; Holomuzki, Nicholas; Crist, Deborah; Grotewold, Erich; Brkljacic, Jelena

    2014-01-01

    Growing healthy plants is essential for the advancement of Arabidopsis thaliana (Arabidopsis) research. Over the last 20 years, the Arabidopsis Biological Resource Center (ABRC) has collected and developed a series of best-practice protocols, some of which are presented in this chapter. Arabidopsis can be grown in a variety of locations, growth media, and environmental conditions. Most laboratory accessions and their mutant or transgenic derivatives flower after 4-5 weeks and set seeds after 7-8 weeks, under standard growth conditions (soil, long day, 23 ºC). Some mutant genotypes, natural accessions, and Arabidopsis relatives require strict control of growth conditions best provided by growth rooms, chambers, or incubators. Other lines can be grown in less-controlled greenhouse settings. Although the majority of lines can be grown in soil, certain experimental purposes require utilization of sterile solid or liquid growth media. These include the selection of primary transformants, identification of homozygous lethal individuals in a segregating population, or bulking of a large amount of plant material. The importance of controlling, observing, and recording growth conditions is emphasized and appropriate equipment required to perform monitoring of these conditions is listed. Proper conditions for seed harvesting and preservation, as well as seed quality control, are also described. Plant transformation and genetic crosses, two of the methods that revolutionized Arabidopsis genetics, are introduced as well.

  18. Regulation of H-Ras-driven MAPK signaling, transformation and tumorigenesis, but not PI3K signaling and tumor progression, by plasma membrane microdomains.

    PubMed

    Michael, J V; Wurtzel, J G T; Goldfinger, L E

    2016-05-30

    In this study, we assessed the contributions of plasma membrane (PM) microdomain targeting to the functions of H-Ras and R-Ras. These paralogs have identical effector-binding regions, but variant C-terminal targeting domains (tDs) which are responsible for lateral microdomain distribution: activated H-Ras targets to lipid ordered/disordered (Lo/Ld) domain borders, and R-Ras to Lo domains (rafts). We hypothesized that PM distribution regulates Ras-effector interactions and downstream signaling. We used tD swap mutants, and assessed effects on signal transduction, cell proliferation, transformation and tumorigenesis. R-Ras harboring the H-Ras tD (R-Ras-tH) interacted with Raf, and induced Raf and ERK phosphorylation similar to H-Ras. R-Ras-tH stimulated proliferation and transformation in vitro, and these effects were blocked by both MEK and PI3K inhibition. Conversely, the R-Ras tD suppressed H-Ras-mediated Raf activation and ERK phosphorylation, proliferation and transformation. Thus, Ras access to Raf at the PM is sufficient for MAPK activation and is a principal component of Ras mitogenesis and transformation. Fusion of the R-Ras extended N-terminal domain to H-Ras had no effect on proliferation, but inhibited transformation and tumor progression, indicating that the R-Ras N-terminus also contributes negative regulation to these Ras functions. PI3K activation was tD independent; however, H-Ras was a stronger activator of PI3K than R-Ras, with either tD. PI3K inhibition nearly ablated transformation by R-Ras-tH, H-Ras and H-Ras-tR, whereas MEK inhibition had a modest effect on Ras-tH-driven transformation but no effect on H-Ras-tR transformation. R-Ras-tH supported tumor initiation, but not tumor progression. While H-Ras-tR-induced transformation was reduced relative to H-Ras, tumor progression was robust and similar to H-Ras. H-Ras tumor growth was moderately suppressed by MEK inhibition, which had no effect on H-Ras-tR tumor growth. In contrast, PI3K inhibition

  19. Studies on the bioassayable growth hormone-like activity of plasma

    NASA Technical Reports Server (NTRS)

    Ellis, S.; Vodian, M. A.; Grindeland, R. E.

    1978-01-01

    Evidence supporting the existence of bioassayable growth hormone-like activity in blood plasma distinct from the growth hormone measurable by radioimmunoassay and from somatomedin is presented. Tibial assays of the growth-hormone-like activity of injected, concentrated normal human and rat plasma in hypophysectomized rats reveal 200- and 50-fold activity excesses, respectively, with respect to the amount of growth hormone detected by radioimmunoassay. The origin of this bioassayable plasma hormone has been localized to the region of the pituitary, the origin of growth hormone, a distribution not followed by somatomedin C. Purification of the bioassayable agent indicates that is has a molecular weight of between 60,000 and 80,000, in contrast to that of growth hormone (20,000), and that the bioassayable activity is distinct from that of somatomedin C. Growth hormone-like activity detected in Cohn fraction IV as well as plasma activity, are found to be collectable on Dowex 50 resin, in contrast to somatomedin C and nonsuppressible insulin-like activity. The formation of bioassayable growth hormone-activity agents from radioimmunoassayable growth hormone and directly in the pituitary is suggested.

  20. TRANSFORMER

    DOEpatents

    Baker, W.R.

    1959-08-25

    Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

  1. Clinical and prognostic significance of serum transforming growth factor-beta1 levels in patients with pancreatic ductal adenocarcinoma

    PubMed Central

    Zhao, J.; Liang, Y.; Yin, Q.; Liu, S.; Wang, Q.; Tang, Y.; Cao, C.

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) has a poor 5-year survival rate of 5%. Biomarkers for the early detection of pancreatic cancer are urgently needed. Transforming growth factor-beta1 (TGF-β1) is elevated in the tissues and plasma of patients with PDAC. However, no studies systemically report prognostic significance of plasma TGF-β1 levels in PDAC. In the present study, we assessed the prognostic significance of serum TGF-β levels in patients with PDAC. TGF-β levels were determined in serum from 146 PDAC patients, and 58 patients with benign pancreatic conditions. Regression models were used to correlate TGF-β levels to gender, age, stage, class, and metastasis. Survival analyses were performed using multivariate Cox models. Serum levels of TGF-β1 distinguished PDAC from benign pancreatic conditions (P<0.001) and healthy control subjects (P<0.001). Serum levels of TGF-β also distinguished tumor stage (P=0.002) and lymph node metastasis (P=0.001). High serum levels of TGF-β1 were significantly correlated with reduced patient survival. Multivariate analysis revealed that TGF-β1, lymph node metastasis and tumor stage were independent factors for PDAC survival. Our results indicate that serum TGF-β1 may be used as a potential prognostic marker for PDAC. PMID:27464025

  2. Sustained activation of fibroblast transforming growth factor-beta/Smad signaling in a murine model of scleroderma.

    PubMed

    Takagawa, Shinsuke; Lakos, Gabriella; Mori, Yasuji; Yamamoto, Toshiyuki; Nishioka, Kiyoshi; Varga, John

    2003-07-01

    Transforming growth factor-beta is responsible for triggering a cascade of events leading to fibrosis in scleroderma. The Smads are intracellular signal transducers recently shown to mediate fibroblast activation and other profibrotic responses elicited by transforming growth factor-betain vitro. To understand better the involvement of Smads in the pathogenesis of fibrosis, we examined Smad expression and activation in situ in a murine model of scleroderma. Bleomycin injections induced striking dermal infiltration with macrophages by 3 d, and progressive fibrosis by 2 wk. Infiltrating macrophages and resident fibroblasts expressed Smad3, the positive mediator for transforming growth factor-beta responses. Importantly, in bleomycin-injected skin, fibroblasts showed predominantly nuclear localization of Smad3 and intense staining for phospho-Smad2/3. Furthermore, phosphorylated Smad2/3 in fibroblasts was detected even after the resolution of inflammation. Expression of Smad7, the endogenous inhibitor of transforming growth factor-beta/Smad signaling, was strongly induced in dermal cells by transforming growth factor-beta, but not by bleomycin injections. Collectively, these results indicate that bleomycin-induced murine scleroderma is associated with rapid and sustained induction of transforming growth factor-beta/Smad signaling in resident dermal fibroblasts. Despite apparent activation of the intracellular transforming growth factor-beta signaling pathway in the lesional dermis, the expression of transforming growth factor-beta-inducible Smad7 was not upregulated. In light of the critical function of Smad7 as an endogenous inhibitor of Smad signaling that restricts the duration and magnitude of transforming growth factor-beta responses, and as a mediator of apoptosis, relative Smad7 deficiency observed in the present studies may account for sustained activation of transforming growth factor-beta/Smad signaling in lesional tissues. These findings raise the

  3. New diagnostic method for monitoring plasma reactor walls: Multiple total internal reflection Fourier transform infrared surface probe

    NASA Astrophysics Data System (ADS)

    Godfrey, Anna R.; Ullal, Saurabh J.; Braly, Linda B.; Edelberg, Erik A.; Vahedi, Vahid; Aydil, Eray S.

    2001-08-01

    Films and adsorbates that deposit on reactor walls during plasma etching and deposition affect the discharge properties such as the charged particle and reactive radical concentrations. A systematic study of this plasma-wall interaction is made difficult by a lack of diagnostic methods that enable one to monitor the chemical nature of the reactor wall surface. A new diagnostic technique based on multiple total internal reflection Fourier transform infrared (MTIR-FTIR) spectroscopy was developed to monitor films and adsorbates on plasma etching and deposition reactor walls with monolayer sensitivity. Applications of this MTIR-FTIR probe are demonstrated. Specifically, we use this probe to (i) detect etch products and films that deposit on the reactor walls during Cl2 plasma etching of Si, (ii) determine the efficacy of a SF6 plasma to clean films deposited on reactor walls during Cl2/O2 etching of Si, and (iii) monitor wafer-to-wafer etching reproducibility.

  4. Increased daylength stimulates plasma growth hormone and gill Na+, K+ and -ATPase Atlantic salmon (Salmo salar )

    USGS Publications Warehouse

    McCormick, S.D.; Bjornsson, Bjorn Thrandur; Sheridan, M.; Eilertson, C.; Carey, J.B.; O'Dea, M.

    1995-01-01

    Atlantic salmon juveniles reared at constant temperature (9–10°C) were exposed to four photoperiod treatment and sampled every 2 weeks from January through May. Fish reared under normal photoperiod exhibited eight-and three fold increases in plasma growth hormone and gill Na+, K+-ATPase activity, respectively, between January and April. Fish exposed to abrupt increases in daylength (LD 15:9) in February or March responded with earlier increases in plasma growth hormone and gill Na+, K+-ATPase activity, and earlier decreases in condition factor relative to fish in the normal photoperiod group. Fish maintained under short daylength (LD 9:15) from January to May exhibited delayed and muted increases in plasma growth hormone and gill Na+, K+-ATPase activity. Plasma thyroxine exhibited a 2.5-fold increase from February to late March in the normal photoperiod group, was generally lower in the LD 9:15 group, but exhibited no obvious response to abrupt increases in daylength. There was an increase in plasma 3,5,3′-triiodo-l-thyronine with time in all groups (43–80%) but no significant response to photoperiod. Plasma levels of somatostatin-25 were highest in the LD 9:15 group, but there was no detectable response to increased daylength in any of the photoperiod treatments. The results indicate that plasma growth hormone is responsive to increased daylength and may be causally related to subsequent increases in gill Na+, K+-ATPase.

  5. [THE ROLE OF TRANSFORMING GROWTH FACTOR-B IN IMMUNOPATHOGENESIS OF DISEASES OF CONNECTIVE TISSUE].

    PubMed

    Rudoi, A S; Moskalev, A V; Sboitchakov, V B

    2016-02-01

    The recent studies of molecular physiology of fibrillin and pathophysiology of inherent disorders of structure and function of connective tissue such as dissection and aneurysm of aorta, myxomatously altered cusps and prolapses of mitral valve, syndrome of hyper-mobility of joints, demonstrated that important role in development of these malformations play alterations of transfer of signals by growth factors and matrix cellular interaction. These conditions under manifesting Marfan's syndrome can be a consequence of anomalies of fibrillin-1 which deficiency unbrakes process of activation of transforming growth factor-β (TGFβ). The involvement of TGFβ in pathogenesis of Marfan's syndrome permits consider antagonists of angiotensin-transforming enzymes as potential pharmaceuticals in therapy of this disease. The article presents analysis of publications' data related to this problem.

  6. Transformation of the Herbicide Sulcotrione into a Root Growth Enhancer Compound by Sequential Photolysis and Hydrolysis.

    PubMed

    Goujon, Eric; Maruel, Sandra; Richard, Claire; Goupil, Pascale; Ledoigt, Gérard

    2016-01-27

    Xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl (1), the main product of sulcotrione phototransformation on plant leaves, was slowly hydrolyzed into 2-hydroxy-4-methylsulfonylbenzoic acid (2) and 1,3-cyclohexanedione (3) in aqueous solution. Interestingly, the rate of hydrolysis was significantly enhanced in the presence of roots of monocotyledonous plants, while the same treatment showed adverse effects on broadleaf weeds. Root growth enhancement varied according to the plant species and concentrations of compound 2, as shown with Zea mays roots. Compound 2 is a derivative of salicylic acid that is known to be a plant signaling messenger. Compound 2 was, therefore, able to mimic some known effects of this phytohormone. This work showed that a pesticide like sulcotrione was transformed into a compound exhibiting a positive impact on plant growth. This study exemplified a rarely reported situation where chemical and biological chain reactions transformed a xenobiotic into a compound exhibiting potential beneficial effects. PMID:26654319

  7. [THE ROLE OF TRANSFORMING GROWTH FACTOR-B IN IMMUNOPATHOGENESIS OF DISEASES OF CONNECTIVE TISSUE].

    PubMed

    Rudoi, A S; Moskalev, A V; Sboitchakov, V B

    2016-02-01

    The recent studies of molecular physiology of fibrillin and pathophysiology of inherent disorders of structure and function of connective tissue such as dissection and aneurysm of aorta, myxomatously altered cusps and prolapses of mitral valve, syndrome of hyper-mobility of joints, demonstrated that important role in development of these malformations play alterations of transfer of signals by growth factors and matrix cellular interaction. These conditions under manifesting Marfan's syndrome can be a consequence of anomalies of fibrillin-1 which deficiency unbrakes process of activation of transforming growth factor-β (TGFβ). The involvement of TGFβ in pathogenesis of Marfan's syndrome permits consider antagonists of angiotensin-transforming enzymes as potential pharmaceuticals in therapy of this disease. The article presents analysis of publications' data related to this problem. PMID:27455564

  8. Mediation of wound-related Rous sarcoma virus tumorigenesis by TFG (transforming growth factor)-. beta

    SciTech Connect

    Sieweke, M.H.; Bissell, M.J. ); Thompson, N.L.; Sporn, M.B. )

    1990-06-29

    In Rous sarcoma virus (RSV)-infected chickens, wounding leads to tumor formation with nearly 100% frequency in tissues that would otherwise remain tumor-free. Identifying molecular mediators of this phenomenon should yield important clues to the mechanisms involved in RSV tumorigenesis. Immunohistochemical staining showed that TGF-{beta} is present locally shortly after wounding, but not in unwounded controls. In addition, subcutaneous administration of recombinant transforming growth factor {beta}1 (TGF-{beta}1) could substitute completely for wounding in tumor induction. A treatment protocol of four doses of 800 nanograms of TGF-{beta} resulted in v-src-expressing tumors with 100% frequency; four doses of only 10 nanograms still led to tumor formation in 80% of the animals. This effect was specific, as other growth factors with suggested roles in would healing did not elicit the same response. Epidermal growth factor (EGF) or TGF-{alpha} had no effect, and platelet-derived growth factor (PDGF) or insulin-like growth factor-1 (IGF-1) yielded only occasional tumors after longer latency. TGF-{beta} release during the would-healing response may thus be a critical event that creates a conducive environment for RSV tumorigenesis and may act as a cofactor for transformation in this system. 31 refs., 3 figs., 2 tabs.

  9. [Effects of nitrogen regulators on fertilizer nitrogen transformation in meadow cinnamon soil and on pakchoi growth].

    PubMed

    Sun, Zhi-Mei; Zhang, Kuo; Liu, Jian-Tao; Si, Huan-Sen; Wang, Yan-Qun

    2012-09-01

    Soil incubation test and pot experiment were conducted to investigate the effects of dicyandiamide (DCD) and its combination with nano-carbon on the transformation of fertilizers (urea and ammonium bicarbonate) nitrogen (N) in meadow cinnamon soil, a typical soil type in North China Plain, and on the growth of pakchoi (Brassica chinensis). In the first two weeks after applying urea and ammonium bicarbonate, the soil NH4+-N and NO3(-)-N contents varied greatly, but little variation was observed since then. The effects of the applied fertilizer N on the pakchoi growth and its N use efficiency differed significantly at early growth stages, but had little difference at harvesting stage. The DCD inhibited the transformation of the fertilizer N (especially ammonium bicarbonate N) into nitrate markedly, and this effect increased with increasing DCD dose. Under the conditions of our experiment, the optimal application rate of DCD was 1.0-1.5% of applied fertilize N, which could increase the pakchoi yield significantly, improve the leaf color, decrease the plant nitrate contents, and increase the fertilizer N use efficiency. The combination of DCD and nano-carbon exerted a synergistic effect on inhibiting soil ammonium oxidation, and also, promoted the pakchoi growth and N utilization at early growth stages significantly and decreased the plant nitrate level at harvesting stage.

  10. [Effects of nitrogen regulators on fertilizer nitrogen transformation in meadow cinnamon soil and on pakchoi growth].

    PubMed

    Sun, Zhi-Mei; Zhang, Kuo; Liu, Jian-Tao; Si, Huan-Sen; Wang, Yan-Qun

    2012-09-01

    Soil incubation test and pot experiment were conducted to investigate the effects of dicyandiamide (DCD) and its combination with nano-carbon on the transformation of fertilizers (urea and ammonium bicarbonate) nitrogen (N) in meadow cinnamon soil, a typical soil type in North China Plain, and on the growth of pakchoi (Brassica chinensis). In the first two weeks after applying urea and ammonium bicarbonate, the soil NH4+-N and NO3(-)-N contents varied greatly, but little variation was observed since then. The effects of the applied fertilizer N on the pakchoi growth and its N use efficiency differed significantly at early growth stages, but had little difference at harvesting stage. The DCD inhibited the transformation of the fertilizer N (especially ammonium bicarbonate N) into nitrate markedly, and this effect increased with increasing DCD dose. Under the conditions of our experiment, the optimal application rate of DCD was 1.0-1.5% of applied fertilize N, which could increase the pakchoi yield significantly, improve the leaf color, decrease the plant nitrate contents, and increase the fertilizer N use efficiency. The combination of DCD and nano-carbon exerted a synergistic effect on inhibiting soil ammonium oxidation, and also, promoted the pakchoi growth and N utilization at early growth stages significantly and decreased the plant nitrate level at harvesting stage. PMID:23286007

  11. Plasma as a tool for growth of 1D and 2D nanomaterials and their conversions

    NASA Astrophysics Data System (ADS)

    Cvelbar, Uros

    2015-09-01

    The growth of 1D and 2D nanostructures in low pressure oxygen plasma is presented with the special stress on metal-oxide nanowires and their deterministic growth mechanisms. Since the resulting nanostructures not always have required properties for applications their modifications are required. Therefore their conversions into different oxides or sulphites/nitrides are required with either molecules, atoms, electrons or photons.

  12. Developmental tumours, early differentiation and the transforming growth factor beta superfamily.

    PubMed

    Mummery, C L; van den Eijnden-van Raaij, A J

    1999-01-01

    Embryonal carcinoma and embryonic stem cells have been very useful models for identifying some of the factors that regulate differentiation in early mammalian development. Here, we present a brief history of their original isolation and characterization and of their later introduction into the Hubrecht Laboratory. We illustrate in a review their contribution to our current understanding of the function of transforming growth factor beta and ligands binding to the receptors of a related factor, activin, in development with some of our own work.

  13. Laboratory evidence for stochastic plasma-wave growth.

    PubMed

    Austin, D R; Hole, M J; Robinson, P A; Cairns, Iver H; Dallaqua, R

    2007-11-16

    The first laboratory confirmation of stochastic growth theory is reported. Floating potential fluctuations are measured in a vacuum arc centrifuge using a Langmuir probe. Statistical analysis of the energy density reveals a lognormal distribution over roughly 2 orders of magnitude, with a high-field nonlinear cutoff whose spatial dependence is consistent with the predicted eigenmode profile. These results are consistent with stochastic growth and nonlinear saturation of a spatially extended eigenmode, the first evidence for stochastic growth of an extended structure.

  14. Laboratory Evidence for Stochastic Plasma-Wave Growth

    NASA Astrophysics Data System (ADS)

    Austin, D. R.; Hole, M. J.; Robinson, P. A.; Cairns, Iver H.; Dallaqua, R.

    2007-11-01

    The first laboratory confirmation of stochastic growth theory is reported. Floating potential fluctuations are measured in a vacuum arc centrifuge using a Langmuir probe. Statistical analysis of the energy density reveals a lognormal distribution over roughly 2 orders of magnitude, with a high-field nonlinear cutoff whose spatial dependence is consistent with the predicted eigenmode profile. These results are consistent with stochastic growth and nonlinear saturation of a spatially extended eigenmode, the first evidence for stochastic growth of an extended structure.

  15. Laboratory Evidence for Stochastic Plasma-Wave Growth

    SciTech Connect

    Austin, D. R.; Hole, M. J.; Robinson, P. A.; Cairns, Iver H.; Dallaqua, R.

    2007-11-16

    The first laboratory confirmation of stochastic growth theory is reported. Floating potential fluctuations are measured in a vacuum arc centrifuge using a Langmuir probe. Statistical analysis of the energy density reveals a lognormal distribution over roughly 2 orders of magnitude, with a high-field nonlinear cutoff whose spatial dependence is consistent with the predicted eigenmode profile. These results are consistent with stochastic growth and nonlinear saturation of a spatially extended eigenmode, the first evidence for stochastic growth of an extended structure.

  16. Polycrystal diamond growth in a microwave plasma torch

    SciTech Connect

    Sergeichev, K. F.; Lukina, N. A.; Bolshakov, A. P.; Ralchenko, V. G.; Arutyunyan, N. R.; Vlasov, I. I.

    2010-12-15

    Diamond films of different structures were deposited on quartz, WC-Co, and molybdenum substrates in a microwave plasma torch discharge in an argon-hydrogen-methane gas mixture in a sealed chamber at pressures close to atmospheric by using the chemical vapor deposition technique. Images of diamond polycrystal films and separate crystals, as well as results of Raman spectroscopy, are presented. The spectra of optical plasma radiation recorded during film deposition demonstrate the presence of intense H{sub {alpha}} hydrogen and C{sub 2} radical bands known as Swan bands.

  17. Plasma stabilisation of metallic nanoparticles on silicon for the growth of carbon nanotubes

    SciTech Connect

    Esconjauregui, S.; Fouquet, M.; Bayer, B. C.; Gamalski, A. D.; Chen Bingan; Xie Rongsi; Hofmann, S.; Robertson, J.; Cepek, C.; Bhardwaj, S.; Ducati, C.

    2012-08-01

    Ammonia (NH{sub 3}) plasma pretreatment is used to form and temporarily reduce the mobility of Ni, Co, or Fe nanoparticles on boron-doped mono- and poly-crystalline silicon. X-ray photoemission spectroscopy proves that NH{sub 3} plasma nitrides the Si supports during nanoparticle formation which prevents excessive nanoparticle sintering/diffusion into the bulk of Si during carbon nanotube growth by chemical vapour deposition. The nitridation of Si thus leads to nanotube vertical alignment and the growth of nanotube forests by root growth mechanism.

  18. Evidence of plasma fluctuations and their effect on the growth of stimulated Brillouin and stimulated Raman scattering in laser plasmas

    SciTech Connect

    Montgomery, D.S.; Afeyan, B.B.; Cobble, J.A.; Fernandez, J.C.; Wilke, M.D.; Glenzer, S.H.; Kirkwood, R.K.; MacGowan, B.J.; Moody, J.D.; Lindman, E.L.; Munro, D.H.; Wilde, B.H.; Rose, H.A.; Dubois, D.F.; Bezzerides, B.; Vu, H.X.

    1998-05-01

    The reflectivity levels of stimulated Brillouin scattering (SBS) in recent large scale length laser plasma experiments is much lower than expected for conditions where the convective gain exponent is expected to be large [J. C. Fern{acute a}ndez {ital et al.}, Phys. Plasmas {bold 4}, 1849 (1997)]. Long-wavelength velocity fluctuations caused during the plasma formation process, or by parametric instabilities themselves, have been proposed as a mechanism to detune SBS in these experiments and reduce its gain [W. L. Kruer {ital et al.}, Phys. Plasmas {bold 3}, 382 (1996); H. A. Rose, Phys. Plasmas {bold 4}, 437 (1997)]. Evidence of large-velocity fluctuation levels is found in the time-resolved SBS spectra from these experiments, and correlates with observed changes in the reflectivity of both SBS and stimulated Raman scattering (SRS). Evidence of fluctuations that increase with increasing plasma density is presented, and their effect on the growth of parametric instabilities is discussed. {copyright} {ital 1998 American Institute of Physics.}

  19. Modeling carbon nanotube growth on the catalyst-substrate surface subjected to reactive plasma [

    SciTech Connect

    Tewari, Aarti; Sharma, Suresh C.

    2014-06-15

    The paper presents a theoretical model to study the growth of the carbon nanotube (CNT) on the catalyst substrate surface subjected to reactive plasma. The charging rate of the CNT, kinetics of electron, ions and neutral atoms, the growth rate of the CNT because of diffusion and accretion of ions on the catalyst nanoparticle inclusion of the issue of the plasma sheath is undertaken in the present model. Numerical calculations on the effect of ion density and temperature and the substrate bias on the growth of the CNT have been carried out for typical glow discharge plasma parameters. It is found that the height of CNT increases with the ion density of carbon ions and radius of CNT decreases with hydrogen ion density. The substrate bias also affects the growth rate of the CNT. The field emission characteristics from the CNTs can be analyzed from the results obtained.

  20. Digital holographic interferometry employing Fresnel transform reconstruction for the study of flow shear stabilized Z-pinch plasmas

    NASA Astrophysics Data System (ADS)

    Ross, M. P.; Shumlak, U.

    2016-10-01

    The ZaP-HD flow Z-pinch project provides a platform to explore how shear flow stabilized Z-pinches could scale to high-energy-density plasma (plasma with pressures exceeding 1 Mbar) and fusion reactor conditions. The Z-pinch is a linear plasma confinement geometry in which the plasma carries axial electric current and is confined by its self-induced magnetic field. ZaP-HD generates shear stabilized, axisymmetric Z-pinches with stable lifetimes approaching 60 μs. The goal of the project is to increase the plasma density and temperature compared to the previous ZaP project by compressing the plasma to smaller radii (≈1 mm). Radial and axial plasma electron density structure is measured using digital holographic interferometry (DHI), which provides the necessary fine spatial resolution. ZaP-HD's DHI system uses a 2 ns Nd:YAG laser pulse with a second harmonic generator (λ = 532 nm) to produce holograms recorded by a Nikon D3200 digital camera. The holograms are numerically reconstructed with the Fresnel transform reconstruction method to obtain the phase shift caused by the interaction of the laser beam with the plasma. This provides a two-dimensional map of line-integrated electron density, which can be Abel inverted to determine the local number density. The DHI resolves line-integrated densities down to 3 × 1020 m-2 with spatial resolution near 10 μm. This paper presents the first application of Fresnel transform reconstruction as an analysis technique for a plasma diagnostic, and it analyzes the method's accuracy through study of synthetic data. It then presents an Abel inversion procedure that utilizes data on both sides of a Z-pinch local number density profile to maximize profile symmetry. Error estimation and Abel inversion are applied to the measured data.

  1. Effects of cold plasma treatment on seed germination and seedling growth of soybean.

    PubMed

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-01-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean.

  2. Effects of cold plasma treatment on seed germination and seedling growth of soybean

    NASA Astrophysics Data System (ADS)

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-07-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean.

  3. Effects of cold plasma treatment on seed germination and seedling growth of soybean

    PubMed Central

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-01-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean. PMID:25080862

  4. Role of plasma activation in the kinetics of CNT growth in PECVD process

    NASA Astrophysics Data System (ADS)

    Lebedeva, Irina; Gavrikov, Alexey; Baranov, Alexey; Belov, Maxim; Knizhnik, Andrey; Potapkin, Boris; Sommerer, Timothy

    2009-10-01

    The work presents kinetic modeling of the effect of acceleration for the growth kinetics of carbon nanotubes by hydrocarbon gas mixture modification with plasma discharge. The plasma activation creates active species in hydrocarbon gas mixture, which can easily adsorb and dissociate on the catalyst surface. So plasma treatment of the gas mixture in the CVD process allows to increase the carbon supply rate by a few orders of magnitude compared to that in thermal CVD process. On the other hand, plasma can also provide etching of carbon species from the catalyst surface. To correctly reproduce both of these effects of plasma, the kinetic model of growth of carbon nanotubes is developed based on first-principles analysis of heterogeneous processes on the catalyst surface and detailed kinetics of gas phase chemistry. The model is used to compare the growth rates of carbon nanotubes in thermal and plasma-enhanced CVD processes and to determine critical gas pressures, at which CNT growth kinetics switches from the adsorption limitation to the limitation by reaction and diffusion on the catalyst.

  5. Transforming growth factor beta mRNA increases during liver regeneration: a possible paracrine mechanism of growth regulation.

    PubMed Central

    Braun, L; Mead, J E; Panzica, M; Mikumo, R; Bell, G I; Fausto, N

    1988-01-01

    Transforming growth factor beta (TGF-beta) is a growth factor with multiple biological properties including stimulation and inhibition of cell proliferation. To determine whether TGF-beta is involved in hepatocyte growth responses in vivo, we measured the levels of TGF-beta mRNA in normal liver and during liver regeneration after partial hepatectomy in rats. TGF-beta mRNA increases in the regenerating liver and reaches a peak (about 8 times higher than basal levels) after the major wave of hepatocyte cell division and mitosis have taken place and after the peak expression of the ras protooncogenes. Although hepatocytes from normal and regenerating liver respond to TGF-beta, they do not synthesize TGF-beta mRNA. Instead, the message is present in liver nonparenchymal cells and is particularly abundant in cell fractions enriched for endothelial cells. TGF-beta inhibits epidermal growth factor-induced DNA synthesis in vitro in hepatocytes from normal or regenerating liver, although the dose-response curves vary according to the culture medium used. We conclude that TGF-beta may function as the effector of an inhibitory paracrine loop that is activated during liver regeneration, perhaps to prevent uncontrolled hepatocyte proliferation. Images PMID:3422749

  6. A functional connection between pRB and transforming growth factor beta in growth inhibition and mammary gland development.

    PubMed

    Francis, Sarah M; Bergsied, Jacqueline; Isaac, Christian E; Coschi, Courtney H; Martens, Alison L; Hojilla, Carlo V; Chakrabarti, Subrata; Dimattia, Gabriel E; Khoka, Rama; Wang, Jean Y J; Dick, Frederick A

    2009-08-01

    Transforming growth factor beta (TGF-beta) is a crucial mediator of breast development, and loss of TGF-beta-induced growth arrest is a hallmark of breast cancer. TGF-beta has been shown to inhibit cyclin-dependent kinase (CDK) activity, which leads to the accumulation of hypophosphorylated pRB. However, unlike other components of TGF-beta cytostatic signaling, pRB is thought to be dispensable for mammary development. Using gene-targeted mice carrying subtle missense changes in pRB (Rb1(DeltaL) and Rb1(NF)), we have discovered that pRB plays a critical role in mammary gland development. In particular, Rb1 mutant female mice have hyperplastic mammary epithelium and defects in nursing due to insensitivity to TGF-beta growth inhibition. In contrast with previous studies that highlighted the inhibition of cyclin/CDK activity by TGF-beta signaling, our experiments revealed that active transcriptional repression of E2F target genes by pRB downstream of CDKs is also a key component of TGF-beta cytostatic signaling. Taken together, our work demonstrates a unique functional connection between pRB and TGF-beta in growth control and mammary gland development.

  7. Impact of epidermal growth factor receptor and transforming growth factor-α on hepatitis C virus-induced hepatocarcinogenesis.

    PubMed

    Badawy, Afkar Abdel-Ghany; El-Hindawi, Ali; Hammam, Olfat; Moussa, Mona; Gabal, Samia; Said, Noha

    2015-10-01

    Epidermal growth factor receptor system plays a central hepato-protective and pro-regenerative role in liver. Transforming growth factor-α (TGF-α) is an important autocrine growth regulator of hepatocytes that plays a role in development of hepatocellular carcinoma (HCC) among patients with chronic hepatitis C (CHC). This study was done on 40 core liver biopsies from patients with CHC, 20 liver specimens from HCC cases on top of CHC as well as five normal controls. All were immunohistochemically stained with epidermal growth factor receptor (EGFR) and TGF-α antibodies. Some selected HCC cases were submitted for FISH technique to detect EGFR gene alteration. By immunohistochemistry EGFR and TGF-α were overexpressed in HCC and cirrhotic cases compared to CHC cases without cirrhosis. Also, their expression was stronger in CHC cases with higher grades of activity and stages of fibrosis compared to lower ones. FISH positive results for EGFR were detected in 33.3% of the examined HCC cases. EGFR and TGF-α can be used as predictive markers for activity, fibrosis, and carcinogenesis in CHC patients. Overexpression of EGFR in HCC patients can be promising in selecting those who can get benefit from anti-EGFR target therapy. PMID:26279457

  8. The prognostic significance of transforming growth factors in human breast cancer.

    PubMed Central

    Murray, P. A.; Barrett-Lee, P.; Travers, M.; Luqmani, Y.; Powles, T.; Coombes, R. C.

    1993-01-01

    Transforming growth factor alpha (TGF alpha) and Transforming growth factor beta-1 (TGF-beta 1) are growth regulatory for breast cancer cell lines in vitro and several studies have suggested that levels of the receptor for TGF alpha, the epidermal growth factor (EGFR) in tumour biopsies predict relapse and survival. We have examined the prognostic significance of TGF alpha, TGF-beta 1 and EGFR mRNA expression in a series of patients with primary breast cancer with a median follow up period of 60 months. In 167 patients the expression of TGF-beta 1 was inversely correlated with node status (P = 0.065) but not ER status, tumour size or menopausal status. Patients with high levels of TGF-beta 1 had a longer disease free interval with a significantly longer probability of survival at 80 months although the overall relapse free survival was not increased. EGFR mRNA expression was measured in 106 patients and was inversely correlated with ER status (P = 0.018). EGFR levels did not predict for early relapse or survival. TGF alpha mRNA levels were measured in 104 patients, no correlation was seen tumour size, node status, Er status, or clinical outcome. PMID:8390290

  9. Heart and liver defects and reduced transforming growth factor beta2 sensitivity in transforming growth factor beta type III receptor-deficient embryos.

    PubMed

    Stenvers, Kaye L; Tursky, Melinda L; Harder, Kenneth W; Kountouri, Nicole; Amatayakul-Chantler, Supavadee; Grail, Dianne; Small, Clayton; Weinberg, Robert A; Sizeland, Andrew M; Zhu, Hong-Jian

    2003-06-01

    The type III transforming growth factor beta (TGFbeta) receptor (TbetaRIII) binds both TGFbeta and inhibin with high affinity and modulates the association of these ligands with their signaling receptors. However, the significance of TbetaRIII signaling in vivo is not known. In this study, we have sought to determine the role of TbetaRIII during development. We identified the predominant expression sites of TbetaRIII mRNA as liver and heart during midgestation and have disrupted the murine TbetaRIII gene by homologous recombination. Beginning at embryonic day 13.5, mice with mutations in TbetaRIII developed lethal proliferative defects in heart and apoptosis in liver, indicating that TbetaRIII is required during murine somatic development. To assess the effects of the absence of TbetaRIII on the function of its ligands, primary fibroblasts were generated from TbetaRIII-null and wild-type embryos. Our results indicate that TbetaRIII deficiency differentially affects the activities of TGFbeta ligands. Notably, TbetaRIII-null cells exhibited significantly reduced sensitivity to TGFbeta2 in terms of growth inhibition, reporter gene activation, and Smad2 nuclear localization, effects not observed with other ligands. These data indicate that TbetaRIII is an important modulator of TGFbeta2 function in embryonic fibroblasts and that reduced sensitivity to TGFbeta2 may underlie aspects of the TbetaRIII mutant phenotype.

  10. An evolutionarily conserved enzyme degrades transforming growth factor- alpha as well as insulin

    PubMed Central

    1989-01-01

    A single enzyme found in both Drosophila and mammalian cells is able to selectively bind and degrade transforming growth factor (TGF)-alpha and insulin, but not EGF, at physiological concentrations. These growth factors are also able to inhibit binding and degradation of one another by the enzyme. Although there are significant immunological differences between the mammalian and Drosophila enzymes, the substrate specificity has been highly conserved. These results demonstrate the existence of a selective TGF-alpha-degrading enzyme in both Drosophila and mammalian cells. The evolutionary conservation of the ability to degrade both insulin and TGF-alpha suggests that this property is important for the physiological role of the enzyme and its potential for regulating growth factor levels. PMID:2670957

  11. Radio-frequency plasma chemical vapor deposition growth of diamond

    NASA Technical Reports Server (NTRS)

    Meyer, Duane E.; Dillon, Rodney O.; Woollam, John A.

    1989-01-01

    Plasma chemical vapor deposition (CVD) at 13.56 MHz has been used to produce diamond particles in two different inductively coupled systems with a mixture of methane and hydrogen. The effect of a diamondlike carbon (DLC) overcoating on silicon, niobium, and stainless-steel substrates has been investigated and in the case of silicon has been found to enhance particle formation as compared to uncoated polished silicon. In addition the use of carbon monoxide in hydrogen has been found to produce well-defined individual faceted particles as well as polycrystalline films on quartz and DLC coated silicon substrates. Plasma CVD is a competitive approach to production of diamond films. It has the advantage over microwave systems of being easily scaled to large volume and high power.

  12. Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone.

    PubMed

    Rivera, César; Monsalve, Francisco; Salas, Juan; Morán, Andrea; Suazo, Iván

    2013-12-01

    Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H2O (n=3), distilled water without the drug and alveolar bone damage; BD/H2O/PRP (n=3), BD and PRP; BD/H2O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects.

  13. Effects of catalyst film thickness on plasma-enhanced carbon nanotube growth

    SciTech Connect

    Hofmann, S.; Cantoro, M.; Kleinsorge, B.; Casiraghi, C.; Parvez, A.; Robertson, J.; Ducati, C.

    2005-08-01

    A systematic study is presented of the influence of catalyst film thickness on carbon nanostructures grown by plasma-enhanced chemical-vapor deposition from acetylene and ammonia mixtures. We show that reducing the Fe/Co catalyst film thickness below 3 nm causes a transition from larger diameter (>40 nm), bamboolike carbon nanofibers to small diameter ({approx}5 nm) multiwalled nanotubes with two to five walls. This is accompanied by a more than 50 times faster growth rate and a faster catalyst poisoning. Thin Ni catalyst films only trigger such a growth transition when pretreated with an ammonia plasma. We observe a limited correlation between this growth transition and the coarsening of the catalyst film before deposition. For a growth temperature of {<=}550 deg. C, all catalysts showed mainly a tip growth regime and a similar activity on untreated silicon, oxidized silicon, and silicon nitride support.

  14. Low edge safety factor operation and passive disruption avoidance in current carrying plasmas by the addition of stellarator rotational transform

    NASA Astrophysics Data System (ADS)

    Pandya, M. D.; ArchMiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Knowlton, S. F.; Ma, X.; Massidda, S.; Maurer, D. A.; Roberds, N. A.; Traverso, P. J.

    2015-11-01

    Low edge safety factor operation at a value less than two ( q (a )=1 /ι̷tot(a )<2 ) is routine on the Compact Toroidal Hybrid device with the addition of sufficient external rotational transform. Presently, the operational space of this current carrying stellarator extends down to q (a )=1.2 without significant n = 1 kink mode activity after the initial plasma current rise phase of the discharge. The disruption dynamics of these low edge safety factor plasmas depend upon the fraction of helical field rotational transform from external stellarator coils to that generated by the plasma current. We observe that with approximately 10% of the total rotational transform supplied by the stellarator coils, low edge q disruptions are passively suppressed and avoided even though q(a) < 2. When the plasma does disrupt, the instability precursors measured and implicated as the cause are internal tearing modes with poloidal, m, and toroidal, n, helical mode numbers of m /n =3 /2 and 4/3 observed on external magnetic sensors and m /n =1 /1 activity observed on core soft x-ray emissivity measurements. Even though the edge safety factor passes through and becomes much less than q(a) < 2, external n = 1 kink mode activity does not appear to play a significant role in the disruption phenomenology observed.

  15. Shape and size transformation of gold nanorods (GNRs) via oxidation process: A reverse growth mechanism

    NASA Astrophysics Data System (ADS)

    Chandrasekar, Govindasamy; Mougin, Karine; Haidara, Hamidou; Vidal, Loïc; Gnecco, Enrico

    2011-02-01

    The anisotropic shape transformation of gold nanorods (GNRs) with H2O2 was observed in the presence of "cethyl trimethylammonium bromide" (CTAB). The adequate oxidative dissolution of GNR is provided by the following autocatalytic scheme with H2O2: Au0 → Au+, Au0 + Aun+ → 2Au3+, n = 1 and 3. The shape transformation of the GNRs was investigated by UV-vis spectroscopy and transmission electron microscopy (TEM). As-synthesised GNRs exhibit transverse plasmon band (TPB) at 523 nm and longitudinal plasmon band (LPB) at 731 nm. Upon H2O2 oxidation, the LPB showed a systematic hypsochromic (blue) shift, while TPB stays at ca. 523 nm. In addition, a new emerging peak observed at ca. 390 nm due to Au(III)-CTAB complex formation during the oxidation. TEM analysis of as-synthesised GNRs with H2O2 confirmed the shape transformation to spherical particles with 10 nm size in 2 h, whereas centrifuged nanorod solution showed no changes in the aspect ratio under the same condition. Au3+ ions produced from oxidation, complex with excess free CTAB and approach the nanorods preferentially at the end, leading to spatially directed oxidation. This work provides some information to the crystal stability and the growth mechanism of GNRs, as both growth and shortening reactions occur preferentially at the edge of single-crystalline GNRs, all directed by Br- ions.

  16. Performance of a Discrete Wavelet Transform for Compressing Plasma Count Data and its Application to the Fast Plasma Investigation on NASA's Magnetospheric Multiscale Mission

    NASA Technical Reports Server (NTRS)

    Barrie, Alexander C.; Yeh, Penshu; Dorelli, John C.; Clark, George B.; Paterson, William R.; Adrian, Mark L.; Holland, Matthew P.; Lobell, James V.; Simpson, David G.; Pollock, Craig J.; Moore, Thomas E.

    2015-01-01

    Plasma measurements in space are becoming increasingly faster, higher resolution, and distributed over multiple instruments. As raw data generation rates can exceed available data transfer bandwidth, data compression is becoming a critical design component. Data compression has been a staple of imaging instruments for years, but only recently have plasma measurement designers become interested in high performance data compression. Missions will often use a simple lossless compression technique yielding compression ratios of approximately 2:1, however future missions may require compression ratios upwards of 10:1. This study aims to explore how a Discrete Wavelet Transform combined with a Bit Plane Encoder (DWT/BPE), implemented via a CCSDS standard, can be used effectively to compress count information common to plasma measurements to high compression ratios while maintaining little or no compression error. The compression ASIC used for the Fast Plasma Investigation (FPI) on board the Magnetospheric Multiscale mission (MMS) is used for this study. Plasma count data from multiple sources is examined: resampled data from previous missions, randomly generated data from distribution functions, and simulations of expected regimes. These are run through the compression routines with various parameters to yield the greatest possible compression ratio while maintaining little or no error, the latter indicates that fully lossless compression is obtained. Finally, recommendations are made for future missions as to what can be achieved when compressing plasma count data and how best to do so.

  17. Growth dynamics of copper oxide nanowires in plasma at low pressures

    SciTech Connect

    Filipič, Gregor; Mozetič, Miran; Cvelbar, Uroš; Baranov, Oleg

    2015-01-28

    The growth time dynamics of the copper oxide nanowires (NWs) in radiofrequency plasma discharge were investigated. Grounded copper samples were treated in argon-oxygen plasma with the discharge power of 150 W for sequenced times up to 20 min. After the treatment, the samples were analysed with scanning electron microscopy and image processing to obtain the length and aspect ratio of the NWs. A growth mode with the saturation was observed in dependence to NW length, where the maximal length of 5 μm was achieved in 20 min. However, the best NW aspect ratio had maximum of about 40 after 10 min of plasma treatment. To describe and understand nanowire growth mechanism, a theoretical model was developed and it is in agreement with the experiment. The model results indicate that different densities of the ion current to the side and top area of NW modify the NW growth in height and width. The NW growth is enhanced by presence of ions, and thus this implies that it can be controlled by discharge power. This explains much faster growth of copper oxide nanowires in plasma environment compared to prolonged thermal treatments.

  18. Modelling Of Generation And Growth Of Nanoparticles In Low-Pressure Plasmas

    SciTech Connect

    Gordiets, B. F.

    2008-09-07

    Theoretical kinetic models of generation and growth of clusters and nanoparticles in low-pressure plasma are briefly rewired. The relatively simple kinetic model is discussed more detail. Simple formulas and equations are given for monomer density; cluster dimension distribution; critical cluster dimension; rate of particle production; particle density and average dimension as well as plasma characteristics. The analytical formula is also obtained for the time delay of the measured LIPEE signal in the 'Laser Induced Particle Explosive Evaporation' experimental method.

  19. Expression of neu protein, epidermal growth factor receptor, and transforming growth factor alpha in breast cancer. Correlation with clinicopathologic parameters.

    PubMed Central

    Lundy, J.; Schuss, A.; Stanick, D.; McCormack, E. S.; Kramer, S.; Sorvillo, J. M.

    1991-01-01

    The major objectives of this study were twofold: to determine 1) if growth factors or growth factor receptors were expressed similarly or differently in a clinically well-characterized group of breast cancer patients and 2) if these phenotypic characteristics were associated with any of the commonly used prognostic parameters. Formalin-fixed paraffin-embedded tumor tissue from 51 node-positive breast cancer patients were analyzed for the expression of neu, epidermal growth factor-receptor (EGF-R), and transforming growth factor alpha (TGF alpha) using immunoperoxidase staining. Positive membranous staining for neu was observed in 15 (29%) tumors. Over-expression of neu was observed in high-grade, estrogen-receptor-negative tumors (P less than 0.05). Epidermal growth factor receptor was expressed in 22 (43%) of the tumors analyzed and found to a greater degree in estrogen-receptor-negative and high-grade tumors (P less than 0.025). A significant correlation between neu and EGF-R expression was also noted. Tumors expressing membranous staining of neu had a greater than 70% chance of expressing EGF-R (P less than 0.01). Expression of TGF alpha was found in 68% of tumors and TGF alpha was detected in grade 1 and 2 tumor to a greater degree than EGF-R. The authors conclude that assaying tumors for these antigens may give additional phenotypic characteristics that can give further insight into the biology of breast cancer. Images Figure 1 Figure 2 Figure 3 PMID:1711294

  20. A study on the maximum power transfer condition in an inductively coupled plasma using transformer circuit model

    SciTech Connect

    Kim, Young-Do; Lee, Hyo-Chang; Chung, Chin-Wook

    2013-09-15

    Correlations between the external discharge parameters (the driving frequency ω and the chamber dimension R) and plasma characteristics (the skin depth δ and the electron-neutral collision frequency ν{sub m}) are studied using the transformer circuit model [R. B. Piejak et al., Plasma Sources Sci. Technol. 1, 179 (1992)] when the absorbed power is maximized in an inductively coupled plasma. From the analysis of the transformer circuit model, the maximum power transfer conditions, which depend on the external discharge parameters and the internal plasma characteristics, were obtained. It was found that a maximum power transfer occurs when δ≈0.38R for the discharge condition at which ν{sub m}/ω≪1, while it occurs when δ≈√(2)√(ω/ν{sub m})R for the discharge condition at which ν{sub m}/ω≫1. The results of this circuit analysis are consistent with the stable last inductive mode region of an inductive-to-capacitive mode transition [Lee and Chung, Phys. Plasmas 13, 063510 (2006)], which was theoretically derived from Maxwell's equations. Our results were also in agreement with the experimental results. From this work, we demonstrate that a simple circuit analysis can be applied to explain complex physical phenomena to a certain extent.

  1. A study on the maximum power transfer condition in an inductively coupled plasma using transformer circuit model

    NASA Astrophysics Data System (ADS)

    Kim, Young-Do; Lee, Hyo-Chang; Chung, Chin-Wook

    2013-09-01

    Correlations between the external discharge parameters (the driving frequency ω and the chamber dimension R) and plasma characteristics (the skin depth δ and the electron-neutral collision frequency νm) are studied using the transformer circuit model [R. B. Piejak et al., Plasma Sources Sci. Technol. 1, 179 (1992)] when the absorbed power is maximized in an inductively coupled plasma. From the analysis of the transformer circuit model, the maximum power transfer conditions, which depend on the external discharge parameters and the internal plasma characteristics, were obtained. It was found that a maximum power transfer occurs when δ ≈0.38R for the discharge condition at which νm/ω ≪1, while it occurs when δ ≈√2 √ω /νm R for the discharge condition at which νm/ω ≫1. The results of this circuit analysis are consistent with the stable last inductive mode region of an inductive-to-capacitive mode transition [Lee and Chung, Phys. Plasmas 13, 063510 (2006)], which was theoretically derived from Maxwell's equations. Our results were also in agreement with the experimental results. From this work, we demonstrate that a simple circuit analysis can be applied to explain complex physical phenomena to a certain extent.

  2. Tunable synthesis and in situ growth of silicon-carbon mesostructures using impermeable plasma

    PubMed Central

    Yaghoubi, Alireza; Mélinon, Patrice

    2013-01-01

    In recent years, plasma-assisted synthesis has been extensively used in large scale production of functional nano- and micro-scale materials for numerous applications in optoelectronics, photonics, plasmonics, magnetism and drug delivery, however systematic formation of these minuscule structures has remained a challenge. Here we demonstrate a new method to closely manipulate mesostructures in terms of size, composition and morphology by controlling permeability at the boundaries of an impermeable plasma surrounded by a blanket of neutrals. In situ and rapid growth of thin films in the core region due to ion screening is among other benefits of our method. Similarly we can take advantage of exceptional properties of plasma to control the morphology of the as deposited nanostructures. Probing the plasma at boundaries by means of observing the nanostructures, further provides interesting insights into the behaviour of gas-insulated plasmas with possible implications on efficacy of viscous heating and non-magnetic confinement. PMID:23330064

  3. Effect of plasma parameters on growth and field emission properties of spherical carbon nanotube tip

    SciTech Connect

    Sharma, Suresh C.; Tewari, Aarti

    2011-06-15

    The effect of plasma parameters (e.g., electron density and temperature, ion density and temperature, neutral atom density and temperature) on the growth (without a catalyst), structure, and field emission properties of a spherical carbon nanotube (CNT) tip has been theoretically investigated. A theoretical model of charge neutrality, including the kinetics of electrons, positively charged ions, and neutral atoms and the energy balance of the various species in plasma, has been developed. Numerical calculations of the radius of the spherical CNT tip for different CNT number densities and plasma parameters have been carried out for the typical glow discharge plasma parameters. It is found that upon an increase in the CNT number density and plasma parameters, the radius of the spherical CNT tip decreases, and consequently the field emission factor for the spherical CNT tip increases.

  4. Patterned growth of carbon nanotubes obtained by high density plasma chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Mousinho, A. P.; Mansano, R. D.

    2015-03-01

    Patterned growth of carbon nanotubes by chemical vapor deposition represents an assembly approach to place and orient nanotubes at a stage as early as when they are synthesized. In this work, the carbon nanotubes were obtained at room temperature by High Density Plasmas Chemical Vapor Deposition (HDPCVD) system. This CVD system uses a new concept of plasma generation, where a planar coil coupled to an RF system for plasma generation was used with an electrostatic shield for plasma densification. In this mode, high density plasmas are obtained. We also report the patterned growth of carbon nanotubes on full 4-in Si wafers, using pure methane plasmas and iron as precursor material (seed). Photolithography processes were used to pattern the regions on the silicon wafers. The carbon nanotubes were characterized by micro-Raman spectroscopy, the spectra showed very single-walled carbon nanotubes axial vibration modes around 1590 cm-1 and radial breathing modes (RBM) around 120-400 cm-1, confirming that high quality of the carbon nanotubes obtained in this work. The carbon nanotubes were analyzed by atomic force microscopy and scanning electron microscopy too. The results showed that is possible obtain high-aligned carbon nanotubes with patterned growth on a silicon wafer with high reproducibility and control.

  5. Uniform surface growth of copper oxide nanowires in radiofrequency plasma discharge and limiting factors

    SciTech Connect

    Filipič, Gregor; Mozetič, Miran; Cvelbar, Uroš; Baranov, Oleg; Ostrikov, Kostya

    2014-11-15

    The uniform growth of copper oxide nanowires on the top of copper plate has been investigated during the exposure to radiofrequency plasma discharge in respect to plasma properties and its localization. The copper samples of 10 mm radius and 1 mm in thickness were exposed to argon-oxygen plasma created at discharge power of 150 W. After 10 min, almost uniform growth of nanowires was achieved over large surface. There were significant distortions in nanowire length and shape near the edges. Based on the experimental results, we developed a theoretical model, which took into account a balance in heat released at the flow of the current to the nanowire and rejected from the nanowire. This model established a dependence of the maximal length of the nanowire at dependence on the plasma parameters, where the limiting factor for nanowire growth and distortions in distribution are ballistic effects of ions and their local fluxes. In contrast, the plasma heating by potential interactions of species has very little influence on the length and smaller deviations in flux are allowed for uniformity of growth.

  6. Study of nonlinear oscillations in a glow discharge plasma using empirical mode decomposition and Hilbert Huang transform

    SciTech Connect

    Wharton, A. M.; Sekar Iyengar, A. N.; Janaki, M. S.

    2013-02-15

    Hilbert Huang transform (HHT) based time series analysis was carried out on nonlinear floating potential fluctuations obtained from hollow cathode glow discharge plasma in the presence of anode glow. HHT was used to obtain contour plots and the presence of nonlinearity was studied. Frequency shift with time, which is a typical nonlinear behaviour, was detected from the contour plots. Various plasma parameters were measured and the concepts of correlation coefficients and the physical contribution of each intrinsic mode function have been discussed. Physically important quantities such as instantaneous energy and their uses in studying physical phenomena such as intermittency and non-stationary data have also been discussed.

  7. Instabilities during the growth of dust successive generations in silane-based plasmas

    SciTech Connect

    Cavarroc, Marjorie; Mikikian, Maxime; Tessier, Yves; Boufendi, Laiefa

    2008-10-15

    Dust growth in silane-based plasmas is known to be a cyclic phenomenon as long as silane is provided. This continuous dust growth leads to an unstable behavior of the complex plasma, characterized by well-defined instabilities. In this paper, a complete study of these instabilities is presented. The electrical analysis is corroborated by an optical one, and high speed video imaging is used to get an insight in the dust cloud behavior. A possible cause of this instability phenomenon is also discussed.

  8. Effect of transforming growth factor beta (TGF-β) receptor I kinase inhibitor on prostate cancer bone growth.

    PubMed

    Wan, Xinhai; Li, Zhi-Gang; Yingling, Jonathan M; Yang, Jun; Starbuck, Michael W; Ravoori, Murali K; Kundra, Vikas; Vazquez, Elba; Navone, Nora M

    2012-03-01

    Transforming growth factor beta 1 (TGF-β1) has been implicated in the pathogenesis of prostate cancer (PCa) bone metastasis. In this study, we tested the antitumor efficacy of a selective TGF-β receptor I kinase inhibitor, LY2109761, in preclinical models. The effect of LY2109761 on the growth of MDA PCa 2b and PC-3 human PCa cells and primary mouse osteoblasts (PMOs) was assessed in vitro by measuring radiolabeled thymidine incorporation into DNA. In vivo, the right femurs of male SCID mice were injected with PCa cells. We monitored the tumor burden in control- and LY2109761-treated mice with MRI analysis and the PCa-induced bone response with X-ray and micro-CT analyses. Histologic changes in bone were studied by performing bone histomorphometric evaluations. PCa cells and PMOs expressed TGF-β receptor I. TGF-β1 induced pathway activation (as assessed by induced expression of p-Smad2) and inhibited cell growth in PC-3 cells and PMOs but not in MDA PCa 2b cells. LY2109761 had no effect on PCa cells but induced PMO proliferation in vitro. As expected, LY2109761 reversed the TGF-β1-induced pathway activation and growth inhibition in PC-3 cells and PMOs. In vivo, LY2109761 treatment for 6weeks resulted in increased volume in normal bone and increased osteoblast and osteoclast parameters. In addition, LY2109761 treatment significantly inhibited the growth of MDA PCa 2b and PC-3 in the bone of SCID mice (p<0.05); moreover, it resulted in significantly less bone loss and change in osteoclast-associated parameters in the PC-3 tumor-bearing bones than in the untreated mice. In summary, we report for the first time that targeting TGF-β receptors with LY2109761 can control PCa bone growth while increasing the mass of normal bone. This increased bone mass in nontumorous bone may be a desirable side effect of LY2109761 treatment for men with osteopenia or osteoporosis secondary to androgen-ablation therapy, reinforcing the benefit of effectively controlling PCa growth

  9. Effect of transforming growth factor beta (TGF-β) receptor I kinase inhibitor on prostate cancer bone growth.

    PubMed

    Wan, Xinhai; Li, Zhi-Gang; Yingling, Jonathan M; Yang, Jun; Starbuck, Michael W; Ravoori, Murali K; Kundra, Vikas; Vazquez, Elba; Navone, Nora M

    2012-03-01

    Transforming growth factor beta 1 (TGF-β1) has been implicated in the pathogenesis of prostate cancer (PCa) bone metastasis. In this study, we tested the antitumor efficacy of a selective TGF-β receptor I kinase inhibitor, LY2109761, in preclinical models. The effect of LY2109761 on the growth of MDA PCa 2b and PC-3 human PCa cells and primary mouse osteoblasts (PMOs) was assessed in vitro by measuring radiolabeled thymidine incorporation into DNA. In vivo, the right femurs of male SCID mice were injected with PCa cells. We monitored the tumor burden in control- and LY2109761-treated mice with MRI analysis and the PCa-induced bone response with X-ray and micro-CT analyses. Histologic changes in bone were studied by performing bone histomorphometric evaluations. PCa cells and PMOs expressed TGF-β receptor I. TGF-β1 induced pathway activation (as assessed by induced expression of p-Smad2) and inhibited cell growth in PC-3 cells and PMOs but not in MDA PCa 2b cells. LY2109761 had no effect on PCa cells but induced PMO proliferation in vitro. As expected, LY2109761 reversed the TGF-β1-induced pathway activation and growth inhibition in PC-3 cells and PMOs. In vivo, LY2109761 treatment for 6weeks resulted in increased volume in normal bone and increased osteoblast and osteoclast parameters. In addition, LY2109761 treatment significantly inhibited the growth of MDA PCa 2b and PC-3 in the bone of SCID mice (p<0.05); moreover, it resulted in significantly less bone loss and change in osteoclast-associated parameters in the PC-3 tumor-bearing bones than in the untreated mice. In summary, we report for the first time that targeting TGF-β receptors with LY2109761 can control PCa bone growth while increasing the mass of normal bone. This increased bone mass in nontumorous bone may be a desirable side effect of LY2109761 treatment for men with osteopenia or osteoporosis secondary to androgen-ablation therapy, reinforcing the benefit of effectively controlling PCa growth

  10. Effect of transforming growth factor beta (TGF-β) receptor I kinase inhibitor on prostate cancer bone growth

    PubMed Central

    Wan, Xinhai; Li, Zhi-Gang; Yingling, Jonathan M.; Yang, Jun; Starbuck, Michael W.; Ravoori, Murali K.; Kundra, Vikas; Vazquez, Elba; Navone, Nora M.

    2012-01-01

    Transforming growth factor beta 1 (TGF-β1) has been implicated in the pathogenesis of prostate cancer (PCa) bone metastasis. In this study, we tested the antitumor efficacy of a selective TGF-β receptor I kinase inhibitor, LY2109761, in preclinical models. The effect of LY2109761 on the growth of MDA PCa 2b and PC-3 human PCa cells and primary mouse osteoblasts (PMOs) was assessed in vitro by measuring radiolabeled thymidine incorporation into DNA. In vivo, the right femurs of male SCID mice were injected with PCa cells. We monitored the tumor burden in control- and LY2109761-treated mice with MRI analysis and the PCa-induced bone response with x-ray and micro-CT analyses. Histologic changes in bone were studied by performing bone histomorphometric evaluations. PCa cells and PMOs expressed TGF-β receptor I. TGF-β1 induced pathway activation (as assessed by induced expression of p-Smad2) and inhibited cell growth in PC-3 cells and PMOs but not in MDA PCa 2b cells. LY2109761 had no effect on PCa cells but induced PMO proliferation in vitro. As expected, LY2109761 reversed the TGF-β1–induced pathway activation and growth inhibition in PC-3 cells and PMOs. In vivo, LY2109761 treatment for 6 weeks resulted in increased volume in normal bone and increased osteoblast and osteoclast parameters. In addition, LY2109761 treatment significantly inhibited the growth of MDA PCa 2b and PC-3 in the bone of SCID mice (p < 0.05); moreover, it resulted in significantly less bone loss and change in osteoclast-associated parameters in the PC-3 tumor–bearing bones than in the untreated mice. In summary, we report for the first time that targeting TGF-β receptors with LY2109761 can control PCa bone growth while increasing the mass of normal bone. This increased bone mass in nontumorous bone may be a desirable side effect of LY2109761 treatment for men with osteopenia or osteoporosis secondary to androgen-ablation therapy, reinforcing the benefit of effectively controlling PCa

  11. Regulation of transglutaminase type II by transforming growth factor-beta 1 in normal and transformed human epidermal keratinocytes.

    PubMed

    George, M D; Vollberg, T M; Floyd, E E; Stein, J P; Jetten, A M

    1990-07-01

    This study examines the effect of transforming growth factor-beta 1 (TGF-beta 1) on the expression of Type I and II transglutaminase in normal human epidermal keratinocytes (NHEK cells). Treatment of undifferentiated NHEK cells with 100 pM TGF-beta 1 caused a 10- to 15-fold increase in the activity of a soluble transglutaminase. Based on its cellular distribution and immunoreactivity this transglutaminase was identified as Type II (tissue) transglutaminase. TGF-beta 1 did not enhance the levels of the membrane-bound Type I (epidermal) transglutaminase activity which is induced during squamous cell differentiation and did not increase Type II transglutaminase activity in differentiated NHEK cells. Several SV40 large T antigen-immortalized NHEK cell lines also exhibited a dramatic increase in transglutaminase Type II activity after TGF-beta 1 treatment; however, TGF-beta 1 did not induce any significant change in transglutaminase activity in the carcinoma-derived cell lines SCC-13, SCC-15, and SQCC/Y1. Half-maximal stimulation of transglutaminase Type II activity in NHEK cells occurred at a dose of 15 pM TGF-beta 1. TGF-beta 2 was about equally effective. This enhancement in transglutaminase activity was related to an increase in the amount of transglutaminase Type II protein as indicated by immunoblot analysis. Northern blot analyses using a specific cDNA probe for Type II transglutaminase showed that exposure of NHEK cells to TGF-beta 1 caused a marked increase in the mRNA levels of this enzyme which could be observed as early as 4 h after the addition of TGF-beta 1. Maximal induction of transglutaminase Type II mRNA occurred between 18 and 24 h. The increase in Type II transglutaminase mRNA levels was blocked by the presence of cycloheximide, suggesting that this increase in mRNA by TGF-beta 1 is dependent on protein synthesis. PMID:1972706

  12. Transforming growth factor β as regulator of cancer stemness and metastasis

    PubMed Central

    Bellomo, Claudia; Caja, Laia; Moustakas, Aristidis

    2016-01-01

    Key elements of cancer progression towards metastasis are the biological actions of cancer stem cells and stromal cells in the tumour microenvironment. Cross-communication between tumour and stromal cells is mediated by secreted cytokines, one of which, the transforming growth factor β (TGFβ), regulates essentially every cell within the malignant tissue. In this article, we focus on the actions of TGFβ on cancer stem cells, cancer-associated fibroblasts and immune cells that assist the overall process of metastatic dissemination. We aim at illustrating intricate connections made by various cells in the tumour tissue and which depend on the action of TGFβ. PMID:27537386

  13. Influence of phase transformation on stress evolution during growth of metal thin films on silicon.

    PubMed

    Fillon, A; Abadias, G; Michel, A; Jaouen, C; Villechaise, P

    2010-03-01

    In situ stress measurements during two-dimensional growth of low mobility metal films on amorphous Si were used to demonstrate the impact of interface reactivity and phase transformation on stress evolution. Using Mo1-xSix films as examples, the results show that the tensile stress rise, which develops after the film has become crystalline, is correlated with an increase in lateral grain size. The origin of the tensile stress is attributed to the volume change resulting from the alloy crystallization, which occurs at a concentration-dependent critical thickness. PMID:20366996

  14. The recombinant proregion of transforming growth factor beta1 (latency-associated peptide) inhibits active transforming growth factor beta1 in transgenic mice.

    PubMed

    Böttinger, E P; Factor, V M; Tsang, M L; Weatherbee, J A; Kopp, J B; Qian, S W; Wakefield, L M; Roberts, A B; Thorgeirsson, S S; Sporn, M B

    1996-06-11

    All three isoforms of transforming growth factors beta (TGF-betal, TGF-beta2, and TGF-beta3) are secreted as latent complexes and activated extracellularly, leading to the release of the mature cytokines from their noncovalently associated proregions, also known as latency-associated peptides (LAPs). The LAP region of TGF-beta1 was expressed in a baculovirus expression system and purified to homogeneity. In vitro assays of growth inhibition and gene induction mediated by TGF-beta3 demonstrate that recombinant TGF-beta1 LAP is a potent inhibitor of the activities of TGF-betal, -beta2, and -beta3. Effective dosages of LAP for 50% neutralization of TGF-beta activities range from 4.7- to 80-fold molar excess depending on the TGF-beta isoform and activity examined. Using 125I-labeled LAP, we show that the intraperitoneal application route is effective for systemic administration of LAP. Comparison of concentrations of LAP in tissues shows a homogenous pattern in most organs with the exception of heart and muscle, in which levels of LAP are 4- to 8-fold lower. In transgenic mice with elevated hepatic levels of bioactive TGF-betal, treatment with recombinant LAP completely reverses suppression of the early proliferative response induced by TGF-beta1 in remnant livers after partial hepatectomy. The results suggest that recombinant LAP is a potent inhibitor of bioactive TGF-beta both in vitro and in vivo, after intraperitoneal administration. Recombinant LAP should be a useful tool for novel approaches to study and therapeutically modulate pathophysiological processes mediated by TGF-beta3.

  15. Harnessing High Density Lipoproteins to Block Transforming Growth Factor Beta and to Inhibit the Growth of Liver Tumor Metastases

    PubMed Central

    Medina-Echeverz, José; Fioravanti, Jessica; Díaz-Valdés, Nancy; Frank, Kathrin; Aranda, Fernando; Gomar, Celia; Ardaiz, Nuria; Dotor, Javier; Umansky, Viktor; Prieto, Jesús; Berraondo, Pedro

    2014-01-01

    Transforming growth factor β (TGF-β) is a powerful promoter of cancer progression and a key target for antitumor therapy. As cancer cells exhibit active cholesterol metabolism, high density lipoproteins (HDLs) appear as an attractive delivery system for anticancer TGFβ-inhibitory molecules. We constructed a plasmid encoding a potent TGF-β-blocking peptide (P144) linked to apolipoprotein A-I (ApoA-I) through a flexible linker (pApoLinkerP144). The ApoLinkerP144 sequence was then incorporated into a hepatotropic adeno-associated vector (AAVApoLinkerP144). The aim was to induce hepatocytes to produce HDLs containing a modified ApoA-I capable of blocking TGF-β. We observed that transduction of the murine liver with pApoLinkerP144 led to the appearance of a fraction of circulating HDL containing the fusion protein. These HDLs were able to attenuate TGF-β signaling in the liver and to enhance IL-12 -mediated IFN-γ production. Treatment of liver metastasis of MC38 colorectal cancer with AAVApoLinkerP144 resulted in a significant reduction of tumor growth and enhanced expression of IFN-γ and GM-CSF in cancerous tissue. ApoLinkerP144 also delayed MC38 liver metastasis in Rag2−/−IL2rγ−/− immunodeficient mice. This effect was associated with downregulation of TGF-β target genes essential for metastatic niche conditioning. Finally, in a subset of ret transgenic mice, a model of aggressive spontaneous metastatic melanoma, AAVApoLinkerP144 delayed tumor growth in association with increased CD8+ T cell numbers in regional lymph nodes. In conclusion, modification of HDLs to transport TGF-β-blocking molecules is a novel and promising approach to inhibit the growth of liver metastases by immunological and non-immunological mechanisms. PMID:24797128

  16. Transforming growth factor beta 1 null mutation in mice causes excessive inflammatory response and early death.

    PubMed Central

    Kulkarni, A B; Huh, C G; Becker, D; Geiser, A; Lyght, M; Flanders, K C; Roberts, A B; Sporn, M B; Ward, J M; Karlsson, S

    1993-01-01

    To delineate specific developmental roles of transforming growth factor beta 1 (TGF-beta 1) we have disrupted its cognate gene in mouse embryonic stem cells by homologous recombination to generate TGF-beta 1 null mice. These mice do not produce detectable amounts of either TGF-beta 1 RNA or protein. After normal growth for the first 2 weeks they develop a rapid wasting syndrome and die by 3-4 weeks of age. Pathological examination revealed an excessive inflammatory response with massive infiltration of lymphocytes and macrophages in many organs, but primarily in heart and lungs. Many lesions resembled those found in autoimmune disorders, graft-vs.-host disease, or certain viral diseases. This phenotype suggests a prominent role for TGF-beta 1 in homeostatic regulation of immune cell proliferation and extravasation into tissues. Images PMID:8421714

  17. Influence of the Al wire placed in the anode axis on the transformation of the deuterium plasma column in the plasma focus discharge

    NASA Astrophysics Data System (ADS)

    Kubes, P.; Paduch, M.; Cikhardtova, B.; Cikhardt, J.; Klir, D.; Kravarik, J.; Rezac, K.; Zielinska, E.; Zaloga, D.; Sadowski, M. J.; Tomaszewski, K.

    2016-06-01

    In this paper, we describe the influence of an Al wire of 270 μm in diameter placed along the anode axis on the transformation of the deuterium pinch column in a megaampere (MA) plasma focus device. The evolution of the pinched column and of the wire corona was investigated by means of the multiframe interferometry, neutron and X-ray diagnostics. The wire corona did not influence considerably on the evolution of dense plasma structures and neutron production, but it increased the plasma density and consequently, the currents around its surface. The distribution of the closed internal currents (ranging hundreds of kA) and associated magnetic fields amounting to 5 T were also estimated in the dense plasma column and in plasmoidal structures at the near-equilibrium state. The description is based on the balance of the plasma pressure and the pressure of the internal poloidal and toroidal current components compressed by the external pinched column. The dominant number of fusion deuterium-deuterium (D-D) neutrons is produced during the evolution of instabilities, when the uninterrupted wire corona (containing deuterium) connects the dense structures of the pinch, and it did not allow the formation of a constriction of the sub-millimeter diameter.

  18. Linear study of the nonmodal growth of drift waves in dusty plasmas

    SciTech Connect

    Manz, P.; Greiner, F.

    2010-06-15

    The main effect of dust on drift wave turbulence is the enhancement of the nonadiabaticity. Previous work found that nonmodal behavior is important in the nonadiabatic regime of the drift wave system. Here, the modal and nonmodal properties of the linear Hasegawa-Wakatani system of dusty plasmas are investigated. The non-normality of the linear evolution operator can lead to enhanced transient growth rates compared to the modal growth rates.

  19. Densification of functional plasma polymers by momentum transfer during film growth

    SciTech Connect

    Hegemann, Dirk; Koerner, Enrico; Blanchard, Noemi; Drabik, Martin; Guimond, Sebastien

    2012-11-19

    Functional plasma polymers were deposited from pure ethylene discharges and with the addition of carbon dioxide or ammonia. The incorporation of oxygen and nitrogen-containing functional groups depends on the fragmentation in the gas phase as well as on the densification during film growth. While a minimum energy per deposited carbon atom is required for cross-linking, the densification and accompanying reduction of functional group incorporation was found to scale linearly with momentum transfer through ion bombardment during film growth.

  20. Circulating transforming growth factor-β1 levels and the risk for kidney disease in African-Americans

    PubMed Central

    Suthanthiran, Manikkam; Gerber, Linda M.; Schwartz, Joseph E.; Sharma, Vijay K.; Medeiros, Mara; Marion, RoseMerie; Pickering, Thomas G.; August, Phyllis

    2013-01-01

    Transforming growth factor-β1 (TGF-β1) is well known to induce progression of experimental renal disease. Here we determined whether there is an association between serum levels of TGF-β1 and the risk factors for progression of clinically relevant renal disorders in 186 black and 147 white adults none of whom had kidney disease or diabetes. Serum TGF-β1 protein levels were positively and significantly associated with plasma renin activity along with the systolic and diastolic blood pressure in blacks but not whites after controlling for age, gender and body mass index. These TGF-β1 protein levels were also significantly associated with body mass index and metabolic syndrome and more predictive of microalbuminuria in blacks than in whites. The differential association between TGF-β1 and renal disease risk factors in blacks and whites suggests an explanation for the excess burden of end-stage renal disease in the black population but this requires validation in an independent cohort. Whether these findings show that it is the circulating levels of TGF-β1 that contributes to renal disease progression or reflects other unmeasured factors will need to be tested in longitudinal studies. PMID:19279557

  1. Low-temperature plasma-deposited silicon epitaxial films: Growth and properties

    DOE PAGES

    Demaurex, Bénédicte; Bartlome, Richard; Seif, Johannes P.; Geissbühler, Jonas; Alexander, Duncan T. L.; Jeangros, Quentin; Ballif, Christophe; De Wolf, Stefaan

    2014-08-05

    Low-temperature (≤ 180 °C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-ehanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems notmore » only from the growth conditions but also from unintentional contamination of the reactor. As a result of our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.« less

  2. Epidermal transformation leads to increased perlecan synthesis with heparin-binding-growth-factor affinity.

    PubMed Central

    Tapanadechopone, P; Tumova, S; Jiang, X; Couchman, J R

    2001-01-01

    Perlecan, a proteoglycan of basement membrane and extracellular matrices, has important roles in both normal biological and pathological processes. As a result of its ability to store and protect growth factors, perlecan may have crucial roles in tumour-cell growth and invasion. Since the biological functions of different types of glycosaminoglycan vary with cellular origin and structural modifications, we analysed the expression and biological functions of perlecan produced by a normal epidermal cell line (JB6) and its transformed counterpart (RT101). Expression of perlecan in tumorigenic cells was significantly increased in both mRNA and protein levels. JB6 perlecan was exclusively substituted with heparan sulphate, whereas that of RT101 contained some additional chondroitin sulphate. Detailed structural analysis of the heparan sulphate (HS) chains from perlecan of both cell types revealed that their overall sulphation and chain length were similar (approximately 60 kDa), but the HS chains of tumour-cell-derived perlecan were less sulphated. This resulted from reduced 2-O- and 6-O-sulphation, but not N-sulphation, and an increase in the proportion of unsulphated disaccharides. Despite this, the heparan sulphate of RT101- and JB6-derived perlecan bound fibroblast growth factor-1, -2, -4 and -7 and heparin-binding epidermal growth factor with similar affinity. Therefore abundant tumour-derived perlecan may support the angiogenic responses seen in vivo and be a key player in tumorigenesis. PMID:11284741

  3. Transforming growth factor-beta requires its target plasminogen activator inhibitor-1 for cytostatic activity.

    PubMed

    Kortlever, Roderik M; Nijwening, Jeroen H; Bernards, René

    2008-09-01

    The cytokine transforming growth factor beta (TGFbeta) has strong antiproliferative activity in most normal cells but contributes to tumor progression in the later stages of oncogenesis. It is not fully understood which TGFbeta target genes are causally involved in mediating its cytostatic activity. We report here that suppression of the TGFbeta target gene encoding plasminogen activator inhibitor-1 (PAI-1) by RNA interference leads to escape from the cytostatic activity of TGFbeta both in human keratinocytes (HaCaTs) and primary mouse embryo fibroblasts. Consistent with this, PAI-1 knock-out mouse embryo fibroblasts are also resistant to TGFbeta growth arrest. Conversely, we show that ectopic expression of PAI-1 in proliferating HaCaT cells induces a growth arrest. PAI-1 knockdown does not interfere with canonical TGFbeta signaling as judged by SMAD phosphorylation and induction of bona fide TGFbeta target genes. Instead, knockdown of PAI-1 results in sustained activation of protein kinase B. Significantly, we find that constitutive protein kinase B activity leads to evasion of the growth-inhibitory action of TGFbeta. Our data are consistent with a model in which induction of PAI-1 by TGFbeta is critical for the induction of proliferation arrest.

  4. The method of impedance transformation for electromagnetic waves propagating in one-dimension plasma photonic crystal

    NASA Astrophysics Data System (ADS)

    Yao, Jingfeng; Yuan, Chengxun; Gao, Ruilin; Jia, Jieshu; Wang, Ying; Zhou, Zhongxiang; Wang, Xiaoou; Wu, Jian; Li, Hui

    2016-08-01

    This study focuses on the transmission of normal-incidence electromagnetic waves in one-dimensional plasma photonic crystals. Using the Maxwell's equations in a medium, a method that is based on the concept of impendence is employed to perform the simulation. The accuracy of the method was evaluated by simulating a one-layer plasma and conventional photonic crystal. In frequency-domain, the transmission and reflection coefficients in the unmagnetized plasma photonic crystal were calculated, and the influence factors on plasma photonic crystals including dielectric constants of dielectric, spatial period, filling factor, plasma frequency, and collision frequency were studied.

  5. Continuous wavelet transform analysis for self-similarity properties of turbulence in magnetized DC glow discharge plasma

    NASA Astrophysics Data System (ADS)

    Sarma, Bornali; Chauhan, Sourabh S.; Wharton, A. M.; Iyengar, A. N. Sekar; Iyengar

    2013-10-01

    Characterization of self-similarity properties of turbulence in magnetized plasma is being carried out in DC glow discharge plasma. The time series floating potential fluctuation experimental data are acquired from the plasma by Langmuir probe. Continuous wavelet transform (CWT) analysis considering db4 mother wavelet has been applied to the experimental data and self-similarity properties are detected by evaluating the Hurst exponent from the wavelet variance plotting. From the CWT spectrum, effort is made to extract a highly correlated frequency by locating the brightest spot. Accordingly, those signals are treated for finding out correlation dimension and the Liapunov exponent so that the exact frequency responsible for the chaotic behavior could be found out.

  6. Growth Hormone Induces Transforming Growth Factor-Beta-Induced Protein in Podocytes: Implications for Podocyte Depletion and Proteinuria.

    PubMed

    Chitra, P Swathi; Swathi, T; Sahay, Rakesh; Reddy, G Bhanuprakash; Menon, Ram K; Kumar, P Anil

    2015-09-01

    The glomerular podocytes form a major size selective barrier for the filtration of serum proteins and reduced podocyte number is a critical event in the pathogenesis of proteinuria during diabetic nephropathy (DN). An elevated level of growth hormone (GH) is implicated as a causative factor in the development of nephropathy in patients with type 1 diabetes mellitus. We have previously shown that podocytes express GH receptor and are a target for GH action. To elucidate the molecular basis for the effects of GH on podocyte depletion, we conducted PCR-array analyses for extracellular matrix and adhesion molecules in podocytes. Our studies reveal that GH increases expression of a gene that encodes transforming growth factor-beta-induced protein (TGFBIp) expression. Similarly, microarray data retrieved from the Nephromine database revealed elevation of TGFBIp in patients with DN. Treatment with GH results in increased secretion of extracellular TGFBIp by podocytes. Both GH and TGFBIp induced apoptosis and epithelial mesenchymal transition (EMT) of podocytes. Exposure of podocytes to GH and TGFBIp resulted in increased migration of cells and altered podocyte permeability to albumin across podocyte monolayer. Administration of GH to rats induced EMT and apoptosis in the glomerular fraction of the kidney. Therefore, we conclude that the GH-dependent increase in TGFBIp in the podocyte is one of the mechanisms responsible for podocyte depletion in DN. PMID:25740786

  7. Expression of transforming growth factor β and fibroblast growth factor 2 in the lens epithelium of Morioka cataract mice.

    PubMed

    Kondo, Tomohiro; Ishiga-Hashimoto, Naoko; Nagai, Hiroaki; Takeshita, Ai; Mino, Masaki; Morioka, Hiroshi; Kusakabe, Ken Takeshi; Okada, Toshiya

    2014-05-01

    In the Morioka cataract (MCT) mice, lens opacity appears at 6 to 8 weeks of age, and swollen lens fiber is electron-microscopically observed at 3 weeks after birth. The present study was designed to characterize the expression of transforming growth factor β (TGFβ) and fibroblast growth factor 2 (FGF2) in the lens epithelium of the MCT mice. Immunohistochemical analysis showed that the expression of TGFβ in the lens epithelium of the MCT mice was stronger than that of the wild-type ddY mice at 2 and 4 weeks after birth. The expression of TGFβ receptors (TGFβRI and TGFβRII) and FGF2 in the lens epithelium of the MCT mice was stronger than that of the wild-type ddY mice at 4 weeks and weaker than that of the wild-type ddY mice at 15 weeks after birth. Using real time polymerase chain reaction (PCR), quantitative RT-PCR analysis showed that expression of TGFβ1 and TGFβ2 mRNA in the lens of 2-week-old MCT mice was significantly higher compared to age-matched wild-type ddY mice. These findings indicate that the lens epithelium of MCT mice has increased expression of TGFβ before cataract affection and that changes in the expression of FGF2 as well as TGFβ may contribute to the progression of the cataract in the mice.

  8. Butachlor, a suspected carcinogen, alters growth and transformation characteristics of mouse liver cells.

    PubMed

    Ou, Y H; Chung, P C; Chang, Y C; Ngo, F Q; Hsu, K Y; Chen, F D

    2000-12-01

    Butachlor is a widely used herbicide in Asia and South America. Previous investigations have indicated that it is a suspected carcinogen. To understand more about the biological effects of butachlor on cultured cells and the mechanism(s) of its carcinogenicity, we studied the alteration of the growth characteristics that was induced by butachlor in normal mouse liver cells (BNL CL2). This study demonstrates that butachlor decreases the population-doubling time of BNL CL2 cells, suggesting that it stimulates cell proliferation. To support this finding, a thymidine incorporation assay was conducted and a similar result that butachlor stimulates cell proliferation was elucidated. In addition, we show that butachlor increases the saturation density of the BNL CL2 cells. When combined with the tumor initiator N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), butachlor transforms cells efficiently, as demonstrated by loss of contact inhibition. These findings indicate that butachlor alters the growth characteristics of BNL CL2 cells and suggest that butachlor may induce malignant transformation through stimulation of cell proliferation, alteration of cell cycle regulation, and suppression of cell density-dependent inhibition of proliferation.

  9. Transforming growth factor-alpha precursors in human colon carcinoma cells.

    PubMed

    Asbert, M; Montaner, B; Pérez-Tomás, R

    2001-06-01

    Among the proteins of the epidermal growth factor family, transforming growth factor-alpha (TGF-alpha) may be an especially reliable indicator of metastasis or prognosis in human colorectal carcinomas. Moreover, anomalous forms of TGF-alpha have been detected in several tissues of cancer origin, suggesting a role of these forms in the development of the disease. This study was designed to identify the presence of TGF-alpha precursors in different colon cancer cell lines by mean of immunocytochemistry and western blotting techniques. Pro-TGF-alpha was detected in all cell lines tested. Staining for pro-TGF-alpha was observed in cytoplasm. Monoclonal antibody to TGF-alpha detected two bands of 20 and 21 kDa. Polyclonal antibody to pro-TGF-alpha revealed five bands ranging from 15 to 24 kDa. All these proteins were also detected in nonmalignant cells expressing a transfected rat pro-TGF-alpha gene. In conclusions, transformation in these human colon carcinoma cells is not due to the presence of anomalous forms of TGF-alpha precursors.

  10. Strong magnetic field-assisted growth of carbon nanofibers and its microstructural transformation mechanism

    PubMed Central

    Luo, Chengzhi; Fu, Qiang; Pan, Chunxu

    2015-01-01

    It is well-known that electric and magnetic fields can control the growth direction, morphology and microstructure of one-dimensional carbon nanomaterials (1-DCNMs), which plays a key role for its potential applications in micro-nano-electrics and devices. In this paper, we introduce a novel process for controlling growth of carbon nanofibers (CNFs) with assistance of a strong magnetic field (up to 0.5 T in the center) in a chemical vapor deposition (CVD) system. The results reveal that: 1) The CNFs get bundled when grown in the presence of a strong magnetic field and slightly get aligned parallel to the direction of the magnetic field; 2) The CNFs diameter become narrowed and homogenized with increase of the magnetic field; 3) With the increase of the magnetic field, the microstructure of CNFs is gradually changed, i.e., the strong magnetic field makes the disordered “solid-cored” CNFs transform into a kind of bamboo-liked carbon nanotubes; 4) We propose a mechanism that the reason for these variations and transformation is due to diamagnetic property of carbon atoms, so that it has direction selectivity in the precipitation process. PMID:25761381

  11. Retinoic acid modulates rat Ito cell proliferation, collagen, and transforming growth factor beta production.

    PubMed Central

    Davis, B H; Kramer, R T; Davidson, N O

    1990-01-01

    Recent studies suggest that vitamin A plays an inhibitory role with respect to "activation" of the hepatic Ito cell, a likely effector of hepatic fibrogenesis. Ito cell "activation" during fibrogenesis is characterized by a decrease in intracellular vitamin A and an increase in cellular proliferation and collagen production. To explore the hypothesis that retinoids have the capacity to diminish Ito cell activation, cultured Ito cells were exposed to retinoic acid and its effects assessed on three key features: cell proliferation, collagen protein production and mRNA abundance, and transforming growth factor beta protein production. Retinoic acid was 100-1,000X more potent than retinol with respect to inhibition of Ito cell proliferation. Interstitial collagen and transforming growth factor beta production were also reduced by 10(-6) M retinoic acid. The relative abundance of type I collagen mRNA however, was not significantly altered. By contrast, retinoic acid administration to rats caused a marked reduction in the abundance of type I collagen mRNA in both total hepatic and purified Ito cell RNA. The relative abundance of rat hepatic fibronectin or apolipoprotein E mRNA was not significantly altered. These studies demonstrate that retinoic acid can differentially modulate several key features of hepatic fibrogenesis in vitro and in vivo. Images PMID:2254460

  12. Strong magnetic field-assisted growth of carbon nanofibers and its microstructural transformation mechanism.

    PubMed

    Luo, Chengzhi; Fu, Qiang; Pan, Chunxu

    2015-01-01

    It is well-known that electric and magnetic fields can control the growth direction, morphology and microstructure of one-dimensional carbon nanomaterials (1-DCNMs), which plays a key role for its potential applications in micro-nano-electrics and devices. In this paper, we introduce a novel process for controlling growth of carbon nanofibers (CNFs) with assistance of a strong magnetic field (up to 0.5 T in the center) in a chemical vapor deposition (CVD) system. The results reveal that: 1) The CNFs get bundled when grown in the presence of a strong magnetic field and slightly get aligned parallel to the direction of the magnetic field; 2) The CNFs diameter become narrowed and homogenized with increase of the magnetic field; 3) With the increase of the magnetic field, the microstructure of CNFs is gradually changed, i.e., the strong magnetic field makes the disordered "solid-cored" CNFs transform into a kind of bamboo-liked carbon nanotubes; 4) We propose a mechanism that the reason for these variations and transformation is due to diamagnetic property of carbon atoms, so that it has direction selectivity in the precipitation process. PMID:25761381

  13. Strong magnetic field-assisted growth of carbon nanofibers and its microstructural transformation mechanism

    NASA Astrophysics Data System (ADS)

    Luo, Chengzhi; Fu, Qiang; Pan, Chunxu

    2015-03-01

    It is well-known that electric and magnetic fields can control the growth direction, morphology and microstructure of one-dimensional carbon nanomaterials (1-DCNMs), which plays a key role for its potential applications in micro-nano-electrics and devices. In this paper, we introduce a novel process for controlling growth of carbon nanofibers (CNFs) with assistance of a strong magnetic field (up to 0.5 T in the center) in a chemical vapor deposition (CVD) system. The results reveal that: 1) The CNFs get bundled when grown in the presence of a strong magnetic field and slightly get aligned parallel to the direction of the magnetic field; 2) The CNFs diameter become narrowed and homogenized with increase of the magnetic field; 3) With the increase of the magnetic field, the microstructure of CNFs is gradually changed, i.e., the strong magnetic field makes the disordered ``solid-cored'' CNFs transform into a kind of bamboo-liked carbon nanotubes; 4) We propose a mechanism that the reason for these variations and transformation is due to diamagnetic property of carbon atoms, so that it has direction selectivity in the precipitation process.

  14. Plasma Astrophysics - Cosmology and the Growth of Cosmic Structure

    SciTech Connect

    Mushotzky, Richard

    2007-08-02

    I will present some of the ways that x-ray spectroscopy can be utilized to determine cosmological parameters focusing on 5 methods: the gas fraction in clusters, the use of the Sunyaev-Zeldovich effect, the detection of resonance scattering in clusters, the use of resonance absorption and emission in background sources and the growth of structure. All of these techniques except the S-Z effect rely heavily on high resolution x-ray spectroscopy and require the next generation of x-ray spectroscopic missions such as Constellation-X. The promise of these techniques is great and they have the potential for precision cosmology with errors similar to those of other precision techniques such as type Ia supernova. If time permits I will also talk about how we can learn about how active galaxies strongly influence the growth of cosmic structure and how broad band high resolution x-ray spectra are necessary to measure the effects of AGN and how much energy they input into the universe and the role of new atomic physics calculations in interpreting these results. A related discussion can be found in a previously published manuscript.

  15. Radioimmunoassay of human growth hormone: technique and application to plasma, cerebrospinal fluid, and pituitary extracts

    PubMed Central

    Thomas, Frances J.; Lloyd, H. M.; Thomas, M. J.

    1972-01-01

    A radioimmunoassay for human growth hormone using activated charcoal is described and its precision, accuracy, and sensitivity are defined. Results are presented for growth hormone measurements in plasma obtained during hypoglycaemia induced with insulin in patients of short stature and during glucose tolerance tests in patients with acromegaly. The method was used to measure growth hormone concentrations in cerebrospinal fluid and in extracts of pituitary tumours. No growth hormone was detected in the cerebrospinal fluid of patients without acromegaly. In patients with acromegaly, the concentration of growth hormone in cerebrospinal fluid was measurable and was considerably elevated in one patient with extrasellar extension of a pituitary tumour. Extracts of chromophobe pituitary tumours contained very small concentrations of growth hormone. In extracts of pituitary tumours removed from acromegalic patients, concentrations fell either below or within the normal range. PMID:5086220

  16. Growth enhancement effects of radish sprouts: atmospheric pressure plasma irradiation vs. heat shock

    NASA Astrophysics Data System (ADS)

    Sarinont, T.; Amano, T.; Kitazaki, S.; Koga, K.; Uchida, G.; Shiratani, M.; Hayashi, N.

    2014-06-01

    We compare growth enhancement effects due to atmospheric air dielectric barrier discharge plasma irradiation and heat shock to seeds of radish sprouts (Raphanus sativus L.). Interactions between radicals and seeds in a short duration of 3 min. lead to the growth enhancement of radish sprouts in a long term of 7 days and the maximum average length is 3.7 times as long as that of control. The growth enhancement effects become gradually weak with time, and hence the ratio of the average length for plasma irradiation to that for control decreases from 3.7 for the first day to 1.3 for 7 day. The average length for heat shock of 60°C for 10 min. and 100°C for 3 min. is longer than that for control, and the maximum average length is 1.3 times as long as that of control. Heat shock has little contribution to the growth enhancement due to plasma irradiation, because the maximum temperature due to plasma irradiation is less than 60°C.

  17. In situ Raman spectroscopy for growth monitoring of vertically aligned multiwall carbon nanotubes in plasma reactor

    SciTech Connect

    Labbaye, T.; Gaillard, M.; Lecas, T.; Kovacevic, E.; Boulmer-Leborgne, Ch.; Guimbretière, G.; Canizarès, A.; Raimboux, N.; Simon, P.; Ammar, M. R.; Strunskus, T.

    2014-11-24

    Portable and highly sensitive Raman setup was associated with a plasma-enhanced chemical vapor deposition reactor enabling in situ growth monitoring of multi-wall carbon nanotubes despite the combination of huge working distance, high growth speed and process temperature and reactive plasma condition. Near Edge X-ray absorption fine structure spectroscopy was used for ex situ sample analysis as a complementary method to in situ Raman spectroscopy. The results confirmed the fact that the “alternating” method developed here can accurately be used for in situ Raman monitoring under reactive plasma condition. The original analytic tool can be of great importance to monitor the characteristics of these nanostructured materials and readily define the ultimate conditions for targeted results.

  18. Theoretical modeling of the plasma-assisted catalytic growth and field emission properties of graphene sheet

    SciTech Connect

    Sharma, Suresh C.; Gupta, Neha

    2015-12-15

    A theoretical modeling for the catalyst-assisted growth of graphene sheet in the presence of plasma has been investigated. It is observed that the plasma parameters can strongly affect the growth and field emission properties of graphene sheet. The model developed accounts for the charging rate of the graphene sheet; number density of electrons, ions, and neutral atoms; various elementary processes on the surface of the catalyst nanoparticle; surface diffusion and accretion of ions; and formation of carbon-clusters and large graphene islands. In our investigation, it is found that the thickness of the graphene sheet decreases with the plasma parameters, number density of hydrogen ions and RF power, and consequently, the field emission of electrons from the graphene sheet surface increases. The time evolution of the height of graphene sheet with ion density and sticking coefficient of carbon species has also been examined. Some of our theoretical results are in compliance with the experimental observations.

  19. Copper-capped carbon nanocones on silicon: plasma-enabled growth control.

    PubMed

    Kumar, Shailesh; Levchenko, Igor; Farrant, David; Keidar, Michael; Kersten, Holger; Ostrikov, Kostya Ken

    2012-11-01

    Controlled self-organized growth of vertically aligned carbon nanocone arrays in a radio frequency inductively coupled plasma-based process is studied. The experiments have demonstrated that the gaps between the nanocones, density of the nanocone array, and the shape of the nanocones can be effectively controlled by the process parameters such as gas composition (hydrogen content) and electrical bias applied to the substrate. Optical measurements have demonstrated lower reflectance of the nanocone array as compared with a bare Si wafer, thus evidencing their potential for the use in optical devices. The nanocone formation mechanism is explained in terms of redistribution of surface and volumetric fluxes of plasma-generated species in a developing nanocone array and passivation of carbon in narrow gaps where the access of plasma ions is hindered. Extensive numerical simulations were used to support the proposed growth mechanism.

  20. Parabens enable suspension growth of MCF-10A immortalized, non-transformed human breast epithelial cells.

    PubMed

    Khanna, Sugandha; Darbre, Philippa D

    2013-05-01

    Parabens (alkyl esters of p-hydroxybenzoic acid) are used extensively as preservatives in consumer products, and intact esters have been measured in several human tissues. Concerns of a potential link between parabens and breast cancer have been raised, but mechanistic studies have centred on their oestrogenic activity and little attention has been paid to any carcinogenic properties. In the present study, we report that parabens can induce anchorage-independent growth of MCF-10A immortalized but non-transformed human breast epithelial cells, a property closely related to transformation and a predictor of tumour growth in vivo. In semi-solid methocel suspension culture, MCF-10A cells produced very few colonies and only of a small size but the addition of 5 × 10(-4) M methylparaben, 10(-5) M n-propylparaben or 10(-5) M n-butylparaben resulted in a greater number of colonies per dish (P < 0.05 in each case) and an increased average colony size (P < 0.001 in each case). Dose-responses showed that concentrations as low as 10(-6) M methylparaben, 10(-7) M n-propylparaben and 10(-7) M n-butylparaben could increase colony numbers (P = 0.016, P = 0.010, P = 0.008, respectively): comparison with a recent measurement of paraben concentrations in human breast tissue samples from 40 mastectomies (Barr et al., 2012) showed that 22/40 of the patients had at least one of the parabens at the site of the primary tumour at or above these concentrations. To our knowledge, this is the first study to report that parabens can induce a transformed phenotype in human breast epithelial cells in vitro, and further investigation is now justified into a potential link between parabens and breast carcinogenesis.

  1. Platelet-rich plasma, plasma rich in growth factors and simvastatin in the regeneration and repair of alveolar bone

    PubMed Central

    RIVERA, CÉSAR; MONSALVE, FRANCISCO; SALAS, JUAN; MORÁN, ANDREA; SUAZO, IVÁN

    2013-01-01

    Platelet preparations promote bone regeneration by inducing cell migration, proliferation and differentiation in the area of the injury, which are essential processes for regeneration. In addition, several studies have indicated that simvastatin (SIMV), widely used for the treatment of hypercholesterolemia, stimulates osteogenesis. The objective of this study was to evaluate the effects of treatment with either platelet-rich plasma (PRP) or plasma rich in growth factors (PRGF) in combination with SIMV in the regeneration and repair of alveolar bone. The jaws of Sprague Dawley rats (n=18) were subjected to rotary instrument-induced bone damage (BD). Animals were divided into six groups: BD/H2O (n=3), distilled water without the drug and alveolar bone damage; BD/H2O/PRP (n=3), BD and PRP; BD/H2O/PRGF (n=3), BD and PRGF; BD/SIMV (n=3), BD and water with SIMV; BD/SIMV/PRP (n=3), BD, PRP and SIMV; and BD/SIMV/PRGF (n=3), BD, PRGF and SIMV. Conventional histological analysis (hematoxylin and eosin staining) revealed that the BD/SIMV group showed indicators for mature bone tissue, while the BD/SIMV/PRP and BD/SIMV/PRGF groups showed the coexistence of indicators for mature and immature bone tissue, with no statistical differences between the platelet preparations. Simvastatin did not improve the effect of platelet-rich plasma and plasma rich in growth factors. It was not possible to determine which platelet preparation produced superior effects. PMID:24250728

  2. P-cadherin regulates human hair growth and cycling via canonical Wnt signaling and transforming growth factor-β2.

    PubMed

    Samuelov, Liat; Sprecher, Eli; Tsuruta, Daisuke; Bíró, Tamás; Kloepper, Jennifer E; Paus, Ralf

    2012-10-01

    P-cadherin is a key component of epithelial adherens junctions, and it is prominently expressed in the hair follicle (HF) matrix. Loss-of-function mutations in CDH3, which encodes P-cadherin, result in hypotrichosis with juvenile macular dystrophy (HJMD), an autosomal recessive disorder featuring sparse and short hair. Here, we attempted to recapitulate some aspects of HJMD in vitro by transfecting normal, organ-cultured human scalp HFs with lipofectamine and CDH3-specific or scrambled control siRNAs. As in HJMD patients, P-cadherin silencing inhibited hair shaft growth, prematurely induced HF regression (catagen), and inhibited hair matrix keratinocyte proliferation. In situ, membrane β-catenin expression and transcription of the β-catenin target gene, axin2, were significantly reduced, whereas glycogen synthase kinase 3 β (GSK3β) and phospho-β-catenin immunoreactivity were increased. These effects were partially reversed by inhibiting GSK3β. P-cadherin silencing reduced the expression of the anagen-promoting growth factor, IGF-1, whereas that of transforming growth factor β 2 (TGFβ2; catagen promoter) was enhanced. Neutralizing TGFβ antagonized the catagen-promoting effects of P-cadherin silencing. In summary, we introduce human HFs as an attractive preclinical model for studying the functions of P-cadherin in human epithelial biology and pathology. This model demonstrates that cadherins can be successfully knocked down in an intact human organ in vitro, and shows that P-cadherin is needed for anagen maintenance by regulating canonical Wnt signaling and suppressing TGFβ2.

  3. Transforming growth factor-beta 1 does not relate to hypertension in pre-eclampsia.

    PubMed

    Hennessy, A; Orange, S; Willis, N; Painter, D M; Child, A; Horvath, J S

    2002-11-01

    1. Pre-eclampsia is a human disease of pregnancy characterized by high blood pressure, proteinuria and end-organ damage, if severe. Pre-eclampsia is thought to be related to changes in early placental development, with the formation of a shallower than normal placental bed. 2. Transforming growth factor (TGF)-beta1 is a multifunctional fibrogenic growth factor involved in immune regulation that is elevated in some populations with a high risk of hypertensive end-organ disease related to increases in endothelin release. Transforming growth factor-beta1 is also an important factor in placental implantation. Alterations in TGF-beta1 may be related to abnormal placental development in early pregnancy and, thus, are a candidate for the development of hypertension in pre-eclampsia. 3. The aim of the present study was to examine the placental distribution and serum concentration of TGF-beta1 in patients with pre-eclampsia compared with normal pregnancy. 4. Patients with pre-eclampsia (n = 12) were compared with patients with normal pregnancy (n = 14). Transforming growth factor-beta1 was determined by TGF-beta1 Max ELISA (Promega, Madsion, WI, USA) after serum dilution (1/150) and acid activation. Placental distribution was determined by immunostaining with TGF-beta1 (Santa Cruz, Santa Cruz, CA, USA; 20 ng/mL) and the villi and decidual trophoblast were scored for intensity and extent of staining. 5. Patients with pre-eclampsia had a mean gestational age of 36 weeks, whereas those with a normal pregnancy had a mean gestational age of 39.0 +/- 0.4 weeks. There was no difference in TGF-beta1 concentration between the two groups (mean (+/-SEM) 27.1 +/- 1.0 vs 26.4 +/- 0.7 pg/mL for normal pregnancy and pre-eclampsia, respectively; P = 0.73, Mann-Whitney U-test). There was no correlation between systolic or diastolic blood pressure and TGF-beta1 concentration (regression analysis P = 0.4 and 0.2). Immunostaining was absent in the villous trophoblast cells and endovascular and

  4. Effects of high voltage nanosecond pulsed plasma and micro DBD plasma on seed germination, growth development and physiological activities in spinach.

    PubMed

    Ji, Sang-Hye; Choi, Ki-Hong; Pengkit, Anchalee; Im, Jun Sup; Kim, Ju Sung; Kim, Yong Hee; Park, Yeunsoo; Hong, Eun Jeong; Jung, Sun Kyung; Choi, Eun-Ha; Park, Gyungsoon

    2016-09-01

    In this study, we analyzed seed germination, seedling growth, and physiological aspects after treatment with high voltage nanosecond pulsed plasma and micro DBD plasma in spinach (Spinacia oleracea L.), a green leafy vegetable known to have low germination rate. Both germination and dry weight of seedlings increased after high voltage pulse shots were applied to spinach seeds. However seeds treated with many shots (10 shots) showed a decrease in germination rate and seedling growth. Seeds treated with air DBD plasma exhibited slightly higher germination and subsequent seedling growth than those treated with N2 plasma. Seed surface was degenerated after treated with high voltage pulsed plasma and micro DBD plasma but no significant difference in the degree of degeneration was observed among micro DBD plasma treatment time. Level of GA3 hormone and mRNA expression of an amylolytic enzyme-related gene in seeds were elevated 1 day after treatment with high voltage pulsed plasma. The relative amount of chlorophyll and total polyphenols in spinach seedlings grown from seeds treated with air DBD plasma was increased in 30 s, 1 min, and 3 min treatments. Taken together, our results suggest a possibility that plasma can enhance seed germination by triggering biochemical processes in seeds. PMID:26944552

  5. Effects of high voltage nanosecond pulsed plasma and micro DBD plasma on seed germination, growth development and physiological activities in spinach.

    PubMed

    Ji, Sang-Hye; Choi, Ki-Hong; Pengkit, Anchalee; Im, Jun Sup; Kim, Ju Sung; Kim, Yong Hee; Park, Yeunsoo; Hong, Eun Jeong; Jung, Sun Kyung; Choi, Eun-Ha; Park, Gyungsoon

    2016-09-01

    In this study, we analyzed seed germination, seedling growth, and physiological aspects after treatment with high voltage nanosecond pulsed plasma and micro DBD plasma in spinach (Spinacia oleracea L.), a green leafy vegetable known to have low germination rate. Both germination and dry weight of seedlings increased after high voltage pulse shots were applied to spinach seeds. However seeds treated with many shots (10 shots) showed a decrease in germination rate and seedling growth. Seeds treated with air DBD plasma exhibited slightly higher germination and subsequent seedling growth than those treated with N2 plasma. Seed surface was degenerated after treated with high voltage pulsed plasma and micro DBD plasma but no significant difference in the degree of degeneration was observed among micro DBD plasma treatment time. Level of GA3 hormone and mRNA expression of an amylolytic enzyme-related gene in seeds were elevated 1 day after treatment with high voltage pulsed plasma. The relative amount of chlorophyll and total polyphenols in spinach seedlings grown from seeds treated with air DBD plasma was increased in 30 s, 1 min, and 3 min treatments. Taken together, our results suggest a possibility that plasma can enhance seed germination by triggering biochemical processes in seeds.

  6. Hammerhead Ribozyme-Mediated Knockdown of mRNA for Fibrotic Growth Factors: Transforming Growth Factor-Beta 1 and Connective Tissue Growth Factor

    PubMed Central

    Robinson, Paulette M.; Blalock, Timothy D.; Yuan, Rong; Lewin, Alfred S.; Schultz, Gregory S.

    2013-01-01

    Excessive scarring (fibrosis) is a major cause of pathologies in multiple tissues, including lung, liver, kidney, heart, cornea, and skin. The transforming growth factor- β (TGF- β) system has been shown to play a key role in regulating the formation of scar tissue throughout the body. Furthermore, connective tissue growth factor (CTGF) has been shown to mediate most of the fibrotic actions of TGF- β, including stimulation of synthesis of extracellular matrix and differentiation of fibroblasts into myofibroblasts. Currently, no approved drugs selectively and specifically regulate scar formation. Thus, there is a need for a drug that selectively targets the TGF- β cascade at the molecular level and has minimal off-target side effects. This chapter focuses on the design of hammerhead ribozymes, measurement of kinetic activity, and assessment of knockdown mRNAs of TGF- β and CTGF in cell cultures. PMID:22131029

  7. Sirtuin Activation: A Role for Plasma Membrane in the Cell Growth Puzzle

    PubMed Central

    2013-01-01

    For more than 20 years, the observation that impermeable oxidants can stimulate cell growth has not been satisfactorily explained. The discovery of sirtuins provides a logical answer to the puzzle. The NADH-dependent transplasma membrane electron transport system, which is stimulated by growth factors and interventions such as calorie restriction, can transfer electrons to external acceptors and protect against stress-induced apoptosis. We hypothesize that the activation of plasma membrane electron transport contributes to the cytosolic NAD+ pool required for sirtuin to activate transcription factors necessary for cell growth and survival. PMID:23033342

  8. Growth of graphene-based films using afterglow of inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Hiramatsu, Mineo; Tomatsu, Masakazu; Kondo, Hiroki; Hori, Masaru

    2014-10-01

    Plasma-enhanced CVD (PECVD) employing methane/hydrogen gases has been used to grow diamond and carbon nanostructures. In the case of graphene growth using PECVD, excessive supply of carbon precursors and ion bombardment on the growing surface would cause secondary nuclei, resulting in small size of graphene grain and degradation in crystallinity. To overcome this issue, in this work, afterglow of inductively coupled plasma (ICP) was used for the growth of graphene. The CVD system is simple and consists of a reaction chamber and a remote radical source that uses an ICP in cylindrical geometry. Methane/hydrogen gases were fed through a quartz tube of 26 mm inner diameter and 20 cm in length. A five-turn rf (13.56 MHz) coil was mounted on the quartz tube. Substrates (Ni-coated Si and Cu foil) were located in the afterglow region of ICP. Growth experiments were carried out for 1-10 min at temperature of 700 C, rf power of 400 W, and total pressure of 100 mTorr. We have successfully fabricated graphene-based films, which was confirmed by the Raman spectrum and SEM image of deposit. We will discuss the planar graphene growth mechanism in terms of precursors and their surface reaction, in conjunction with the growth experiments using microwave plasma and ICP in planar geometry.

  9. Spontaneous healing and growth of locked magnetic island chains in toroidal plasmas

    SciTech Connect

    Fitzpatrick, R.; Waelbroeck, F. L.

    2012-11-15

    Recent experiments have demonstrated that locked magnetic island chains in stellarator plasmas spontaneously heal under certain conditions, and spontaneously grow under others. A formalism initially developed to study magnetic island dynamics in tokamak plasmas is employed to investigate this phenomenon. It is found that island healing/growth transitions can be caused either by a breakdown in torque balance in the vicinity of the island chain, or by an imbalance between the various terms in the island width evolution equation. The scaling of the healing/growth thresholds with the standard dimensionless plasma parameters {beta}, {nu}{sub *}, and {rho}{sub *} is determined. In accordance with the experimental data, it is found that island healing generally occurs at high {beta} and low {nu}{sub *}, and island growth at low {beta} and high {nu}{sub *}. In further agreement, it is found that island healing is accompanied an ion poloidal velocity shift in the electron diamagnetic direction, and island growth by a velocity shift in the ion diamagnetic direction. Finally, it is found that there is considerable hysteresis in the healing/growth cycle, as is also seen experimentally.

  10. Dust particle growth in rf silane plasmas using two-dimensional multi-pass laser light scattering

    NASA Astrophysics Data System (ADS)

    Byoung Chai, Kil; Seon, C. R.; Park, S.; Choe, W.

    2009-10-01

    We measured a spatio-temporal distribution of particle size and a spatial growth rate in a capacitively coupled silane plasma using in situ multi-pass laser light scattering. The two-dimensional measurement was accomplished using a low power He-Ne laser and a set of spherical mirrors across the plasma that enables us to span multiple beam paths over the plasma region in the vertical direction from the electrode sheath to the bulk plasma. In temporal, the measurement result shows two particle growth periods in which the fast particle growth (nucleation) is followed by the slow particle growth (coagulation). In spatial, the fastest particle growth occurred at the highest vertical position that corresponds to the furthest position from the sheath. The particle coagulation modeling indicates that it is consistent with the largest proto particle creation rate in the plasma bulk.

  11. Coordinated Regulation of Apoptosis and Cell Proliferation by Transforming Growth Factor β1 in Cultured Uterine Epithelial Cells

    NASA Astrophysics Data System (ADS)

    Rotello, Rocco J.; Lieberman, Rita C.; Purchio, Anthony F.; Gerschenson, Lazaro E.

    1991-04-01

    Cell and tissue growth is regulated through a complex interplay of stimulatory and inhibitory signals. We describe two biological actions of transforming growth factor β 1 (TGF-β 1) in primary cultures of rabbit uterine epithelial cells: (i) inhibition of cell proliferation and (ii) a concomitant increase in cells undergoing apoptosis (programmed cell death). It is proposed that proliferation and apoptosis together comprise normal cell growth regulation.

  12. Effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of white pekin ducks.

    PubMed

    Xie, Ming; Tang, Jing; Wen, Zhiguo; Huang, Wei; Hou, Shuisheng

    2014-12-01

    A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin B6-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (p<0.05) when pyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin B6 status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (p<0.05). According to quadratic regression, the supplemental pyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate

  13. Prediction of pregnancy viability in bovine in vitro-produced embryos and recipient plasma with Fourier transform infrared spectroscopy

    PubMed Central

    Muñoz, M.; Uyar, A.; Correia, E.; Díez, C.; Fernandez-Gonzalez, A.; Caamaño, J. N.; Martínez-Bello, D.; Trigal, B.; Humblot, P.; Ponsart, C.; Guyader-Joly, C.; Carrocera, S.; Martin, D.; Marquant Le Guienne, B.; Seli, E.; Gomez, E.

    2014-01-01

    We analyzed embryo culture medium (CM) and recipient blood plasma using Fourier transform infrared (FTIR) metabolomics to predict pregnancy outcome. Individually cultured, in vitro-produced (IVP) blastocysts were transferred to recipients as fresh and vitrified-warmed. Spent CM and plasma samples were evaluated using FTIR. The discrimination capability of the classifiers was assessed for accuracy, sensitivity (pregnancy), specificity (nonpregnancy), and area under the receiver operator characteristic curve (AUC). Within all IVP fresh embryos (birth rate = 52%), high AUC were obtained at birth, especially with expanded blastocysts (CM: 0.80 ± 0.053; plasma: 0.89 ± 0.034). The AUC of vitrified IVP embryos (birth rate = 31%) were 0.607 ± 0.038 (CM, expanded blastocysts) and 0.672 ± 0.023 (plasma, all stages). Recipient plasma generally predicted pregnancy outcome better than did embryo CM. Embryos and recipients with improved pregnancy viability were identified, which could increase the economic benefit to the breeding industry. PMID:24997663

  14. Sorption and mineral-promoted transformation of synthetic hormone growth promoters in soil systems.

    PubMed

    Qu, Shen; Kolodziej, Edward P; Cwiertny, David M

    2014-12-24

    This work examines the fate of synthetic growth promoters (trenbolone acetate, melengestrol acetate, and zeranol) in sterilized soil systems, focusing on their sorption to organic matter and propensity for mineral-promoted reactions. In organic-rich soil matrices (e.g., Pahokee Peat), the extent and reversibility of sorption did not generally correlate with compound hydrophobicity (e.g., K(ow) values), suggesting that specific binding interactions (e.g., potentially hydrogen bonding through C17 hydroxyl groups for the trenbolone and melengestrol families) can also contribute to uptake. In soils with lower organic carbon contents (1-5.9% OC), evidence supports sorption occurring in parallel with surface reaction on inorganic mineral phases. Subsequent experiments with pure mineral phases representative of those naturally abundant in soil (e.g., iron, silica, and manganese oxides) suggest that growth promoters are prone to mineral-promoted oxidation, hydrolysis, and/or nucleophilic (e.g., H2O or OH(-)) addition reactions. Although reaction products remain unidentified, this study shows that synthetic growth promoters can undergo abiotic transformation in soil systems, a previously unidentified fate pathway with implications for their persistence and ecosystem effects in the subsurface.

  15. Transforming growth factor-beta and its implication in the malignancy of gliomas.

    PubMed

    Roy, Laurent-Olivier; Poirier, Marie-Belle; Fortin, David

    2015-03-01

    Malignant gliomas are the most common type of primary malignant brain tumors. They are characterized by enhanced growing capabilities, neoangiogenic proliferation, and extensive infiltration of the brain parenchyma, which make their complete surgical resection impossible. Together with transient and refractory responses to standard therapy, these aggressive neoplasms are incurable and present a median survival of 12 to 14 months. Transforming growth factor-beta (TGF-β) is a pleiotropic cytokine of which two of the three isoforms expressed in humans have been shown to be overexpressed proportionally to the histologic grade of glioma malignancy. The increase of chromosomal aberrations and genetic mutations observed in glioma cells turns TGF-β into an oncogene. For that reason, it plays critical roles in glioma progression through induction of several genes implicated in many carcinogenic processes such as proliferation, angiogenesis, and invasion. Consequently, investigators have begun developing innovative therapeutics targeting this growth factor or its signaling pathway in an attempt to hinder TGF-β's appalling effects in order to refine the treatment of malignant gliomas and improve their prognosis. In this paper, we extensively review the TGF-β-induced oncogenic pathways and discuss the diverse new molecules targeting this growth factor. PMID:24590691

  16. Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

    PubMed Central

    Jiang, Lei; Lai, Yiu-Kay; Zhang, Jin-Fang; Chan, Chu-Yan; Lu, Gang; Lin, Marie CM; He, Ming-Liang; Li, Ji-Cheng; Kung, Hsiang-Fu

    2012-01-01

    AIM: To investigate the role of transforming growth factor (TGF)-β-inducible early gene 1 (TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma (HCC) cells. METHODS: Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium (MTT) assay. The expression changes of Smad2, Smad3, Smad4, Smad7, TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line (MIHA), a TGF-β-sensitive hepatoma cell line (Hep3B) and two TGF-β-insensitive hepatoma cell lines (HepG2 and Bel7404) were examined. SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined. Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines (Bel7404 and HepG2). MTT assay and 4’,6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis, respectively. The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis, and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system. RESULTS: TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line, Hep3B, but not in the resistant cell lines. The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1, whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines, which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1. Our data further suggested that stathmin was a direct target of TIEG1, as stathmin was significantly downregulated by TIEG1 overexpression, and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner. CONCLUSION: Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells. PMID:22563190

  17. Immunohistochemical localization of the epidermal growth factor, transforming growth factor alpha, and their receptor in the human mesonephros and metanephros.

    PubMed

    Bernardini, N; Bianchi, F; Lupetti, M; Dolfi, A

    1996-07-01

    The distribution of epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and EGF/TGF alpha receptor were studied by means of immunohistochemical methods starting from the very early stages of human embryonic kidney development. Mesonephros and metanephros were examined in order to detect immunoreactive staining in serial sectioned embryos and fetal kidneys. Anti-EGF immunoprecipitates were found in the S-shaped mesonephric vesicles of 6-week old embryos as well as in the mesonephric duct albeit with a lower degree of reactivity. Intense reactivity was observed in the metanephros within the blastemic caps of the same gestational period; the reaction was weaker within the ureteric bud branches. Bowman's capsule, proximal tubules, and collecting ducts were also reactive in the fetal kidney to varying degrees. The distribution of TGF alpha reactivity in the mesonephros was similar to that observed for EGF but with a lower intensity. In contrast, there was no reactivity in the metanephros, at least during the embyronic periods examined. By the 11th week of gestation, an intense reactivity for TGF alpha polipeptide was shown in the fetal kidney at the level of the proximal tubules and Bowman's capsule; distal tubules as well as all urinary structures from the collecting ducts to the pelvis were less reactive. Finally, EGF/TGF alpha receptor reactivity was identified by the 6th week of development, being more intense in the mesonephros at the level of the mesonephric duct cells. In the metanephros, the ureteric bud-derived branches were reactive, whereas most of the blastemic tissue did not stain. By the 11th week, only the collecting ducts and the remaining urinary structures contained reaction products: Reactivity was distributed to the tissues originating from the ureteric bud branching. Taking into account recent advances in knowledge about the biology of growth factors, the hypothesis is proposed that the secretory components (vesicles

  18. Effect of Cold Plasma Treatment on Seed Germination and Growth of Wheat

    NASA Astrophysics Data System (ADS)

    Jiang, Jiafeng; He, Xin; Li, Ling; Li, Jiangang; Shao, Hanliang; Xu, Qilai; Ye, Renhong; Dong, Yuanhua

    2014-01-01

    This study investigated the effect of cold helium plasma treatment on seed germination, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential (6.0%) and germination rate (6.7%) compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Compared with the control, plant height (20.3%), root length (9.0%) and fresh weight (21.8%) were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content (9.8%), nitrogen (10.0%) and moisture content (10.0%) were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t · ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield.

  19. Serum and seminal plasma insulin-like growth factor-1 in male infertility

    PubMed Central

    Lee, Hyo Serk; Park, Yong-Seog; Lee, Joong Shik

    2016-01-01

    Objective Growth hormone and its mediator, insulin-like growth factor-1 (IGF-1), have been suggested to exert gonadotropic actions in both humans and animals. The present study was conducted to assess the relationship between serum IGF-1 concentration, seminal plasma concentration, and sperm parameter abnormalities. Methods A total of 79 men were enrolled in this study from December 2011 to July 2012 and were prospectively analyzed. Patient parameters analyzed included age, body mass index, smoking status, urological history, and fertility history. Patients were divided into four groups based on their semen parameters: normal (A, n=31), abnormal sperm motility (B, n=12), abnormal sperm morphology (C, n=20), and two or more abnormal parameters (D, n=16). Patient seminal plasma and serum IGF-1 concentrations were determined. Results Patient baseline characteristics were not significantly different between any of the groups. The serum IGF-1 levels in groups B, C, and D were significantly lower than the levels in group A; however, the seminal plasma IGF-1 levels were not significantly different between any of the groups. Conclusion Men with abnormal sperm parameters had significantly lower levels of serum IGF-1 compared with men with normal sperm parameters. Seminal plasma IGF-1 levels, however, did not differ significantly between the groups investigated here. Further investigations will be required to determine the exact mechanisms by which growth hormone and IGF-1 affect sperm quality. PMID:27358827

  20. Effects of ions and atomic hydrogen in plasma-assisted growth of single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Denysenko, I.; Ostrikov, K.; Yu, M. Y.; Azarenkov, N. A.

    2007-10-01

    The growth of single-walled carbon nanotubes (SWCNTs) in plasma-enhanced chemical vapor deposition (PECVD) is studied using a surface diffusion model. It is shown that at low substrate temperatures (⩽1000K), the atomic hydrogen and ion fluxes from the plasma can strongly affect nanotube growth. The ion-induced hydrocarbon dissociation can be the main process that supplies carbon atoms for SWCNT growth and is responsible for the frequently reported higher (compared to thermal chemical vapor deposition) nanotube growth rates in plasma-based processes. On the other hand, excessive deposition of plasma ions and atomic hydrogen can reduce the diffusion length of the carbon-bearing species and their residence time on the nanotube lateral surfaces. This reduction can adversely affect the nanotube growth rates. The results here are in good agreement with the available experimental data and can be used for optimizing SWCNT growth in PECVD.

  1. Evidence against a blood derived origin for transforming growth factor beta induced protein in corneal disorders caused by mutations in the TGFBI gene

    PubMed Central

    Karring, Henrik; Valnickova, Zuzana; Thøgersen, Ida B.; Hedegaard, Chris J.; Møller-Pedersen, Torben; Kristensen, Torsten; Klintworth, Gordon K.

    2007-01-01

    Purpose Several inherited corneal disorders in humans result from mutations in the transforming growth factor beta induced gene (TGFBI), which encodes for the extracellular transforming growth factor beta induced protein (TGFBIp) that is one of the most abundant proteins in the cornea. We previously reported a significant amount of TGFBIp in plasma by immunoblotting using the only TGFBIp antiserum (anti-p68βig-h3) available at that time (anti-p68βig-h3 was generated against residues Val210-His683 of TGFBIp). This observation raised the possibility that a fraction of corneal TGFBIp may originate from the plasma. However, recent experiments in our laboratory indicated that the anti-p68βig-h3 antiserum cross-reacts with an environmental protein contaminant. Therefore, we investigated the specificity of the originally utilized anti-p68βig-h3 antiserum and re-evaluated the amount of TGFBIp in human plasma by immunoblotting using a new specific antiserum. Methods The observed cross-reactivity of the previously utilized anti-p68βig-h3 antiserum was tested by immunoblotting and the antigen identity was determined by mass spectrometry. A part of human TGFBI encoding an NH2-terminal 11.4 kDa fragment of TGFBIp (residues Gly134-Ile236) was amplified by polymerase chain reaction (PCR) and cloned in E. coli. The TGFBIp fragment was expressed in E. coli, purified by Ni2+-affinity chromatography, and used to immunize rabbits to produce a specific antiserum (anti-TGFBIp134-236). To enhance the detection of possible TGFBIp in plasma by allowing a higher sample load, albumin and immunoglobulin G (IgG) were specifically depleted from normal human plasma by affinity chromatography. The presence of TGFBIp in plasma was investigated by immunoblotting using the anti-TGFBIp134-236 antiserum. Purified TGFBIp from porcine corneas was used for estimation of the TGFBIp detection limit. Results The previously utilized TGFBIp antiserum, anti-p68βig-h3, cross-reacted with human keratin-1

  2. Connective tissue growth factor/CCN2-null mouse embryonic fibroblasts retain intact transforming growth factor-{beta} responsiveness

    SciTech Connect

    Mori, Yasuji; Hinchcliff, Monique; Wu, Minghua; Warner-Blankenship, Matthew; Lyons, Karen M.

    2008-03-10

    Background: The matricellular protein connective tissue growth factor (CCN2) has been implicated in pathological fibrosis, but its physiologic role remains elusive. In vitro, transforming growth factor-{beta} (TGF-{beta}) induces CCN2 expression in mesenchymal cells. Because CCN2 can enhance profibrotic responses elicited by TGF-{beta}, it has been proposed that CCN2 functions as an essential downstream signaling mediator for TGF-{beta}. To explore this notion, we characterized TGF-{beta}-induced activation of fibroblasts from CCN2-null (CCN2{sup -/-}) mouse embryos. Methods: The regulation of CCN2 expression was examined in vivo in a model of fibrosis induced by bleomycin. Cellular TGF-{beta} signal transduction and regulation of collagen gene expression were examined in CCN2{sup -/-} MEFs by immunohistochemistry, Northern, Western and RT-PCR analysis, immunocytochemistry and transient transfection assays. Results: Bleomycin-induced skin fibrosis in the mouse was associated with substantial CCN2 up-regulation in lesional fibroblasts. Whereas in vitro proliferation rate of CCN2{sup -/-} MEFs was markedly reduced compared to wild type MEFs, TGF-{beta}-induced activation of the Smad pathways, including Smad2 phosphorylation, Smad2/3 and Smad4 nuclear accumulation and Smad-dependent transcriptional responses, were unaffected by loss of CCN2. The stimulation of COL1A2 and fibronectin mRNA expression and promoter activity, and of corresponding protein levels, showed comparable time and dose-response in wild type and CCN2{sup -/-} MEFs, whereas stimulation of alpha smooth muscle actin and myofibroblast transdifferentiation showed subtle impairment in MEFs lacking CCN2. Conclusion: Whereas endogenous CCN2 plays a role in regulation of proliferation and TGF-{beta}-induced myofibroblast transdifferentiation, it appears to be dispensable for Smad-dependent stimulation of collagen and extracellular matrix synthesis in murine embryonic fibroblasts.

  3. Effect of overexpression of radish plasma membrane aquaporins on water-use efficiency, photosynthesis and growth of Eucalyptus trees.

    PubMed

    Tsuchihira, Ayako; Hanba, Yuko T; Kato, Naoki; Doi, Tomonori; Kawazu, Tetsu; Maeshima, Masayoshi

    2010-03-01

    Eucalyptus is a diverse genus of flowering trees with more than 700 genotypic species which are mostly native to Australia. We selected 19 wild provenances of Eucalyptus camaldulensis grown in Australia, compared their growth rate and drought tolerance and determined the protein levels of plasma membrane aquaporins (PIPs). There was a positive relationship between the drought tolerance and PIP content. PIPs are divided into two subgroups, PIP1 and PIP2. Most members of the PIP2 subgroup, but not PIP1 subgroup, exhibit water channel activity. We introduced two radish (Raphanus sativus L.) PIPs, RsPIP1;1 and RsPIP2;1, into a hybrid clone of Eucalyptus grandis and Eucalyptus urophylla to examine the effect of their overexpression. Expression of these genes was confirmed by real-time polymerase chain reaction (PCR) and the protein accumulation of RsPIP2;1 by immunoblotting. Drought tolerance was not enhanced in transgenic lines of either gene. However, one transgenic line expressing RsPIP2;1 showed high photosynthesis activity and growth rate under normal growth conditions. For RsPIP1;1-transformed lines, the RsPIP1;1 protein did not accumulate, and the abundance of endogenous PIP1 and PIP2 was decreased. The endogenous PIP1 and PIP2 genes were suppressed in these lines. Therefore, the decreased levels of PIP1 and PIP2 protein may be due to co-suppression of the PIP genes and/or high turnover of PIP proteins. RsPIP1;1-expressing lines gave low values of photosynthesis and growth compared with the control. These results suggest that down-regulation of PIP1 and PIP2 causes serious damage and that up-regulation of PIP2 improves the photosynthetic activity and growth of Eucalyptus trees.

  4. Interferon-alpha inhibits murine macrophage transforming growth factor-beta mRNA expression.

    PubMed

    Dhanani, S; Huang, M; Wang, J; Dubinett, S M

    1994-06-01

    Transforming growth factor-beta (TGF-beta), a multifunctional polypeptide is produced by a wide variety of cells and regulates a broad array of physiological and pathological functions. TGF-beta appears to play a central role in pulmonary fibrosis and may contribute to tumor-associated immunosuppression. Alveolar macrophages are a rich source of TGF-beta and are intimately involved in lung inflammation. We therefore chose to study TGF-beta regulation in murine alveolar macrophages as well as an immortalized peritoneal macrophage cell line (IC-21). Murine macrophages were incubated with cytokines to evaluate their role in regulating TGF-beta mRNA expression. We conclude that IFN-alpha downregulates TGF-beta mRNA expression in murine macrophages. PMID:8088926

  5. Role of transforming growth factor-beta (TGF) beta in the physiopathology of rheumatoid arthritis.

    PubMed

    Gonzalo-Gil, Elena; Galindo-Izquierdo, María

    2014-01-01

    Transforming growth factor-beta (TGF-β) is a cytokine with pleiotropic functions in hematopoiesis, angiogenesis, cell proliferation, differentiation, migration and apoptosis. Although its role in rheumatoid arthritis is not well defined, TGF-β activation leads to functional immunomodulatory effects according to environmental conditions. The function of TGF-β in the development of arthritis in murine models has been extensively studied with controversial results. Recent findings point to a non-relevant role for TGF-β in a mice model of collagen-induced arthritis. The study of TGF-β on T-cell responses has shown controversial results as an inhibitor or promoter of the inflammatory response. This paper presents a review of the role of TGF-β in animal models of arthritis.

  6. Transforming growth factor-β: an important mediator in Helicobacter pylori-associated pathogenesis

    PubMed Central

    Li, Nianshuang; Xie, Chuan; Lu, Nong-Hua

    2015-01-01

    Helicobacter pylori (H.pylori) is a Gram-negative, microaerophilic, helical bacillus that specifically colonizes the gastric mucosa. The interaction of virulence factors, host genetic factors, and environmental factors contributes to the pathogenesis of H. pylori-associated conditions, such as atrophic gastritis and intestinal metaplasia. Infection with H. pylori has recently been recognized as the strongest risk factor for gastric cancer. As a pleiotropic cytokine, transforming growth factor (TGF)-β regulates various biological processes, including cell cycle, proliferation, apoptosis, and metastasis. Recent studies have shed new light on the involvement of TGF-β signaling in the pathogenesis of H. pylori infection. This review focuses on the potential etiological roles of TGF-β in H. pylori-mediated gastric pathogenesis. PMID:26583078

  7. Transforming growth factor-beta1 mediates cellular response to DNA damage in situ

    NASA Technical Reports Server (NTRS)

    Ewan, Kenneth B.; Henshall-Powell, Rhonda L.; Ravani, Shraddha A.; Pajares, Maria Jose; Arteaga, Carlos; Warters, Ray; Akhurst, Rosemary J.; Barcellos-Hoff, Mary Helen

    2002-01-01

    Transforming growth factor (TGF)-beta1 is rapidly activated after ionizing radiation, but its specific role in cellular responses to DNA damage is not known. Here we use Tgfbeta1 knockout mice to show that radiation-induced apoptotic response is TGF-beta1 dependent in the mammary epithelium, and that both apoptosis and inhibition of proliferation in response to DNA damage decrease as a function of TGF-beta1 gene dose in embryonic epithelial tissues. Because apoptosis in these tissues has been shown previously to be p53 dependent, we then examined p53 protein activation. TGF-beta1 depletion, by either gene knockout or by using TGF-beta neutralizing antibodies, resulted in decreased p53 Ser-18 phosphorylation in irradiated mammary gland. These data indicate that TGF-beta1 is essential for rapid p53-mediated cellular responses that mediate cell fate decisions in situ.

  8. CYLD negatively regulates transforming growth factor-β-signalling via deubiquitinating Akt

    PubMed Central

    Lim, Jae Hyang; Jono, Hirofumi; Komatsu, Kensei; Woo, Chang-Hoon; Lee, Jiyun; Miyata, Masanori; Matsuno, Takashi; Xu, Xiangbin; Huang, Yuxian; Zhang, Wenhong; Park, Soo Hyun; Kim, Yu-Il; Choi, Yoo-Duk; Shen, Huahao; Heo, Kyung-Sun; Xu, Haodong; Bourne, Patricia; Koga, Tomoaki; Xu, Haidong; Yan, Chen; Wang, Binghe; Chen, Lin-Feng; Feng, Xin-Hua; Li, Jian-Dong

    2012-01-01

    Lung injury, whether induced by infection or caustic chemicals, initiates a series of complex wound-healing responses. If uncontrolled, these responses may lead to fibrotic lung diseases and loss of function. Thus, resolution of lung injury must be tightly regulated. The key regulatory proteins required for tightly controlling the resolution of lung injury have yet to be identified. Here we show that loss of deubiquitinase CYLD led to the development of lung fibrosis in mice after infection with Streptococcus pneumoniae. CYLD inhibited transforming growth factor-β-signalling and prevented lung fibrosis by decreasing the stability of Smad3 in an E3 ligase carboxy terminus of Hsc70-interacting protein-dependent manner. Moreover, CYLD decreases Smad3 stability by deubiquitinating K63-polyubiquitinated Akt. Together, our results unveil a role for CYLD in tightly regulating the resolution of lung injury and preventing fibrosis by deubiquitinating Akt. These studies may help develop new therapeutic strategies for preventing lung fibrosis. PMID:22491319

  9. Proton NMR assignment and secondary structural elements of human transforming growth factor. alpha

    SciTech Connect

    Brown, S.C.; Mueller, L.; Jeffs, P.W. )

    1989-01-24

    The {sup 1}H NMR spectrum of human transforming growth factor {alpha} (hTGF-{alpha}) has been completely assigned, and secondary structural elements have been identified as a preliminary step in determining the structure of this protein by distance geometry methods. Many of these structural elements closely correspond to those previously found in a truncated human EGF and murine EGF. These include the presence of an antiparallel {beta}-sheet between residues G19 and C34 with a type I {beta}-turn at V25-D28, a type II {beta}-turn at H35-Y38, and another short {beta}-sheet between residues Y38-V39 and H45-A46.

  10. Effect of Cellulose Acetate Beads on the Release of Transforming Growth Factor-β.

    PubMed

    Nishise, Shoichi; Abe, Yasuhiko; Nomura, Eiki; Sato, Takeshi; Sasaki, Yu; Iwano, Daisuke; Yagi, Makoto; Sakuta, Kazuhiro; Shibuya, Rika; Mizumoto, Naoko; Kanno, Nana; Ueno, Yoshiyuki

    2015-08-01

    Transforming growth factor-β (TGF-β) is released by activated platelets and induces the differentiation of T-helper 17 from naïve T cells. Contact between blood and cellulose acetate (CA) beads induces cytokine release, although their inflammatory effects on TGF-β release are unclear. We aimed to clarify the effect of CA beads on the release of TGF-β in vitro. We incubated peripheral blood with and without CA beads and measured platelets and TGF-β. Compared with blood samples incubated without beads, the platelet count and amount of TGF-β significantly decreased in blood samples incubated with CA beads. In conclusion, CA beads inhibited the release of TGF-β from adsorbed platelets. The biological effects of this reduction of TGF-β release during platelet adsorption to CA beads need further clarification.

  11. Transforming growth factor Beta2 is required for valve remodeling during heart development.

    PubMed

    Azhar, Mohamad; Brown, Kristen; Gard, Connie; Chen, Hwudaurw; Rajan, Sudarsan; Elliott, David A; Stevens, Mark V; Camenisch, Todd D; Conway, Simon J; Doetschman, Thomas

    2011-09-01

    Although the function of transforming growth factor beta2 (TGFβ2) in epithelial mesenchymal transition (EMT) is well studied, its role in valve remodeling remains to be fully explored. Here, we used histological, morphometric, immunohistochemical and molecular approaches and showed that significant dysregulation of major extracellular matrix (ECM) components contributed to valve remodeling defects in Tgfb2(-/-) embryos. The data indicated that cushion mesenchymal cell differentiation was impaired in Tgfb2(-/-) embryos. Hyaluronan and cartilage link protein-1 (CRTL1) were increased in hyperplastic valves of Tgfb2(-/-) embryos, indicating increased expansion and diversification of cushion mesenchyme into the cartilage cell lineage during heart development. Finally, Western blot and immunohistochemistry analyses indicate that the activation of SMAD2/3 was decreased in Tgfb2(-/-) embryos during valve remodeling. Collectively, the data indicate that TGFβ2 promotes valve remodeling and differentiation by inducing matrix organization and suppressing cushion mesenchyme differentiation into cartilage cell lineage during heart development.

  12. Regulation of the transforming growth factor β pathway by reversible ubiquitylation.

    PubMed

    Al-Salihi, Mazin A; Herhaus, Lina; Sapkota, Gopal P

    2012-05-01

    The transforming growth factor β (TGFβ) signalling pathway plays a central role during embryonic development and in adult tissue homeostasis. It regulates gene transcription through a signalling cascade from cell surface receptors to intracellular SMAD transcription factors and their nuclear cofactors. The extent, duration and potency of signalling in response to TGFβ cytokines are intricately regulated by complex biochemical processes. The corruption of these regulatory processes results in aberrant TGFβ signalling and leads to numerous human diseases, including cancer. Reversible ubiquitylation of pathway components is a key regulatory process that plays a critical role in ensuring a balanced response to TGFβ signals. Many studies have investigated the mechanisms by which various E3 ubiquitin ligases regulate the turnover and activity of TGFβ pathway components by ubiquitylation. Moreover, recent studies have shed new light into their regulation by deubiquitylating enzymes. In this report, we provide an overview of current understanding of the regulation of TGFβ signalling by E3 ubiquitin ligases and deubiquitylases.

  13. Effect of transforming growth factor-alpha on inositol phospholipid metabolism in human epidermoid carcinoma cells

    SciTech Connect

    Kato, M.; Takenawa, T.; Twardzik, D.R.

    1988-08-01

    Transforming growth factor-alpha (TGF-alpha) stimulates (in a dose-dependent manner) the incorporation of (/sup 32/P)Pi into phosphatidylinositol (PI), phosphatidylinositol 4-phosphate (PIP), phosphatidylinositol 4,5-bisphosphate (PIP2), and phosphatidic acid (PA) in the human epidermoid carcinoma cell line (A431). The effect of TGF-alpha on the incorporation was found to be similar to that of EGF. On the other hand, a striking difference in the activation of diacylglycerol (DG) kinase activity was seen between TGF-alpha and EGF. At least 100 times more TGF-alpha was required to achieve maximal stimulation of DG kinase activity relative to EGF. These results suggest that the activation of DG kinase by TGF-alpha may involve a mechanism independent from or subsequent to activation of the EGF receptor.

  14. The pleiotropic roles of transforming growth factor beta inhomeostasis and carcinogenesis of endocrine organs.

    SciTech Connect

    Fleisch, Markus C.; Maxwell, Christopher A.; Barcellos-Hoff,Mary-Helen

    2006-01-13

    Transforming growth factor beta (TGF-beta) is a ubiquitous cytokine that plays a critical role in numerous pathways regulating cellular and tissue homeostasis. TGF-beta is regulated by hormones and is a primary mediator of hormone response in uterus, prostate and mammary gland. This review will address the role of TGF-beta in regulating hormone dependent proliferation and morphogenesis. The subversion of TGF-beta regulation during the processes of carcinogenesis, with particular emphasis on its effects on genetic stability and epithelial to mesenchymal transition (EMT), will also be examined. An understanding of the multiple and complex mechanisms of TGF-beta regulation of epithelial function, and the ultimate loss of TGF-beta function during carcinogenesis, will be critical in the design of novel therapeutic interventions for endocrine-related cancers.

  15. Transforming growth factor beta differentially modulates the inducible nitric oxide synthase gene in distinct cell types.

    PubMed

    Gilbert, R S; Herschman, H R

    1993-08-31

    Nitric oxide is a mediator of paracrine cell signalling. An inducible form of nitric oxide synthase (iNOS) is expressed in macrophages and in Swiss 3T3 cells. Transforming growth factor beta (TGF-beta) is a cytokine that modulates many cellular functions. We find that TGF-beta cannot induce iNOS mRNA expression, either in macrophage cell lines or in Swiss 3T3 cells. However, TGF-beta attenuates lipopolysaccharide induction of iNOS mRNA in macrophages. In contrast, TGF-beta enhances iNOS induction by phorbol ester, serum or lipopolysaccharide in 3T3 cells. Thus TGF-beta can inhibit or augment iNOS mRNA induction in response to primary inducers, depending on the cell type in question.

  16. Stromal inhibition of prostatic epithelial cell proliferation not mediated by transforming growth factor beta.

    PubMed Central

    Kooistra, A.; van den Eijnden-van Raaij, A. J.; Klaij, I. A.; Romijn, J. C.; Schröder, F. H.

    1995-01-01

    The paracrine influence of prostatic stroma on the proliferation of prostatic epithelial cells was investigated. Stromal cells from the human prostate have previously been shown to inhibit anchorage-dependent as well as anchorage-independent growth of the prostatic tumour epithelial cell lines PC-3 and LNCaP. Antiproliferative activity, mediated by a diffusible factor in the stromal cell conditioned medium, was found to be produced specifically by prostatic stromal cells. In the present study the characteristics of this factor were examined. It is demonstrated that prostate stroma-derived inhibiting factor is an acid- and heat-labile, dithiothreitol-sensitive protein. Although some similarities with type beta transforming growth factor (TGF-beta)-like inhibitors are apparent, evidence is presented that the factor is not identical to TGF-beta or to the TGF-beta-like factors activin and inhibin. Absence of TGF-beta activity was shown by the lack of inhibitory response of the TGF-beta-sensitive mink lung cell line CCL-64 to prostate stromal cell conditioned medium and to concentrated, partially purified preparations of the inhibitor. Furthermore, neutralising antibodies against TGF-beta 1 or TGF-beta 2 did not cause a decline in the level of PC-3 growth inhibition caused by partially purified inhibitor. Using Northern blot analyses, we excluded the involvement of inhibin or activin. It is concluded that the prostate stroma-derived factor may be a novel growth inhibitor different from any of the currently described inhibiting factors. Images Figure 5 PMID:7543773

  17. Inhibition of spermidine synthase gene expression by transforming growth factor-beta 1 in hepatoma cells.

    PubMed Central

    Nishikawa, Y; Kar, S; Wiest, L; Pegg, A E; Carr, B I

    1997-01-01

    We screened genes responsive to transforming growth factor-beta (TGF-beta 1) protein in a human hepatoma cell line (Hep3B) using a PCR-mediated differential display technique, in order to investigate the mechanisms involved in TGF-beta-induced growth suppression. We found a gene that was down-regulated by TGF-beta 1 to be completely identical in an approx. 620 bp segment to the gene for the enzyme spermidine synthase, which mediates the conversion of putrescine into spermidine. Both spermidine synthase mRNA expression and its enzyme activity were decreased after TGF-beta 1 treatment of Hep3B cells. The inhibition of spermidine synthase gene expression by TGF-beta 1 protein was also observed in other hepatoma cell lines. The expression of genes for other biosynthetic enzymes in polyamine metabolism (ornithine decarboxylase and S-adenosylmethionine decarboxylase) was also inhibited to the same extent as for spermidine synthase, while the gene expression of spermidine/spermine N1-acetyltransferase, a catabolic enzyme, was relatively resistant to TGF-beta 1. Spermine levels in Hep3B cells were decreased by TGF-beta 1 treatment, although the levels of spermidine and putrescine were unchanged, probably due to compensation by remaining spermidine/spermine N1-acetyltransferase activity. Exogenously added spermidine or spermine, but not putrescine, partially antagonized the growth-inhibitor effects of TGF-beta 1 on Hep3B cells. Our data suggest that down-regulation of gene expression of the enzymes involved in polyamine metabolism, including spermidine synthase, may be associated with the mechanism of TGF-beta-induced growth suppression. PMID:9020892

  18. Observation of Rayleigh-Taylor-instability growth in a plasma regime with magnetic and viscous stabilization

    NASA Astrophysics Data System (ADS)

    Adams, Colin

    2015-11-01

    Rayleigh-Taylor-instability (RTI) growth during the interaction between a high-Mach-number, unmagnetized plasma jet and a stagnated, magnetized plasma is observed in a regime where the growth of short-wavelength modes is influenced by plasma viscosity and magnetic fields. The time evolution of mode growth at the mostly planar interface is captured by a multi-frame fast camera. Interferometry, spectroscopy, photodiode, and magnetic probe diagnostics are employed to experimentally infer ni, Te, Z , acceleration, B -->, and ion viscosity in the vicinity of the evolving interface. As the instability grows, an evolution from mode wavelengths of ~ 1 . 7 cm to ~ 2 . 8 cm is observed. The growth time (~ 10 μs) and wavelength (~ 1 cm) of the observed modes agree with theoretical predictions computed from the experimentally inferred density (~1014 cm-3), deceleration (~109 m /s2), and magnetic field (~ 15 G in direction of wavevector). Furthermore, comparisons of experimental data with idealized magnetohydrodynamic simulations (which include a physical viscosity model) suggest that both magnetic and viscous stabilization contribute to the observed mode evolution. These data are relevant for benchmarking astrophysical and magneto-inertial-fusion-relevant computations of RTI. Supported by the LANL LDRD Program; PLX facility construction supported by OFES.

  19. Role of transforming growth factor Beta in corneal function, biology and pathology.

    PubMed

    Tandon, A; Tovey, J C K; Sharma, A; Gupta, R; Mohan, R R

    2010-08-01

    Transforming growth factor-beta (TGFbeta) is a pleiotropic multifunctional cytokine that regulates several essential cellular processes in many parts of the body including the cornea. Three isoforms of TGFbeta are known in mammals and the human cornea expresses all of them. TGFbeta1 has been shown to play a central role in scar formation in adult corneas whereas TGFbeta2 and TGFbeta3 have been implicated to play a critical role in corneal development and scarless wound healing during embryogenesis. The biological effects of TGFbeta in the cornea have been shown to follow Smad dependent as well as Smad-independent signaling pathways depending upon cellular responses and microenvironment. Corneal TGFbeta expression is necessary for maintaining corneal integrity and corneal wound healing. On the other hand, TGFbeta is perhaps the most important cytokine in the pathogenesis of fibrotic disease in the cornea. Although the transformation of keratocytes to myofibroblasts induced by TGFbeta is largely believed to cause corneal fibrosis or scarring, the precise molecular mechanism(s) involved in this process is still unknown. Currently no drugs are available to treat corneal scarring effectively without causing significant side effects. Many approaches to treat TGFbeta-mediated corneal scarring are under investigation. These include blocking of TGFbeta, TGFbeta receptor, TGFbeta function and/or TGFbeta maturation. Other strategies such as modulating keratocyte proliferation, apoptosis, transcription and DNA condensation are also being investigated. The potential of gene therapy to neutralize the pathologic effects of TGFbeta has also been demonstrated recently.

  20. Expression and localization of epidermal growth factor, transforming growth factor-α and epidermal growth factor receptor in the canine testis

    PubMed Central

    TAMADA, Hiromichi; TAKEMOTO, Kohei; TOMINAGA, Masato; KAWATE, Noritoshi; TAKAHASHI, Masahiro; HATOYA, Shingo; MATSUYAMA, Satoshi; INABA, Toshio; SAWADA, Tsutomu

    2015-01-01

    Gene expression of epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and EGF receptor (EGF-R) and the localization of the corresponding proteins in the canine testis were studied. Levels of mRNA expressions were determined by semiquantitative reverse transcription polymerase chain reaction in the testes of the peripubertal (4–6 months), young adult (3–4 years), advanced adult (7–8 years) and senescent (11–16 years) groups. The EGF-R mRNA level in the testes of the peripubertal group was significantly higher than those in the other groups, whereas there was no difference in EGF and TGF-α mRNA levels among groups. Immunohistochemical stainings for EGF, TGF-α and EGF-R in the testis revealed that immunoreactivity in the seminiferous epithelium and Sertoli cell was weak and nonspecific for the stage of spermatogenesis, and distinct staining was found in Leydig cells. These results suggest that the EGF family of growth factors may be involved in testicular maturation and function in the dog. PMID:26498203

  1. Regulation of proliferation of embryonic heart mesenchyme: Role of transforming growth factor-beta 1 and the interstitial matrix

    SciTech Connect

    Choy, M.; Armstrong, M.T.; Armstrong, P.B. )

    1990-10-01

    Proliferation of atrioventricular cushion mesenchyme of the embryonic avian heart maintained in three-dimensional aggregate culture is stimulated by interaction with the interstitial matrix. Chicken serum or transforming growth factor-beta 1, which stimulates proliferation, induces matrix deposition in regions of the aggregate showing high labeling indices with tritiated thymidine. Dispersed heart mesenchyme interstitial matrix introduced into serum-free culture is incorporated into the aggregate and stimulates cellular proliferation similar to serum or transforming growth factor-beta 1. Proliferation is reversibly inhibited by the peptide Gly-Arg-Gly-Asp-Ser-Pro. It is suggested that transforming growth factor-beta 1 stimulates the production of interstitial matrix and that a sufficient stimulus for proliferation in this system is the presence of the matrix, which acts as the adhesive support for cellular anchorage.

  2. A Histologically Distinctive Interstitial Pneumonia Induced by Overexpression of the Interleukin 6, Transforming Growth Factor β1, or Platelet-Derived Growth Factor B Gene

    NASA Astrophysics Data System (ADS)

    Yoshida, Mitsuhiro; Sakuma, Junko; Hayashi, Seiji; Abe, Kin'ya; Saito, Izumu; Harada, Shizuko; Sakatani, Mitsunoir; Yamamoto, Satoru; Matsumoto, Norinao; Kaneda, Yasufumi; Kishmoto, Tadamitsu

    1995-10-01

    Interstitial pneumonia is characterized by alveolitis with resulting fibrosis of the interstitium. To determine the relevance of humoral factors in the pathogenesis of interstitial pneumonia, we introduced expression vectors into Wistar rats via the trachea to locally overexpress humoral factors in the lungs. Human interleukin (IL) 6 and IL-6 receptor genes induced lymphocytic alveolitis without marked fibroblast proliferation. In contrast, overexpression of human transforming growth factor β1 or human platelet-derived growth factor B gene induced only mild or apparent cellular infiltration in the alveoli, respectively. However, both factors induced significant proliferation of fibroblasts and deposition of collagen fibrils. These histopathologic changes induced by the transforming growth factor β1 and platelet-derived growth factor B gene are partly akin to those changes seen in lung tissues from patients with pulmonary fibrosis and markedly contrast with the changes induced by overexpression of the IL-6 and IL-6 receptor genes that mimics lymphocytic interstitial pneumonia.

  3. Age- and sex-associated plasma proteomic changes in growth hormone receptor gene-disrupted mice.

    PubMed

    Ding, Juan; Berryman, Darlene E; Jara, Adam; Kopchick, John J

    2012-08-01

    Growth hormone receptor gene-disrupted (GHR-/-) mice are dwarf, insulin sensitive, and long lived despite being obese. In order to identify characteristics associated with their increased longevity, we studied age-related plasma proteomic changes in these mice. Male and female GHR-/- mice and their littermate controls were followed longitudinally at 8, 16, and 24 months of ages for plasma proteomic analysis. Relative to control littermates, GHR-/- mice had increased levels of apolipoprotein A-4 and retinol-binding protein-4 and decreased levels of apolipoprotein E, haptoglobin, and mannose-binding protein-C. Female GHR-/- mice showed decreased inflammatory cytokines including interleukin-1β and monocyte chemotactic protein-1. Additionally, sex differences were found in specific isoforms of apolipoprotein E, RBP-4, haptoglobin, albumin, and hemoglobin subunit beta. In conclusion, we find plasma proteomic changes in GHR-/- mice that favor a longer life span as well as sex differences indicative of an improved health span in female mice. PMID:22156438

  4. Characterization of epidermal growth factor receptors on plasma membranes isolated from rat gastric mucosa

    SciTech Connect

    Hori, R.; Nomura, H.; Iwakawa, S.; Okumura, K. )

    1990-06-01

    The binding of human epidermal growth factor (hEGF), beta-urogastrone, to plasma membranes isolated from rat gastric mucosa was studied to characterize gastric EGF receptors. The binding of ({sup 125}I)hEGF was temperature dependent, reversible, and saturable. A single class of binding sites for EGF with a dissociation constant of 0.42 nM and maximal binding capacity of 42 fmol/mg protein was suggested. There was little change in the binding of ({sup 125}I)hEGF upon addition of peptide hormones (secretin, insulin), antiulcer drugs (cimetidine), or an ulcer-inducing reagent (aspirin). Cross-linking of ({sup 125}I)hEGF to gastric plasma membranes with the use of disuccinimidyl suberate resulted in the labeling of a protein of 150 kDa. These results indicate the presence of EGF receptors on plasma membranes of rat gastric mucosa.

  5. Transforming growth factor-beta regulates stearoyl coenzyme A desaturase expression through a Smad signaling pathway.

    PubMed

    Samuel, William; Nagineni, Chandrasekharam N; Kutty, R Krishnan; Parks, W Tony; Gordon, Joel S; Prouty, Stephen M; Hooks, John J; Wiggert, Barbara

    2002-01-01

    The regulation of stearoyl-CoA desaturase (SCD), a rate-limiting enzyme in the synthesis of unsaturated fatty acids, is physiologically important because the ratio of saturated to unsaturated fatty acids is thought to control cellular functions by modulating the structural integrity and fluidity of cell membranes. Transforming growth factor-beta (TGF-beta), a multifunctional cytokine, increased SCD mRNA expression in cultured human retinal pigment epithelial cells. This response was elicited by all three TGF-beta isoforms, beta1, beta2, and beta3. However, SCD mRNA expression was not increased either by other members of the TGF-beta family or by other growth factors or cytokines. TGF-beta also increased SCD mRNA expression in several other cell lines tested. The increase in SCD mRNA expression was preceded by a marked increase in Smad2 phosphorylation in TGF-beta-treated human retinal pigment epithelial cells. TGF-beta did not induce SCD mRNA expression in a Smad4-deficient cell line. However, Smad4 overexpression restored the TGF-beta effect in this cell line. Moreover, TGF-beta-induced SCD mRNA expression was effectively blocked by the overexpression of Smad7, an inhibitory Smad. Thus, a TGF-beta signal transduction pathway involving Smad proteins appears to regulate the cellular expression of the SCD gene, and this regulation may play an important role in lipid metabolism.

  6. Development and application of fully functional epitope-tagged forms of transforming growth factor-beta.

    PubMed

    Wolfraim, Lawrence A; Alkemade, Gonnie M; Alex, Biju; Sharpe, Shellyann; Parks, W Tony; Letterio, John J

    2002-08-01

    Administration of transforming growth factor-beta (TGF-beta) has been found to be of therapeutic benefit in various mouse disease models and has potential clinical usefulness. However, the ability to track the distribution of exogenously administered, recombinant forms of these proteins has been restricted by cross-reactivity with endogenous TGF-beta and related TGF-beta isoforms. We describe novel FLAG- and hemagglutinin (HA)-tagged versions of mature TGF-beta1 that retain full biological activity as demonstrated by their ability to inhibit the growth of Mv1Lu epithelial cells, and to induce phosphorylation of the TGF-beta signaling intermediate, smad 2. Intracellular FLAG- and HA-TGF-beta1 can be detected in transfected cells by confocal immunofluorescence microscopy. We also describe sandwich ELISAs designed to specifically detect epitope-tagged TGF-beta and demonstrate the utility of these tagged ligands as probes for TGF-beta receptor expression by flow cytometry. The design of these fully functional epitope-tagged TGF-beta proteins should facilitate studies such as the evaluation of in vivo peptide pharmacodynamics and trafficking of TGF-beta ligand-receptor complexes.

  7. Demonstration of single crystal growth via solid-solid transformation of a glass

    DOE PAGES

    Savytskii, Dmytro; Knorr, Brian; Dierolf, Volkmar; Jain, Himanshu

    2016-03-18

    Many advanced technologies have relied on the availability of single crystals of appropriate material such as silicon for microelectronics or superalloys for turbine blades. Similarly, many promising materials could unleash their full potential if they were available in a single crystal form. However, the current methods are unsuitable for growing single crystals of these oftentimes incongruently melting, unstable or metastable materials. Here we demonstrate a strategy to overcome this hurdle by avoiding the gaseous or liquid phase, and directly converting glass into a single crystal. Specifically, Sb2S3 single crystals are grown in Sb-S-I glasses as an example of this approach.more » In this first unambiguous demonstration of an all-solid-state glass → crystal transformation, extraneous nucleation is avoided relative to crystal growth via spatially localized laser heating and inclusion of a suitable glass former in the composition. Lastly, the ability to fabricate patterned single-crystal architecture on a glass surface is demonstrated, providing a new class of micro-structured substrate for low cost epitaxial growth, active planar devices, etc.« less

  8. Regulation of experimental autoimmune neuritis by transforming growth factor-beta 1.

    PubMed

    Gregorian, S K; Lee, W P; Beck, L S; Rostami, A; Amento, E P

    1994-06-01

    Experimental autoimmune neuritis (EAN) is a T-cell-mediated autoimmune disease characterized by demyelination and mononuclear cell infiltration of the peripheral nervous system. It is induced in Lewis rats by administration of myelin P2 protein or a synthetic peptide (SP-26) corresponding to amino acid residues 53-78 of bovine P2 protein. The effects of transforming growth factor-beta 1 (TGF-beta 1) on the clinical signs, histological changes, cell-mediated immune responses, and secretion of interferon-gamma (IFN-gamma) by lymphoid cells of rats with EAN were examined. Systemic administration of TGF-beta 1 markedly inhibited the clinical signs and histological changes of EAN when given intraperitoneally every other day for Days 0 through 18. In addition, it decreased proliferative responses and reduced the delayed-type hypersensitivity (DTH) response to SP-26 compared to control rats. The reduction in clinical severity correlated with skin test unresponsiveness (DTH) to the disease-inducing agent (SP-26) as well to decreased cellular responsiveness to the antigen in vitro. The decrease in cellular responsiveness extended to a decrease in at least one T cell lymphokine, IFN-gamma. The profound effect of TGF-beta on disease progression in EAN, a T-cell-mediated process, is consistent with a direct effect of this growth factor on T lymphocytes. PMID:7515330

  9. Transforming growth factor-{beta}2 enhances differentiation of cardiac myocytes from embryonic stem cells

    SciTech Connect

    Kumar, Dinender . E-mail: Dinender.Kumar@uvm.edu; Sun, Baiming

    2005-06-24

    Stem cell therapy holds great promise for the treatment of injured myocardium, but is challenged by a limited supply of appropriate cells. Three different isoforms of transforming growth factor-{beta} (TGF-{beta}) -{beta}1, -{beta}2, and -{beta}3 exhibit distinct regulatory effects on cell growth, differentiation, and migration during embryonic development. We compared the effects of these three different isoforms on cardiomyocyte differentiation from embryonic stem (ES) cells. In contrast to TGF-{beta}1, or -{beta}3, treatment of mouse ES cells with TGF-{beta}2 isoform significantly increased embryoid body (EB) proliferation as well as the extent of the EB outgrowth that beat rhythmically. At 17 days, 49% of the EBs treated with TGF-{beta}2 exhibited spontaneous beating compared with 15% in controls. Cardiac myocyte specific protein markers sarcomeric myosin and {alpha}-actin were demonstrated in beating EBs and cells isolated from EBs. In conclusion, TGF-{beta}2 but not TGF-{beta}1, or -{beta}3 promotes cardiac myocyte differentiation from ES cells.

  10. Demonstration of single crystal growth via solid-solid transformation of a glass

    NASA Astrophysics Data System (ADS)

    Savytskii, Dmytro; Knorr, Brian; Dierolf, Volkmar; Jain, Himanshu

    2016-03-01

    Many advanced technologies have relied on the availability of single crystals of appropriate material such as silicon for microelectronics or superalloys for turbine blades. Similarly, many promising materials could unleash their full potential if they were available in a single crystal form. However, the current methods are unsuitable for growing single crystals of these oftentimes incongruently melting, unstable or metastable materials. Here we demonstrate a strategy to overcome this hurdle by avoiding the gaseous or liquid phase, and directly converting glass into a single crystal. Specifically, Sb2S3 single crystals are grown in Sb-S-I glasses as an example of this approach. In this first unambiguous demonstration of an all-solid-state glass → crystal transformation, extraneous nucleation is avoided relative to crystal growth via spatially localized laser heating and inclusion of a suitable glass former in the composition. The ability to fabricate patterned single-crystal architecture on a glass surface is demonstrated, providing a new class of micro-structured substrate for low cost epitaxial growth, active planar devices, etc.

  11. Wnt3a upregulates transforming growth factor-β-stimulated VEGF synthesis in osteoblasts.

    PubMed

    Natsume, Hideo; Tokuda, Haruhiko; Matsushima-Nishiwaki, Rie; Kato, Kenji; Yamakawa, Kengo; Otsuka, Takanobu; Kozawa, Osamu

    2011-07-01

    It is recognized that Wnt3a affects bone metabolism via the canonical Wnt/β-catenin signalling pathway. We have previously shown that transforming growth factor-β (TGF-β) stimulates the synthesis of vascular endothelial growth factor (VEGF) via p44/p42 mitogen-activated protein (MAP) kinase, stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK) and p38 MAP kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the effect of Wnt3a on TGF-β-stimulated VEGF synthesis in these cells. Wnt3a, which alone had little effect on the VEGF levels, significantly enhanced the TGF-β-stimulated VEGF release. Lithium chloride and SB216763, inhibitors of glycogen synthase kinase 3β, markedly amplified the TGF-β-stimulated VEGF release. Wnt3a failed to affect the TGF-β-induced phosphorylation of Smad2, p44/p42 MAP kinase, p38 MAP kinase or SAPK/JNK. Wnt3a and lithium chloride strengthened the VEGF mRNA expression induced by TGF-β. These results strongly suggest that Wnt3a upregulates VEGF synthesis stimulated by TGF-β via activation of the canonical pathway in osteoblasts.

  12. Transforming Growth Factor Beta 3 Is Required for Excisional Wound Repair In Vivo

    PubMed Central

    Le, Mark; Naridze, Rachelle; Morrison, Jasmine; Biggs, Leah C.; Rhea, Lindsey; Schutte, Brian C.; Kaartinen, Vesa; Dunnwald, Martine

    2012-01-01

    Wound healing is a complex process that relies on proper levels of cytokines and growth factors to successfully repair the tissue. Of particular interest are the members of the transforming growth factor family. There are three TGF-ß isoforms–TGF- ß 1, 2, and 3, each isoform showing a unique expression pattern, suggesting that they each play a distinct function during development and repair. Previous studies reported an exclusive role for TGF-ß 3 in orofacial development and a potent anti-scarring effect. However, the role of TGF- ß 3 in excisional wound healing and keratinocyte migration remains poorly understood. We tested the effect of TGF-ß 3 levels on excisional cutaneous wounds in the adult mouse by directly injecting recombinant TGF-ß 3 or neutralizing antibody against TGF-ß 3 (NAB) in the wounds. Our results demonstrate that TGF-ß 3 does not promote epithelialization. However, TGF-ß 3 is necessary for wound closure as wounds injected with neutralizing antibody against TGF-ß 3 showed increased epidermal volume and proliferation in conjunction with a delay in keratinocyte migration. Wild type keratinocytes treated with NAB and Tgfb3-deficient keratinocytes closed an in vitro scratch wound with no delay, suggesting that our in vivo observations likely result from a paracrine effect. PMID:23110169

  13. Proliferating cell nuclear antigen in oesophageal diseases; correlation with transforming growth factor alpha expression.

    PubMed Central

    Jankowski, J; McMenemin, R; Yu, C; Hopwood, D; Wormsley, K G

    1992-01-01

    This study was designed to correlate mucosal proliferation in Barrett's oesophagus with expression of a growth promoting peptide, transforming growth factor alpha (TGF alpha). Oesophageal mucosa was studied from 50 patients with oesophageal disease who had been treated by oesophagectomy. Histological analysis showed a range of oesophageal pathology - 18 patients had gastric type Barrett's mucosa, 18 had intestinal type Barrett's mucosa, and 14 had oesophageal adenocarcinomas. Sections were stained immunohistochemically for proliferating cell nuclear antigen (PCNA) (an index of cellular proliferation) and TGF alpha. PCNA immunostaining was seen mainly in the basal cells of the neck/foveolar epithelial compartment of the glands in Barrett's oesophagus. However, in mucosa with high grade dysplasia, the proliferative compartment extended upwards into the superficial layers of the glands. At least 2000 cells were counted in each patient to determine the proportion with PCNA immunoreactivity (PCNA labelling index). The labelling index was highest in adenocarcinoma (25%) and in Barrett's intestinal type mucosa with high grade dysplasia (26%) compared with intestinal type mucosa with no significant dysplasia (20%) and Barrett's gastric type mucosa (12%). There was a significant positive correlation between PCNA labelling indices and TGF alpha expression in Barrett's mucosa (p less than 0.01). In glands showing high grade dysplasia, TGF alpha immunoreactivity was seen in the same regions of the glands as PCNA immunoreactivity, indicating the possibility of involvement of TGF alpha in (pre) neoplastic proliferation in Barrett's oesophagus. Images Figure 2 Figure 5 PMID:1351861

  14. Production and response of a human prostatic cancer line to transforming growth factor-like molecules.

    PubMed Central

    MacDonald, A.; Chisholm, G. D.; Habib, F. K.

    1990-01-01

    Serum-free media conditioned by the androgen insensitive human prostate cancer cell line DU145 showed immunological transforming growth factor-alpha (TGF alpha) activity, as well as competing activity in epidermal growth factor (EGF) radioreceptor assays (RRA). Furthermore, there were factors in the conditioned media which inhibited and stimulated DNA synthesis by DU145 cells in a dose-dependent fashion. Fractionation of the concentrated conditioned media by reverse-phase high performance liquid chromatography revealed several peaks containing EGF-like competitive activity only one of which demonstrated TGF alpha activity. However, none of the peaks corresponded to immunoreactive EGF. Measurement of EGF receptors on DU145 cells by competition and saturation analysis revealed high levels of receptors (mean +/- s.d. = 2.5 +/- 1 x 10(5) surface receptors per cell) which were of high affinity (Kd +/- s.d. = 1.0 +/- 0.5 nmol l-1). Although DU145 cells express high levels of EGF receptors, DNA synthesis was only minimally affected by exogenous EGF and TGF alpha. PMID:2223575

  15. Regulation of experimental autoimmune neuritis by transforming growth factor-beta 1.

    PubMed

    Gregorian, S K; Lee, W P; Beck, L S; Rostami, A; Amento, E P

    1994-06-01

    Experimental autoimmune neuritis (EAN) is a T-cell-mediated autoimmune disease characterized by demyelination and mononuclear cell infiltration of the peripheral nervous system. It is induced in Lewis rats by administration of myelin P2 protein or a synthetic peptide (SP-26) corresponding to amino acid residues 53-78 of bovine P2 protein. The effects of transforming growth factor-beta 1 (TGF-beta 1) on the clinical signs, histological changes, cell-mediated immune responses, and secretion of interferon-gamma (IFN-gamma) by lymphoid cells of rats with EAN were examined. Systemic administration of TGF-beta 1 markedly inhibited the clinical signs and histological changes of EAN when given intraperitoneally every other day for Days 0 through 18. In addition, it decreased proliferative responses and reduced the delayed-type hypersensitivity (DTH) response to SP-26 compared to control rats. The reduction in clinical severity correlated with skin test unresponsiveness (DTH) to the disease-inducing agent (SP-26) as well to decreased cellular responsiveness to the antigen in vitro. The decrease in cellular responsiveness extended to a decrease in at least one T cell lymphokine, IFN-gamma. The profound effect of TGF-beta on disease progression in EAN, a T-cell-mediated process, is consistent with a direct effect of this growth factor on T lymphocytes.

  16. Demonstration of single crystal growth via solid-solid transformation of a glass

    PubMed Central

    Savytskii, Dmytro; Knorr, Brian; Dierolf, Volkmar; Jain, Himanshu

    2016-01-01

    Many advanced technologies have relied on the availability of single crystals of appropriate material such as silicon for microelectronics or superalloys for turbine blades. Similarly, many promising materials could unleash their full potential if they were available in a single crystal form. However, the current methods are unsuitable for growing single crystals of these oftentimes incongruently melting, unstable or metastable materials. Here we demonstrate a strategy to overcome this hurdle by avoiding the gaseous or liquid phase, and directly converting glass into a single crystal. Specifically, Sb2S3 single crystals are grown in Sb-S-I glasses as an example of this approach. In this first unambiguous demonstration of an all-solid-state glass → crystal transformation, extraneous nucleation is avoided relative to crystal growth via spatially localized laser heating and inclusion of a suitable glass former in the composition. The ability to fabricate patterned single-crystal architecture on a glass surface is demonstrated, providing a new class of micro-structured substrate for low cost epitaxial growth, active planar devices, etc. PMID:26988919

  17. Disrupted pulmonary vascular development and pulmonary hypertension in transgenic mice overexpressing transforming growth factor-alpha.

    PubMed

    Le Cras, Timothy D; Hardie, William D; Fagan, Karen; Whitsett, Jeffrey A; Korfhagen, Thomas R

    2003-11-01

    Pulmonary vascular disease plays a major role in morbidity and mortality in infant and adult lung diseases in which increased levels of transforming growth factor (TGF)-alpha and its receptor EGFR have been associated. The aim of this study was to determine whether overexpression of TGF-alpha disrupts pulmonary vascular development and causes pulmonary hypertension. Lung-specific expression of TGF-alpha in transgenic mice was driven with the human surfactant protein (SP)-C promoter. Pulmonary arteriograms and arterial counts show that pulmonary vascular development was severely disrupted in TGF-alpha mice. TGF-alpha mice developed severe pulmonary hypertension and vascular remodeling characterized by abnormally extensive muscularization of small pulmonary arteries. Pulmonary vascular development was significantly improved and pulmonary hypertension and vascular remodeling were prevented in bi-transgenic mice expressing both TGF-alpha and a dominant-negative mutant EGF receptor under the control of the SP-C promoter. Vascular endothelial growth factor (VEGF-A), an important angiogenic factor produced by the distal epithelium, was decreased in the lungs of TGF-alpha adults and in the lungs of infant TGF-alpha mice before detectable abnormalities in pulmonary vascular development. Hence, overexpression of TGF-alpha caused severe pulmonary vascular disease, which was mediated through EGFR signaling in distal epithelial cells. Reductions in VEGF may contribute to the pathogenesis of pulmonary vascular disease in TGF-alpha mice.

  18. Demonstration of single crystal growth via solid-solid transformation of a glass.

    PubMed

    Savytskii, Dmytro; Knorr, Brian; Dierolf, Volkmar; Jain, Himanshu

    2016-01-01

    Many advanced technologies have relied on the availability of single crystals of appropriate material such as silicon for microelectronics or superalloys for turbine blades. Similarly, many promising materials could unleash their full potential if they were available in a single crystal form. However, the current methods are unsuitable for growing single crystals of these oftentimes incongruently melting, unstable or metastable materials. Here we demonstrate a strategy to overcome this hurdle by avoiding the gaseous or liquid phase, and directly converting glass into a single crystal. Specifically, Sb2S3 single crystals are grown in Sb-S-I glasses as an example of this approach. In this first unambiguous demonstration of an all-solid-state glass → crystal transformation, extraneous nucleation is avoided relative to crystal growth via spatially localized laser heating and inclusion of a suitable glass former in the composition. The ability to fabricate patterned single-crystal architecture on a glass surface is demonstrated, providing a new class of micro-structured substrate for low cost epitaxial growth, active planar devices, etc. PMID:26988919

  19. Plasma concentrations of organohalogenated pollutants in predatory bird nestlings: associations to growth rate and dietary tracers.

    PubMed

    Bustnes, Jan O; Bårdsen, Bård J; Herzke, Dorte; Johnsen, Trond V; Eulaers, Igor; Ballesteros, Manuel; Hanssen, Sveinn A; Covaci, Adrian; Jaspers, Veerle L B; Eens, Marcel; Sonne, Christian; Halley, Duncan; Moum, Truls; Nøst, Therese Haugdal; Erikstad, Kjell E; Ims, Rolf Anker

    2013-11-01

    The extent to which persistent organic pollutants (POPs) with different physicochemical properties originated from the food (dietary input) was assessed in raptor nestlings. Lipophilic polychlorinated biphenyl (PCB) 153, 1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), and hexachlorobenzene (HCB), and protein-bound perfluorooctane sulfonate (PFOS), were measured repeatedly in blood plasma of individual goshawk (Accipiter gentilis) and white-tailed eagle (Haliaeetus albicilla) nestlings, 1 to 3 wk after hatching and near fledging. Maternally derived POPs dilute as nestlings grow (growth dilution), and increasing plasma concentrations would indicate dietary input. First, plasma concentrations given no dietary input were estimated, and concentrations of p,p'-DDE, HCB, and notably PFOS were significantly higher than predicted from a growth-dilution scenario (approximately 1.5-fold to 2.5-fold higher; p < 0.001). In contrast, PCB 153 declined in both species, although concentrations were still higher than predicted in white-tailed eagle nestlings (p < 0.05). Second, the relationships between plasma POP concentrations and trophic position (δ(15) N) and dietary carbon source (δ(13) C) were analyzed, controlling for growth rate. Both δ(15) N and δ(13) C (measured in body feathers) were significantly associated to the accumulation of most POPs, except PFOS. In conclusion, pollutant data acquired in plasma of nestling raptors should be interpreted and further investigated in the light of individual feeding ecology, and the use of raptor nestlings as sentinels for POP monitoring could be optimized by correcting for different factors such as body condition, brood size, and age.

  20. Plasma concentrations of organohalogenated pollutants in predatory bird nestlings: associations to growth rate and dietary tracers.

    PubMed

    Bustnes, Jan O; Bårdsen, Bård J; Herzke, Dorte; Johnsen, Trond V; Eulaers, Igor; Ballesteros, Manuel; Hanssen, Sveinn A; Covaci, Adrian; Jaspers, Veerle L B; Eens, Marcel; Sonne, Christian; Halley, Duncan; Moum, Truls; Nøst, Therese Haugdal; Erikstad, Kjell E; Ims, Rolf Anker

    2013-11-01

    The extent to which persistent organic pollutants (POPs) with different physicochemical properties originated from the food (dietary input) was assessed in raptor nestlings. Lipophilic polychlorinated biphenyl (PCB) 153, 1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), and hexachlorobenzene (HCB), and protein-bound perfluorooctane sulfonate (PFOS), were measured repeatedly in blood plasma of individual goshawk (Accipiter gentilis) and white-tailed eagle (Haliaeetus albicilla) nestlings, 1 to 3 wk after hatching and near fledging. Maternally derived POPs dilute as nestlings grow (growth dilution), and increasing plasma concentrations would indicate dietary input. First, plasma concentrations given no dietary input were estimated, and concentrations of p,p'-DDE, HCB, and notably PFOS were significantly higher than predicted from a growth-dilution scenario (approximately 1.5-fold to 2.5-fold higher; p < 0.001). In contrast, PCB 153 declined in both species, although concentrations were still higher than predicted in white-tailed eagle nestlings (p < 0.05). Second, the relationships between plasma POP concentrations and trophic position (δ(15) N) and dietary carbon source (δ(13) C) were analyzed, controlling for growth rate. Both δ(15) N and δ(13) C (measured in body feathers) were significantly associated to the accumulation of most POPs, except PFOS. In conclusion, pollutant data acquired in plasma of nestling raptors should be interpreted and further investigated in the light of individual feeding ecology, and the use of raptor nestlings as sentinels for POP monitoring could be optimized by correcting for different factors such as body condition, brood size, and age. PMID:23861300

  1. Growth of electron plasma waves above and below f(p) in the electron foreshock

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.; Fung, Shing F.

    1988-01-01

    This paper investigates the conditions required for electron beams to drive wave growth significantly above and below the electron plasma frequency, f(p), by numerically solving the linear dispersion equation. It is shown that kinetic growth well below f(p) may occur over a broad range of frequencies due to the beam instability, when the electron beam is slow, dilute, and relatively cold. Alternatively, a cold or sharp feature at low parallel velocities in the distribution function may drive kinetic growth significantly below f(p). Kinetic broadband growth significantly above f(p) is explained in terms of faster warmer beams. A unified qualitative theory for the narrow-band and broad-band waves is proposed.

  2. A continuum-scale model of hydrogen precipitate growth in tungsten plasma-facing materials

    NASA Astrophysics Data System (ADS)

    Kolasinski, R. D.; Cowgill, D. F.; Causey, R. A.

    2011-08-01

    The low solubility of hydrogen in tungsten leads to the growth of near-surface hydrogen precipitates during high-flux plasma exposure, strongly affecting migration and trapping in the material. We have developed a continuum-scale model of precipitate growth that leverages existing techniques for simulating the evolution of 3He gas bubbles in metal tritides. The present approach focuses on bubble growth by dislocation loop punching, assuming a diffusing flux to nucleation sites that arises from ion implantation. The bubble size is dictated by internal hydrogen pressure, the mechanical properties of the material, as well as local stresses. In this article, we investigate the conditions required for bubble growth. Recent focused ion beam (FIB) profiling studies that reveal the sub-surface damage structure provide an experimental database for comparison with the modeling results.

  3. Nanostructure growth by helium plasma irradiation to tungsten in sputtering regime

    NASA Astrophysics Data System (ADS)

    Noiri, Y.; Kajita, S.; Ohno, N.

    2015-08-01

    The formation of nanostructure on tungsten (W) surface due to Helium (He) plasma irradiation can be harmful for fusion reactors. Up to now, W nanostructure growth was investigated mainly without sputtering. Under sputtering regime, nanostructure growth competes with erosion due to sputtering. In this study, the nanostructure growth was investigated in the linear divertor simulator NAGDIS-II at incident ion energy range of 200-500 eV. The growth of nanostructures was investigated by experiments and calculations under the sputtering regime. With increasing incident ion energy, the thickness of nanostructured W layer saturated rapidly at a lower He fluence, resulting in thinner W nanostructured layer. The erosion rate of the top of the W nanostructured layer was obtained from the comparison with the numerical calculation.

  4. Colloidal plasmas in space - Some aspects of condensation and growth of solids

    NASA Technical Reports Server (NTRS)

    De, B. R.; Arrhenius, G.

    1979-01-01

    The abundant occurrence of colloidal plasma clouds in the observable universe is reviewed, and the possible locales of condensation of cosmic solids identified. The physical properties of the condensation environment and the thermal physics of the plasma-cluster medium are outlined. In the light of these discussions, an attempt is made to identify the salient features of the processes of nucleation and growth in space. It is suggested that the conventional nucleation theory is inadequate when applied to the tenuous, partially excited, partially ionized multispecies cosmic vapor phase, and that studies relying on the physics of progressive molecule growth in such environments hold promise of understanding the process of transition of a cluster from the size of a few atomic mass units through the macromolecular range into what may be characterized as the bulk condensed phase.

  5. High active nitrogen flux growth of GaN by plasma assisted molecular beam epitaxy

    SciTech Connect

    McSkimming, Brian M. Speck, James S.; Chaix, Catherine

    2015-09-15

    In the present study, the authors report on a modified Riber radio frequency (RF) nitrogen plasma source that provides active nitrogen fluxes more than 30 times higher than those commonly used for plasma assisted molecular beam epitaxy (PAMBE) growth of gallium nitride (GaN) and thus a significantly higher growth rate than has been previously reported. GaN films were grown using N{sub 2} gas flow rates between 5 and 25 sccm while varying the plasma source's RF forward power from 200 to 600 W. The highest growth rate, and therefore the highest active nitrogen flux, achieved was ∼7.6 μm/h. For optimized growth conditions, the surfaces displayed a clear step-terrace structure with an average RMS roughness (3 × 3 μm) on the order of 1 nm. Secondary ion mass spectroscopy impurity analysis demonstrates oxygen and hydrogen incorporation of 1 × 10{sup 16} and ∼5 × 10{sup 17}, respectively. In addition, the authors have achieved PAMBE growth of GaN at a substrate temperature more than 150 °C greater than our standard Ga rich GaN growth regime and ∼100 °C greater than any previously reported PAMBE growth of GaN. This growth temperature corresponds to GaN decomposition in vacuum of more than 20 nm/min; a regime previously unattainable with conventional nitrogen plasma sources. Arrhenius analysis of the decomposition rate shows that samples with a flux ratio below stoichiometry have an activation energy greater than decomposition of GaN in vacuum while samples grown at or above stoichiometry have decreased activation energy. The activation energy of decomposition for GaN in vacuum was previously determined to be ∼3.1 eV. For a Ga/N flux ratio of ∼1.5, this activation energy was found to be ∼2.8 eV, while for a Ga/N flux ratio of ∼0.5, it was found to be ∼7.9 eV.

  6. Growth of diamond films from microwave plasma in CH 4-CO 2 mixtures

    NASA Astrophysics Data System (ADS)

    Balestrino, G.; Marinelli, M.; Milani, E.; Paoletti, A.; Paroli, P.; Pinter, I.; Tebano, A.; Luce, G.

    1993-04-01

    We have studied the growth of diamond films from microwave plasma using gas mixtures of CH 4-CO 2 (not previously reported in the literature) onto Si substrates. The diamond phase is obtained in the molar ratio range 0.7 ⩽ CO 2/ CH 4 ⩽ 1.38 ± 0.05, in close agreement with the empirical model of Bachmann et al., with relevant implications for the diamond precursor species. The film morphology varies appreciably in the above range, the best films being obtained just at the border with the no-growth region.

  7. Analysis of Epithelial-Mesenchymal Transition Induced by Transforming Growth Factor β.

    PubMed

    Valcourt, Ulrich; Carthy, Jonathon; Okita, Yukari; Alcaraz, Lindsay; Kato, Mitsuyasu; Thuault, Sylvie; Bartholin, Laurent; Moustakas, Aristidis

    2016-01-01

    In recent years, the importance of the cell biological process of epithelial-mesenchymal transition (EMT) has been established via an exponentially growing number of reports. EMT has been documented during embryonic development, tissue fibrosis, and cancer progression in vitro, in animal models in vivo and in human specimens. EMT relates to many molecular and cellular alterations that occur when epithelial cells undergo a switch in differentiation that generates mesenchymal-like cells with newly acquired migratory and invasive properties. In addition, EMT relates to a nuclear reprogramming similar to the one occurring in the generation of induced pluripotent stem cells. Via such a process, EMT is gradually established to promote the generation and maintenance of adult tissue stem cells which under disease states such as cancer, are known as cancer stem cells. EMT is induced by developmental growth factors, oncogenes, radiation, and hypoxia. A prominent growth factor that causes EMT is transforming growth factor β (TGF-β).A series of molecular and cellular techniques can be applied to define and characterize the state of EMT in diverse biological samples. These methods range from DNA and RNA-based techniques that measure the expression of key EMT regulators and markers of epithelial or mesenchymal differentiation to functional assays of cell mobility, invasiveness and in vitro stemness. This chapter focuses on EMT induced by TGF-β and provides authoritative protocols and relevant reagents and citations of key publications aiming at assisting newcomers that enter this prolific area of biomedical sciences, and offering a useful reference tool to pioneers and aficionados of the field. PMID:26520123

  8. Inhibition of transforming growth factor β signaling promotes epiblast formation in mouse embryos.

    PubMed

    Ghimire, Sabitri; Heindryckx, Björn; Van der Jeught, Margot; Neupane, Jitesh; O'Leary, Thomas; Lierman, Sylvie; De Vos, Winnok H; Chuva de Sousa Lopes, Susana; Deroo, Tom; De Sutter, Petra

    2015-02-15

    Early lineage segregation in preimplantation embryos and maintenance of pluripotency in embryonic stem cells (ESCs) are both regulated by specific signaling pathways. Small molecules have been shown to modulate these signaling pathways. We examined the influence of several small molecules and growth factors on second-lineage segregation of the inner cell mass toward hypoblast and epiblast lineage during mouse embryonic preimplantation development. We found that the second-lineage segregation is influenced by activation or inhibition of the transforming growth factor (TGF)β pathway. Inhibition of the TGFβ pathway from the two-cell, four-cell, and morula stages onward up to the blastocyst stage significantly increased the epiblast cell proliferation. The epiblast formed in the embryos in which TGFβ signaling was inhibited was fully functional as demonstrated by the potential of these epiblast cells to give rise to pluripotent ESCs. Conversely, activating the TGFβ pathway reduced epiblast formation. Inhibition of the glycogen synthase kinase (GSK)3 pathway and activation of bone morphogenetic protein 4 signaling reduced the formation of both epiblast and hypoblast cells. Activation of the protein kinase A pathway and of the Janus kinase/signal transducer and activator of transcription 3 pathway did not influence the second-lineage segregation in mouse embryos. The simultaneous inhibition of three pathways--TGFβ, GSK3β, and the fibroblast growth factor (FGF)/extracellular signal-regulated kinases (Erk)--significantly enhanced the proliferation of epiblast cells than that caused by inhibition of either TGFβ pathway alone or by combined inhibition of the GSK3β and FGF/Erk pathways only.

  9. Inhibition of Transforming Growth Factor β Signaling Promotes Epiblast Formation in Mouse Embryos

    PubMed Central

    Ghimire, Sabitri; Heindryckx, Björn; Van der Jeught, Margot; Neupane, Jitesh; O'Leary, Thomas; Lierman, Sylvie; De Vos, Winnok H.; Chuva de Sousa Lopes, Susana; Deroo, Tom

    2015-01-01

    Early lineage segregation in preimplantation embryos and maintenance of pluripotency in embryonic stem cells (ESCs) are both regulated by specific signaling pathways. Small molecules have been shown to modulate these signaling pathways. We examined the influence of several small molecules and growth factors on second-lineage segregation of the inner cell mass toward hypoblast and epiblast lineage during mouse embryonic preimplantation development. We found that the second-lineage segregation is influenced by activation or inhibition of the transforming growth factor (TGF)β pathway. Inhibition of the TGFβ pathway from the two-cell, four-cell, and morula stages onward up to the blastocyst stage significantly increased the epiblast cell proliferation. The epiblast formed in the embryos in which TGFβ signaling was inhibited was fully functional as demonstrated by the potential of these epiblast cells to give rise to pluripotent ESCs. Conversely, activating the TGFβ pathway reduced epiblast formation. Inhibition of the glycogen synthase kinase (GSK)3 pathway and activation of bone morphogenetic protein 4 signaling reduced the formation of both epiblast and hypoblast cells. Activation of the protein kinase A pathway and of the Janus kinase/signal transducer and activator of transcription 3 pathway did not influence the second-lineage segregation in mouse embryos. The simultaneous inhibition of three pathways—TGFβ, GSK3β, and the fibroblast growth factor (FGF)/extracellular signal-regulated kinases (Erk)—significantly enhanced the proliferation of epiblast cells than that caused by inhibition of either TGFβ pathway alone or by combined inhibition of the GSK3β and FGF/Erk pathways only. PMID:25245024

  10. Dynamics of Transforming Growth Factor Beta Signaling in Wound Healing and Scarring

    PubMed Central

    Finnson, Kenneth W.; McLean, Sarah; Di Guglielmo, Gianni M.; Philip, Anie

    2013-01-01

    Significance Wound healing is an intricate biological process in which the skin, or any other tissue, repairs itself after injury. Normal wound healing relies on the appropriate levels of cytokines and growth factors to ensure that cellular responses are mediated in a coordinated manner. Among the many growth factors studied in the context of wound healing, transforming growth factor beta (TGF-β) is thought to have the broadest spectrum of effects. Recent Advances Many of the molecular mechanisms underlying the TGF-β/Smad signaling pathway have been elucidated, and the role of TGF-β in wound healing has been well characterized. Targeting the TGF-β signaling pathway using therapeutic agents to improve wound healing and/or reduce scarring has been successful in pre-clinical studies. Critical Issues Although TGF-β isoforms (β1, β2, β3) signal through the same cell surface receptors, they display distinct functions during wound healing in vivo through mechanisms that have not been fully elucidated. The challenge of translating preclinical studies targeting the TGF-β signaling pathway to a clinical setting may require more extensive preclinical research using animal models that more closely mimic wound healing and scarring in humans, and taking into account the spatial, temporal, and cell-type–specific aspects of TGF-β isoform expression and function. Future Directions Understanding the differences in TGF-β isoform signaling at the molecular level and identification of novel components of the TGF-β signaling pathway that critically regulate wound healing may lead to the discovery of potential therapeutic targets for treatment of impaired wound healing and pathological scarring. PMID:24527343

  11. Effect of transforming growth factor beta on synthesis of glycosaminoglycans by human lung fibroblasts

    SciTech Connect

    Dubaybo, B.A.; Thet, L.A. )

    1990-09-01

    The processes of lung growth, injury, and repair are characterized by alterations in fibroblast synthesis and interstitial distribution of extracellular matrix components. Transforming growth factor beta (TGF-beta), which is postulated to play a role in modulating lung repair, alters the distribution of several matrix components such as collagen and fibronectin. We studied the effect of TGF-beta on the synthesis and distribution of the various glycosaminoglycans (GAGs) and whether these effects may explain its role in lung repair. Human diploid lung fibroblasts (IMR-90) were exposed to various concentrations of TGF-beta (0-5 nM) for variable periods of time (0-18 h). Newly synthesized GAGs were labeled with either (3H)glucosamine or (35S)sulfate. Individual GAGs were separated by size exclusion chromatography after serial enzymatic and chemical digestions and quantitated using scintillation counting. There was a dose-dependent increase in total GAG synthesis with maximal levels detected after 6 h of exposure. This increase was noted in all individual GAG types measured and was observed in both the cell associated GAGs (cell-matrix fraction) as well as the GAGs released into the medium (medium fraction). In the cell-matrix fraction, TGF-beta increased the proportion of heparan sulfate that was membrane bound as well as the proportion of dermatan sulfate in the intracellular compartment. In the medium fraction, TGF-beta increased the proportion of hyaluronic acid, chondroitin sulfate and dermatan sulfate released. We conclude that the role of TGF-beta in lung growth and repair may be related to increased synthesis of GAGs by human lung fibroblasts as well as alterations in the distribution of individual GAGs.

  12. Analysis of Epithelial-Mesenchymal Transition Induced by Transforming Growth Factor β.

    PubMed

    Valcourt, Ulrich; Carthy, Jonathon; Okita, Yukari; Alcaraz, Lindsay; Kato, Mitsuyasu; Thuault, Sylvie; Bartholin, Laurent; Moustakas, Aristidis

    2016-01-01

    In recent years, the importance of the cell biological process of epithelial-mesenchymal transition (EMT) has been established via an exponentially growing number of reports. EMT has been documented during embryonic development, tissue fibrosis, and cancer progression in vitro, in animal models in vivo and in human specimens. EMT relates to many molecular and cellular alterations that occur when epithelial cells undergo a switch in differentiation that generates mesenchymal-like cells with newly acquired migratory and invasive properties. In addition, EMT relates to a nuclear reprogramming similar to the one occurring in the generation of induced pluripotent stem cells. Via such a process, EMT is gradually established to promote the generation and maintenance of adult tissue stem cells which under disease states such as cancer, are known as cancer stem cells. EMT is induced by developmental growth factors, oncogenes, radiation, and hypoxia. A prominent growth factor that causes EMT is transforming growth factor β (TGF-β).A series of molecular and cellular techniques can be applied to define and characterize the state of EMT in diverse biological samples. These methods range from DNA and RNA-based techniques that measure the expression of key EMT regulators and markers of epithelial or mesenchymal differentiation to functional assays of cell mobility, invasiveness and in vitro stemness. This chapter focuses on EMT induced by TGF-β and provides authoritative protocols and relevant reagents and citations of key publications aiming at assisting newcomers that enter this prolific area of biomedical sciences, and offering a useful reference tool to pioneers and aficionados of the field.

  13. ICPP: Identification and Quantification of Elementary Plasma Surface Processes during thin Film Growth

    NASA Astrophysics Data System (ADS)

    Keudell, A. V.

    2000-10-01

    The quantification of elementary plasma surface processes in glow discharges used for thin film deposition, is mandatory for a complete description of these low temperature plasmas. Since the surface to volume ratio in these discharge systems is often large, all particle densities in the discharge can be strongly influenced by any surface reactions. The identification and quantification of these surface processes will be illustrated for the plasma deposition of amorphous hydrogenated carbon films. A variety of experiments will be discussed ranging from plasma experiments using the cavity technique or ionization threshold mass spectrometry as well as a new class of experiments using quantified radical beams to quantify surface reactions in terms of sticking coefficients directly. It is shown that the reactivity of the hydrocarbon radicals depends strongly on the state of hybridization of the hydrocarbon growth precursor, and that the sticking coefficients for various hydrocarbon radicals are strongly influenced by the simultaneous interaction of several reactive species with the film surface. With the knowledge of these interaction mechanisms and the quantification of the corresponding cross sections, a better understanding of growth processes has become possible, ranging from the deposition of polycrystalline diamond in microwave discharges to the formation of re-deposited layers in fusion experiments.

  14. Large plasma-membrane depolarization precedes rapid blue-light-induced growth inhibition in cucumber

    NASA Technical Reports Server (NTRS)

    Spalding, E. P.; Cosgrove, D. J.

    1989-01-01

    Blue-light (BL)-induced suppression of elongation of etiolated Cucumis sativus L. hypocotyls began after a 30-s lag time, which was halved by increasing the fluence rate from 10 to 100 micromoles m-2 s-1. Prior to the growth suppression, the plasma-membrane of the irradiated cells depolarized by as much as 100 mV, then returned within 2-3 min to near its initial value. The potential difference measured with surface electrodes changed with an identical time course but opposite polarity. The lag time for the change in surface potential showed an inverse dependence on fluence rate, similar to the lag for the growth inhibition. Green light and red light caused neither the electrical response nor the rapid inhibition of growth. The depolarization by BL did not propagate to nonirradiated regions and exhibited a refractory period of about 10 min following a BL pulse. Fluence-response relationships for the electrical and growth responses provide correlational evidence that the plasma-membrane depolarization reflects an event in the transduction chain of this light-growth response.

  15. Overview of Transforming Growth Factor β Superfamily Involvement in Glioblastoma Initiation and Progression.

    PubMed

    Nana, Andre Wendindonde; Yang, Pei-Ming; Lin, Hung-Yun

    2015-01-01

    Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive of human brain tumors and has a stunning progression with a mean survival of one year from the date of diagnosis. High cell proliferation, angiogenesis and/or necrosis are histopathological features of this cancer, which has no efficient curative therapy. This aggressiveness is associated with particular heterogeneity of the tumor featuring multiple genetic and epigenetic alterations, but also with implications of aberrant signaling driven by growth factors. The transforming growth factor β (TGFβ) superfamily is a large group of structurally related proteins including TGFβ subfamily members Nodal, Activin, Lefty, bone morphogenetic proteins (BMPs) and growth and differentiation factor (GDF). It is involved in important biological functions including morphogenesis, embryonic development, adult stem cell differentiation, immune regulation, wound healing and inflammation. This superfamily is also considered to impact on cancer biology including that of GBM, with various effects depending on the member. The TGFβ subfamily, in particular, is overexpressed in some GBM types which exhibit aggressive phenotypes. This subfamily impairs anti-cancer immune responses in several ways, including immune cells inhibition and major histocompatibility (MHC) class I and II abolishment. It promotes GBM angiogenesis by inducing angiogenic factors such as vascular endothelial growth factor (VEGF), plasminogen activator inhibitor (PAI-I) and insulin- like growth factor-binding protein 7 (IGFBP7), contributes to GBM progression by inducing metalloproteinases (MMPs), "pro-neoplastic" integrins (αvβ3, α5β1) and GBM initiating cells (GICs) as well as inducing a GBM mesenchymal phenotype. Equally, Nodal promotes GICs, induces cancer metabolic switch and supports GBM cell proliferation, but is negatively regulated by Lefty. Activin promotes GBM cell proliferation while GDF yields immune-escape function

  16. Contribution of radicals and ions in catalyzed growth of single-walled carbon nanotubes from low-temperature plasmas

    SciTech Connect

    Marvi, Z.; Xu, S.; Foroutan, G.; Ostrikov, K.

    2015-01-15

    The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon flux on the SWCNT growth rate is quantified. The dependence of the growth parameters on the substrate temperature is also investigated. The effects of the plasma sheath parameters on the growth parameters are different in low- and high-substrate temperature regimes. The optimum substrate temperature and applied DC bias are estimated to maximize the growth rate of the single-walled carbon nanotubes.

  17. H-ras-transformed NRK-52E renal epithelial cells have altered growth, morphology, and cytoskeletal structure that correlates with renal cell carcinoma in vivo.

    PubMed

    Best, C J; Tanzer, L R; Phelps, P C; Merriman, R L; Boder, G G; Trump, B F; Elliget, K A

    1999-04-01

    We studied the effect of the ras oncogene on the growth kinetics, morphology, cytoskeletal structure, and tumorigenicity of the widely used NRK-52E rat kidney epithelial cell line and two H-ras oncogene-transformed cell lines, H/1.2-NRK-52E (H/1.2) and H/6.1-NRK-52E (H/6.1). Population doubling times of NRK-52E, H/1.2, and H/6.1 cells were 28, 26, and 24 h, respectively, with the transformed cells reaching higher saturation densities than the parent cells. NRK-52E cells had typical epithelial morphology with growth in colonies. H/1.2 and H/6.1 cell colonies were more closely packed, highly condensed, and had increased plasma membrane ruffling compared to parent cell colonies. NRK-52E cells showed microfilament, microtubule, and intermediate filament networks typical of epithelial cells, while H/1.2 and H/6.1 cells showed altered cytoskeleton architecture, with decreased stress fibers and increased microtubule and intermediate filament staining at the microtubule organizing center. H/1.2 and H/6.1 cells proliferated in an in vitro soft agar transformation assay, indicating anchorage-independence, and rapidly formed tumors in vivo with characteristics of renal cell carcinoma, including mixed populations of sarcomatoid, granular, and clear cells. H/6.1 cells consistently showed more extensive alterations of growth kinetics, morphology, and cytoskeleton than H/1.2 cells, and formed tumors of a more aggressive phenotype. These data suggest that analysis of renal cell characteristics in vitro may have potential in predicting tumor behavior in vivo, and significantly contribute to the utility of these cell lines as in vitro models for examining renal epithelial cell biology and the role of the ras proto-oncogene in signal transduction involving the cytoskeleton.

  18. Real Variable Inversion of Laplace Transforms: An Application in Plasma Physics.

    ERIC Educational Resources Information Center

    Bohn, C. L.; Flynn, R. W.

    1978-01-01

    Discusses the nature of Laplace transform techniques and explains an alternative to them: the Widder's real inversion. To illustrate the power of this new technique, it is applied to a difficult inversion: the problem of Landau damping. (GA)

  19. CHMP6 and VPS4A mediate recycling of Ras to the plasma membrane to promote growth factor signaling

    PubMed Central

    Zheng, Ze-Yi; Cheng, Chiang-Min; Fu, Xin-Rong; Chen, Liuh-Yow; Xu, Lizhong; Terrillon, Sonia; Wong, Stephen T.; Bar-Sagi, Dafna; Songyang, Zhou; Chang, Eric C.

    2011-01-01

    While Ras is well-known to function on the plasma membrane (PM) to mediate growth factor signaling, increasing evidence suggests that Ras has complex roles in the cytoplasm. To uncover these roles, we screened a cDNA library and isolated H-Ras-binding proteins that also influence Ras functions. Many isolated proteins regulate trafficking involving endosomes; CHMP6/VPS20 and VPS4A, which interact with ESCRT-III, were chosen for further study. We showed that the binding is direct and occurs in endosomes. Furthermore, the binding is most efficient when H-Ras has a functional effector-binding-loop and is GTP-bound and ubiquitylated. CHMP6 and VPS4A also bound N-Ras, but not K-Ras. Repressing CHMP6 and VPS4A blocked Ras-induced transformation, which correlated with inefficient Ras localization to the PM as measured by cell fractionation and photobleaching. Moreover, silencing CHMP6 and VPS4A also blocked EGFR recycling. These data suggest that Ras interacts with key ESCRT-III components to promote recycling of itself and EGFR back to the PM to create a positive feedback loop to enhance growth factor signaling. PMID:22231449

  20. Plasma insulin-like growth factor-I, testosterone and morphological changes in the growth of captive agile gibbons ( Hylobates agilis) from birth to adolescence.

    PubMed

    Suzuki, Juri; Kato, Akino; Maeda, Norihiko; Hashimoto, Chihiro; Uchikoshi, Makiko; Mizutani, Toshiaki; Doke, Chisato; Matsuzawa, Tetsuro

    2003-07-01

    We examined growth changes in concentrations of plasma insulin-like growth factor-1 (IGF-1) and testosterone, and somatometric parameters in two captive male agile gibbons from birth to about 4 years of age, to examine the evolution of growth patterns in primates. Plasma IGF-1 concentrations in agile gibbons generally increased with age with values ranging from 200 to 1100 ng/ml. The growth profiles in plasma IGF-1 in the gibbons were similar to those reported for chimpanzees. The highest concentrations of plasma testosterone (230 and 296 ng/dl) were observed within the first 0.3 years from birth, then the concentrations rapidly decreased and fluctuated below 100 ng/dl. Continuously higher IGF-1 concentrations were observed after 2.6 and 3.5 years of age. The profiles of plasma testosterone in these gibbons also resembled those of other primates including humans. However, their plasma testosterone levels in both neonate and adult stages (60 ng/dl) were lower than those reported for macaques and chimpanzees of respective stages. The obtained growth profiles of plasma IGF-1 and testosterone suggest that the adolescent phase starts around 2.6 or 3.5 years of age in male agile gibbons. The growth trend in many morphological parameters including body weight showed a linear increase without a significant growth spurt at approximately the onset of puberty. Head length and first digit length had reached a plateau during the study period. Brachial index, which indicates the relative length of forearm to upper arm, significantly increased gradually through the growth period. This result indicates that forearm becomes relatively longer than the upper arm with growth, which may be an evolutionary adaptation for brachiation.

  1. Numerical Modeling of an RF Argon-Silane Plasma with Dust Particle Nucleation and Growth

    NASA Astrophysics Data System (ADS)

    Girshick, Steven; Agarwal, Pulkit

    2012-10-01

    We have developed a 1-D numerical model of an RF argon-silane plasma in which dust particles nucleate and grow. This model self-consistently couples a plasma module, a chemistry module and an aerosol module. The plasma module solves population balance equations for electrons and ions, the electron energy equation under the assumption of a Maxwellian velocity distribution, and Poisson's equation for the electric field. The chemistry module treats silane dissociation and reactions of silicon hydrides containing up to two silicon atoms. The aerosol module uses a sectional method to model particle size and charge distributions. The nucleation rate is equated to the rates of formation of anions containing two Si atoms, and a heterogeneous reaction model is used to model particle surface growth. Aerosol effects considered include particle charging, coagulation, and particle transport by neutral drag, ion drag, electric force, gravity and Brownian diffusion. Simulation results are shown for the case of a 13.56 MHz plasma at a pressure of 13 Pa and applied RF voltage of 100 V (amplitude), with flow through a showerhead electrode. These results show the strong coupling between the plasma and the spatiotemporal evolution of the nanoparticle cloud.

  2. Numerical and experimental investigations of MHD processes of energy transforming in inhomogenious gas-plasma flows

    SciTech Connect

    Slavin, V.S.; Gavrilov, V.M.; Lobasova, M.S.

    1995-12-31

    The results of experimental and theoretical research of MHD interaction processes of a plasma clot with carrying gas flow in Faraday MHD channel with continuous electrodes are represented. Two possible situations are being analysed: (1) working medium is air without seed, plasma clot is an equilibrium are stabilized with radiation (T-layer); (2) argon without seed, plasma exists in the form of a non-equilibrium are stabilized with electrons energy losses in elastic collisions with gas atoms. The experiment was being carried in a linear MHD channel started by a shock tube. Plasma clot was formed by an impulse electric discharge in a gasodynamic nozzle being placed between a throat and MHD channel. Self-supported current layer (T-layer) was being formed of a plasma clot under the influence of Lorentz force and Joule dissipation in the MHD channel. For compensation of near electrode voltage drop a charged battery of condensers was connected to the MHD channel electrodes instead of the load resistor. Plasma layer has steadily passed through the MHD channel {approximately}1.5 m length. In this case its parameters check well with the calculations performed on the basis of a piston model. Plasma clot initiation regime realized in this experiment was being simulated with the help of non-stationary quasi-one-dimensional design programm. Identity of the major calculation and experimental results has been shown. Dynamics of impulse strong current discharge has been studied; in so doing the role of gasodynamic expansion of a discharge zone and ionized air radiation in overall energy balance is determined.

  3. Functional mapping of quantitative trait loci underlying growth trajectories using a transform-both-sides logistic model.

    PubMed

    Wu, Rongling; Ma, Chang-Xing; Lin, Min; Wang, Zuoheng; Casella, George

    2004-09-01

    The incorporation of developmental control mechanisms of growth has proven to be a powerful tool in mapping quantitative trait loci (QTL) underlying growth trajectories. A theoretical framework for implementing a QTL mapping strategy with growth laws has been established. This framework can be generalized to an arbitrary number of time points, where growth is measured, and becomes computationally more tractable, when the assumption of variance stationarity is made. In practice, however, this assumption is likely to be violated for age-specific growth traits due to a scale effect. In this article, we present a new statistical model for mapping growth QTL, which also addresses the problem of variance stationarity, by using a transform-both-sides (TBS) model advocated by Carroll and Ruppert (1984, Journal of the American Statistical Association 79, 321-328). The TBS-based model for mapping growth QTL cannot only maintain the original biological properties of a growth model, but also can increase the accuracy and precision of parameter estimation and the power to detect a QTL responsible for growth differentiation. Using the TBS-based model, we successfully map a QTL governing growth trajectories to a linkage group in an example of forest trees. The statistical and biological properties of the estimates of this growth QTL position and effect are investigated using Monte Carlo simulation studies. The implications of our model for understanding the genetic architecture of growth are discussed.

  4. Studies of plasma zinc, copper, caeruloplasmin, and growth hormone: with special reference to carcinoma of the bronchus.

    PubMed

    Andrews, G S

    1979-04-01

    The levels of plasma zinc, copper, caeruloplasmin, and growth hormone were determined in a group of normal people and in four groups of patients who were suffering from carcinoma of the bronchus, other forms of malignancy, chest illnesses, and diseases other than chest illness or malignancy. The plasma zinc was higher, and the plasma copper lower, in people without malignancy below the age of 30 years than they were in other age groups.It was confirmed that about 66% of patients with carcinoma of the bronchus had plasma zinc levels less than 11.5 mumol/l but low levels were also found in 23% of other cases of malignancy and in 9% of the other patients. In carcinoma of the bronchus the low plasma zinc was found to be associated with epidermoid and anaplastic tumours and was to some extent related to the duration of the disease. In carcinoma of the bronchus the plasma copper was found to be higher than in all other groups, and values higher than 26.5 mumol/l were considered to support a diagnosis of carcinoma of the bronchus. There was, however, no relationship between the increase in the plasma copper and the decrease in the plasma zinc.Raised caeruloplasmin levels above 420 mg/l were found in 65% of cases of carcinoma of the bronchus, and these high levels were usually associated with raised plasma copper. Growth hormone was normal in all groups except six patients with carcinoma of the bronchus with secondary carcinoma of the liver, in whom it was raised. Surgical operations lowered plasma zinc and raised growth hormone but did not affect plasma copper.A plasma zinc below 11.5 mumol/l is helpful in the diagnosis of carcinoma of the bronchus, but by itself it is not sufficiently specific to be considered diagnostic or to form a reliable screening test. A raised plasma copper and a raised plasma caeruloplasmin were useful supportive findings.

  5. Isolation from Animal Tissue and Genetic Transformation of Coxiella burnetii Are Facilitated by an Improved Axenic Growth Medium▿

    PubMed Central

    Omsland, Anders; Beare, Paul A.; Hill, Joshua; Cockrell, Diane C.; Howe, Dale; Hansen, Bryan; Samuel, James E.; Heinzen, Robert A.

    2011-01-01

    We recently described acidified citrate cysteine medium (ACCM), which supports host cell-free (axenic) growth of Coxiella burnetii. After 6 days of incubation, greater than 3 logs of growth was achieved with the avirulent Nine Mile phase II (NMII) strain. Here, we describe modified ACCM and culture conditions that support improved growth of C. burnetii and their use in genetic transformation and pathogen isolation from tissue samples. ACCM was modified by replacing fetal bovine serum with methyl-β-cyclodextrin to generate ACCM-2. Cultivation of NMII in ACCM-2 with moderate shaking and in 2.5% oxygen yielded 4 to 5 logs of growth over 7 days. Similar growth was achieved with the virulent Nine Mile phase I and G isolates of C. burnetii. Colonies that developed after 6 days of growth in ACCM-2 agarose were approximately 0.5 mm in diameter, roughly 5-fold larger than those formed in ACCM agarose. By electron microscopy, colonies consisted primarily of the C. burnetii small cell variant morphological form. NMII was successfully cultured in ACCM-2 when medium was inoculated with as little as 10 genome equivalents contained in tissue homogenates from infected SCID mice. A completely axenic C. burnetii genetic transformation system was developed using ACCM-2 that allowed isolation of transformants in about 2 1/2 weeks. Transformation experiments demonstrated clonal populations in colonies and a transformation frequency of approximately 5 × 10−5. Cultivation in ACCM-2 will accelerate development of C. burnetii genetic tools and provide a sensitive means of primary isolation of the pathogen from Q fever patients. PMID:21478315

  6. Short-pulse excitation of microwave plasma for efficient diamond growth

    NASA Astrophysics Data System (ADS)

    Yamada, Hideaki; Chayahara, Akiyoshi; Mokuno, Yoshiaki

    2016-08-01

    To realize a variety of potential applications of diamonds, particularly in the area of power electronics, it is indispensable to improve their growth efficiency. Most conventional approaches have tried to achieve this simply by increasing the gas temperature; however, this makes it difficult to grow large diamond crystals. To improve the growth efficiency while lowering the gas temperature, we propose that using a pulse-modulated microwave plasma with a sub-millisecond pulse width can enhance the power efficiency of the growth rate of single-crystal diamonds. We found that using a sub-millisecond pulse-mode discharge could almost double the growth rate obtained using continuous mode discharge for a fixed average microwave power and gas pressure. A comparison between experimental observations of the optical emission spectra of the discharge and a numerical simulation of the gas temperature suggests that a decrease in the gas temperature was achieved, and highlights the importance of electron-dominated reactions for obtaining the enhancement of the growth rate. This result will have a large impact in the area of diamond growth because it enables diamond growth to be more power efficient at reduced temperatures.

  7. A growth diagram for plasma-assisted molecular beam epitaxy of GaN nanocolumns on Si(111)

    SciTech Connect

    Fernandez-Garrido, S.; Grandal, J.; Calleja, E.; Sanchez-Garcia, M. A.; Lopez-Romero, D.

    2009-12-15

    The morphology of GaN samples grown by plasma-assisted molecular beam epitaxy on Si(111) was systematically studied as a function of impinging Ga/N flux ratio and growth temperature (730-850 deg. C). Two different growth regimes were identified: compact and nanocolumnar. A growth diagram was established as a function of growth parameters, exhibiting the transition between growth regimes, and showing under which growth conditions GaN cannot be grown due to thermal decomposition and Ga desorption. Present results indicate that adatoms diffusion length and the actual Ga/N ratio on the growing surface are key factors to achieve nanocolumnar growth.

  8. Plasma volume methodology: Evans blue, hemoglobin-hematocrit, and mass density transformations

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Hinghofer-Szalkay, H.

    1985-01-01

    Methods for measuring absolute levels and changes in plasma volume are presented along with derivations of pertinent equations. Reduction in variability of the Evans blue dye dilution technique using chromatographic column purification suggests that the day-to-day variability in the plasma volume in humans is less than + or - 20 m1. Mass density determination using the mechanical-oscillator technique provides a method for measuring vascular fluid shifts continuously for assessing the density of the filtrate, and for quantifying movements of protein across microvascular walls. Equations for the calculation of volume and density of shifted fluid are presented.

  9. Role of LncRNA-activated by transforming growth factor beta in the progression of hepatitis C virus-related liver fibrosis.

    PubMed

    Fu, Na; Niu, Xuemin; Wang, Yang; Du, Huijuan; Wang, Baoyu; Du, Jinghua; Li, Ya; Wang, Rongqi; Zhang, Yuguo; Zhao, Suxian; Sun, Dianxing; Qiao, Liang; Nan, Yuemin

    2016-08-01

    Long non-coding RNA (LncRNA)-activated by transforming growth factor-beta (LncRNA-ATB) is a key regulator of transforming growth factor-beta (TGF-β) signaling pathway, and is positively correlated with the development of liver cirrhosis and vascular invasion of hepatocellular carcinoma (HCC). However, the role of LncRNA-ATB in hepatitis C virus (HCV)-related liver fibrosis remains largely unknown. In the present study, we confirmed a high expression level of LncRNA-ATB in the liver tissues and plasma samples of patients with HCV-related hepatic fibrosis, and the plasma level of LncRNA-ATB was significantly correlated with liver fibrosis stages. Furthermore, increased expression level of LncRNA-ATB was also present in activated hepatic stellate cells (HSCs), and knockdown of LncRNA-ATB inhibited the expression of alpha-smooth muscle actin (α-SMA) and alpha-1 type I collagen (Col1A1). LncRNA-ATB was found to share the common miRNA responsive element of miR-425-5p with TGF-β type II receptor (TGF-βRII) and SMAD2. Ectopic expression of LncRNA-ATB in HSCs could upregulate the protein expression of TGF-βRII and SMAD2 by inhibiting the endogenous miR-425-5p. Moreover, overexpression of miR-425-5p could partly abrogate the expression of TGF-βRII and SMAD2 induced by LncRNA-ATB. Hence, we conclude that LncRNA-ATB promotes HCV-induced liver fibrogenesis by activating HSCs and increasing collagen I production through competitively binding to miR-425-5p. LncRNA-ATB may be a novel diagnostic biomarker and a potential therapeutic target for HCV-related hepatic fibrosis. PMID:27585228

  10. Plasma Instability Growth Rates in the F-Region Cusp Ionosphere

    NASA Astrophysics Data System (ADS)

    Moen, J. I.; Daabakk, Y.; Oksavik, K.; Clausen, L.; Bekkeng, T. A.; Abe, T.; Saito, Y.; Baddeley, L. J.; Lorentzen, D. A.; Sigernes, F.; Yeoman, T. K.

    2014-12-01

    There are at least two different micro-instability processes that applies to the F-region cusp/polar cap ionosphere. These are the Gradient Drift Instability (GDI) and the Kelvin Helmholtz Instability (KHI). Due to space weather effects on radio communication and satellite signals it is of practical interest to assess the relative importance of these two instability modes and to quantify their growth rates. The Investigation of Cusp Irregularities (ICI) rocket program has been developed to investigate these plasma instabilities and formation scintillation irregularities. High resolution measurements are critical to get realistic quantities on the growth rates. The results achieved so far demonstrates that cusp ionosphere precipitation can give rise to km scale plasma structures on which grow rates are down to a few tens of seconds compared to earlier measures of ten minutes based on ground observations. This has to do with the spatial resolution required for these measurements. Growth rates for the KHI instability is found to be of the same order, which is consistent with growth rates calculated from the EISCAT Svalbard Radar. I.e. both instability modes can be highly efficient in the cusp ionosphere.

  11. Human plasma epidermal growth factor/beta-urogastrone is associated with blood platelets.

    PubMed Central

    Oka, Y; Orth, D N

    1983-01-01

    Human epidermal growth factor (hEGF) has previously been isolated from urine and probably is identical to human beta-urogastrone (hUG). Immunoreactive hEGF/UG has been found in the plasma of normal subjects. In this study, using immunoaffinity chromatography to extract hEGF/UG from plasma, we found that immunoreactive hEGF/UG in blood was associated with blood platelets. It was present in platelet-rich, but not platelet-poor plasma and serum, and was found predominantly in the platelet fraction of whole blood. Sephadex G-50 Fine gel-exclusion chromatography of an extract of outdated blood bank platelets revealed two hEGF/UG components, one of which eluted in the void volume, and the other of which coeluted with purified standard hEGF/UG. The former hEGF/UG component was a high-molecular weight form that was cleaved into hEGF/UG by incubation with either mouse EGF/UG-associated arginine esterase or trypsin. It appeared to be identical to the high-molecular weight hEGF/UG previously reported in human urine, except for its apparently equal activities in radioimmunoassay and radioreceptor assay. The latter hEGF/UG component was immunologically, biologically, and physiochemically indistinguishable from highly purified hEGF/UG from human urine and was immunologically different from purified human platelet-derived growth factor. Platelet-associated hEGF/UG may account for the mitogenic activity of serum in cell lines in which platelet-derived growth factor is not active. Since hEGF/UG appears to be liberated from platelets during coagulation, platelet-associated EGF/UG may be involved in normal vascular and tissue repair and in the pathogenesis of atherosclerotic lesions. The discovery that the EGF/UG in plasma is associated with blood platelets raises important new possibilities for its role in human health and disease. PMID:6603475

  12. Increased susceptibility to atrial fibrillation secondary to atrial fibrosis in transgenic goats expressing transforming growth factor - B1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in people with significant morbidity and mortality. There is a strong association between atrial fibrosis and AF. Transforming growth factor B1 (TGF-B1) is an essential mediator of atrial fibrosis in animal models and human pat...

  13. Growth habit and photo-synthetic activity of shoot cultures of Medicago sativa L. transformed with the oryzacystatin II gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In vitro maintained shoot cultures of alfalfa (Medicago sativa L. cv. Zajeÿarska 83) that were transformed with the oryzacystatin II (OCII) gene and propagated on growth regulator-free medium were subjected to analysis of morphological characteristics and photosynthetic activity. The most striking f...

  14. Vertebral Artery Aneurysm Mimicking as Left Subclavian Artery Aneurysm in a Patient with Transforming Growth Factor Beta Receptor II Mutation.

    PubMed

    Afifi, Rana O; Dhillon, Baltej Singh; Sandhu, Harleen K; Charlton-Ouw, Kristofer M; Estrera, Anthony L; Azizzadeh, Ali

    2015-10-01

    We report successful endovascular repair of a left vertebral artery aneurysm in a patient with transforming growth factor beta receptor II mutation. The patient was initially diagnosed with a left subclavian artery aneurysm on computed tomography angiography. The patient consented to publication of this report.

  15. Tyrosine dephosphorylation of nuclear proteins mimics transforming growth factor {beta}1 stimulation of {alpha}2(I) collagen gene expression

    SciTech Connect

    Greenwel, P.; Hu, Wei; Ramirez, F.; Kohanski, R.A.

    1995-12-01

    This report describes how the transforming growth factor {beta}1 (TGF-{beta}1) stimulates the transcription of the gene coding for collagen I (COL1A2). The report goes on to correlate tyrosine dephosphorylation, increased binding of a transcriptional complex and TGF-{beta}1 stimulation of gene expression. 33 refs., 8 figs., 1 tab.

  16. Potassium inhibits dietary salt-induced transforming growth factor-beta production.

    PubMed

    Ying, Wei-Zhong; Aaron, Kristal; Wang, Pei-Xuan; Sanders, Paul W

    2009-11-01

    Human and animal studies demonstrate an untoward effect of excess dietary NaCl (salt) intake on cardiovascular function and life span. The endothelium in particular augments the production of transforming growth factor (TGF)-beta, a fibrogenic growth factor, in response to excess dietary salt intake. This study explored the initiating mechanism that regulates salt-induced endothelial cell production of TGF-beta. Male Sprague-Dawley rats were given diets containing different amounts of NaCl and potassium for 4 days. A bioassay for TGF-beta demonstrated increased (35.2%) amounts of active TGF-beta in the medium of aortic ring segments from rats on the high-salt diet compared with rats maintained on a 0.3% NaCl diet. Inhibition of the large-conductance, calcium-activated potassium channel inhibited dietary salt-induced vascular production of TGF-beta but did not affect production of TGF-beta by ring segments from rats on the low-salt diet. Immunohistochemical and Western analyses demonstrated the alpha subunit of the calcium-activated potassium channel in endothelial cells. Increasing medium [K+] inhibited production of dietary salt-induced vascular production levels of total and active TGF-beta but did not alter TGF-beta production by aortic rings from rats on the 0.3% NaCl diet. Increasing dietary potassium content decreased urinary active TGF-beta in animals receiving the high-salt diet but did not change urinary active TGF-beta in animals receiving the low-salt diet. The findings demonstrated an interesting interaction between the dietary intake of potassium and excess NaCl and further showed the fundamental role of the endothelial calcium-activated potassium channel in the vascular response to excess salt intake.

  17. Transforming growth factor: beta signaling is essential for limb regeneration in axolotls.

    PubMed

    Lévesque, Mathieu; Gatien, Samuel; Finnson, Kenneth; Desmeules, Sophie; Villiard, Eric; Pilote, Mireille; Philip, Anie; Roy, Stéphane

    2007-01-01

    Axolotls (urodele amphibians) have the unique ability, among vertebrates, to perfectly regenerate many parts of their body including limbs, tail, jaw and spinal cord following injury or amputation. The axolotl limb is the most widely used structure as an experimental model to study tissue regeneration. The process is well characterized, requiring multiple cellular and molecular mechanisms. The preparation phase represents the first part of the regeneration process which includes wound healing, cellular migration, dedifferentiation and proliferation. The redevelopment phase represents the second part when dedifferentiated cells stop proliferating and redifferentiate to give rise to all missing structures. In the axolotl, when a limb is amputated, the missing or wounded part is regenerated perfectly without scar formation between the stump and the regenerated structure. Multiple authors have recently highlighted the similarities between the early phases of mammalian wound healing and urodele limb regeneration. In mammals, one very important family of growth factors implicated in the control of almost all aspects of wound healing is the transforming growth factor-beta family (TGF-beta). In the present study, the full length sequence of the axolotl TGF-beta1 cDNA was isolated. The spatio-temporal expression pattern of TGF-beta1 in regenerating limbs shows that this gene is up-regulated during the preparation phase of regeneration. Our results also demonstrate the presence of multiple components of the TGF-beta signaling machinery in axolotl cells. By using a specific pharmacological inhibitor of TGF-beta type I receptor, SB-431542, we show that TGF-beta signaling is required for axolotl limb regeneration. Treatment of regenerating limbs with SB-431542 reveals that cellular proliferation during limb regeneration as well as the expression of genes directly dependent on TGF-beta signaling are down-regulated. These data directly implicate TGF-beta signaling in the

  18. Relation of spontaneous transformation in cell culture to adaptive growth and clonal heterogeneity.

    PubMed

    Rubin, A L; Yao, A; Rubin, H

    1990-01-01

    Cell transformation in culture is marked by the appearance of morphologically altered cells that continue to multiply to form discrete foci in confluent sheets when the surrounding cells are inhibited. These foci occur spontaneously in early-passage NIH 3T3 cells grown to confluency in 10% calf serum (CS) but are not seen in cultures grown to confluency in 2% CS. However, repeated passage of the cells at low density in 2% CS gives rise to an adapted population that grows to increasingly higher saturation densities and produces large numbers of foci in 2% CS. The increased saturation density of the adapted population in 2% CS is retained upon repeated passage in 10% CS, but the number and size of the foci produced in 2% CS gradually decrease under this regime. Clonal analysis confirms that the focus-forming potential of most if not all of the cells in a population increases in response to a continuously applied growth constraint, although only a small fraction of the population may actually form foci in a given assay. The acquired capacity for focus formation varies widely in clones derived from the adapted population and changes in diverse ways upon further passage of the clones. We propose that the adaptive changes result from progressive selection of successive phenotypic variations in growth capacity that occur spontaneously. The process designated progressive state selection resolves the apparent dichotomy between spontaneous mutation with selection on the one hand and induction on the other, by introducing selection among fluctuating states or metabolic patterns rather than among genetically altered cells.

  19. On the low-temperature growth mechanism of single walled carbon nanotubes in plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Shariat, M.; Shokri, B.; Neyts, E. C.

    2013-12-01

    Despite significant progress in single walled carbon nanotube (SWCNT) production by plasma enhanced chemical vapor deposition (PECVD), the growth mechanism in this method is not clearly understood. We employ reactive molecular dynamics simulations to investigate how plasma-based deposition allows growth at low temperature. We first investigate the SWCNT growth mechanism at low and high temperatures under conditions similar to thermal CVD and PECVD. We then show how ion bombardment during the nucleation stage increases the carbon solubility in the catalyst at low temperature. Finally, we demonstrate how moderate energy ions sputter amorphous carbon allowing for SWCNT growth at 500 K.

  20. Plasma biomarker profiling in the detection of growth promoter use in calves.

    PubMed

    Mooney, M H; Situ, C; Cacciatore, G; Hutchinson, T; Elliott, C; Bergwerff, A A

    2008-05-01

    The detection of illicit growth promoter use during meat production within the European Union is reliant on residue testing which is a limiting factor on the number of animals which can be tested and consequently compromises the efficacy of testing procedures. The present study examined a novel detection strategy based on the profiling of plasma component concentrations in response to growth promoter administrations. Calves subjected to nortestosterone decanoate, 17beta-oestradiol benzoate and dexamethasone were found to have altered urea, aminoterminal propeptide of type III procollagen and sex hormone binding globulin profiles in response to treatments. These findings demonstrate the potential of using the identification of perturbed profiles within a panel of biomarkers which cover a spectrum of biological activity to reveal growth promoter abuse.

  1. Nitrogen Plasma Instabilities and the Growth of Silicon Nitride by Electron Cyclotron Resonance Microwave Plasma Chemical Vapor Deposition

    NASA Technical Reports Server (NTRS)

    Pool, F. S.

    1996-01-01

    Nitrogen plasma instabilities have been identified through fluctuations in the ion current density and substrate floating potential. The plasma characteristics for both nitrogen and silane-nitrogen plasmas are consistent with a transition from an underdense to overdense plasma at 0.9 and 1.0 mTorr respectively.

  2. Loss of transforming growth factor-beta 2 leads to impairment of central synapse function

    PubMed Central

    Heupel, Katharina; Sargsyan, Vardanush; Plomp, Jaap J; Rickmann, Michael; Varoqueaux, Frédérique; Zhang, Weiqi; Krieglstein, Kerstin

    2008-01-01

    Background The formation of functional synapses is a crucial event in neuronal network formation, and with regard to regulation of breathing it is essential for life. Members of the transforming growth factor-beta (TGF-β) superfamily act as intercellular signaling molecules during synaptogenesis of the neuromuscular junction of Drosophila and are involved in synaptic function of sensory neurons of Aplysia. Results Here we show that while TGF-β2 is not crucial for the morphology and function of the neuromuscular junction of the diaphragm muscle of mice, it is essential for proper synaptic function in the pre-Bötzinger complex, a central rhythm organizer located in the brainstem. Genetic deletion of TGF-β2 in mice strongly impaired both GABA/glycinergic and glutamatergic synaptic transmission in the pre-Bötzinger complex area, while numbers and morphology of central synapses of knock-out animals were indistinguishable from their wild-type littermates at embryonic day 18.5. Conclusion The results demonstrate that TGF-β2 influences synaptic function, rather than synaptogenesis, specifically at central synapses. The functional alterations in the respiratory center of the brain are probably the underlying cause of the perinatal death of the TGF-β2 knock-out mice. PMID:18854036

  3. Targeting the Transforming Growth Factor-β Signaling Pathway in Human Cancer

    PubMed Central

    Nagaraj, Nagathihalli S

    2009-01-01

    The transforming growth factor-β (TGF-β) signaling pathway plays a pivotal role in diverse cellular processes. TGF-β switches its role from tumor suppressor in normal or dysplastic cells to a tumor promoter in advanced cancers. It is widely believed that Smad-dependent pathway is involved in TGF-β tumor suppressive functions, whereas activation of Smad-independent pathways coupled with the loss of tumor suppressor functions of TGF-β is important for its pro-oncogenic functions. TGF-β signaling has been considered as a very suitable therapeutic target. The discovery of oncogenic actions of TGF-β has generated a great deal of enthusiasm for developing TGF-β signaling inhibitors for the treatment of cancer. The challenge is to identify the group of patients where targeted tumors are not only refractory to TGF-β-induced tumor suppressor functions but also responsive to tumor promoting effects of TGF-β. TGF-β pathway inhibitors including small and large molecules have now entered clinical trials. Preclinical studies with these inhibitors have shown promise in a variety of different tumor models. Here we emphasize on the mechanisms of signaling and specific targets of the TGF-β pathway that are critical effectors of tumor progression and invasion. This report also focuses on the therapeutic intervention of TGF-β signaling in human cancers. PMID:20001556

  4. Transforming Growth Factor β Drives Hemogenic Endothelium Programming and the Transition to Hematopoietic Stem Cells.

    PubMed

    Monteiro, Rui; Pinheiro, Philip; Joseph, Nicola; Peterkin, Tessa; Koth, Jana; Repapi, Emmanouela; Bonkhofer, Florian; Kirmizitas, Arif; Patient, Roger

    2016-08-22

    Hematopoietic stem cells (HSCs) are self-renewing multipotent stem cells that generate mature blood lineages throughout life. They, together with hematopoietic progenitor cells (collectively known as HSPCs), emerge from hemogenic endothelium in the floor of the embryonic dorsal aorta by an endothelial-to-hematopoietic transition (EHT). Here we demonstrate that transforming growth factor β (TGFβ) is required for HSPC specification and that it regulates the expression of the Notch ligand Jagged1a in endothelial cells prior to EHT, in a striking parallel with the epithelial-to-mesenchymal transition (EMT). The requirement for TGFβ is two fold and sequential: autocrine via Tgfβ1a and Tgfβ1b produced in the endothelial cells themselves, followed by a paracrine input of Tgfβ3 from the notochord, suggesting that the former programs the hemogenic endothelium and the latter drives EHT. Our findings have important implications for the generation of HSPCs from pluripotent cells in vitro. PMID:27499523

  5. Structure-function analysis of synthetic and recombinant derivatives of transforming growth factor alpha.

    PubMed Central

    Defeo-Jones, D; Tai, J Y; Wegrzyn, R J; Vuocolo, G A; Baker, A E; Payne, L S; Garsky, V M; Oliff, A; Riemen, M W

    1988-01-01

    Transforming growth factor alpha (TGF-alpha) is a 50-amino-acid peptide that stimulates cell proliferation via binding to cell surface receptors. To identify the structural features of TGF-alpha that govern receptor-ligand interactions, we prepared synthetic peptide fragments and recombinant mutant proteins of TGF-alpha. These TGF-alpha derivatives were tested in receptor binding and mitogenesis assays. Synthetic peptides representing the N terminus, the C terminus, or the individual disulfide constrained rings of TGF-alpha did not exhibit receptor-binding or mitogenic activity. Replacement of the cysteines with alanines at positions 8 and 21, 16 and 32, and 34 and 43 or at positions 8 and 21 and 34 and 43 yielded inactive mutant proteins. However, mutant proteins containing substitutions or deletions in the N-terminal region retained significant biologic activity. Conservative amino acid changes at residue 29 or 38 or both and a nonconservative amino acid change at residue 12 had little effect on binding or mitogenesis. However, nonconservative amino acid changes at residues 15, 38, and 47 produced dramatic decreases in receptor binding (23- to 71-fold) and mitogenic activity (38- to 125-fold). These studies indicate that at least three distinct regions of TGF-alpha contribute to biologic activity. PMID:2850475

  6. Transforming growth factor-beta 1 is decreased in remodeling hypertensive bovine pulmonary arteries.

    PubMed Central

    Botney, M D; Parks, W C; Crouch, E C; Stenmark, K; Mecham, R P

    1992-01-01

    The development of pulmonary hypertension in hypoxic newborn calves is associated with a complex pattern of increased tropoelastin and type I procollagen synthesis and deposition by smooth muscle cells in large elastic pulmonary arteries compared to normoxic controls. We examined the possibility that transforming growth factor-beta 1 (TGF-beta 1) may be associated with the production of extracellular matrix protein in this model of pulmonary hypertension. Medial smooth muscle cells in both normotensive and hypertensive vessels, as assessed by immunohistochemistry, were the major source of TGF-beta 1. Staining was confined to foci of smooth muscle cells in the outer media and appeared greater in normotensive than hypertensive vessels. Consistent with the immunohistochemistry, a progressive, age-dependent increase in normotensive pulmonary artery TGF-beta 1 mRNA was observed after birth, whereas TGF-beta 1 mRNA remained at low, basal levels in hypertensive, remodeling pulmonary arteries. These observations suggest that local expression of TGF-beta 1 is not associated with increased extracellular matrix protein synthesis in this model of hypoxic pulmonary hypertension. Images PMID:1569202

  7. Integration of sexual trauma in a religious narrative: transformation, resolution and growth among contemplative nuns.

    PubMed

    Durà-Vilà, Glòria; Littlewood, Roland; Leavey, Gerard

    2013-02-01

    The psychological consequences of sexual abuse are generally serious and enduring, particularly when the perpetrator is known and trusted by the survivor. This paper explores the experiences of five contemplative nuns who were sexually abused by priests and the spiritual journeys that followed. In the context of an ethnographic study of contemplative practice, participant observation and in-depth interviews were used to examine the ways that the nuns sought to make sense of their experiences through a long process of solitary introspection. The pursuit of meaning was shaped by religious beliefs relating to forgiveness, sacrifice, and salvation. Thus, trauma was transformed into a symbolic religious narrative that shaped their sense of identity. They were able to restructure core beliefs and to manage their current relationships with priests more securely. They described regaining their spiritual well-being in ways that suggest a form of posttraumatic spiritual growth. We conclude by discussing the findings in the light of the existing literature on the interaction of trauma and spirituality.

  8. Ursolic acid, an antagonist for transforming growth factor (TGF)-beta1.

    PubMed

    Murakami, Shigeru; Takashima, Hajime; Sato-Watanabe, Mariko; Chonan, Sumi; Yamamoto, Koji; Saitoh, Masako; Saito, Shiuji; Yoshimura, Hiromitsu; Sugawara, Koko; Yang, Junshan; Gao, Nannan; Zhang, Xinggao

    2004-05-21

    Transforming growth factor-beta (TGF-beta), a multifunctional cytokine which is involved in extracellular matrix modulation, has a major role in the pathogenesis and progression of fibrotic diseases. We now report the effects of ursolic acid on TGF-beta1 receptor binding and TGF-beta1-induced cellular functions in vitro. Ursolic acid inhibited [(125)I]-TGF-beta1 receptor binding to Balb/c 3T3 mouse fibroblasts with an IC(50) value of 6.9+/-0.8 microM. Ursolic acid dose-dependently recovered reduced proliferation of Minc Mv1Lu cells in the presence of 5 nM of TGF-beta1 and attenuated TGF-beta1-induced collagen synthesis and production in human fibroblasts. Molecular dynamics simulations suggest that ursolic acid may interact with the hydrophobic region of the dimeric interface and thereby inhibit the binding of TGF-beta1 to its receptor. All these findings taken together show that ursolic acid functions as an antagonist for TGF-beta1. This is the first report to show that a small molecule can inhibit TGF-beta1 receptor binding and influence functions of TGF-beta1.

  9. Diosgenin attenuates hepatic stellate cell activation through transforming growth factor-β/Smad signaling pathway

    PubMed Central

    Xie, Wei-Lin; Jiang, Rong; Shen, Xiao-Lu; Chen, Zhi-Yu; Deng, Xiao-Ming

    2015-01-01

    Activation of hepatic stellate cells (HSC) plays a pivotal role in the development of hepatic fibrosis. Transforming growth factor-β1 (TGF-β1) is considered to be the main stimuli factor responsible for the activation of HSC. Diosgenin is a steroidal saponin found in several plants including Solanum and Dioscorea species, and it inhibited high glucose-induced renal tubular fibrosis. However, the effects of diosgenin against hepatic fibrosis remain elusive. Therefore, in this study, we investigated the effects of diosgenin on TGF-β1-induced HSCs and elucidate the possible mechanism of its anti-fibrotic effect. Our results demonstrated that diosgenin inhibited TGF-β1-induced HSC proliferation, reduced the expression of collagen I and α-smooth muscle actin (α-SMA), as well as the expression of TGF-β receptor I (TGF-β RI) and II. Moreover, diosgenin suppressed TGF-β1-induced phosphorylation of Smad3 in HSCs. In conclusion, our data demonstrate that diosgenin inhibited HSC-T6 cell proliferation and activation, at least in part, via the TGF-β1/Smad signaling pathway. These results provide that diosgenin may have potential to treat liver fibrosis. PMID:26884947

  10. Transforming growth factor-beta signaling in thoracic aortic aneurysm development: a paradox in pathogenesis

    PubMed Central

    Jones, Jeffrey A.; Spinale, Francis G.; Ikonomidis, John S.

    2008-01-01

    Thoracic aortic aneurysms (TAAs) are potentially devastating, and due to their asymptomatic behavior, pose a serious health risk characterized by the lack of medical treatment options and high rates of surgical morbidity and mortality. Independent of the inciting stimuli (biochemical/mechanical), TAA development proceeds by a multifactorial process influenced by both cellular and extracellular mechanisms, resulting in alterations of the structure and composition of the vascular extracellular matrix (ECM). While the role of enhanced ECM proteolysis in TAA formation remains undisputed, little attention has been focused on the upstream signaling events that drive the remodeling process. Recent evidence highlighting the dysregulation of transforming growth factor-beta (TGF-β) signaling in ascending TAAs from Marfan syndrome patients has stimulated an interest in this intracellular signaling pathway. However, paradoxical discoveries have implicated both enhanced TGF-β signaling and loss of function TGF-β receptor mutations, in aneurysm formation; obfuscating a clear functional role for TGF-β in aneurysm development. In an effort to elucidate this subject, TGF-β signaling and its role in vascular remodeling and pathology will be reviewed, with the aim of identifying potential mechanisms of how TGF-β signaling may contribute to the formation and progression of TAA. PMID:18765947

  11. Overexpressed homeobox B9 regulates oncogenic activities by transforming growth factor-β1 in gliomas

    SciTech Connect

    Fang, Liping; Xu, Yinghui; Zou, Lijuan

    2014-03-28

    Highlights: • HOXB9 is overexpressed in gliomas. • HOXB9 over expression had shorter survival time than down expression in gliomas. • HOXB9 stimulated the proliferation, migration and sphere formation of glioma cells. • Activation of TGF-β1 contributed to HOXB9-induced oncogenic activities. - Abstract: Glioma is the leading cause of deaths related to tumors in the central nervous system. The mechanisms of gliomagenesis remain elusive to date. Homeobox B9 (HOXB9) has a crucial function in the regulation of gene expression and cell survival, but its functions in glioma formation and development have yet to be elucidated. This study showed that HOXB9 expression in glioma tissues was significantly higher than that in nontumor tissues. Higher HOXB9 expression was also significantly associated with advanced clinical stage in glioma patients. HOXB9 overexpression stimulated the proliferation, migration, and sphere formation of glioma cells, whereas HOXB9 knockdown elicited an opposite effect. HOXB9 overexpression also increased the tumorigenicity of glioma cells in vivo. Moreover, the activation of transforming growth factor-β1 contributed to HOXB9-induced oncogenic activities. HOXB9 could be used as a predictable biomarker to be detected in different pathological and histological subtypes in glioma for diagnosis or prognosis.

  12. Genetic variations in the transforming growth factor beta pathway as predictors of bladder cancer risk.

    PubMed

    Wei, Hua; Kamat, Ashish M; Aldousari, Saad; Ye, Yuanqing; Huang, Maosheng; Dinney, Colin P; Wu, Xifeng

    2012-01-01

    Bladder cancer is the fifth most common cancer in the United States, and identifying genetic markers that may predict susceptibility in high-risk population is always needed. The purpose of our study is to determine whether genetic variations in the transforming growth factor-beta (TGF-β) pathway are associated with bladder cancer risk. We identified 356 single-nucleotide polymorphisms (SNPs) in 37 key genes from this pathway and evaluated their association with cancer risk in 801 cases and 801 controls. Forty-one SNPs were significantly associated with cancer risk, and after adjusting for multiple comparisons, 9 remained significant (Q-value ≤0.1). Haplotype analysis further revealed three haplotypes within VEGFC and two haplotypes in EGFR were significantly associated with increased bladder cancer risk compared to the most common haplotype. Classification and regression tree analysis further revealed potential high-order gene-gene interactions, with VEGFC: rs3775194 being the initial split, which suggests that this variant is responsible for the most variation in risk. Individuals carrying the common genotype for VEGFC: rs3775194 and EGFR: rs7799627 and the variant genotype for VEGFR: rs4557213 had a 4.22-fold increase in risk, a much larger effect magnitude than that conferred by common genotype for VEGFR: rs4557213. Our study provides the first epidemiological evidence supporting a connection between TGF-β pathway variants and bladder cancer risk.

  13. Role of transforming growth factor-beta in the development of the mouse embryo

    PubMed Central

    1987-01-01

    Using immunohistochemical methods, we have investigated the role of transforming growth factor-beta (TGF-beta) in the development of the mouse embryo. For detection of TGF-beta in 11-18-d-old embryos, we have used a polyclonal antibody specific for TGF-beta type 1 and the peroxidase-antiperoxidase technique. Staining of TGF-beta is closely associated with mesenchyme per se or with tissues derived from mesenchyme, such as connective tissue, cartilage, and bone. TGF-beta is conspicuous in tissues derived from neural crest mesenchyme, such as the palate, larynx, facial mesenchyme, nasal sinuses, meninges, and teeth. Staining of all of these tissues is greatest during periods of morphogenesis. In many instances, intense staining is seen in mesenchyme when critical interactions with adjacent epithelium occur, as in the development of hair follicles, teeth, and the submandibular gland. Marked staining is also seen when remodeling of mesenchyme or mesoderm occurs, as during formation of digits from limb buds, formation of the palate, and formation of the heart valves. The presence of TGF-beta is often coupled with pronounced angiogenic activity. The histochemical results are discussed in terms of the known biochemical actions of TGF-beta, especially its ability to control both synthesis and degradation of both structural and adhesion molecules of the extracellular matrix. PMID:3320058

  14. Effect of transforming growth factor-β3 on mono and multilayer chondrocytes.

    PubMed

    Sefat, Farshid; Youseffi, Mansour; Khaghani, Seyed Ali; Soon, Chin Fhung; Javid, Farideh

    2016-07-01

    Articular cartilage is an avascular and flexible connective tissue found in joints. It produces a cushioning effect at the joints and provides low friction to protect the ends of the bones from wear and tear/damage. It has poor repair capacity and any injury can result pain and loss of mobility. Transforming growth factor-beta (TGF-β), a cytokine superfamily, regulates cell function, including differentiation and proliferation. Although the function of the TGF-βs in various cell types has been investigated, their function in cartilage repair is as yet not fully understood. The effect of TGF-β3 in biological regulation of primary chondrocyte was investigated in this work. TGF-β3 provided fibroblastic morphology to chondrocytes and therefore overall reduction in cell proliferation was observed. The length of the cells supplemented with TGF-β3 were larger than the cells without TGF-β3 treatment. This was caused by the fibroblast like cells (dedifferentiated chondrocytes) which occupied larger areas compared to cells without TGF-β3 addition. The healing process of the model wound closure assay of chondrocyte multilayer was slowed down by TGF-β3, and this cytokine negatively affected the strength of chondrocyte adhesion to the cell culture surface. PMID:27108397

  15. Association of transforming growth-factor alpha gene polymorphisms with nonsyndromic cleft palate only (CPO)

    SciTech Connect

    Shiang, R. ); Lidral, A.C.; Ardinger, H.H.; Murray, J.C.; Romitti, P.A.; Munger, R.G.; Buetow, K.H.

    1993-10-01

    Genetic analysis and tissue-specific expression studies support a role for transforming growth-factor alpha (TGFA) in craniofacial development. Previous studies have confirmed an association of alleles for TGFA with nonsyndromic cleft lip with or without cleft palate (CL/P) in humans. The authors carried out a retrospective association study to determine whether specific allelic variants of the TGFA gene are also associated with cleft palate only (CPO). The PCR products from 12 overlapping sets of primers to the TGFA cDNA were examined by using single-strand conformational polymorphism analysis. Four DNA polymorphic sites for TGFA were identified in the 3[prime] untranslated region of the TGFA gene. These variants, as well as previously identified RFLPs for TGFA, were characterized in case and control populations for CPO by using X[sup 2] analysis. A significant association between alleles of TGFA and CPO was identified which further supports a role for this gene as one of the genetic determinants of craniofacial development. Sequence analysis of the variants disclosed a cluster of three variable sites within 30 bp of each other in the 3[prime] untranslated region previously associated with an antisense transcript. These studies extend the role for TGFA in craniofacial morphogenesis and support an interrelated mechanism underlying nonsyndromic forms of CL/P. 46 refs., 3 figs., 3 tabs.

  16. Transforming growth factor receptor type II (ec-TβR II) behaves as a halophile.

    PubMed

    Saini, Komal; Khan, M Ashhar I; Chakrapani, Sumit; Deep, Shashank

    2015-01-01

    The members of transforming growth factor β family (TGF-β) are multifunctional proteins but their main role is to control cell proliferation and differentiation. Polypeptides of TGF-β family function by binding to two related, functionally distinct transmembrane receptor kinases, first to the type II (TβR II) followed by type I receptor (TβR I). The paper describes, in details, the stability of wt-ec-TβR II under different conditions. The stability of wt-ec-TβR II was observed at different pH and salt concentration using fluorescence spectroscopy. Stability of ec-TβR II decreases with decrease in pH. Interestingly, the addition of salt increases the stability of the TβRII at pH 5.0 as observed for halophiles. Computational analysis using DELPHI suggests that this is probably due to the decrease in repulsion between negatively charged residues at surface on the addition of salt. This is further confirmed by the change in the stability of receptor on mutation of some of the residues (D32A) at surface.

  17. Diosgenin attenuates hepatic stellate cell activation through transforming growth factor-β/Smad signaling pathway.

    PubMed

    Xie, Wei-Lin; Jiang, Rong; Shen, Xiao-Lu; Chen, Zhi-Yu; Deng, Xiao-Ming

    2015-01-01

    Activation of hepatic stellate cells (HSC) plays a pivotal role in the development of hepatic fibrosis. Transforming growth factor-β1 (TGF-β1) is considered to be the main stimuli factor responsible for the activation of HSC. Diosgenin is a steroidal saponin found in several plants including Solanum and Dioscorea species, and it inhibited high glucose-induced renal tubular fibrosis. However, the effects of diosgenin against hepatic fibrosis remain elusive. Therefore, in this study, we investigated the effects of diosgenin on TGF-β1-induced HSCs and elucidate the possible mechanism of its anti-fibrotic effect. Our results demonstrated that diosgenin inhibited TGF-β1-induced HSC proliferation, reduced the expression of collagen I and α-smooth muscle actin (α-SMA), as well as the expression of TGF-β receptor I (TGF-β RI) and II. Moreover, diosgenin suppressed TGF-β1-induced phosphorylation of Smad3 in HSCs. In conclusion, our data demonstrate that diosgenin inhibited HSC-T6 cell proliferation and activation, at least in part, via the TGF-β1/Smad signaling pathway. These results provide that diosgenin may have potential to treat liver fibrosis. PMID:26884947

  18. Transforming Growth Factors β Coordinate Cartilage and Tendon Differentiation in the Developing Limb Mesenchyme*

    PubMed Central

    Lorda-Diez, Carlos I.; Montero, Juan A.; Martinez-Cue, Carmen; Garcia-Porrero, Juan A.; Hurle, Juan M.

    2009-01-01

    Transforming growth factor β (TGFβ) signaling has an increasing interest in regenerative medicine as a potential tool to repair cartilages, however the chondrogenic effect of this pathway in developing systems is controversial. Here we have analyzed the function of TGFβ signaling in the differentiation of the developing limb mesoderm in vivo and in high density micromass cultures. In these systems highest signaling activity corresponded with cells at stages preceding overt chondrocyte differentiation. Interestingly treatments with TGFβs shifted the differentiation outcome of the cultures from chondrogenesis to fibrogenesis. This phenotypic reprogramming involved down-regulation of Sox9 and Aggrecan and up-regulation of Scleraxis, and Tenomodulin through the Smad pathway. We further show that TGFβ signaling up-regulates Sox9 in the in vivo experimental model system in which TGFβ treatments induce ectopic chondrogenesis. Looking for clues explaining the dual role of TGFβ signaling, we found that TGFβs appear to be direct inducers of the chondrogenic gene Sox9, but the existence of transcriptional repressors of TGFβ signaling modulates this role. We identified TGF-interacting factor Tgif1 and SKI-like oncogene SnoN as potential candidates for this inhibitory function. Tgif1 gene regulation by TGFβ signaling correlated with the differential chondrogenic and fibrogenic effects of this pathway, and its expression pattern in the limb marks the developing tendons. In functional experiments we found that Tgif1 reproduces the profibrogenic effect of TGFβ treatments. PMID:19717568

  19. Transforming growth factor-beta (TGF-beta) and programmed cell death in the vertebrate retina.

    PubMed

    Duenker, Nicole

    2005-01-01

    Programmed cell death (PCD) is a precisely regulated phenomenon essential for the homeostasis of multicellular organisms. Developmental systems, particularly the nervous system, have provided key observations supporting the physiological role of PCD. We have recently shown that transforming growth factor-beta (TGF-beta) plays an important role in mediating ontogenetic PCD in the nervous system. As part of the central nervous system the developing retina serves as an ideal model system for investigating apoptotic processes during neurogenesis in vivo as it is easily accessible experimentally and less complex due to its limited number of different neurons. This review summarizes data indicating a pivotal role of TGF-beta in mediating PCD in the vertebrate retina. The following topics are discussed: expression of TGF-beta isoforms and receptors in the vertebrate retina, the TGF-beta signaling pathway, functions and molecular mechanisms of PCD in the nervous system, TGF-beta-mediated retinal apoptosis in vitro and in vivo, and interactions of TGF-beta with other pro- and anti-apoptotic factors.

  20. Cardiac fibroblasts are predisposed to convert into myocyte phenotype: Specific effect of transforming growth factor. beta

    SciTech Connect

    Eghbali, M.; Tomek, R.; Woods, C.; Bhambi, B. )

    1991-02-01

    Cardiac fibroblasts are mainly responsible for the synthesis of major extracellular matrix proteins in the heart, including fibrillar collagen types I and III and fibronectin. In this report we show that these cells, when stimulated by transforming growth factor {beta}{sub 1} (TGF-{beta}{sub 1}), acquire certain myocyte-specific properties. Cultured cardiac fibroblasts from adult rabbit heart were treated with TGF-{beta}{sub 1}, (10-15 ng/ml) for different periods of time. Northern hybridization analysis of total RNA showed that cells treated with TGF-{beta}{sub 1} became stained with a monoclonal antibody to muscle-specific actin. After treatment of quiescent cells with TGF-{beta}{sub 1}, cell proliferation (as measured by ({sup 3}H)thymidine incorporation) was moderately increased. Cultured cardiac fibroblasts at the subconfluent stage, when exposed to TGF-{beta}{sub 1} in the presence of 10% fetal bovine serum, gave rise to a second generation of slowly growing cells that expressed muscle-specific actin filaments. The findings demonstrate that cardiac fibroblasts can be made to differentiate into cells that display many characteristics of cardiac myocytes. TGF-{beta}{sub 1} seems to be a specific inducer of such conversion.

  1. Metformin is a novel suppressor for transforming growth factor (TGF)-β1

    PubMed Central

    Xiao, Han; Zhang, Jianshu; Xu, Zhonghe; Feng, Yenan; Zhang, Mingliang; Liu, Jianli; Chen, Ruifei; Shen, Jing; Wu, Jimin; Lu, Zhizhen; Fang, Xiaohong; Li, Jingyuan; Zhang, Youyi

    2016-01-01

    Metformin is a widely used first-line antidiabetic drug that has been shown to protect against a variety of specific diseases in addition to diabetes, including cardiovascular disorders, polycystic ovary syndrome, and cancer. However, the precise mechanisms underlying the diverse therapeutic effects of metformin remain elusive. Here, we report that transforming growth factor-β1 (TGF-β1), which is involved in the pathogenesis of numerous diseases, is a novel target of metformin. Using a surface plasmon resonance-based assay, we identified the direct binding of metformin to TGF-β1 and found that metformin inhibits [125I]-TGF-β1 binding to its receptor. Furthermore, based on molecular docking and molecular dynamics simulations, metformin was predicted to interact with TGF-β1 at its receptor-binding domain. Single-molecule force spectroscopy revealed that metformin reduces the binding probability but not the binding force of TGF-β1 to its type II receptor. Consequently, metformin suppresses type II TGF-β1 receptor dimerization upon exposure to TGF-β1, which is essential for downstream signal transduction. Thus, our results indicate that metformin is a novel TGF-β suppressor with therapeutic potential for numerous diseases in which TGF-β1 hyperfunction is indicated. PMID:27349853

  2. Integration of sexual trauma in a religious narrative: Transformation, resolution and growth among contemplative nuns

    PubMed Central

    Littlewood, Roland; Leavey, Gerard

    2013-01-01

    The psychological consequences of sexual abuse are generally serious and enduring, particularly when the perpetrator is known and trusted by the survivor. This paper explores the experiences of five contemplative nuns who were sexually abused by priests and the spiritual journeys that followed. In the context of an ethnographic study of contemplative practice, participant observation and in-depth interviews were used to examine the ways that the nuns sought to make sense of their experiences through a long process of solitary introspection. The pursuit of meaning was shaped by religious beliefs relating to forgiveness, sacrifice, and salvation. Thus, trauma was transformed into a symbolic religious narrative that shaped their sense of identity. They were able to restructure core beliefs and to manage their current relationships with priests more securely. They described regaining their spiritual well-being in ways that suggest a form of posttraumatic spiritual growth. We conclude by discussing the findings in the light of the existing literature on the interaction of trauma and spirituality. PMID:23296289

  3. Detecting transforming growth factor-β release from liver cells using an aptasensor integrated with microfluidics.

    PubMed

    Matharu, Zimple; Patel, Dipali; Gao, Yandong; Haque, Amranul; Zhou, Qing; Revzin, Alexander

    2014-09-01

    We developed a cell-culture/biosensor platform consisting of aptamer-modified Au electrodes integrated with reconfigurable microfluidics for monitoring of transforming growth factor-beta 1 (TGF-β1), an important inflammatory and pro-fibrotic cytokine. Aptamers were thiolated, labeled with redox reporters, and self-assembled on gold surfaces. The biosensor was determined to be specific for TGF-β1 with an experimental detection limit of 1 ng/mL and linear range extending to 250 ng/mL. Upon determining figures of merit, aptasensor was miniaturized and integrated with human hepatic stellate cells inside microfluidic devices. Reconfigurable microfluidics were developed to ensure that seeding of "sticky" stromal cells did not foul the electrode and compromise sensor performance. This microsystem with integrated aptasensors was used to monitor TGF-β1 release from activated stellate cells over the course of 20 h. The electrochemical response went down upon infusing anti-TGF-β1 antibodies into the microfluidic devices containing activated stellate cells. To further validate aptasensor responses, stellate cells were stained for markers of activation (e.g., alpha smooth muscle actin) and were also tested for presence of TGF-β1 using enzyme linked immunosorbent assay (ELISA). Given the importance of TGF-β1 as a fibrogenic signal, a microsystem with integrated biosensors for local and continuous detection of TGF-β1 may prove to be an important tool to study fibrosis of the liver and other organs.

  4. Transforming Growth Factor Beta Receptor I Inhibitor Sensitizes Drug-resistant Pancreatic Cancer Cells to Gemcitabine

    PubMed Central

    Kim, Yeon Jeong; Hwang, Jae Seok; Hong, Young Bin; Bae, Insoo; Seong, Yeon-Sun

    2012-01-01

    Background Resistance to gemcitabine is a major obstacle in the treatment of advanced pancreatic cancer. Previous exploration of protein kinase inhibitors demonstrated that blocking transforming growth factor-β (TGFβ) signal enhances the efficacy of gemcitabine in pancreatic cancer cells. Materials and Methods We analyzed the cell viability after combinational treatment of TGFβ receptor I (TβRI) inhibitors, SB431542 and SB525334 with gemcitabine in pancreatic cancer cells. In addition, apoptotic cell death and cell migration were measured. Results Combination with TβRI inhibitors significantly augmented the cytotoxicity of gemcitabine in both parental and gemcitabine resistant pancreatic cancer cells. SB525334 significantly increased apoptotic cell death in gemcitabine-resistant cells. Treatment of SB525334 also reduced AKT signal pathway, which plays crucial role in gemcitabine resistance. Migration assay also revealed that blocking TβRI reduces cell migration. Conclusion Chemotherapeutic approaches using SB525334 might enhance the treatment benefit of the gemcitabine-containing regimens in the treatment of pancreatic cancer patients. PMID:22399597

  5. Transforming growth factor-β2 is sequestered in preterm human milk by chondroitin sulfate proteoglycans.

    PubMed

    Namachivayam, Kopperuncholan; Coffing, Hayley P; Sankaranarayanan, Nehru Viji; Jin, Yingzi; MohanKumar, Krishnan; Frost, Brandy L; Blanco, Cynthia L; Patel, Aloka L; Meier, Paula P; Garzon, Steven A; Desai, Umesh R; Maheshwari, Akhil

    2015-08-01

    Human milk contains biologically important amounts of transforming growth factor-β2 isoform (TGF-β2), which is presumed to protect against inflammatory gut mucosal injury in the neonate. In preclinical models, enterally administered TGF-β2 can protect against experimental necrotizing enterocolitis, an inflammatory bowel necrosis of premature infants. In this study, we investigated whether TGF-β bioactivity in human preterm milk could be enhanced for therapeutic purposes by adding recombinant TGF-β2 (rTGF-β2) to milk prior to feeding. Milk-borne TGF-β bioactivity was measured by established luciferase reporter assays. Molecular interactions of TGF-β2 were investigated by nondenaturing gel electrophoresis and immunoblots, computational molecular modeling, and affinity capillary electrophoresis. Addition of rTGF-β2 (20-40 nM) to human preterm milk samples failed to increase TGF-β bioactivity in milk. Milk-borne TGF-β2 was bound to chondroitin sulfate (CS) containing proteoglycan(s) such as biglycan, which are expressed in high concentrations in milk. Chondroitinase treatment of milk increased the bioactivity of both endogenous and rTGF-β2, and consequently, enhanced the ability of preterm milk to suppress LPS-induced NF-κB activation in macrophages. These findings provide a mechanism for the normally low bioavailability of milk-borne TGF-β2 and identify chondroitinase digestion of milk as a potential therapeutic strategy to enhance the anti-inflammatory effects of preterm milk.

  6. Differential expression of transforming growth factor-beta in the interstitial tissue of testis during aging.

    PubMed

    Jung, Jae-Chang; Park, Geun-Tae; Kim, Kook-Hee; Woo, Ju Hyung; An, Jung-Min; Kim, Ki-Chul; Chung, Hae Young; Bae, Young-Seuk; Park, Jeen Woo; Kang, Shin-Sung; Lee, Young-Sup

    2004-05-01

    Transforming growth factor-betas (TGF-betas) have significant effects on testis development. The pattern of TGF-beta expression in aging testis has not been established to date. We examined age-related changes in the expression of TGF-beta and its receptors in the testis using Western blot analysis. TGF-beta1 expression increased continuously in aging rat testis, whereas no age-associated changes were observed for TGF-beta3. Strong expression of TGF-beta2, as well as type I and II receptors was observed in 12-month-old testis, but following this time, expression decreased dramatically. Interestingly, TGF-beta2 and -beta3 displayed strong and similar expression patterns in liver, regardless of age, suggesting that the down-regulation of TGF-beta2 is testis-specific. We observed significant induction of p53 and p21WAF1 in 18-month-old testis that appeared to correspond with aging. Moreover, caloric restriction (CR) prevented age-related decrease in TGF-beta2 expression. Using immunohistochemistry, we showed that all TGF-beta1, -beta2, and -beta3 proteins are expressed primarily in interstitial cells, which are located in the space between adjoining seminiferous tubules. Our data collectively indicate that aging in the testis is regulated by differential expression of TGF-beta proteins, and decreased levels of TGF-beta2 contribute to the aging process.

  7. Genetic programs of epithelial cell plasticity directed by transforming growth factor-β

    PubMed Central

    Zavadil, Jiri; Bitzer, Markus; Liang, Dan; Yang, Yaw-Ching; Massimi, Aldo; Kneitz, Susanne; Piek, Ester; Böttinger, Erwin P.

    2001-01-01

    Epithelial–mesenchymal transitions (EMTs) are an essential manifestation of epithelial cell plasticity during morphogenesis, wound healing, and tumor progression. Transforming growth factor-β (TGF-β) modulates epithelial plasticity in these physiological contexts by inducing EMT. Here we report a transcriptome screen of genetic programs of TGF-β-induced EMT in human keratinocytes and propose functional roles for extracellular response kinase (ERK) mitogen-activated protein kinase signaling in cell motility and disruption of adherens junctions. We used DNA arrays of 16,580 human cDNAs to identify 728 known genes regulated by TGF-β within 4 hours after treatment. TGF-β-stimulated ERK signaling mediated regulation of 80 target genes not previously associated with this pathway. This subset is enriched for genes with defined roles in cell–matrix interactions, cell motility, and endocytosis. ERK-independent genetic programs underlying the onset of EMT involve key pathways and regulators of epithelial dedifferentiation, undifferentiated transitional and mesenchymal progenitor phenotypes, and mediators of cytoskeletal reorganization. The gene expression profiling approach delineates complex context-dependent signaling pathways and transcriptional events that determine epithelial cell plasticity controlled by TGF-β. Investigation of the identified pathways and genes will advance the understanding of molecular mechanisms that underlie tumor invasiveness and metastasis. PMID:11390996

  8. Association of Transforming Growth Factor Alpha Polymorphisms with Nonsyndromic Cleft Lip and Palate in Iranian Population

    PubMed Central

    Ebadifar, Asghar; Hamedi, Roya; Khorram Khorshid, Hamid Reza; Saliminejad, Kioomars; Kamali, Koorosh; Aghakhani Moghadam, Fatemeh; Esmaeili Anvar, Nazanin; Ameli, Nazilla

    2015-01-01

    Background: Cleft lip with or without cleft palate (CL/P) is one of the most common congenital anomalies and the etiology of orofacial clefts is multifactorial. Transforming growth factor alpha (TGFA) is expressed at the medial edge epithelium of fusing palatal shelves during craniofacial development. In this study, the association of two important TGFA gene polymorphisms, BamHI (rs11466297) and RsaI (rs3732248), with CL/P was evaluated in an Iranian population. Methods: The frequencies of BamHI and RsaI variations were determined in 105 unrelated Iranian subjects with nonsyndromic CL/P and 218 control subjects using PCR and RFLP methods, and the results were compared with healthy controls. A p-value of <0.05 was considered statistically significant. Results: The BamHI AC genotype was significantly higher (p=0.016) in the patients (12.4%) than the control group (5.0%). The BamHI C allele was significantly higher (p=0.001; OR=3.4, 95% CI: 1.6–7.4) in the cases (8.0%) compared with the control group (2.5%). Conclusion: Our study showed that there was an association between the TGFA BamHI variation and nonsyndromic CL/P in Iranian population. PMID:26605011

  9. Transforming Growth Factor-β and Endoglin Signaling Orchestrate Wound Healing

    PubMed Central

    Valluru, Manoj; Staton, Carolyn A.; Reed, Malcolm W. R.; Brown, Nicola J.

    2011-01-01

    Physiological wound healing is a complex process requiring the temporal and spatial co-ordination of various signaling networks, biomechanical forces, and biochemical signaling pathways in both hypoxic and non-hypoxic conditions. Although a plethora of factors are required for successful physiological tissue repair, transforming growth factor beta (TGF-β) expression has been demonstrated throughout wound healing and shown to regulate many processes involved in tissue repair, including production of ECM, proteases, protease inhibitors, migration, chemotaxis, and proliferation of macrophages, fibroblasts of the granulation tissue, epithelial and capillary endothelial cells. TGF-β mediates these effects by stimulating signaling pathways through a receptor complex which contains Endoglin. Endoglin is expressed in a broad spectrum of proliferating and stem cells with elevated expression during hypoxia, and regulates important cellular functions such as proliferation and adhesion via Smad signaling. This review focuses on how the TGF-β family and Endoglin, regulate stem cell availability, and modulate cellular behavior within the wound microenvironment, includes current knowledge of the signaling pathways involved, and explores how this information may be applicable to inflammatory and/or angiogenic diseases such as fibrosis, rheumatoid arthritis and metastatic cancer. PMID:22164144

  10. Transforming growth factor-β1 in carcinogenesis, progression, and therapy in cervical cancer.

    PubMed

    Zhu, Haiyan; Luo, Hui; Shen, Zhaojun; Hu, Xiaoli; Sun, Luzhe; Zhu, Xueqiong

    2016-06-01

    Transforming growth factor β1 (TGF-β1) is a multifunctional cytokine that plays important roles in cervical tumor formation, invasion, progression, and metastasis. TGF-β1 functions as a tumor inhibitor in precancerous lesions and early stage cancers of cervix whereas as a tumor promoter in later stage. This switch from a tumor inhibitor to a tumor promoter might be due to various alterations in TGF-β signaling pathway, such as mutations or loss of expression of TGF-β receptors and SMAD proteins. Additionally, the oncoproteins of human papillomaviruses have been shown to stimulate TGF-β1 expression, which in turn suppresses host immune surveillance. Thus, in addition to driving tumor cell migration and metastasis, TGF-β1 is believed to play a key role in promoting human papillomavirus infection by weakening host immune defense. In this article, we will discuss the role of TGF-β1 in the expression, carcinogenesis, progression, and therapy in cervical cancers. A better understanding of this cytokine in cervical carcinogenesis is essential for critical evaluation of this cytokine as a potential prognostic marker and therapeutic target. PMID:27010470

  11. Immunocytochemical localization of latent transforming growth factor-beta1 activation by stimulated macrophages

    NASA Technical Reports Server (NTRS)

    Chong, H.; Vodovotz, Y.; Cox, G. W.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1999-01-01

    Transforming growth factor-beta1 (TGF-beta) is secreted in a latent form consisting of mature TGF-beta noncovalently associated with its amino-terminal propeptide, which is called latency associated peptide (LAP). Biological activity depends upon the release of TGF-beta from the latent complex following extracellular activation, which appears to be the key regulatory mechanism controlling TGF-beta action. We have identified two events associated with latent TGF-beta (LTGF-beta) activation in vivo: increased immunoreactivity of certain antibodies that specifically detect TGF-beta concomitant with decreased immunoreactivity of antibodies to LAP. Macrophages stimulated in vitro with interferon-gamma and lipopolysaccharide reportedly activate LTGF-beta via cell membrane-bound protease activity. We show through dual immunostaining of paraformaldehyde-fixed macrophages that such physiological TGF-beta activation is accompanied by a loss of LAP immunoreactivity with concomitant revelation of TGF-beta epitopes. The induction of TGF-beta immunoreactivity colocalized with immunoreactive betaglycan/RIII in activated macrophages, suggesting that LTGF-beta activation occurs on the cell surface. Confocal microscopy of metabolically active macrophages incubated with antibodies to TGF-beta and betaglycan/RIII prior to fixation supported the localization of activation to the cell surface. The ability to specifically detect and localize LTGF-beta activation provides an important tool for studies of its regulation.

  12. Transforming growth factor beta (TGF-β) isomers influence cell detachment of MG-63 bone cells.

    PubMed

    Sefat, Farshid; Khaghani, Seyed Ali; Nejatian, Touraj; Genedy, Mohammed; Abdeldayem, Ali; Moghaddam, Zoha Salehi; Denyer, Morgan C T; Youseffi, Mansour

    2015-12-01

    Bone repair and wound healing are modulated by different stimuli. There is evidence that Transforming Growth Factor-beta (TGF-β) super-family of cytokines have significant effects on bone structure by regulating the replication and differentiation of chondrocytes, osteoblasts and osteoclasts. There is also significant evidence that interactions with extracellular matrix molecules influence cell behaviour. In this study cell surface attachment was examined via a trypsinization assay using various TGF-β isomers in which the time taken to trypsinize cells from the surface provided a means of assessing the strength of attachment. Three TGF-β isomers (TGF-β1, 2 and 3), four combined forms (TGF-β(1+2), TGF-β(1+3), TGF-β(2+3) and TGF-β(1+2+3)) along with four different controls (BSA, HCl, BSA/HCl and negative control) were investigated in this study. The results indicated that treatment with TGF-β1, 2, 3 and HCl decreased cell attachment, however, this effect was significantly greater in the case of TGF-β3 (p<0.001) indicating perhaps that TGF-β3 does not act alone in cell detachment, but instead functions synergistically with signalling pathways that are dependent on the availability of hydrogen ions. Widefield Surface Plasmon Resonance (WSPR) microscope was also used to investigate cell surface interactions.

  13. Metformin is a novel suppressor for transforming growth factor (TGF)-β1

    NASA Astrophysics Data System (ADS)

    Xiao, Han; Zhang, Jianshu; Xu, Zhonghe; Feng, Yenan; Zhang, Mingliang; Liu, Jianli; Chen, Ruifei; Shen, Jing; Wu, Jimin; Lu, Zhizhen; Fang, Xiaohong; Li, Jingyuan; Zhang, Youyi

    2016-06-01

    Metformin is a widely used first-line antidiabetic drug that has been shown to protect against a variety of specific diseases in addition to diabetes, including cardiovascular disorders, polycystic ovary syndrome, and cancer. However, the precise mechanisms underlying the diverse therapeutic effects of metformin remain elusive. Here, we report that transforming growth factor-β1 (TGF-β1), which is involved in the pathogenesis of numerous diseases, is a novel target of metformin. Using a surface plasmon resonance-based assay, we identified the direct binding of metformin to TGF-β1 and found that metformin inhibits [125I]-TGF-β1 binding to its receptor. Furthermore, based on molecular docking and molecular dynamics simulations, metformin was predicted to interact with TGF-β1 at its receptor-binding domain. Single-molecule force spectroscopy revealed that metformin reduces the binding probability but not the binding force of TGF-β1 to its type II receptor. Consequently, metformin suppresses type II TGF-β1 receptor dimerization upon exposure to TGF-β1, which is essential for downstream signal transduction. Thus, our results indicate that metformin is a novel TGF-β suppressor with therapeutic potential for numerous diseases in which TGF-β1 hyperfunction is indicated.

  14. Analysis of the transforming growth factor-beta 1 gene promoter polymorphisms in early osseointegrated implant failure.

    PubMed

    Dos Santos, Maria Cristina Leme Godoy; Campos, Maria Isabela Guimarães; Souza, Ana Paula; Scarel-Caminaga, Raquel Mantuaneli; Mazzonetto, Renato; Line, Sergio Roberto Peres

    2004-09-01

    Transforming growth factor-beta 1 is a multifunctional cytokine involved in extracellular matrix deposition, reduction of inflammation, and promotion of wound healing. Single nucleotide polymorphisms in the promoter region of human transforming growth factor-beta 1 gene, C-509T and G-800A, have been shown to increase the transcriptional activity of this cytokine and have been associated with a variety of diseases. The objective of this study was to investigate the possible association between these single nucleotide polymorphisms and the early implant failure. A sample of 68 nonsmoking patients was divided into two groups: a test group comprising 28 patients with one or more early failed implants and a control group consisting of 40 individuals with one or more healthy implants. Genomic DNA from oral mucosa was amplified by polymerase chain reaction and analyzed by restriction fragment length polymorphism. The significance of the differences in observed frequencies of single nucleotide polymorphisms was assessed using the chi square test and Fisher's exact test. The cited single nucleotide polymorphisms in transforming growth factor-beta 1 were analyzed in combination as haplotype using the computer program ARLEQUIN. The authors did not observe significant differences in the allele and genotypes to both single nucleotide polymorphisms of transforming growth factor-beta 1 gene (C-509T and G-800A) between control and early implant failure groups. The distribution of the haplotypes arranged as allele and genotypes were similar between control and test groups. These results indicate that C-509T and G-800A polymorphisms in the transforming growth factor-beta 1 gene are not associated separately or in haplotype combinations with early implant failure, suggesting that the presence of those single nucleotide polymorphisms alone do not constitute a genetic risk factor for early implant failure in the Brazilian population. PMID:15359164

  15. Transformational, Large Area Fabrication of Nanostructured Materials Using Plasma Arc Lamps

    SciTech Connect

    2009-03-01

    This factsheet describes a study that will address critical additional steps over large areas of as-synthesized nanostructured materials, such as annealing, phase transformation, or activation of dopants, dramatically reducing the processing costs of the solid-state lighting and photovoltaic materials.

  16. Effects of Ambient Humidity on Plant Growth Enhancement by Atmospheric Air Plasma Irradiation to Plant Seeds

    NASA Astrophysics Data System (ADS)

    Sarinont, Thapanut; Amano, Takaaki; Koga, Kazunori; Shiratani, Masaharu

    2015-09-01

    Humidity is an important factor for plasma-bio applications because composition of species generated by atmospheric pressure plasmas significantly depends on the humidity. Here we have examined effects of humidity on the growth enhancement to study the mechanism. Experiments were carried out with a scalable DBD device. 10 seeds of Raphanus sativus L. were set for x = 5 mm and y = 3 mm below the electrodes. The humidity Hair was 10 - 90 %Rh. The ratio of length of plants with plasma irradiation to that of control increases from 1.2 for Hair = 10 %Rh to 2.5 for Hair = 50 %Rh. The ratio is 2.5 for Hair = 50-90 %Rh. This humidity dependence is similar to the humidity dependence of O2+-H2O,H3O*, NO2--H2Oand NO3--H2Odensities, whereas it is different from that of other species such as O3, NO, and so on. The similarity gives information on key species for the growth enhancement.

  17. Transforming Growth Factor Beta 1 Augments Calvarial Defect Healing and Promotes Suture Regeneration

    PubMed Central

    Shakir, Sameer; MacIsaac, Zoe M.; Naran, Sanjay; Smith, Darren M.; Bykowski, Michael R.; Cray, James J.; Craft, Timothy K.; Wang, Dan; Weiss, Lee; Campbell, Phil G.; Mooney, Mark P.; Losee, Joseph E.

    2015-01-01

    Background: Repair of complex cranial defects is hindered by a paucity of appropriate donor tissue. Bone morphogenetic protein 2 (BMP2) and transforming growth factor beta 1 (TGFβ1) have been shown separately to induce bone formation through physiologically distinct mechanisms and potentially improve surgical outcome for cranial defect repair by obviating the need for donor tissue. We hypothesize that a combination of BMP2 and TGFβ1 would improve calvarial defect healing by augmenting physiologic osteogenic mechanisms. Methods/Results: Coronal suturectomies (3×15 mm) were performed in 10-day-old New Zealand White rabbits. DermaMatrix™ (3×15mm) patterned with four treatments (vehicle, 350 ng BMP2, 200 ng TGFβ1, or 350 ng BMP2+200 ng TGFβ1) was placed in suturectomy sites and rabbits were euthanized at 6 weeks of age. Two-dimensional (2D) defect healing, bone volume, and bone density were quantified by computed tomography. Regenerated bone was qualitatively assessed histologically. One-way analysis of variance revealed significant group main effects for all bone quantity measures. Analysis revealed significant differences in 2D defect healing, bone volume, and bone density between the control group and all treatment groups, but no significant differences were detected among the three growth factor treatment groups. Qualitatively, TGFβ1 treatment produced bone with morphology most similar to native bone. TGFβ1-regenerated bone contained a suture-like tissue, growing from the lateral edge of the defect margin toward the midline. Unique to the BMP2 treatment group, regenerated bone contained lacunae with chondrocytes, demonstrating the presence of endochondral ossification. Conclusions/Significance: Total healing in BMP2 and TGFβ1 treatment groups is not significantly different. The combination of BMP2+TGFβ1 did not significantly increase bone healing compared with treatment with BMP2 or TGFβ1 alone postoperatively at 4 weeks. We highlight the

  18. Porous tricalcium phosphate and transforming growth factor used for anterior spine surgery.

    PubMed

    Steffen, T; Stoll, T; Arvinte, T; Schenk, R K

    2001-10-01

    Harvesting autologous bone graft from the iliac crest is associated with considerable secondary morbidity. Bone graft substitutes such as porous ceramics are increasingly used for spinal surgery. This paper presents the results of an animal study in which beta-tricalcium phosphate (beta-TCP) bone substitutes were used for anterior spinal surgery in sheep and baboons. The presented baboon study also investigated the effect of impregnating the ceramic material with transforming growth factor (TGF). In the first study, using the sheep model, a stand-alone instrumented anterior fusion was performed. The animals were randomized into three treatment groups: autologous bone, beta-TCP granules, and sham group. The results were analyzed biomechanically and histologically at three survival intervals: 8, 16 and 32 weeks. An additional animal group was added later, with ceramic pre-filled implants. In the second study, a baboon model was used to assess the osteointegration of a 15-mm-diameter porous beta-TCP block into the vertebral body. The experiment was partially motivated by a new surgical procedure proposed for local bone graft harvest. Three treatment groups were used: beta-TCP plug, beta-TCP plug impregnated with TGF-beta3, and a sham group with empty defect. The evaluation for all animals included computer tomograms at 3 and 6 months, as well as histology at 6 months. In the sheep model, the mechanical evaluation failed to demonstrate differences between treatment groups. This was because massive anterior bone bridges formed in almost all the animals, masking the effects of individual treatments. Histologically, beta-TCP was shown to be a good osteoconductor. While multiple signs of implant micromotion were documented, pre-filling the cages markedly improved the histological fusion outcomes. In the baboon study, the beta-TCP plugs were completely osteointegrated at 6 months. For the group that used ceramic plugs impregnated with TGF-beta3, no incremental advantage was

  19. Human pulmonary acinar aplasia: reduction of transforming growth factor-beta ligands and receptors.

    PubMed

    Chen, M F; Gray, K D; Prentice, M A; Mariano, J M; Jakowlew, S B

    1999-07-01

    Pulmonary hypoplasia has been found in the human neonatal autopsy population and has been attributed to an alteration in epithelial-mesenchymal interactions during development of the lung. Pulmonary acinar aplasia is a very rare and severe form of pulmonary hypoplasia. The transforming growth factor-betas (TGF-beta) are multifunctional regulatory peptides that are secreted by a variety of normal and malignant cells and are expressed in developing organs including the lung; their tissue distribution patterns have possible significance for signaling roles in many epithelial-mesenchymal interactions. Here, we report our examination of TGF-beta in the lungs of a term female infant diagnosed with pulmonary acinar aplasia whose autopsy revealed extremely hypoplastic lungs with complete absence of alveolar ducts and alveoli. Immunohistochemical and in situ hybridization analyses were used to localize and measure the proteins and mRNA, respectively, for TGF-beta1, TGF-beta2, TGF-beta3, and TGF-beta type I and type II receptors (TGF-beta RI and RII) in formalin-fixed and paraffin-embedded sections of these hypoplastic lungs and normal lungs. Immunostaining for TGF-beta1, TGF-beta2, and TGF-beta RI and RII was significantly lower in the bronchial epithelium and muscle of the hypoplastic lungs than in normal lungs, whereas no difference was detected in staining for other proteins including Clara cell 10-kD protein, adrenomedullin, hepatocyte growth factor/scatter factor, and hepatocyte growth factor receptor/Met in the hypoplastic and normal lungs or in the liver and kidneys of this infant compared with normal liver and kidney. In addition, in situ hybridization showed that TGF-beta1 and TGF-beta RI transcripts were considerably reduced in the bronchial epithelium of the hypoplastic lung compared with normal lung. These results show that there is a selective reduction of TGF-beta in pulmonary acinar aplasia and suggest that the signaling action of TGF-beta in epithelial

  20. Chronic ethanol feeding inhibits plasma levels of insulin-like growth factor-1

    SciTech Connect

    Sonntag, W.E.; Boyd, R.L.

    1988-01-01

    The purpose of this study was to determine whether the generalized catabolic effects of chronic ethanol may be associated with a decline in plasma of insulin-like growth factor-1 (IGF-1). Male Sprague-Dawley rats were fed a liquid diet containing 5% ethanol or pair-fed a diet made isocaloric with maltose-dextrin. Animals were maintained on this diet for either 12 days or 4.5 months. Another groups of animals were fed control diet ad libitum for 2 weeks. After 12 days of feeding, plasma concentrations of IGF-1 in ad libitum fed rats were 771 +/- 41 ng/ml which was greater than concentrations in either pair-fed or ethanol-fed rats. After 4.5 months of feeding, plasma levels of IGF-1 in ad libitum and pair-fed rats were similar to the 12 day study. However, a significant decrease in plasma levels of IGF-1 was observed in ethanol-fed animals over the 4.5 month period. Results of a similar study in rats fed a high-fat diet for 4.5 months were similar to those found with the low-fat diet.

  1. Evolution of Plasma-Exposed Tungsten Surfaces Due to Helium Diffusion and Bubble Growth

    NASA Astrophysics Data System (ADS)

    Hammond, Karl; Hu, Lin; Maroudas, Dimitrios; Wirth, Brian; PSI-SciDAC Team

    2013-10-01

    Helium from linear plasma devices and tokamak plasmas causes the formation of microscopic features, termed ``fuzz'' or ``coral,'' on the surface of plasma-exposed materials after only a few hours of plasma exposure. The details of such surface modifications are only beginning to be understood. This study examines the initial and intermediate stages of fuzz formation by large-length-scale molecular dynamics (MD) simulations of helium-implanted tungsten over time scales of up to microseconds using single-crystalline and polycrystalline supercell models of tungsten. The large-scale MD simulations employ state-of-the-art many-body interatomic potentials and implantation depth distributions for the insertion of helium atoms into the tungsten matrix constructed based on MD simulations of helium-atom impingement onto tungsten surfaces under prescribed thermal and implantation conditions. The large-scale MD simulations reveal surface features formed via the sequence of helium implantation, diffusion of helium atoms and their aggregation to form bubbles, growth of bubbles and consequent production of tungsten self-interstitial atoms, organization of those atoms into prismatic loops, glide of those loops to the surface, and bubble rupture.

  2. Diamond growth on Fe-Cr-Al alloy by H2-plasma enhanced graphite etching

    NASA Astrophysics Data System (ADS)

    Li, Y. S.; Hirose, A.

    2007-04-01

    Without intermediate layer and surface pretreatment, adherent diamond films with high initial nucleation density have been deposited on Fe-15Cr-5Al (wt. %) alloy substrate. The deposition was performed using microwave hydrogen plasma enhanced graphite etching in a wide temperature range from 370to740°C. The high nucleation density and growth rate of diamond are primarily attributed to the unique precursors used (hydrogen plasma etched graphite) and the chemical nature of the substrate. The improvement in diamond adhesion to steel alloys is ascribed to the important role played by Al, mitigation of the catalytic function of iron by suppressing the preferential formation of loose graphite intermediate phase on steel surface.

  3. Growth of aligned carbon nanotubes on carbon microfibers by dc plasma-enhanced chemical vapor deposition

    SciTech Connect

    Chen, L H.; AuBuchon, J F.; Chen, I C.; Daraio, C; Ye, X R.; Gapin, A; Jin, Sungho; Wang, Chong M.

    2006-01-16

    It is shown that unidirectionally aligned carbon nanotubes can be grown on electrically conductive network of carbon microfibers via control of buffer layer material and applied electric field during dc plasma chemical vapor deposition growth. Ni catalyst deposition on carbon microfiber produces relatively poorly aligned nanotubes with significantly varying diameters and lengths obtained. The insertion of Ti 5 nm thick underlayer between Ni catalyst layer and C microfiber substrate significantly alters the morphology of nanotubes, resulting in much better aligned, finer diameter, and longer array of nanotubes. This beneficial effect is attributed to the reduced reaction between Ni and carbon paper, as well as prevention of plasma etching of carbon paper by inserting a Ti buffer layer. Such a unidirectionally aligned nanotube structure on an open-pore conductive substrate structure may conveniently be utilized as a high-surface-area base electrodes for fuel cells, batteries, and other electrochemical and catalytic reactions.

  4. In situ growth rate measurement and nucleation enhancement for microwave plasma CVD of diamond

    NASA Astrophysics Data System (ADS)

    Stoner, B. R.; Williams, B. E.; Wolter, S. D.; Nishimura, K.; Glass, J. T.

    1992-02-01

    Laser reflection interferometry (LRI) has been shown to be a useful in situ technique for measuring growth rate of diamond during microwave plasma chemical vapor deposition (MPCVD). Current alternatives to LRI usually involve ex situ analysis such as cross-sectional SEM or profilometry. The ability to measure the growth rate in 'real-time' has allowed the variation of processing parameters during a single deposition and thus the extraction of much more information in a fraction of the time. In situ monitoring of growth processes also makes it possible to perform closed loop process control with better reproducibility and quality control. Unfortunately, LRI requires a relatively smooth surface to avoid surface scattering and the commensurate drop in reflected intensity. This problem was remedied by greatly enhancing the diamond particle nucleation via the deposition of an intermediate carbon layer using substrate biasing. When an unscratched silicon wafer is pretreated by biasing negatively relative to ground while in a methane-hydrogen plasma, nucleation densities much higher than those achieved on scratched silicon wafers are obtained. The enhanced nucleation allows a complete film composed of small grains to form in a relatively short time, resulting in a much smoother surface than is obtained from a film grown at lower nucleation densities.

  5. Plasma membrane ganglioside sialidase regulates axonal growth and regeneration in hippocampal neurons in culture.

    PubMed

    Rodriguez, J A; Piddini, E; Hasegawa, T; Miyagi, T; Dotti, C G

    2001-11-01

    It has been long recognized that the ganglioside GM1 plays a role in axonal growth and neuronal differentiation. However, the involvement of plasma membrane GM1 has been difficult to elucidate. This is possible now thanks to the recent cloning of plasma membrane ganglioside sialidase (PMGS), the enzyme responsible for the localized hydrolysis of oligosialogangliosides into GM1. In this work we show that PMGS mRNA and protein levels are high at early developmental stages of the hippocampus and low in adulthood both in vivo and in vitro. We also demonstrate that inhibition of PMGS activity blocks axonal elongation, whereas the increase in PMGS activity dramatically enhances axon growth and accelerates the polarization of cytoskeletal proteins. Finally, we show that axotomy close to the cell body in PMGS overexpressing neurons results in the regrowth of the original axon instead of randomly, as is the case in control neurons. In all, these results imply that PMGS activity through the modulation of GM1 surface levels is an important component of the machinery controlling axonal growth. We hypothesize that increasing PMGS activity in the adult nervous system may be useful to improve regeneration after nerve damage. PMID:11606627

  6. Growth of ultrananocrystalline diamond film by DC Arcjet plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Chen, G. C.; Li, B.; Yan, Z. Q.; Liu, J.; Lu, F. X.; Ye, H.

    2012-06-01

    Self-standing diamond films were grown by DC Arcjet plasma enhanced chemical vapor deposition (CVD). The feed gasses were Ar/H2/CH4, in which the flow ratio of CH4 to H2 (F/F) was varied from 5% to 20%. Two distinct morphologies were observed by scanning electron microscope (SEM), i.e. the "pineapple-like" morphology and the "cauliflower-like" morphology. It was found that the morphologies of the as-grown films are strongly dependent on the flow ratio of CH4 to H2 in the feed gasses. High resolution transmission electron microscope (HRTEM) survey results revealed that there were nanocrystalline grains within the "pineapple-like" films whilst there were ultrananocrystalline grains within "cauliflower-like" films. X-ray diffraction (XRD) results suggested that (110) crystalline plane was the dominant surface in the "cauliflower-like" films whilst (100) crystalline plane was the dominant surface in the "pineapple-like" films. Raman spectroscopy revealed that nanostructured carbon features could be observed in both types of films. Plasma diagnosis was carried out in order to understand the morphology dependent growth mechanism. It could be concluded that the film morphology was strongly influenced by the density of gas phases. The gradient of C2 radical was found to be different along the growth direction under the different growth conditions.

  7. [Spray-dried plasma in diets for weaned piglets: influence on growth and underlying mechanisms].

    PubMed

    van Dijk, A J

    2002-09-01

    Spray-dried animal plasma (SDAP) is a by-product of slaughter plants. The plasma obtained from slaughtered pigs or ruminants is spray-dried and used for the production of human foodstuffs and animal feeds. SDAP added to the diet of weaned piglets has considerable positive effects on the growth performance of piglets. In a meta-analysis, it was calculated from 68 comparisons between SDAP-containing diets and control diets that the SDAP-induced change in average daily gain (ADG) and average daily feed intake (ADFI) in the first 2 weeks after weaning was +26.8% and +24.5%, respectively. Two experiments demonstrated that dietary SDAP can reduce post-weaning diarrhoea. The aim of the research described in this thesis was to learn more about the mechanisms underlying the growth- and health-promoting properties of SDAP in the diet of weaned piglets. Results showed that dietary SDPP has positive effects on the post-weaning growth performance and health of piglets. These effects are more pronounced in piglets kept under suboptimal conditions and/or high infection pressure, and in piglets fed on diets lacking anti-microbial growth promoters. SDAP acts by influencing the gastrointestinal microflora: it appears to affect pathogenic bacteria rather than exert a general anti-bacterial effect leading to nutrient sparing, as has been described for anti-microbial growth promoters. SDAP has great potential as treatment for immuno-compromised mammals, such as neonates, and for animals in which antibiotic treatment is not possible, for instance when there is a ban against antibiotics or when multi-resistant bacteria are involved. PMID:12244856

  8. A unique receptor-independent mechanism by which insulinlike growth factor I regulates the availability of insulinlike growth factor binding proteins in normal and transformed human fibroblasts.

    PubMed Central

    Conover, C A

    1991-01-01

    Insulin-like growth factor I and II (IGF-I and IGF-II) associate with specific IGF binding proteins (IGFBPs) present in plasma and extracellular fluids that can modulate the anabolic effects of these peptides. IGF-I has been shown to increase IGFBP concentrations in vivo and in vitro, but the mechanism and significance of this action are unknown. We examined these issues using normal and simian virus 40-transformed adult human fibroblasts (SV40-HF) in culture. Treatment with IGF-I markedly stimulated the appearance of IGFBP-3 (42/38 kD doublet), a 36 kD IGFBP, and 28-32 kD IGFBPs in the medium of these cells, as assessed by Western ligand blotting; IGF-I decreased levels of 24 kD IGFBP in normal HF cultures. The IGF-I-induced change in IGFBP levels was not a type I IGF receptor-mediated effect on IGFBP synthesis because (a) high concentrations of insulin did not mimic IGF-I's effect; (b) IGF-II and IGF-I analogues having reduced affinity for the IGF-I receptor were equipotent with IGF-I in increasing medium IGFBPs; (c) [QAYL]IGF-I, and IGF-I analogue having normal receptor affinity and decreased affinity for IGFBPs, had no effect; and (d) alpha IR-3, a monoclonal antibody specific for the type I IGF receptor, did not block IGF-I-stimulated increases in IGFBPs. In physiological studies, preincubation with 1 nM IGF-I had no effect on type I IGF receptor binding in normal HF and SV40-HF. In contrast, preincubation of cells with an equivalent concentration of [QAYL]IGF-I downregulated the receptors 40-50%. Changes in cell surface receptor number were reflected in cell responsiveness to IGF-I-stimulated [3H]thymidine incorporation and [3H]aminoisobutyric acid uptake. In conclusion, IGF-I regulates the availability of specific IGFBPs in cultured human fibroblasts by a novel receptor-independent mechanism. Rapid changes in levels of soluble IGFBPs as a direct response to extracellular IGF-I, in turn, modulate IGF-I peptide and receptor interaction, and may constitute an

  9. Study of particle nucleation and growth in low pressure silane plasmas

    NASA Astrophysics Data System (ADS)

    Bhandarkar, Upendra Vijendra

    Study of particle nucleation in processing plasmas has received increased attention in recent years. On the one hand, particle generation is considered harmful (in the semiconductor industry) and on the other hand particles generated with specific size, composition and crystallinity are useful for many material and opto-electronic applications. An important claim is that solar cells demonstrate stable efficiencies if the incorporated silicon films are deposited under conditions that are at the onset of particle formation in the plasma. To eliminate particles or to grow them with specific requirements needs a thorough knowledge of how various parameters (reactor pressure, input power, gas temperature, substrate temperatures, input gas composition) affect the growth of particles. Several experimental and numerical studies have been performed towards this end. However, explanations for a large number of fundamental issues are not yet known. To address these key issues we have developed a quasi-zero dimensional model that couples chemistry and particle growth under silane plasma conditions. The addition of diffusion losses for species and particles makes the model quasi-zero dimensional. The following are the key results: (1) In answer to the debate regarding the pathways to cluster formation, our mechanism predicts that the main clustering pathway in silane plasmas proceeds via anion-neutral reactions that involve silyl or silylene anions reacting with silane to give larger silyl or silylene anions with hydrogen elimination. (2) The model also answers the question regarding the critical particle density for particle coagulation to begin: the positive ion density represents the critical density for coagulation. Coagulation is usually hindered due to negative charging of particles in plasmas. Particle concentrations higher than the positive ion concentration allow for significant neutral and even positive fractions that sets in coagulation. (3) Finally we answer a

  10. Chromium (VI) induced changes in growth and root plasma membrane redox activities in pea plants.

    PubMed

    Pandey, Vivek; Dixit, Vivek; Shyam, Radhey

    2009-03-01

    The effect of chromium (Cr) on growth as well as root plasma membrane redox reactions and superoxide radical production was studied in pea (Pisum sativum L. cv. Azad) plants exposed for 7 days to 20 and 200 microM Cr (VI), respectively, supplied as potassium dichromate. The growth of pea plants declined significantly at 200 microM Cr, as indicated by reduced leaf area and biomass. Relative to the control plants (no Cr exposure), the Cr content of roots increased significantly, both at 20 and 200 microM Cr. Following exposure to 200 microM Cr, there was a significant increase in root lipid peroxidation and hydrogen peroxide (H(2)O(2)) content, while both the Fv/Fm ratio and chlorophyll content were reduced. Exposure to Cr increased NADPH-dependent superoxide production in pea root plasma membrane vesicles, with the effect being more significant at 200 microM Cr than at 20 microM Cr. Treatment with Cr rapidly increased the activities of NADPH oxidase: relative to the controls, plants exposed to 20 microM Cr showed approximately a 67% increase in activity while there was a threefold increase in those plants exposed to 200 microM Cr. NADH-ferricyanide oxido-reductase activity was found to be inhibited by 16 and 51% at 20 and 200 microM Cr, respectively. The results of this study suggest that exposure to excess Cr damages pea root plasma membrane structure and function, resulting in decreased photosynthesis and poor plant growth.

  11. Plasma insulin-like growth factor-I concentrations in yearling chinook salmon (Oncorhynchus tshawytscha) migrating from the Snake River Basin, USA

    USGS Publications Warehouse

    Congleton, J.L.; Biga, P.R.; Peterson, B.C.

    2003-01-01

    During the parr-to-smolt transformation (smoltification) of juvenile salmonids, preadaptive changes in osmoregulatory and ionoregulatory ability are regulated in part by the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis. If food intake is sufficient, plasma IGF-I increases during smoltification. On the other hand, plasma IGF-I typically decreases in fasting fish and other vertebrate animals. Because food availability is limited for juvenile salmonids undertaking an extended 6- to 12-week spring migration to and through the Snake-Columbia River hydropower system (northwestern USA), IGF-I concentrations might be expected to decrease, potentially compromising seawater tolerance. To address this possibility, yearling chinook salmon Oncorhynchus tshawytscha reared in three Snake River Basin hatcheries were sampled before release and at two downstream dams. Dry masses of migrating fish either did not increase during the migration (in 2000, an average-flow year), or decreased significantly (in 2001, a low-flow year). In both years, plasma IGF-I levels were significantly higher (1.6-fold in 2000, 3.7-fold in 2001) for fish sampled at the last dam on the lower Columbia River than for fish sampled prior to release. Plasma IGF-I concentrations in migrating fish may, nonetheless, have been nutritionally down-regulated to some degree, because plasma IGF-I concentrations in juvenile chinook salmon captured at a Snake River dam and transported to the laboratory increased in fed groups, but decreased in unfed groups. The ability of migrating smolts to maintain relatively elevated IGF-I levels despite restricted food intake and loss of body mass is likely related to smoltification-associated changes in hormonal balance. ?? 2004 Kluwer Academic Publishers.

  12. A comparison of fasting plasma insulin and growth hormone concentrations in marasmic, kwashiorkor, marasmic-kwashiorkor and underweight children.

    PubMed

    Robinson, H; Picou, D

    1977-05-01

    Fasting plasma insulin and growth hormone concentrations were measured in 24 marasmic, 11 kwashiorkor, 16 marasmic-kwashiorkor, and 4 underweight children. Hormone measurements were made by a special modification of the Hales and Randle double antibody immunoassay with increased sensitivity in the concentration range 0-25 micronU/ml. Fasting plasma insulin was low in marasmus, kwashiorkor, and marasmic-kwashiorkor children, and increased to normal levels after recovery. Fasting plasma growth hormone was elevated in all groups during malnutrition and was significantly decreased to normal levels after recovery. There were no significant differences in plasma insulin or growth hormone levels between the different clinical types of severe protein energy malnutrition. These hormonal changes in severe protein energy malnutrition are of complex and not fully understood etiology. However, recovered children appear to have a hormonal pattern similar to that described in normal control infants and children.

  13. Spectroscopic analysis of H2/CH4 microwave plasma and fast growth rate of diamond single crystal

    NASA Astrophysics Data System (ADS)

    Derkaoui, N.; Rond, C.; Hassouni, K.; Gicquel, A.

    2014-06-01

    One of the best ways to increase the diamond growth rate is to couple high microwave power to the plasma. Indeed, increasing the power density leads to increase gas temperature the atomic hydrogen density in the plasma bulk, and to produce more hydrogen and methyl at the diamond surface. Experimental and numerical approaches were used to study the microwave plasma under high power densities conditions. Gas temperature was measured by optical emission spectroscopy and H-atom density using actinometry. CH3-radical density was obtained using a 1D model that describes temperatures and plasma composition from the substrate to the top of the reactor. The results show that gas temperature in the plasma bulk, atomic hydrogen, and methyl densities at the diamond surface highly increase with the power density. As a consequence, measurements have shown that diamond growth rate also increases. At very high power density, we measured a growth rate of 40 μm/h with an H-atom density of 5 × 1017 cm-3 which corresponds to a H2 dissociation rate higher than 50%. Finally, we have shown that the growth rate can be framed between a lower and an upper limit as a function depending only on the maximum of H-atom density measured or calculated in the plasma bulk. The results also demonstrated that increasing fresh CH4 by an appropriate injection into the boundary layer is a potential way to increase the diamond growth rates.

  14. Templated growth of diamond optical resonators via plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Hu, E. L.

    2016-08-01

    We utilize plasma-enhanced chemical vapor deposition through a patterned silica mask for templated diamond growth to create optical resonators. The pyramid-shaped structures have quality factors Q up to 600, measured using confocal photoluminescence spectroscopy, and mode volumes V as small as 2.5 (λ/n) 3 for resonances at wavelengths λ between 550 and 650 nm, and refractive index n, obtained using finite-difference time-domain simulations. Bright luminescence from nitrogen-vacancy and silicon-vacancy centers in the grown diamond is observed. The resonator design and fabrication technique obviates any etching of diamond, which preserves emitter properties in a pristine host lattice.

  15. Aerosynthesis: Growths of Vertically Aligned Carbon Nanofibers with Air DC Plasma

    SciTech Connect

    Kodumagulla, A; Varanasi, V; Pearce, Ryan; Wu, W-C; Hensley, Dale K; Tracy, Joseph B; McKnight, Timothy E; Melechko, Anatoli

    2014-01-01

    Vertically aligned carbon nanofibers (VACNF) have been synthesized in a mixture of acetone and air using catalytic DC plasma enhanced chemical vapor deposition. Typically, ammonia or hydrogen is used as etchant gas in the mixture to remove carbon that otherwise passivates the catalyst surface and impedes growth. Our demonstration of using air as the etchant gas opens up a possibility that ion etching could be sufficient to maintain the catalytic activity state during synthesis. It also demonstrates the path toward growing VACNFs in open atmosphere.

  16. Perspectives and challenges in regenerative medicine using plasma rich in growth factors.

    PubMed

    Anitua, Eduardo; Alkhraisat, Mohammad H; Orive, Gorka

    2012-01-10

    Plasma rich in growth factors (PRGF-Endoret) is an endogenous therapeutic technology that is gaining interest in regenerative medicine due to its potential to stimulate and accelerate tissue healing and bone regeneration. This autologous biotechnology is designed for the in situ delivery of multiple cellular modulators and the formation of a fibrin scaffold, thereby providing different formulations that can be widely used in numerous medical and scientific fields including dentistry, oral implantology, orthopedics, ulcer treatment and tissue engineering among others. Here we discuss the important progress that has been accomplished in this field. Furthermore, a comprehensive outlook of the intriguing therapeutic applications of this technology is presented.

  17. Transforming growth factor-beta1 upregulates myostatin expression in mouse C2C12 myoblasts.

    PubMed

    Budasz-Rwiderska, M; Jank, M; Motyl, T

    2005-06-01

    Myostatin (MSTN) and transforming growth factor-beta1 (TGF-beta1) belong to the same TGF-beta superfamily of proteins. They are involved in regulation of skeletal muscle growth and development as well as muscle catabolism. The aim of the present study was to investigate the relationship between MSTN and TGF-beta1 expression in proliferating and differentiating mouse C2C12 myoblasts cultured in normal and catabolic conditions and to evaluate the effect of exogenous TGF-beta1 as well as "knock down" of TGF-beta1 receptor type II on MSTN expression in proliferating and differentiating myogenic cells. The direct effect of TGF-beta1 on myostatin was also examined. Myostatin expression increased gradually with cell confluency in proliferating cultures, while the level of TGF-beta1, detected in the form of a 100 kDa small latent complex diminished. Myostatin expression was accompanied by a partial cell cycle arrest. Three forms of myostatin were found: a 52 kDa precursor, a 40 kDa latency associated propeptide, and a 26 kDa active peptide. A decrease in myostatin and TGF-beta1 levels was observed during the first three days of differentiation, which was subsequently followed by significant increase of their expression during next three to four days of differentiation. Catabolic state induced by dexamethasone significantly increased the level of all forms of myostatin as well as latent (100 kDa) and active (25 kDa) forms of TGF-beta1 in differentiating myoblasts in a dose dependent manner. Exogenous TGF-beta1 (2 ng/ml) significantly increased myostatin levels both in proliferating and differentiating C2C12 myoblasts, whereas silencing of the TGF-beta1 receptor II gene significantly lowered myostatin level in examined cells. The presented results indicate that TGF-beta1 may control myostatin-related regulation of myogenesis through up-regulation of myostatin, predominantly in the course of terminal differentiation and glucocorticoid-dependent catabolic stimulation.

  18. Transforming Growth Factor-α Improves Memory Impairment and Neurogenesis Following Ischemia Reperfusion

    PubMed Central

    Alipanahzadeh, Hassan; Soleimani, Mansooreh; Soleimani Asl, Sara; Pourheydar, Bagher; Nikkhah, Ali; Mehdizadeh, Mehdi

    2014-01-01

    Objective Stroke is most important cause of death and disability in adults. The hippocampal CA1 and sub-ventricular zone neurons are vulnerable to ischemia that can impair memory and learning functions. Although neurogenesis normally occurs in the dentate gyrus (DG) of the hippocampus and sub-ventricular zone (SVZ) following brain damage, this response is unable to compensate for severely damaged areas. This study aims to assess both neurogenesis and the neuroprotective effects of transforming growth factor-alpha (TGF-α) on the hippocampus and SVZ following ischemia-reperfusion. Materials and Methods In this experimental study, a total of 48 male Wistar rats were divided into the following groups: surgical (n=12), phosphate buffered saline (PBS) treated vehicle shams (n=12), ischemia (n=12) and treatment (n=12) groups. Ischemia was induced by common carotid occlusion for 30 minutes followed by reperfusion, and TGF-α was then injected into the right lateral ventricle. Spatial memory was assessed using Morris water maze (MWM). Nestin and Bcl-2 family protein expressions were studied by immunohistochemistry (IHC) and Western blot methods, respectively. Finally, data were analyzed using Statistical Package for the Social Sciences (SPSS, SPSS Inc., Chicago, USA) version 16 and one-way analysis of variance (ANOVA). Results TGF-α injection significantly increased nestin expression in both the hippocampal DG and SVZ areas. TGF-α treatment caused a significant decrease in Bax expression and an increase in Bcl-2 anti-apoptotic protein expression in the hippocampus. Our results showed a significant increase in the number of pyramidal neurons. Memory also improved significantly following TGF-α treatment. Conclusion Our findings proved that TGF-α reduced ischemic injury and played a neuroprotective role in the pathogenesis of ischemic injury. PMID:24611146

  19. Regulation of Transforming Growth Factor-β1–driven Lung Fibrosis by Galectin-3

    PubMed Central

    MacKinnon, Alison C.; Gibbons, Michael A.; Farnworth, Sarah L.; Leffler, Hakon; Nilsson, Ulf J.; Delaine, Tamara; Simpson, A. John; Forbes, Stuart J.; Hirani, Nik; Gauldie, Jack

    2012-01-01

    Rationale: Idiopathic pulmonary fibrosis (IPF) is a chronic dysregulated response to alveolar epithelial injury with differentiation of epithelial cells and fibroblasts into matrix-secreting myofibroblasts resulting in lung scaring. The prognosis is poor and there are no effective therapies or reliable biomarkers. Galectin-3 is a β-galactoside binding lectin that is highly expressed in fibrotic tissue of diverse etiologies. Objectives: To examine the role of galectin-3 in pulmonary fibrosis. Methods: We used genetic deletion and pharmacologic inhibition in well-characterized murine models of lung fibrosis. Further mechanistic studies were performed in vitro and on samples from patients with IPF. Measurements and Main Results: Transforming growth factor (TGF)-β and bleomycin-induced lung fibrosis was dramatically reduced in mice deficient in galectin-3, manifest by reduced TGF-β1–induced EMT and myofibroblast activation and collagen production. Galectin-3 reduced phosphorylation and nuclear translocation of β-catenin but had no effect on Smad2/3 phosphorylation. A novel inhibitor of galectin-3, TD139, blocked TGF-β–induced β-catenin activation in vitro and in vivo and attenuated the late-stage progression of lung fibrosis after bleomycin. There was increased expression of galectin-3 in the bronchoalveolar lavage fluid and serum from patients with stable IPF compared with nonspecific interstitial pneumonitis and controls, which rose sharply during an acute exacerbation suggesting that galectin-3 may be a marker of active fibrosis in IPF and that strategies that block galectin-3 may be effective in treating acute fibrotic exacerbations of IPF. Conclusions: This study identifies galectin-3 as an important regulator of lung fibrosis and provides a proof of principle for galectin-3 inhibition as a potential novel therapeutic strategy for IPF. PMID:22095546

  20. Transforming growth factor-ß1 genotype and susceptibility to chronic obstructive pulmonary disease

    PubMed Central

    Wu, L; Chau, J; Young, R; Pokorny, V; Mills, G; Hopkins, R; McLean, L; Black, P

    2004-01-01

    Background: Only a few long term smokers develop symptomatic chronic obstructive pulmonary disease (COPD) and this may be due, at least in part, to genetic susceptibility to the disease. Transforming growth factor ß1 (TGF-ß1) has a number of actions that make it a candidate for a role in the pathogenesis of COPD. We have investigated a single nucleotide polymorphism at exon 1 nucleotide position 29 (T→C) of the TGF-ß1 gene that produces a substitution at codon 10 (Leu→Pro). Methods: The frequency of this polymorphism was determined in 165 subjects with COPD, 140 healthy blood donors, and 76 smokers with normal lung function (resistant smokers) using the polymerase chain reaction and restriction enzyme fragment length polymorphism. Results: The distribution of genotypes was Leu-Leu (41.8%), Leu-Pro (50.3%), and Pro-Pro (7.9%) for subjects with COPD, which was significantly different from the control subjects (blood donors: Leu-Leu (29.3%), Leu-Pro (52.1%) and Pro-Pro (18.6%), p = 0.006; resistant smokers: Leu-Leu (28.9%), Leu-Pro (51.3%) and Pro-Pro (19.7%), p = 0.02). The Pro10 allele was less common in subjects with COPD (33%) than in blood donors (45%; OR = 0.62, 95% CI 0.45 to 0.86, p = 0.005) and resistant smokers (45%; OR = 0.59, 95% CI 0.40 to 0.88, p = 0.01). Conclusions: The proline allele at codon 10 of the TGF-ß1 gene occurs more commonly in control subjects than in individuals with COPD. This allele is associated with increased production of TGF-ß1 which raises the possibility that TGF-ß1 has a protective role in COPD. PMID:14760152

  1. Transforming growth factor-β2 is sequestered in preterm human milk by chondroitin sulfate proteoglycans

    PubMed Central

    Namachivayam, Kopperuncholan; Coffing, Hayley P.; Sankaranarayanan, Nehru Viji; Jin, Yingzi; MohanKumar, Krishnan; Frost, Brandy L.; Blanco, Cynthia L.; Patel, Aloka L.; Meier, Paula P.; Garzon, Steven A.; Desai, Umesh R.

    2015-01-01

    Human milk contains biologically important amounts of transforming growth factor-β2 isoform (TGF-β2), which is presumed to protect against inflammatory gut mucosal injury in the neonate. In preclinical models, enterally administered TGF-β2 can protect against experimental necrotizing enterocolitis, an inflammatory bowel necrosis of premature infants. In this study, we investigated whether TGF-β bioactivity in human preterm milk could be enhanced for therapeutic purposes by adding recombinant TGF-β2 (rTGF-β2) to milk prior to feeding. Milk-borne TGF-β bioactivity was measured by established luciferase reporter assays. Molecular interactions of TGF-β2 were investigated by nondenaturing gel electrophoresis and immunoblots, computational molecular modeling, and affinity capillary electrophoresis. Addition of rTGF-β2 (20–40 nM) to human preterm milk samples failed to increase TGF-β bioactivity in milk. Milk-borne TGF-β2 was bound to chondroitin sulfate (CS) containing proteoglycan(s) such as biglycan, which are expressed in high concentrations in milk. Chondroitinase treatment of milk increased the bioactivity of both endogenous and rTGF-β2, and consequently, enhanced the ability of preterm milk to suppress LPS-induced NF-κB activation in macrophages. These findings provide a mechanism for the normally low bioavailability of milk-borne TGF-β2 and identify chondroitinase digestion of milk as a potential therapeutic strategy to enhance the anti-inflammatory effects of preterm milk. PMID:26045614

  2. Cellular localization of transforming growth factor-beta expression in bleomycin-induced pulmonary fibrosis.

    PubMed Central

    Zhang, K.; Flanders, K. C.; Phan, S. H.

    1995-01-01

    Bleomycin-induced pulmonary fibrosis is associated with increased lung transforming growth factor-beta (TGF-beta) gene expression, but cellular localization of the source of this expression has not been unequivocally established. In this study, lung fibrosis was induced in rats by endotracheal bleomycin injection on day 0 and, on selected days afterwards, lungs were harvested for in situ hybridization, immunohistochemical and histochemical analyses for TGF-beta 1 mRNA and protein expression, and cell identification. The results show that control lungs express essentially no detectable TGF-beta 1 mRNA or protein in the parenchyma. Before day 3 after bleomycin treatment, scattered bronchiolar epithelial cells, mononuclear cells, and eosinophils expressed elevated levels of TGF-beta 1. Between days 3 and 14, there was a major increase in the number of eosinophils, myofibroblasts, and fibroblasts strongly expressing TGF-beta 1 mRNA and protein. TGF-beta 1-producing cells were predominantly localized within areas of injury and active fibrosis. After day 14, the intensity and number of TGF-beta 1-expressing cells significantly declined and were predominantly found in fibroblasts in fibrotic areas. The expression of TGF-beta 1 protein was generally coincident with that for mRNA with the exception of bronchiolar epithelial cells in which strong protein expression was unaccompanied by a commensurate increase in mRNA. The study demonstrates that myofibroblasts, fibroblasts, and eosinophils represent the major sources of increased lung TGF-beta 1 expression in this model of pulmonary fibrosis. Images Figure 2 Figure 3 Figure 4 PMID:7543734

  3. Orofacial clefts, parental cigarette smoking, and transforming growth factor-alpha gene variants

    SciTech Connect

    Shaw, G.M.; Wasserman, C.R.; O`Malley, C.D.

    1996-03-01

    Results of studies determine whether women who smoke during early pregnancy are at increased risk of delivering infants with orofacial clefts have been mixed, and recently a gene-environment interaction between maternal smoking, transforming growth factor-alpha (TGFa), and clefting has been reported. Using a large population-based case-control study, we investigated whether parental periconceptional cigarette smoking was associated with an increased risk for having offspring with orofacial clefts. We also investigated the influence of genetic variation of the TGFa locus on the relation between smoking and clefting. Parental smoking information was obtained from telephone interviews with mothers of 731 (84.7% of eligible) orofacial cleft case infants and with mothers of 734 (78.2%) nonmalformed control infants. DNA was obtained from newborn screening blood spots and genotyped for the allelic variants of TGFa. We found that risks associated with maternal smoking were most elevated for isolated cleft lip with or without cleft palate, (odds ratio 2.1 [95% confidence interval 1.3-3.6]) and for isolated cleft palate (odds ratio 2.2 [1.1-4.5]) when mothers smoked {ge} 20 cigarrettes/d. These risks for white infants ranged from 3-fold to 11-fold across phenotypic groups. Paternal smoking was not associated with clefting among the offspring of nonsmoking mothers, and passive smoke exposures were associated with at most slightly increased risks. This study offers evidence that the risk for orofacial clefting in infants may be influenced by maternal smoke exposures alone as well as in combination (gene-environment interaction) with the presence of the uncommon TGFa allele. 56 refs., 5 tabs.

  4. Expression and clinical significance of the transforming growth factor-β signalling pathway in endometrial cancer

    PubMed Central

    Mhawech-Fauceglia, Paulette; Akers, Stacey; DuPont, Nefertiti Chianti; Clark, Kimberly; Lele, Shashikant; Liu, Song

    2016-01-01

    Aims To evaluate the components of the transforming growth factor (TGF)-β–Smad signalling pathway in human endometrial cancer (EC). Methods and results TGF-β1, TGF-β receptor type I, TGF-β receptor type II, Smad2, Smad3, Smad4, Skil and Disabled-2 (DAB2) mRNA levels were determined by reverse transcriptase polymerase chain reaction on EC cell lines and in 70 EC tissues. Immunohistochemistry for Skil and DAB2 antibodies was performed on 362 EC cases. Decreased mRNA levels of all eight components of the TGF-β pathway tested were found in the majority of 70 cases. For DAB2, the mRNA level was correlated with protein expression level (P = 0.04). The Skil mRNA level was associated with tumour stage (P = 0.03), and the Smad2/3/4 mRNA level with tumour grade (P = 0.03, P = 0.02, and P = 0.00, respectively). The Smad4 mRNA level was also associated with tumour size (P = 0.05), subtype (P = 0.04), and disease-free survival (DFS) (P = 0.05). The TGF-β1 mRNA level was associated with DFS (P = 0.04). Finally, tumours with positive Skil protein expression had a shorter recurrence time, whereas, those with positive DAB2 protein expression had a longer recurrence time. Conclusions Down-regulation of the TGF-β–Smad signalling pathway might be responsible for the pathogenesis of human EC, and some of its components appeared to be prognostic factors. Exploration of future therapy targeting the TGF-β–Smad pathway is warranted in EC. PMID:21771027

  5. Hydrogen Sulfide Inhibits Transforming Growth Factor-β1-Induced EMT via Wnt/Catenin Pathway

    PubMed Central

    Tao, Jie; Lan, Zhen; Hei, Hongya; Tian, Lulu; Pan, Wanma; Wang, Li; Zhang, Xuemei

    2016-01-01

    Hydrogen sulfide (H2S) has anti-fibrotic potential in lung, kidney and other organs. The exogenous H2S is released from sodium hydrosulfide (NaHS) and can influence the renal fibrosis by blocking the differentiation of quiescent renal fibroblasts to myofibroblasts. But whether H2S affects renal epithelial-to-mesenchymal transition (EMT) and the underlying mechanisms remain unknown. Our study is aimed at investigating the in vitro effects of H2S on transforming growth factor-β1 (TGF-β1)-induced EMT in renal tubular epithelial cells (HK-2 cells) and the associated mechanisms. The induced EMT is assessed by Western blotting analysis on the expressions of α-SMA, E-cadherin and fibronectin. HK-2 cells were treated with NaHS before incubating with TGF-β1 to investigate its effect on EMT and the related molecular mechanism. Results demonstrated that NaHS decreased the expression of α-SMA and fibronectin, and increased the expression of E-cadherin. NaHS reduced the expression of TGF-β receptor type I (TβR I) and TGF-β receptor type II (TβR II). In addition, NaHS attenuated TGF-β1-induced increase of β-catenin expression and ERK phosphorylation. Moreover, it inhibited the TGF-β1-induced nuclear translocation of ββ-catenin. These effects of NaHS on fibronectin, E-cadherin and TβR I were abolished by the ERK inhibitor U0126 or β-catenin inhibitor XAV939, or β-catenin siRNA interference. We get the conclusion that NaHS attenuated TGF-β1-induced EMT in HK-2 cells through both ERK-dependent and β-catenin-dependent pathways. PMID:26760502

  6. Transforming growth factor-β3 promotes facial nerve injury repair in rabbits

    PubMed Central

    WANG, YANMEI; ZHAO, XINXIANG; HUOJIA, MUHTER; XU, HUI; ZHUANG, YOUMEI

    2016-01-01

    The present study investigated the effects of transforming growth factor (TGF)-β3 on the regeneration of facial nerves in rabbits. A total of 20 adult rabbits were randomly divided into three equal groups: Normal control (n=10), surgical control (n=10) and TGF-β3 treatment (n=10). The total number and diameter of the regenerated nerve fibers was significantly increased in the TGF-β3 treatment group, as compared with in the surgical control group (P<0.01). Furthermore, in the TGF-β3 treatment group, the epineurial repair of the facial nerves was intact and the nerve fibers, which were arranged in neat rows, were morphologically intact with visible myelin swelling. However, in the surgical control group, the epineurial repair was incomplete, as demonstrated by: Atrophic nerve fibers, partially disappeared axons and myelin of uneven thickness with fuzzy borders. Electron microscopy demonstrated that the regenerated fibers in the TGF-β3 treatment group were predominantly myelinated, with clear-layered myelin sheath structures and axoplasms rich in organelles. Although typical layered myelin sheath structures were observed in the surgical control group, the myelin sheaths of the myelinated nerve fibers were poorly developed and few organelles were detected in the axoplasms. Neuro-electrophysiological examination demonstrated that, as compared with the surgical control group, the latency period of the action potentials in the TGF-β3 treatment group were shorter, whereas the stimulus amplitudes of the action potentials were significantly increased (P<0.01). The results of the present study suggest that TGF-β3 may improve the regeneration of facial nerves following trauma or injury. PMID:26997982

  7. MicroRNA-326 regulates profibrotic functions of transforming growth factor-β in pulmonary fibrosis.

    PubMed

    Das, Sudipta; Kumar, Manish; Negi, Vinny; Pattnaik, Bijay; Prakash, Y S; Agrawal, Anurag; Ghosh, Balaram

    2014-05-01

    Idiopathic pulmonary fibrosis (IPF) is a fatal disorder resulting from the progressive remodeling of lungs, with no known effective treatment. Although transforming growth factor (TGF)-β has a well-established role in lung fibrosis, clinical experience with neutralizing antibodies to TGF-β has been disappointing, and strategies to directly suppress TGF-β1 secretion are needed. In this study we used a combination of in silico, in vitro, and in vivo approaches to identify microRNAs involved in TGF-β1 regulation and to validate the role of miR-326 in pulmonary fibrosis.We show that hsa-miR-326 regulates TGF-β1 expression and that hsa-miR-326 levels are inversely correlated to TGF-β1 protein levels in multiple human cell lines. The increase in TGF-β1 expression during the progression of bleomycin-induced lung fibrosis in mice was associated with loss of mmu-miR-326. Restoration of mmu-miR-326 levels by intranasal delivery of miR-326 mimics was sufficient to inhibit TGF-β1 expression and attenuate the fibrotic response. Moreover, human IPF lung specimens had markedly diminished miR-326 expression as compared with nonfibrotic lungs. Additional targets of miR-326 controlling TGF-β signaling and fibrosis-related pathways were identified, and miR-326 was found to down-regulate profibrotic genes, such as Ets1, Smad3, and matrix metalloproteinase 9, whereas it up-regulates antifibrotic genes, such as Smad7. Our results suggest for the first time that miR-326 plays a key role in regulating TGF-β1 expression and other profibrotic genes and could be useful in developing better therapeutic strategies for alleviating lung fibrosis.

  8. Amyloid beta-peptide possesses a transforming growth factor-beta activity.

    PubMed

    Huang, S S; Huang, F W; Xu, J; Chen, S; Hsu, C Y; Huang, J S

    1998-10-16

    Amyloid beta-peptide (Abeta) of 39-42 amino acid residues is a major constituent of Alzheimer's disease neurite plaques. Abeta aggregates (fibrils) are believed to be responsible for neuronal damage and dysfunction, as well as microglia and astrocyte activation in disease lesions by multiple mechanisms. Since Abeta aggregates possess the multiple valencies of an FAED motif (20th to 23rd amino acid residues), which resembles the putative transforming growth factor-beta (TGF-beta) active site motif, we hypothesize that Abeta monomers and Abeta aggregates may function as TGF-beta antagonists and partial agonists, analogous to previously described monovalent and multivalent TGF-beta peptide antagonists and agonists (Huang, S. S., Liu, Q., Johnson, F. E., Konish, Y., and Huang, J. S. (1997) J. Biol. Chem. 272, 27155-27159). Here, we report that the Abeta monomer, Abeta-(1-40) and its fragment, containing the motif inhibit radiolabeled TGF-beta binding to cell-surface TGF-beta receptors in mink lung epithelial cells (Mv1Lu cells). Abeta-(1-40)-bovine serum albumin conjugate (Abeta-(1-40)-BSA), a multivalent synthetic analogue of Abeta aggregates, exhibited cytotoxicity toward bovine cerebral endothelial cells and rat post-mitotic differentiated hippocampal neuronal cells (H19-7 cells) and inhibitory activities of radiolabeled TGF-beta binding to TGF-beta receptors and TGF-beta-induced plasminogen activator inhibitor-1 expression, that were approximately 100-670 times more potent than those of Abeta-(1-40) monomers. At less than micromolar concentrations, Abeta-(1-40)-BSA but not Abeta-(1-40) monomers inhibited proliferation of Mv1Lu cells. Since TGF-beta is an organizer of responses to neurodegeneration and is also found in neurite plaques, the TGF-beta antagonist and partial agonist activities of Abeta monomers and aggregates may play an important role in the pathogenesis of the disease.

  9. Activity-dependent release of transforming growth factor-beta in a neuronal network in vitro.

    PubMed

    Lacmann, A; Hess, D; Gohla, G; Roussa, E; Krieglstein, K

    2007-12-12

    For neurotrophins and also for members of the transforming growth factor beta (TGF-beta) family an activity-dependent regulation of synthesis and release has been proposed. Together with the observation that the secretion of neurotransmitters is initiated by neurotrophic factors, it is reasonable to assume that they might act as retrograde modulators enhancing the efficacy and stabilization of synapses. In the present study, we have tested this hypothesis and studied the release and regulation of TGF-beta in vitro using mouse primary hippocampal neurons at embryonic day E16.5 as model. We show that neuronal activity regulates TGF-beta release and TGF-beta expression in vitro. Treatment of the cultures with KCl, 3-veratroylveracevine (veratridine), glutamate or carbamylcholine chloride (carbachol) increased the levels of secreted TGF-beta, as assessed by the MLEC/plasminogen activator inhibitor (PAI)-luciferase-assay, whereas TGF-beta release stimulated by KCl or veratridine was reduced in the presence of tetrodotoxin or 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). In addition, application of glutamate significantly upregulated expression of TGF-beta2 and TGF-beta3 in the culture. Notably, KCl stimulation caused Smad (composite term from SMA (C. elegans) and MAD=mothers against dpp (Drosophila)) translocation into the nucleus and upregulated TGF-beta inducible early gene (Tieg1) expression, demonstrating that activity-dependent released TGF-beta may exert autocrine actions and thereby activate the TGF-beta-dependent signaling pathway. Together, these results suggest an activity-dependent release and gene transcription of TGF-beta from mouse hippocampal neurons in vitro as well as subsequent autocrine functions of the released TGF-beta within the hippocampal network.

  10. Transforming growth factor-β inhibits cystogenesis in human autosomal dominant polycystic kidney epithelial cells.

    PubMed

    Elberg, Dorit; Jayaraman, Siddarth; Turman, Martin A; Elberg, Gerard

    2012-08-01

    Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of kidney failure and characterized by the formation of multiple fluid-filled cysts in the kidneys. It is believed that environmental factors may play an important role in the disease progression. However, the molecular identity of autocrine/paracrine factors influencing cyst formation is largely unknown. In this study, we identified transforming growth factor-β2 (TGF-β2) secreted by normal human kidney (NHK) and ADPKD cells as an inhibitor of cystogenesis in 3D culture system using ADPKD cells from human kidneys. TGF-β2 was identified in conditioned media (CM) of NHK and ADPKD cells as a latent factor activated by heat in vitro. While all TGF-β isoforms recombinant proteins (TGF-β1, -β2, or -β3) displayed a similar inhibitory effect on cyst formation, TGF-β2 was the predominant isoform detected in CM. The involvement of TGF-β2 in the suppression of cyst formation was demonstrated by using a TGF-β2 specific blocking antibody and a TGF-β receptor I kinase inhibitor. TGF-β2 inhibited cyst formation by a mechanism other than activation of p38 mitogen-activated protein (MAP) kinase that mediated cell death in ADPKD cells. Further, we found that TGF-β2 modulated expression of various genes involved in cell-cell and cell-matrix interactions and extracellular matrix proteins that may play a role in the regulation of cystogenesis. Collectively, our results suggest that TGF-β2 secreted by renal epithelial cells may be an inhibitor of cystogenesis influencing the progression of ADPKD.

  11. Invasive candidiasis stimulates hepatocyte and monocyte production of active transforming growth factor beta.

    PubMed

    Letterio, J J; Lehrnbecher, T; Pollack, G; Walsh, T J; Chanock, S J

    2001-08-01

    Candida albicans is an opportunistic fungal pathogen and a major cause of morbidity and mortality in patients with compromised immune function. The cytokine response to tissue invasion by C. albicans can influence the differentiation and function of lymphocytes and other mononuclear cells that are critical components of the host response. While the production of transforming growth factor beta (TGF-beta) has been documented in mice infected with C. albicans and is known to suppress phagocyte function, the cellular source and role of this cytokine in the pathogenesis of systemic candidiasis are not well understood. We have investigated the source of production of TGF-beta by immunohistochemical studies in tissue samples from patients with an uncommon complication of lymphoreticular malignancy, chronic disseminated candidiasis (CDC), and from a neutropenic-rabbit model of CDC. Liver biopsy specimens from patients with documented CDC demonstrated intense staining for extracellular matrix-associated TGF-beta1 within inflammatory granulomas, as well as staining for TGF-beta1 and TGF-beta3 within adjacent hepatocytes. These results correlate with the immunolocalization of TGF-beta observed in livers of infected neutropenic rabbits, using a neutralizing antibody that recognizes the mature TGF-beta protein. Human peripheral blood monocytes incubated with C. albicans in vitro release large amounts of biologically active TGF-beta1. The data demonstrate that local production of active TGF-betas by hepatocytes and by infected mononuclear cells is a component of the response to C. albicans infection that most probably contributes to disease progression in the immunocompromised host.

  12. Redox-mediated activation of latent transforming growth factor-beta 1

    NASA Technical Reports Server (NTRS)

    Barcellos-Hoff, M. H.; Dix, T. A.; Chatterjee, A. (Principal Investigator)

    1996-01-01

    Transforming growth factor beta 1 (TGF beta) is a multifunctional cytokine that orchestrates response to injury via ubiquitous cell surface receptors. The biological activity of TGF beta is restrained by its secretion as a latent complex (LTGF beta) such that activation determines the extent of TGF beta activity during physiological and pathological events. TGF beta action has been implicated in a variety of reactive oxygen-mediated tissue processes, particularly inflammation, and in pathologies such as reperfusion injury, rheumatoid arthritis, and atherosclerosis. It was recently shown to be rapidly activated after in vivo radiation exposure, which also generates reactive oxygen species (ROS). In the present studies, the potential for redox-mediated LTGF beta activation was investigated using a cell-free system in which ROS were generated in solution by ionizing radiation or metal ion-catalyzed ascorbate reaction. Irradiation (100 Gray) of recombinant human LTGF beta in solution induced 26% activation compared with that elicited by standard thermal activation. Metal-catalyzed ascorbate oxidation elicited extremely efficient recombinant LTGF beta activation that matched or exceeded thermal activation. The efficiency of ascorbate activation depended on ascorbate concentrations and the presence of transition metal ions. We postulate that oxidation of specific amino acids in the latency-conferring peptide leads to a conformation change in the latent complex that allows release of TGF beta. Oxidative activation offers a novel route for the involvement of TGF beta in tissue processes in which ROS are implicated and endows LTGF beta with the ability to act as a sensor of oxidative stress and, by releasing TGF beta, to function as a signal for orchestrating the response of multiple cell types. LTGF beta redox sensitivity is presumably directed toward recovery of homeostasis; however, oxidation may also be a mechanism of LTGF beta activation that can be deleterious during

  13. Neuroprotection by glial metabotropic glutamate receptors is mediated by transforming growth factor-beta.

    PubMed

    Bruno, V; Battaglia, G; Casabona, G; Copani, A; Caciagli, F; Nicoletti, F

    1998-12-01

    The medium collected from cultured astrocytes transiently exposed to the group-II metabotropic glutamate (mGlu) receptor agonists (2S,1'R, 2'R,3'R)-2-(2,3-dicarboxycyclopropyl)glycine (DCG-IV) or (S)-4-carboxy-3-hydroxyphenylglycine (4C3HPG) is neuroprotective when transferred to mixed cortical cultures challenged with NMDA (). The following data indicate that this particular form of neuroprotection is mediated by transforming growth factor-beta (TGFbeta). (1) TGFbeta1 and -beta2 were highly neuroprotective against NMDA toxicity, and their action was less than additive with that produced by the medium collected from astrocytes treated with DCG-IV or 4C3HPG (GM/DCG-IV or GM/4C3HPG); (2) antibodies that specifically neutralized the actions of TGFbeta1 or -beta2 prevented the neuroprotective activity of DCG-IV or 4C3HPG, as well as the activity of GM/DCG-IV or GM/4C3HPG; and (3) a transient exposure of cultured astrocytes to either DCG-IV or 4C3HPG led to a delayed increase in both intracellular and extracellular levels of TGFbeta. We therefore conclude that a transient activation of group-II mGlu receptors (presumably mGlu3 receptors) in astrocytes leads to an increased formation and release of TGFbeta, which in turn protects neighbor neurons against excitotoxic death. These results offer a new strategy for increasing the local production of neuroprotective factors in the CNS. PMID:9822720

  14. Induction of apoptosis in cultured hepatocytes and in regressing liver by transforming growth factor beta 1.

    PubMed Central

    Oberhammer, F A; Pavelka, M; Sharma, S; Tiefenbacher, R; Purchio, A F; Bursch, W; Schulte-Hermann, R

    1992-01-01

    In previous studies hepatocytes undergoing cell death by apoptosis but not normal hepatocytes in rat liver showed immunostaining for transforming growth factor beta 1 (TGF-beta 1). Staining was much stronger with antibodies recognizing the pro-region of TGF-beta 1 than the mature peptide itself. Therefore we investigated the ability of both forms of TGF-beta 1 to induce apoptosis in primary cultures of rat hepatocytes. Mature TGF-beta 1 induced rounding up of the cells and fragmentation into multiple vesicles. As revealed by the DNA-specific stain H33258, the chromatin of these cells condensed and segregated into masses at the nuclear membrane; this was obviously followed by fragmentation of the nucleus. Ultrastructurally the cytoplasm was well preserved, as demonstrated by the presence of intact cell organelles. These features strongly suggest the occurrence of apoptosis. Quantification of nuclei with condensed chromatin revealed that mature TGF-beta 1 was 30-fold more effective than the TGF-beta 1 latency-associated protein complex. Finally, we administered TGF-beta 1 in vivo using an experimental model in which regression of rat liver was initiated by a short preceding treatment with the hepatomitogen cyproterone acetate. Two doses of TGF-beta 1, each 1 nM/kg, augmented the incidence of apoptotic hepatocytes 5-fold. Equimolar doses of TGF-beta 1 latency-associated protein complex were ineffective. These studies suggest that TGF-beta 1 is involved in the initiation of apoptosis in the liver and that the mature form of TGF-beta 1 is the active principle. Images PMID:1608949

  15. Genetic polymorphisms in transforming growth factor beta-1 (TGFB1) and childhood asthma and atopy

    PubMed Central

    Li, Huiling; Romieu, Isabelle; Wu, Hao; Sienra-Monge, Juan-Jose; Ramírez-Aguilar, Matiana; del Río-Navarro, Blanca Estela; Lara-Sánchez, Irma del Carmen; Kistner, Emily O.; Gjessing, Håkon K.; London, Stephanie J.

    2007-01-01

    Transforming growth factor beta-1 (TGFB1) may influence asthma by modulating allergic airway inflammation and airway remodeling. The role of single nucleotide polymorphisms (SNPs) of TGFB1 in asthma remains inconclusive. We examined TGFB1 SNPs in relation to asthma risk and degree of atopy among 546 case-parent triads, consisting of asthmatics aged 4 to 17 years and their parents in Mexico City. Atopy to 24 aeroallergens was determined by skin prick tests. We genotyped five TGFB1 SNPs, including two known functional SNPs [C-509T (rs1800469), T869C (rs1982073)] and three others (rs7258445, rs1800472, rs8179181), using TaqMan and Masscode assays. We analyzed the data using log-linear and polytomous logistic methods. Three associated SNPs, including the two known functional SNPs, were statistically significantly related to asthma risk. Individuals carrying the T allele of C-509T had an increased risk of asthma [relative risk (RR) = 1.42, 95% confidence interval (CI) = 1.08–1.87 for one copy; RR (95%CI) = 1.95 (1.36–2.78) for two copies]. For T869C, the RRs (95%CI) were 1.47 (1.09–1.98) for one and 2.00 (1.38–2.90) for two copies of the C allele. Similar results were found for rs7258445. The haplotype containing all three risk alleles conferred an increased risk of asthma (RR = 1.48, 95% CI = 1.11–1.95 for one copy; RR = 1.77, 95% CI = 1.22–2.57 for two copies). These three SNPs were also related to the degree of atopy. This largest study to date of genetic variation in TGFB1 and asthma and atopy adds to increasing evidence for a role in these disorders. PMID:17333284

  16. Zoledronic acid suppresses transforming growth factor-β-induced fibrogenesis by human gingival fibroblasts

    PubMed Central

    KOMATSU, YUKO; IBI, MIHO; CHOSA, NAOYUKI; KYAKUMOTO, SEIKO; KAMO, MASAHARU; SHIBATA, TOSHIYUKI; SUGIYAMA, YOSHIKI; ISHISAKI, AKIRA

    2016-01-01

    Bisphosphonates (BPs) are analogues of pyro-phosphate that are known to prevent bone resorption by inhibiting osteoclast activity. Nitrogen-containing BPs, such as zoledronic acid (ZA), are widely used in the treatment of osteoporosis and bone metastasis. However, despite having benefits, ZA has been reported to induce BP-related osteonecrosis of the jaw (BRONJ) in cancer patients. The molecular pathological mechanisms responsible for the development of BRONJ, including necrotic bone exposure after tooth extraction, remain to be elucidated. In this study, we examined the effects of ZA on the transforming growth factor-β (TGF-β)-induced myofibroblast (MF) differentiation of human gingival fibroblasts (hGFs) and the migratory activity of hGFs, which are important for wound closure by fibrous tissue formation. The ZA maximum concentration in serum (Cmax) was found to be approximately 1.47 µM, which clinically, is found after the intravenous administration of 4 mg ZA, and ZA at this dose is considered appropriate for the treatment of cancer bone metastasis or bone diseases, such as Erdheim-Chester disease. At Cmax, ZA significantly suppressed i) the TGF-β-induced promotion of cell viability, ii) the TGF-β-induced expression of MF markers such as α-smooth muscle actin (α-SMA) and type I collagen, iii) the TGF-β-induced migratory activity of hGFs and iv) the expression level of TGF-β type I receptor on the surfaces of hGFs, as well as the TGF-β-induced phosphorylation of Smad2/3. Thus, ZA suppresses TGF-β-induced fibrous tissue formation by hGFs, possibly through the inhibition of Smad-dependent signal transduction. Our findings partly elucidate the molecular mechanisms underlying BRONJ and may prove to be beneficial to the identification of drug targets for the treatment of this symptom at the molecular level. PMID:27176567

  17. Molecular characterisation of sea bream (Sparus aurata) transforming growth factor beta1.

    PubMed

    Tafalla, C; Aranguren, R; Secombes, C J; Castrillo, J L; Novoa, B; Figueras, A

    2003-05-01

    A transforming growth factor beta1 (TGF beta1) full length cDNA was characterised and sequenced from the head kidney of sea bream (Sparus aurata) previously challenged with a nodavirus. The cloned cDNA of 1778bp contains a predicted open reading frame of 379 amino acids, which includes the mature peptide region of 112 amino acids. The regulating region of the peptide possesses four potential N-linked glycosylation sites (N-X-T/S), as well as an RGD integrin binding site, an RKKR tetrabasic cut site and nine conserved cysteines all characteristic of the TGF beta superfamily. Compared to other teleost TGF beta1 genes, the sea bream TGF beta1 is most closely related to hybrid striped bass (Moronesaxatilis xM. chrysops) TGF beta1 (80% amino acid identity). The genomic organisation of TGF beta1 was determined through the generation of contiguous PCR clones. The sea bream TGF beta1 gene is approximately 3.6kb in length and consists of five coding regions. Two introns are absent in comparison to the genomic organisation of rainbow trout Oncorhynchus mykiss TGF beta1, whilst an additional intron not present in other sequenced TGF beta genes, but present in the trout TGF beta1 gene, is conserved in sea bream.A reverse transcription polymerase chain reaction (RT-PCR) assay was developed to study TGF beta expression in different sea bream tissues. Constitutive TGF beta1 expression was detected in the liver, brain, muscle, kidney, heart, gills and spleen of sea bream, as well as in head kidney macrophages and blood leucocytes.

  18. Immunohistochemical detection of active transforming growth factor-beta in situ using engineered tissue

    NASA Technical Reports Server (NTRS)

    Barcellos-Hoff, M. H.; Ehrhart, E. J.; Kalia, M.; Jirtle, R.; Flanders, K.; Tsang, M. L.; Chatterjee, A. (Principal Investigator)

    1995-01-01

    The biological activity of transforming growth factor-beta 1 (TGF-beta) is governed by dissociation from its latent complex. Immunohistochemical discrimination of active and latent TGF-beta could provide insight into TGF-beta activation in physiological and pathological processes. However, evaluation of immunoreactivity specificity in situ has been hindered by the lack of tissue in which TGF-beta status is known. To provide in situ analysis of antibodies to differentiate between these functional forms, we used xenografts of human tumor cells modified by transfection to overexpress latent TGF-beta or constitutively active TGF-beta. This comparison revealed that, whereas most antibodies did not differentiate between TGF-beta activation status, the immunoreactivity of some antibodies was activation dependent. Two widely used peptide antibodies to the amino-terminus of TGF-beta, LC(1-30) and CC(1-30) showed marked preferential immunoreactivity with active TGF-beta versus latent TGF-beta in cryosections. However, in formalin-fixed, paraffin-embedded tissue, discrimination of active TGF-beta by CC(1-30) was lost and immunoreactivity was distinctly extracellular, as previously reported for this antibody. Similar processing-dependent extracellular localization was found with a neutralizing antibody raised to recombinant TGF-beta. Antigen retrieval recovered cell-associated immunoreactivity of both antibodies. Two antibodies to peptides 78-109 showed mild to moderate preferential immunoreactivity with active TGF-beta only in paraffin sections. LC(1-30) was the only antibody tested that discriminated active from latent TGF-beta in both frozen and paraffin-embedded tissue. Thus, in situ discrimination of active versus latent TGF-beta depends on both the antibody and tissue preparation. We propose that tissues engineered to express a specific form of a given protein provide a physiological setting in which to evaluate antibody reactivity with specific functional forms of a

  19. Differential regulation of mesothelial cell fibrinolysis by transforming growth factor beta 1.

    PubMed

    Falk, P; Ma, C; Chegini, N; Holmdahl, L

    2000-10-01

    Inflammation and tissue trauma during the surgical procedure reduce the peritoneal fibrinolytic capacity. These conditions promote adhesion formation, and are associated with increased expression of transforming growth factor beta 1 (TGF-beta1). The objective of the present study was to investigate whether TGF-beta1 regulates the expression of fibrinolytic components in peritoneal mesothelial cells. Human peritoneal mesothelial cells (HPMC) were cultured and treated with various concentrations of human recombinant TGF-beta1 (0.1, 1.0 and 10 ng/mL) for 24 h. Levels of tissue- and urokinase plasminogen activator (t-PA and uPA), plasminogen activator inhibitor type-1 (PAI-1) and type-2 (PAI-2) mRNA and protein were assessed by quantitative reverse transcriptase polymerase chain reaction (Q-RT-PCR) and ELISA, respectively. HPMC expressed these components at the gene and protein level. TGF-beta1 downregulated, dose-dependently t-PA mRNA and protein to about 50% of control values (p = 0.0010), and doubled PAI-1 protein production (p = 0.0008) compared to untreated controls. Although uPA gene expression increased in cells exposed to TGF-beta1, the corresponding protein concentration in conditioned media did not. PAI-2 was not affected, either at the gene or protein level. In conclusion, the results indicate that fibrinolytic capacity of mesothelial cells is reduced by TGF-beta1, suggesting that peritoneal adhesion formation induced by TGF-beta1 may be mediated, in part, through reduction in fibrin degradation capacity at an early stage of peritoneal tissue repair.

  20. High growth rate homoepitaxial diamond film deposition at high temperatures by microwave plasma-assisted chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Vohra, Yogesh K. (Inventor); McCauley, Thomas S. (Inventor)

    1997-01-01

    The deposition of high quality diamond films at high linear growth rates and substrate temperatures for microwave-plasma chemical vapor deposition is disclosed. The linear growth rate achieved for this process is generally greater than 50 .mu.m/hr for high quality films, as compared to rates of less than 5 .mu.m/hr generally reported for MPCVD processes.

  1. The protective effects of ambroxol on radiation lung injury and influence on production of transforming growth factor beta1 and tumor necrosis factor alpha.

    PubMed

    Xia, De-Hong; Xi, Lei; Xv, Chen; Mao, Wei-Dong; Shen, Wei-Sheng; Shu, Zhong-Qin; Yang, Hong-Zhi; Dai, Min

    2010-09-01

    The aim of this article was to investigate the effect of ambroxol on radiation lung injury and the expression of transforming growth factor beta(1) (TGF-beta(1)), as well as tumor necrosis factor alpha (TNF-alpha) in plasma. Totally, 120 patients with locally advanced lung cancer in radiotherapy were randomized into treatment and control groups. Patients in the treatment group took ambroxol orally at a dosage of 90 mg, three times per day for 3 months from the beginning of radiotherapy. The expression of TGF-beta(1) and TNF-alpha in plasma was analyzed. The clinical symptoms and lung diffusing capacity were monitored using high resolving power computed tomography. The level of TGF-beta(1) in the control group was increased (11.8 +/- 5.5 ng/ml), whereas in ambroxol-treated patients, the increase was not significant (5.6 +/- 2.6 ng/ml, P < 0.001). Radiotherapy-induced elevation of TNF-alpha levels, seen in control patients, was also abolished after treatment with ambroxol (5.1 +/- 1.0 vs. 2.4 +/- 0.8 ng/ml, P < 0.001). In the treatment group, carbon monoxide diffusion capacity was not significantly decreased at 6, 12, and 18 months post-radiotherapy, compared with the control group (P < 0.05). Ambroxol decreased the expression of TGF-beta(1) and TNF-alpha, and minimized the diminishment of lung diffusion capacity after radiotherapy.

  2. Normalisation of plasma growth hormone levels improved cardiac dysfunction due to acromegalic cardiomyopathy with severe fibrosis.

    PubMed

    Yokota, Fumiko; Arima, Hiroshi; Hirano, Miho; Uchikawa, Tomohiro; Inden, Yasuya; Nagatani, Tetsuya; Oiso, Yutaka

    2010-09-19

    A 51-year-old man was referred to the Department of Cardiology in our hospital due to severe congestive heart failure and ventricular arrhythmias in March 2008. He had repeated ventricular tachycardia for years and the left ventricular ejection fraction (EF) was 11% on admission. A myocardial biopsy revealed that over 50% cardiomyocytes were replaced by fibrosis. Due to the typical acromegalic features, he was referred to the endocrinology department and diagnosed as acromegaly. He was treated with octreotide for 8 months followed by trans-sphenoidal surgery. The plasma levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) decreased by octreotide and normalised by surgery after which the cardiac function improved drastically. The current case demonstrates that cardiac dysfunction in acromegaly could be recovered by normalisation of GH and IGF-1 even in the presence of severe fibrosis in the myocardium.

  3. The Swine Plasma Metabolome Chronicles "Many Days" Biological Timing and Functions Linked to Growth.

    PubMed

    Bromage, Timothy G; Idaghdour, Youssef; Lacruz, Rodrigo S; Crenshaw, Thomas D; Ovsiy, Olexandra; Rotter, Björn; Hoffmeier, Klaus; Schrenk, Friedemann

    2016-01-01

    The paradigm of chronobiology is based almost wholly upon the daily biological clock, or circadian rhythm, which has been the focus of intense molecular, cellular, pharmacological, and behavioral, research. However, the circadian rhythm does not explain biological timings related to fundamental aspects of life history such as rates of tissue/organ/body size development and control of the timing of life stages such as gestation length, age at maturity, and lifespan. This suggests that another biological timing mechanism is at work. Here we focus on a "many days" (multidien) chronobiological period first observed as enigmatic recurring growth lines in developing mammalian tooth enamel that is strongly associate with all adult tissue, organ, and body masses as well as life history attributes such as gestation length, age at maturity, weaning, and lifespan, particularly among the well studied primates. Yet, knowledge of the biological factors regulating the patterning of mammalian life, such as the development of body size and life history structure, does not exist. To identify underlying molecular mechanisms we performed metabolome and genome analyses from blood plasma in domestic pigs. We show that blood plasma metabolites and small non-coding RNA (sncRNA) drawn from 33 domestic pigs over a two-week period strongly oscillate on a 5-day multidien rhythm, as does the pig enamel rhythm. Metabolomics and genomics pathway analyses actually reveal two 5-day rhythms, one related to growth in which biological functions include cell proliferation, apoptosis, and transcription regulation/protein synthesis, and another 5-day rhythm related to degradative pathways that follows three days later. Our results provide experimental confirmation of a 5-day multidien rhythm in the domestic pig linking the periodic growth of enamel with oscillations of the metabolome and genome. This association reveals a new class of chronobiological rhythm and a snapshot of the biological bases that

  4. The Swine Plasma Metabolome Chronicles "Many Days" Biological Timing and Functions Linked to Growth

    PubMed Central

    Bromage, Timothy G.; Idaghdour, Youssef; Lacruz, Rodrigo S.; Crenshaw, Thomas D.; Ovsiy, Olexandra; Rotter, Björn; Hoffmeier, Klaus; Schrenk, Friedemann

    2016-01-01

    The paradigm of chronobiology is based almost wholly upon the daily biological clock, or circadian rhythm, which has been the focus of intense molecular, cellular, pharmacological, and behavioral, research. However, the circadian rhythm does not explain biological timings related to fundamental aspects of life history such as rates of tissue/organ/body size development and control of the timing of life stages such as gestation length, age at maturity, and lifespan. This suggests that another biological timing mechanism is at work. Here we focus on a "many days" (multidien) chronobiological period first observed as enigmatic recurring growth lines in developing mammalian tooth enamel that is strongly associate with all adult tissue, organ, and body masses as well as life history attributes such as gestation length, age at maturity, weaning, and lifespan, particularly among the well studied primates. Yet, knowledge of the biological factors regulating the patterning of mammalian life, such as the development of body size and life history structure, does not exist. To identify underlying molecular mechanisms we performed metabolome and genome analyses from blood plasma in domestic pigs. We show that blood plasma metabolites and small non-coding RNA (sncRNA) drawn from 33 domestic pigs over a two-week period strongly oscillate on a 5-day multidien rhythm, as does the pig enamel rhythm. Metabolomics and genomics pathway analyses actually reveal two 5-day rhythms, one related to growth in which biological functions include cell proliferation, apoptosis, and transcription regulation/protein synthesis, and another 5-day rhythm related to degradative pathways that follows three days later. Our results provide experimental confirmation of a 5-day multidien rhythm in the domestic pig linking the periodic growth of enamel with oscillations of the metabolome and genome. This association reveals a new class of chronobiological rhythm and a snapshot of the biological bases that

  5. In situ investigation of growth modes during plasma-assisted molecular beam epitaxy of (0001) GaN

    SciTech Connect

    Koblmueller, G.; Fernandez-Garrido, S.; Calleja, E.; Speck, J. S.

    2007-10-15

    Real-time analysis of the growth modes during homoepitaxial (0001) GaN growth by plasma-assisted molecular beam epitaxy was performed using reflection high energy electron diffraction. A growth mode map was established as a function of Ga/N flux ratio and growth temperature, exhibiting distinct transitions between three-dimensional (3D), layer-by-layer, and step-flow growth modes. The layer-by-layer to step-flow growth transition under Ga-rich growth was surfactant mediated and related to a Ga adlayer coverage of one monolayer. Under N-rich conditions the transition from 3D to layer-by-layer growth was predominantly thermally activated, facilitating two-dimensional growth at temperatures of thermal decomposition.

  6. Insights in the plasma-assisted growth of carbon nanotubes through atomic scale simulations: effect of electric field.

    PubMed

    Neyts, Erik C; van Duin, Adri C T; Bogaerts, Annemie

    2012-01-18

    Carbon nanotubes (CNTs) are nowadays routinely grown in a thermal CVD setup. State-of-the-art plasma-enhanced CVD (PECVD) growth, however, offers advantages over thermal CVD. A lower growth temperature and the growth of aligned freestanding single-walled CNTs (SWNTs) makes the technique very attractive. The atomic scale growth mechanisms of PECVD CNT growth, however, remain currently entirely unexplored. In this contribution, we employed molecular dynamics simulations to focus on the effect of applying an electric field on the SWNT growth process, as one of the effects coming into play in PECVD. Using sufficiently strong fields results in (a) alignment of the growing SWNTs, (b) a better ordering of the carbon network, and (c) a higher growth rate relative to thermal growth rate. We suggest that these effects are due to the small charge transfer occurring in the Ni/C system. These simulations constitute the first study of PECVD growth of SWNTs on the atomic level. PMID:22126536

  7. Low temperature plasma processing for cell growth inspired carbon thin films fabrication.

    PubMed

    Kumar, Manish; Piao, Jin Xiang; Jin, Su Bong; Lee, Jung Heon; Tajima, Satomi; Hori, Masaru; Han, Jeon Geon

    2016-09-01

    The recent bio-applications (i.e. bio-sensing, tissue engineering and cell proliferation etc.) are driving the fundamental research in carbon based materials with functional perspectives. High stability in carbon based coatings usually demands the high density deposition. However, the standard techniques, used for the large area and high throughput deposition of crystalline carbon films, often require very high temperature processing (typically >800 °C in inert atmosphere). Here, we present a low temperature (<150 °C) pulsed-DC plasma sputtering process, which enables sufficient ion flux to deposit dense unhydrogenated carbon thin films without any need of substrate-bias or post-deposition thermal treatments. It is found that the control over plasma power density and pulsed frequency governs the density and kinetic energy of carbon ions participating during the film growth. Subsequently, it controls the contents of sp(3) and sp(2) hybridizations via conversion of sp(2) to sp(3) hybridization by ion's energy relaxation. The role of plasma parameters on the chemical and surface properties are presented and correlated to the bio-activity. Bioactivity tests, carried out in mouse fibroblast L-929 and Sarcoma osteogenic (Saos-2) bone cell lines, demonstrate promising cell-proliferation in these films. PMID:27036854

  8. Investigation of the growth mechanisms of diglyme plasma polymers on amyloid fibril networks

    NASA Astrophysics Data System (ADS)

    Li, Yali; Reynolds, Nicholas P.; Styan, Katie E.; Muir, Benjamin W.; Forsythe, John S.; Easton, Christopher D.

    2016-01-01

    Within the area of biomaterials research, the ability to tailor a materials surface chemistry while presenting a biomimetic topography is a useful tool for studying cell-surface and cell-cell interactions. For the study reported here we investigated the deposition of diglyme plasma polymer films (DGpp) onto amyloid fibril networks (AFNs), which have morphologies that mimic the extracellular matrix. We extend our previous work to observe that the nanoscale contours of the AFNs are well preserved even under thick layers of DGpp. The width of the surface features is positively correlated to the DGpp thickness. DGpp film growth conformed to the underlying fibril features, with a gradual smoothing out of the resultant surface topography. Further, to understand how the films grow on top of AFNs, X-ray photoelectron spectroscopy depth profiling was employed to determine the elemental composition within the coating, perpendicular to the plane of the substrate. It was found that AFNs partially fragment during the initial stage of plasma polymerisation, and these fragments then mix with the growing DGpp to form an intermixed interface region above the AFN. The findings in this study are likely applicable to situations where plasma polymerisation is used to apply an overcoat to adsorbed organic and/or biological molecules.

  9. Differential cell cycle response of nontumorigenic and tumorigenic human papillomavirus-positive keratinocytes towards transforming growth factor-beta1.

    PubMed

    Hasskarl, J; Butz, K; Whitaker, N; Ullmann, A; Dürst, M; Hoppe-Seyler, F

    2000-01-01

    Human papillomaviruses (HPVs) are causative agents of a number of malignancies in humans, including cervical cancer. Their tumorigenic potential is linked to expression of the viral E6/E7 genes which can interfere with normal cell cycle control by targeting p53, p21WAF1, p27KIP1, and pRb. We show here that nontumorigenic and tumorigenic HPV-positive keratinocytes (HPK) exhibit striking differences in the response of cell cycle regulatory genes towards transforming growth factor beta-beta1. Treatment with this agent led to an efficient induction of p53 and the growth-inhibitory p15INK4 and p21WAF1 genes only in nontumorigenic HPKs and was linked to an efficient reduction in viral E6/E7 oncogene expression. This was associated with increased pRb levels, exhibiting sustained hypophosphorylation, and a permanent growth arrest in the G1 phase of the cell cycle. In contrast, tumorigenic HPKs exhibited only a modest rise in p53 protein levels and a substantially reduced induction of the p15INK4 and p21WAF1 genes, which was linked to a lesser degree of viral oncogene repression. In addition, tumorigenic HPKs rapidly resumed cell growth after a transient G1 arrest, concomitantly with the reappearance of hyperphosphorylated pRb. These results support the notion that the progression of HPV-positive cells to a malignant phenotype is associated with increased resistance to growth inhibition by transforming growth factor-beta1. This is linked in the tumorigenic cells to a lack of persistent G1 arrest, inefficient induction of several cell cycle control genes involved in growth inhibition, and inefficient repression of the growth-promoting viral E6/E7 oncogenes. PMID:10794545

  10. Platelet-derived growth factor-BB and transforming growth factor beta 1 selectively modulate glycosaminoglycans, collagen, and myofibroblasts in excisional wounds.

    PubMed Central

    Pierce, G. F.; Vande Berg, J.; Rudolph, R.; Tarpley, J.; Mustoe, T. A.

    1991-01-01

    Recombinant platelet-derived growth factor (PDGF) and transforming growth factor beta 1 (TGF-beta 1) influence the rate of extracellular matrix formed in treated incisional wounds. Because incisional healing processes are difficult to quantify, a full-thickness excisional wound model in the rabbit ear was developed to permit detailed analyses of growth-factor-mediated tissue repair. In the present studies, quantitative and qualitative differences in acute inflammatory cell influx, glycosaminoglycan (GAG) deposition, collagen formation, and myofibroblast generation in PDGF-BB (BB homodimer)- and TGF-beta 1-treated wounds were detected when analyzed histochemically and ultrastructurally. Although both growth factors significantly augmented extracellular matrix formation and healing in 10-day wounds compared with controls (P less than 0.002). PDGF-BB markedly increased macrophage influx and GAG deposition, whereas TGF-beta 1 selectively induced significantly more mature collagen bundles at the leading edge of new granulation tissue (P = 0.007). Transforming growth factor-beta 1-treated wound fibroblasts demonstrated active collagen fibrillogenesis and accretion of subfibrils at the ultrastructural level. Myofibroblasts, phenotypically modified fibroblasts considered responsible for wound contraction, were observed in control, but were absent in early growth-factor-treated granulating wounds. These results provide important insights into the mechanisms of soft tissue repair and indicate that 1) PDGF-BB induces an inflammatory response and provisional matrix synthesis within wounds that is qualitatively similar but quantitatively increased compared with normal wounds; 2) TGF-beta 1 preferentially triggers synthesis and more rapid maturation of collagen within early wounds; and 3) both growth factors inhibit the differentiation of fibroblasts into myofibroblasts, perhaps because wound contraction is not required, due to increased extracellular matrix synthesis. Images

  11. Mechanism for magnetic field generation and growth in Rayleigh-Taylor unstable inertial confinement fusion plasmas

    SciTech Connect

    Srinivasan, Bhuvana; Tang Xianzhu

    2012-08-15

    Rayleigh-Taylor instabilities (RTI) in inertial confinement fusion (ICF) implosions are expected to generate magnetic fields at the gas-ice interface and at the ice-ablator interface. The focus here is on the gas-ice interface where the temperature gradient is the largest. A Hall-MHD model is used to study the magnetic field generation and growth for 2-D single-mode and multimode RTI in a stratified two-fluid plasma, the two fluids being ions and electrons. Self-generated magnetic fields are observed and these fields grow as the RTI progresses via the {nabla}n{sub e} Multiplication-Sign {nabla}T{sub e} term in the generalized Ohm's law. Srinivasan et al.[Phys. Rev. Lett. 108, 165002 (2012)] present results of the magnetic field generation and growth, and some scaling studies in 2-dimensions. The results presented here study the mechanism behind the magnetic field generation and growth, which is related to fluid vorticity generation by RTI. The magnetic field wraps around the bubbles and spikes and concentrates in flux bundles at the perturbed gas-ice interface where fluid vorticity is large. Additionally, the results of Srinivasan et al.[Phys. Rev. Lett. 108, 165002 (2012)] are described in greater detail. Additional scaling studies are performed to determine the growth of the self-generated magnetic field as a function of density, acceleration, perturbation wavelength, Atwood number, and ion mass.

  12. Mechanism for magnetic field generation and growth in Rayleigh-Taylor unstable inertial confinement fusion plasmas

    NASA Astrophysics Data System (ADS)

    Srinivasan, Bhuvana; Tang, Xian-Zhu

    2012-08-01

    Rayleigh-Taylor instabilities (RTI) in inertial confinement fusion (ICF) implosions are expected to generate magnetic fields at the gas-ice interface and at the ice-ablator interface. The focus here is on the gas-ice interface where the temperature gradient is the largest. A Hall-MHD model is used to study the magnetic field generation and growth for 2-D single-mode and multimode RTI in a stratified two-fluid plasma, the two fluids being ions and electrons. Self-generated magnetic fields are observed and these fields grow as the RTI progresses via the ∇ne×∇Te term in the generalized Ohm's law. Srinivasan et al. [Phys. Rev. Lett. 108, 165002 (2012)] present results of the magnetic field generation and growth, and some scaling studies in 2-dimensions. The results presented here study the mechanism behind the magnetic field generation and growth, which is related to fluid vorticity generation by RTI. The magnetic field wraps around the bubbles and spikes and concentrates in flux bundles at the perturbed gas-ice interface where fluid vorticity is large. Additionally, the results of Srinivasan et al. [Phys. Rev. Lett. 108, 165002 (2012)] are described in greater detail. Additional scaling studies are performed to determine the growth of the self-generated magnetic field as a function of density, acceleration, perturbation wavelength, Atwood number, and ion mass.

  13. Growth mechanisms of plasma-assisted molecular beam epitaxy of green emission InGaN/GaN single quantum wells at high growth temperatures

    SciTech Connect

    Yang, W. C.; Wu, C. H.; Tseng, Y. T.; Chiu, S. Y.; Cheng, K. Y.

    2015-01-07

    The results of the growth of thin (∼3 nm) InGaN/GaN single quantum wells (SQWs) with emission wavelengths in the green region by plasma-assisted molecular beam epitaxy are present. An improved two-step growth method using a high growth temperature up to 650 °C is developed to increase the In content of the InGaN SQW to 30% while maintaining a strong luminescence intensity near a wavelength of 506 nm. The indium composition in InGaN/GaN SQW grown under group-III-rich condition increases with increasing growth temperature following the growth model of liquid phase epitaxy. Further increase in the growth temperature to 670 °C does not improve the photoluminescence property of the material due to rapid loss of indium from the surface and, under certain growth conditions, the onset of phase separation.

  14. Plasma intact fibroblast growth factor 23 levels in women with anorexia nervosa

    PubMed Central

    Otani, Makoto; Takimoto, Yoshiyuki; Moriya, Junko; Yoshiuchi, Kazuhiro; Akabayashi, Akira

    2008-01-01

    Background Fibroblast growth factor (FGF)23 is a novel phosphaturic factor associated with inorganic phosphate homeostasis. Previous human studies have shown that serum FGF23 levels increase in response to a high phosphate diet. For anorexia nervosa (AN) patients, inorganic phosphate homeostasis is important in the clinical course, such as in refeeding syndrome. The purpose of this study was to determine plasma levels of intact FGF23 (iFGF23) in restricting-type AN (AN-R) patients, binge-eating/purging-type AN (AN-BP) patients, and healthy controls. Methods The subjects consisted of 6 female AN-R patients, 6 female AN-BP patients, and 11 healthy female controls; both inpatients and outpatients were included. Plasma iFGF23, 1,25-dihydroxyvitamin D (1,25-(OH)2D), and 25-hydroxyvitamin D (25-OHD) levels were measured. Data are presented as the median and the range. A two-tailed Mann-Whitney U-test with Bonferroni correction was used to assess differences among the three groups, and a value of p < 0.017 was considered statistically significant. Results There were no differences between AN-R patients and controls in the iFGF23 and 1,25-(OH)2D levels. In AN-BP patients, the iFGF23 level (41.3 pg/ml; range, 6.1–155.5 pg/ml) was significantly higher than in controls (3.8 pg/ml; range, not detected-21.3 pg/ml; p = 0.001), and the 1,25-(OH)2D was significantly lower in AN-BP patients (7.0 pg/ml; range, 4.2–33.7 pg/ml) than in controls (39.7 pg/ml; range, 6.3–58.5 pg/ml; p = 0.015). No differences in plasma 25-OHD levels were observed among the groups. Conclusion This preliminary study is the first to show that plasma iFGF23 levels are increased in AN-BP patients, and that these elevated plasma FGF23 levels might be related to the decrease in plasma 1,25-(OH)2D levels. PMID:18412981

  15. Investigation on growth behavior of CNTs synthesized by atmospheric pressure plasma enhanced chemical vapor deposition system on Fe catalyzed substrate.

    PubMed

    Choi, Bum Ho; Kim, Won Jae; Kim, Young Baek; Lee, Jong Ho; Park, Jong Woon; Kim, Woo Sam; Shin, Dong Chan

    2008-10-01

    We have studied growth behavior of carbon nanotubes (CNTs) on iron (Fe) catalyzed substrate using newly developed atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) system. To investigate the improved growth performance with simple equipment and process on large scale, a new AP-PECVD system containing different concept on downstream gas was designed and manufactured. As a catalyst, either sputtered or evaporated Fe thin film on SiO2/Si substrate was used and acetylene gas was used as a carbon source. We observed growth behavior of CNTs such as height, rate and density were strongly affected by plasma power. The maximum height of 427 microm and 267 microm was synthesized under RF plasma power of 30 W for 30 min and 40 W for 3 min, respectively. The growth rate dramatically increased to 6.27 times as plasma power increased from 30 to 40 W which opens the possibility the mass production of CNTs. By SEM and TEM observation, it was verified the grown CNTs was consists of mixture of single-wall and multi-wall CNTs. The graphitization ratio was measured to be 0.93, indicating that the graphitized CNTs forest was formed and relatively high purity of CNTs was synthesized, being useful for nano-composite materials to reinforce the strength. From our experiments, we can observe that the height and growth rate of CNTs is strong function of plasma power. PMID:19198378

  16. Induction of Transforming Growth Factor Beta Receptors following Focal Ischemia in the Rat Brain

    PubMed Central

    Pál, Gabriella; Lovas, Gábor; Dobolyi, Arpád

    2014-01-01

    Transforming growth factor-βs (TGF-βs) regulate cellular proliferation, differentiation, and survival. TGF-βs bind to type I (TGF-βRI) and II receptors (TGF-βRII), which are transmembrane kinase receptors, and an accessory type III receptor (TGF-βRIII). TGF-β may utilize another type I receptor, activin-like kinase receptor (Alk1). TGF-β is neuroprotective in the middle cerebral artery occlusion (MCAO) model of stroke. Recently, we reported the expression pattern of TGF-β1-3 after MCAO. To establish how TGF-βs exert their actions following MCAO, the present study describes the induction of TGF-βRI, RII, RIII and Alk1 at 24 h, 72 h and 1 mo after transient 1 h MCAO as well as following 24 h permanent MCAO using in situ hybridization histochemistry. In intact brain, only TGF-βRI had significant expression: neurons in cortical layer IV contained TGF-βRI. At 24 h after the occlusion, no TGF-β receptors showed induction. At 72 h following MCAO, all four types of TGF-β receptors were induced in the infarct area, while TGF-βRI and RII also appeared in the penumbra. Most cells with elevated TGF-βRI mRNA levels were microglia. TGF-βRII co-localized with both microglial and endothelial markers while TGF-βRIII and Alk1 were present predominantly in endothels. All four TGF-β receptors were induced within the lesion 1 mo after the occlusion. In particular, TGF-βRIII was further induced as compared to 72 h after MCAO. At this time point, TGF-βRIII signal was predominantly not associated with blood vessels suggesting its microglial location. These data suggest that TGF-β receptors are induced after MCAO in a timely and spatially regulated fashion. TGF-β receptor expression is preceded by increased TGF-β expression. TGF-βRI and RII are likely to be co-expressed in microglial cells while Alk1, TGF-βRII, and RIII in endothels within the infarct where TGF-β1 may be their ligand. At later time points, TGF-βRIII may also appear in glial cells to potentially

  17. Urinary active transforming growth factor β in feline chronic kidney disease.

    PubMed

    Lawson, J S; Syme, H M; Wheeler-Jones, C P D; Elliott, J

    2016-08-01

    The cytokine transforming growth factor beta 1 (TGF-β1) has been widely implicated in the development and progression of renal fibrosis in chronic kidney disease (CKD) in humans and in experimental models. The aims of this study were to assess the association between urinary active TGF-β1 and (a) development of CKD in a cross-sectional study, (b) deterioration of renal function over 1 year in a longitudinal study, and (c) renal histopathological parameters in cats. A human active TGF-β1 ELISA was validated for use in feline urine. Cross-sectional analysis revealed no significant difference in urinary active TGF-β1:creatinine ratio (aTGF-β1:UCr) between groups with differing renal function. Longitudinally, non-azotaemic cats that developed CKD demonstrated a significant (P = 0.028) increase in aTGF-β1:UCr approximately 6 months before the development of azotaemia, which remained elevated (P = 0.046) at diagnosis (approximately 12 months prior, 8.4 pg/mg; approximately 6 months prior, 22.2 pg/mg; at CKD diagnosis, 24.6 pg/mg). In the histopathology study, aTGF-β1:UCr was significantly higher in cats with moderate (P = 0.02) and diffuse (P = 0.005) renal fibrosis than in cats without fibrosis. Cats with moderate renal inflammation had significantly higher urinary active aTGF-β1 concentrations than cats with mild (P = 0.035) or no inflammatory change (P = 0.004). The parameter aTGF-β1:UCr was independently associated with Log urine protein:creatinine ratio in a multivariable analysis of clinicopathological parameters and interstitial fibrosis score in a multivariable analysis of histopathological features. These results suggest that urinary aTGF-β1 reflects the severity of renal pathology. Increases in urinary aTGF-β1 followed longitudinally in individual cats may indicate the development of CKD. PMID:27387717

  18. Production of Gastrointestinal Tumors in Mice by Modulating Latent Transforming Growth Factor Beta 1 Activation

    PubMed Central

    Shibahara, Kotaro; Ota, Mitsuhiko; Horiguchi, Masahito; Yoshinaga, Keiji; Melamed, Jonathan; Rifkin, Daniel B

    2012-01-01

    Transforming growth factor-β (TGF-β) and its signaling pathways are important mediators in the suppression of cancers of the gastrointestinal (GI) tract. TGF-β is released from cells in a latent complex consisting of TGF-β, the TGF-β propeptide (LAP) and a latent TGF-β binding protein (LTBP). We previously generated mice in which the LTBP-binding cysteine residues in LAP TGF-β1 were mutated to serine precluding covalent interactions with LTBP. These Tgfb1C33S/C33S mice develop multiorgan inflammation and tumors consistent with reduced TGF-β1 activity. To test whether further reduction in active TGF-β levels would yield additional tumors and a phenotype more similar to Tgfb1-/- mice, we generated mice that express TGF-β1C33S and are deficient in either integrin β8 or TSP-1, known activators of latent TGF-β1. In addition we generated mice that have one mutant allele and one null allele at the Tgfb1 locus, reasoning that these mice should synthesize half the total amount of TGF-β1 as Tgfb1C33S/C33S mice and the amount of active TGF-β1 would be correspondingly decreased compared to Tgfb1C33S/C33S mice. These compound mutant mice displayed more severe inflammation and higher tumor numbers than the parental Tgfb1C33S/C33S animals. The level of active TGF-β1 in compound mutant mice appeared to be decreased compared to Tgfb1C33S/C33S mice as determined from analyses of surrogate markers of active TGF-β, such as P-Smad2, C-Myc, KI-67, and markers of cell cycle traverse. We conclude that these mutant mice provide a useful system for modulating TGF-β levels in a manner that determines tumor number and inflammation within the GI tract. PMID:23117884

  19. Expression of transforming growth factor β receptor II in mesenchymal stem cells from systemic sclerosis patients

    PubMed Central

    Vanneaux, Valérie; Farge-Bancel, Dominique; Lecourt, Séverine; Baraut, Julie; Cras, Audrey; Jean-Louis, Francette; Brun, Cécilia; Verrecchia, Franck; Larghero, Jérôme; Michel, Laurence

    2013-01-01

    Objectives The present work aimed to evaluate the expression of transforming growth factor-β (TGF-β) receptors on bone marrow-derived multipotent mesenchymal stromal cells (MSCs) in patients with systemic sclerosis (SSc) and the consequences of TGF-β activation in these cells, since MSC have potential therapeutic interest for SSc patients and knowing that TGF-β plays a critical role during the development of fibrosis in SSc. Design This is a prospective research study using MSC samples obtained from SSc patients and compared with MSC from healthy donors. Setting One medical hospital involving collaboration between an internal medicine department for initial patient recruitment, a clinical biotherapeutic unit for MSC preparation and an academic laboratory for research. Participants 9 patients with diffuse SSc for which bone marrow (BM) aspiration was prescribed by sternum aspiration before haematopoietic stem cell transplantation, versus nine healthy donors for normal BM. Primary and secondary outcome measures TGF-β, TGF-β receptor types I (TBRI) and II (TBRII) mRNA and protein expression were assessed by quantitative PCR and flow cytometry, respectively, in MSC from both SSc patients and healthy donors. MSC were exposed to TGF-β and assessed for collagen 1α2 synthesis and Smad expression. As positive controls, primary cultures of dermal fibroblasts were also analysed. Results Compared with nine controls, MSC from nine SSc patients showed significant increase in mRNA levels (p<0.002) and in membrane expression (p<0.0001) of TBRII. In response to TGF-β activation, a significant increase in collagen 1α synthesis (p<0.05) and Smad-3 phosphorylation was upregulated in SSc MSC. Similar results were obtained on eight SSc-derived dermal fibroblasts compared to six healthy controls. Conclusions TBRII gene and protein expression defect in MSC derived from SSc patients may have pathological significance. These findings should be taken into account when considering

  20. Low dose radiation interactions with the transformation growth factor (TFG)-beta pathway

    NASA Astrophysics Data System (ADS)

    Maslowski, Amy Jesse

    A major limiting factor for long-term, deep-space missions is the radiation dose to astronauts. Because the dose to the astronauts is a mixed field of low- and high-LET radiation, there is a need to understand the effects of both radiation types on whole tissue; however, there are limited published data on the effects of high-LET (linear-energy-transfer) radiation on tissue. Thus, we designed a perfusion chamber system for rat trachea in order to mimic in vivo respiratory tissue. We successfully maintained the perfused tracheal tissue ex vivo in a healthy and viable condition for up to three days. In addition, this project studied the effects of high-LET Fe particles on the overall transformation growth factor (TGF)-beta response after TGF-beta inactivation and compared the results to the TGF-beta response post x-ray irradiation. It was found that a TGF-beta response could be measured in the perfused tracheal tissue, for x-ray and Fe particle irradiations, despite the high autofluorescent background intrinsic to tissue. However, after comparing the TGF-beta response of x-ray irradiation to High-Z-High-energy (HZE) irradiation, there was not a significant difference in radiation types. The TGF-beta response in x-ray and HZE irradiated perfusion chambers was also measured over time post irradiation. It was found that for 6 hour and 8 hour post irradiation, the TGF-beta response was higher for lower doses of radiation than for higher doses. This is in contrast to the 0 hour fixation which found the TGF-beta response to increase with increased dose. The inverse relationship found for 6 hour and 8 hour fixation times may indicate a threshold response for TGF-beta response; i.e., for low doses, a threshold of dose must be reached for an immediate TGF-beta response, otherwise the tissue responds more slowly to the irradiation damage. This result was unexpected and will require further investigation to determine if the threshold can be determined for the 250 kVp x-rays and

  1. The types II and III transforming growth factor-beta receptors form homo-oligomers

    PubMed Central

    1994-01-01

    Affinity-labeling experiments have detected hetero-oligomers of the types I, II, and III transforming growth factor beta (TGF-beta) receptors which mediate intracellular signaling by TGF-beta, but the oligomeric state of the individual receptor types remains unknown. Here we use two types of experiments to show that a major portion of the receptor types II and III forms homo-oligomers both in the absence and presence of TGF-beta. Both experiments used COS-7 cells co-transfected with combinations of these receptors carrying different epitope tags at their extracellular termini. In immunoprecipitation experiments, radiolabeled TGF-beta was bound and cross-linked to cells co-expressing two differently tagged type II receptors. Sequential immunoprecipitations using anti-epitope monoclonal antibodies showed that type II TGF-beta receptors form homo-oligomers. In cells co- expressing epitope-tagged types II and III receptors, a low level of co- precipitation of the ligand-labeled receptors was observed, indicating that some hetero-oligomers of the types II and III receptors exist in the presence of ligand. Antibody-mediated cross-linking studies based on double-labeling immunofluorescence explored co-patching of the receptors at the cell surface on live cells. In cells co-expressing two differently tagged type II receptors or two differently tagged type III receptors, forcing one receptor into micropatches by IgG induced co- patching of the receptor carrying the other tag, labeled by noncross- linking monovalent Fab'. These studies showed that homo-oligomers of the types II and III receptors exist on the cell surface in the absence or presence of TGF-beta 1 or -beta 2. In cells co-expressing types II and III receptors, the amount of heterocomplexes at the cell surface was too low to be detected in the immunofluorescence co-patching experiments, confirming that hetero-oligomers of the types II and III receptors are minor and probably transient species. PMID:8027173

  2. Binding of transforming growth factor-beta (TGF-beta) to pregnancy zone protein (PZP). Comparison to the TGF-beta-alpha 2-macroglobulin interaction.

    PubMed

    Philip, A; Bostedt, L; Stigbrand, T; O'Connor-McCourt, M D

    1994-04-15

    Pregnancy zone protein (PZP) is quantitatively the most important pregnancy-associated plasma protein and it has strong similarity to alpha 2-macroglobulin. Since alpha 2-macroglobulin is a binding protein for transforming growth factors-beta (TGF-beta), it was of interest to test whether the related protein, PZP, also binds to these growth-regulatory proteins. Using affinity-labelling methods, we demonstrate that PZP binds both TGF-beta 1 and TGF-beta 2 and that the binding characteristics are similar to those of the TGF-beta-alpha 2-macroglobulin interaction. TGF-beta 2 and TGF-beta 1 bind to PZP in a predominantly noncovalent manner in vitro. TGF-beta 1 and TGF-beta 2 bind to both the dimeric and tetrameric forms of PZP. Our studies also indicate that PZP binds TGF-beta 2 with higher affinity than TGF-beta 1. Finally, we demonstrate that PZP inhibits the binding of TGF-beta 1 and TGF-beta 2 to their cell surface receptors. The increased level of PZP during pregnancy may affect the action of TGF-beta by regulating the distribution, clearance and/or general availability of TGF-beta. The preferential binding of TGF-beta 2 over TGF-beta 1 by PZP implies that PZP may differentially regulate the action of TGF-beta 1 and TGF-beta 2.

  3. Differential response of nontumorigenic and tumorigenic human papillomavirus type 16-positive epithelial cells to transforming growth factor beta 1.

    PubMed

    Braun, L; Dürst, M; Mikumo, R; Gruppuso, P

    1990-11-15

    The transforming growth factor (TGF) beta s are multifunctional polypeptide growth factors with diverse biological effects, including inhibition of epithelial cell proliferation both in vitro and in vivo. To investigate the possible role of TGF beta 1 in the regulation of papillomavirus infection and papillomavirus-associated transformation, we compared the response to TGF beta 1 of normal keratinocytes, human papillomavirus, type 16 (HPV 16)-positive-immortalized keratinocytes (nontumorigenic), and HPV 16-positive cervical carcinoma cells (tumorigenic) with respect to DNA synthesis and protooncogene expression. All HPV 16-immortalized cell lines were nearly as inhibited by TGF beta 1 as normal keratinocytes, whereas two cervical carcinoma cell lines (Caski and Siha) were refractory to growth inhibition by TGF beta 1. Cell surface receptors for TGF beta 1 were present on both normal and carcinoma cell lines. In all cases, growth inhibition by TGF beta 1 was accompanied by suppression of Steady-state levels of c-myc mRNA. In contrast, TGF beta 1 induced the expression of c-jun mRNA transcripts in normal, immortalized, and tumorigenic cells. We also studied the effect of TGF beta 1 on HPV 16 mRNA expression. Steady-state levels of HPV 16 mRNA transcripts were suppressed by TGF beta 1 in the nontumorigenic HPK cells but were unaffected in the tumorigenic lines. These findings suggest that TGF beta 1 may be an in vivo modulator of HPV infection and that loss of responsiveness to this growth inhibitory signal may be involved in HPV-associated malignant transformation. PMID:2171761

  4. Increased expression of heme oxygenase-1 in human retinal pigment epithelial cells by transforming growth factor-beta.

    PubMed

    Kutty, R K; Nagineni, C N; Kutty, G; Hooks, J J; Chader, G J; Wiggert, B

    1994-05-01

    Antibodies specific for heme oxygenase-1 (HO-1) were produced in rabbits, using the multiple antigen peptide (MAP) technique, and were employed to investigate the ability of transforming growth factor-beta 1 (TGF-beta 1) to induce the HO-1 protein in cultured human retinal pigment epithelial (RPE) cells. Western blot analyses showed that the cytokine induced HO-1 in these cells in a time- and dose-dependent manner. TGF-beta 1 also increased the mRNA for HO-1 in treated cells prior to the increase in HO-1 protein. The induction was effectively blocked by a neutralizing antibody preparation against TGF-beta 1. When tested under similar conditions, other growth factors such as basic fibroblast growth factor-I, platelet-derived growth factor, insulin-like growth factor, transforming growth factor-alpha, and epidermal growth factor did not show appreciable induction of HO-1. Lipopolysaccharide, tumor necrosis factor-alpha, and interferon-gamma were also not inducers, although TGF-beta 2 effectively induced HO-1. Heavy metal ions and thiol reagents were also highly potent inducers of HO-1 in human RPE cells. The induction of HO-1 by TGF-beta 1 was also observed in bovine choroid fibroblasts, but not in HELA, HEL or bovine corneal fibroblasts. Our results demonstrate for the first time that HO-1 can be induced by an important cytokine, TGF-beta 1, causing an increase in the expression of both HO-1 message and protein in specific neuroepithelial and fibroblast cells.

  5. Distinct roles for mammalian target of rapamycin complexes in the fibroblast response to transforming growth factor-beta.

    PubMed

    Rahimi, Rod A; Andrianifahanana, Mahefatiana; Wilkes, Mark C; Edens, Maryanne; Kottom, Theodore J; Blenis, John; Leof, Edward B

    2009-01-01

    Transforming growth factor-beta (TGF-beta) promotes a multitude of diverse biological processes, including growth arrest of epithelial cells and proliferation of fibroblasts. Although the TGF-beta signaling pathways that promote inhibition of epithelial cell growth are well characterized, less is known about the mechanisms mediating the positive response to this growth factor. Given that TGF-beta has been shown to promote fibrotic diseases and desmoplasia, identifying the fibroblast-specific TGF-beta signaling pathways is critical. Here, we investigate the role of mammalian target of rapamycin (mTOR), a known effector of phosphatidylinositol 3-kinase (PI3K) and promoter of cell growth, in the fibroblast response to TGF-beta. We show that TGF-beta activates mTOR complex 1 (mTORC1) in fibroblasts but not epithelial cells via a PI3K-Akt-TSC2-dependent pathway. Rapamycin, the pharmacologic inhibitor of mTOR, prevents TGF-beta-mediated anchorage-independent growth without affecting TGF-beta transcriptional responses or extracellular matrix protein induction. In addition to mTORC1, we also examined the role of mTORC2 in TGF-beta action. mTORC2 promotes TGF-beta-induced morphologic transformation and is required for TGF-beta-induced Akt S473 phosphorylation but not mTORC1 activation. Interestingly, both mTOR complexes are necessary for TGF-beta-mediated growth in soft agar. These results define distinct and overlapping roles for mTORC1 and mTORC2 in the fibroblast response to TGF-beta and suggest that inhibitors of mTOR signaling may be useful in treating fibrotic processes, such as desmoplasia. PMID:19117990

  6. A parametric study of the linear growth of magnetospheric EMIC waves in a hot plasma

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Cao, Xing; Gu, Xudong; Ni, Binbin; Zhou, Chen; Shi, Run; Zhao, Zhengyu

    2016-06-01

    Since electromagnetic ion cyclotron (EMIC) waves in the terrestrial magnetosphere play a crucial role in the dynamic losses of relativistic electrons and energetic protons and in the ion heating, it is important to pursue a comprehensive understanding of the EMIC wave dispersion relation under realistic circumstances, which can shed significant light on the generation, amplification, and propagation of magnetospheric EMIC waves. The full kinetic linear dispersion relation is implemented in the present study to evaluate the linear growth of EMIC waves in a multi-ion (H+, He+, and O+) magnetospheric plasma that also consists of hot ring current protons. Introduction of anisotropic hot protons strongly modifies the EMIC wave dispersion surface and can result in the simultaneous growth of H+-, He+-, and O+-band EMIC emissions. Our parametric analysis demonstrates that an increase in the hot proton concentration can produce the generation of H+- and He+-band EMIC waves with higher possibility. While the excitation of H+-band emissions requires relatively larger temperature anisotropy of hot protons, He+-band emissions are more likely to be triggered in the plasmasphere or plasmaspheric plume where the background plasma is denser. In addition, the generation of He+-band waves is more sensitive to the variation of proton temperature than H+-band waves. Increase of cold heavy ion (He+ and O+) density increases the H+ cutoff frequency and therefore widens the frequency coverage of the stop band above the He+ gyrofrequency, leading to a significant damping of H+-band EMIC waves. In contrast, O+-band EMIC waves characteristically exhibit the temporal growth much weaker than the other two bands, regardless of all considered variables, suggesting that O+-band emissions occur at a rate much lower than H+- and He+-band emissions, which is consistent with the observations.

  7. Disilane as a growth rate catalyst of plasma deposited microcrystalline silicon thin films

    NASA Astrophysics Data System (ADS)

    Dimitrakellis, P.; Kalampounias, A. G.; Spiliopoulos, N.; Amanatides, E.; Mataras, D.; Lahootun, V.; Coeuret, F.; Madec, A.

    2016-07-01

    The effect of small disilane addition on the gas phase properties of silane-hydrogen plasmas and the microcrystalline silicon thin films growth is presented. The investigation was conducted in the high pressure regime and for constant power dissipation in the discharge with the support of plasma diagnostics, thin film studies and calculations of discharge microscopic parameters and gas dissociation rates. The experimental data and the calculations show a strong effect of disilane on the electrical properties of the discharge in the pressure window from 2 to 3 Torr that is followed by significant raise of the electron number density and the drop of the sheaths electric field intensity. Deposition rate measurements show an important four to six times increase even for disilane mole fractions as low as 0.3 %. The deposition rate enhancement was followed by a drop of the material crystalline volume fraction but films with crystallinity above 40 % were deposited with different combinations of total gas pressure, disilane and silane molar ratios. The enhancement was partly explained by the increase of the electron impact dissociation rate of silane which rises by 40% even for 0.1% disilane mole fraction. The calculations of the gas usage, the dissociation and the deposition efficiencies show that the beneficial effect on the growth rate is not just the result of the increase of Si-containing molecules density but significant changes on the species participating to the deposition and the mechanism of the film growth are caused by the disilane addition. The enhanced participation of the highly sticking to the surface radical such as disilylene, which is the main product of disilane dissociation, was considered as the most probable reason for the significant raise of the deposition efficiency. The catalytic effect of such type of radical on the surface reactivity of species with lower sticking probability is further discussed, while it is also used to explain the restricted

  8. Inhibition of transforming growth factor α (TGF-α)-mediated growth effects in ovarian cancer cell lines by a tyrosine kinase inhibitor ZM 252868

    PubMed Central

    Simpson, B J B; Bartlett, J M S; Macleod, K G; Rabiasz, G; Miller, E P; Rae, A L; Gordge, P; Leake, R E; Miller, W R; Smyth, J; Langdon, S P

    1999-01-01

    The modulating effects of the epidermal growth factor (EGF) receptor-specific tyrosine kinase inhibitor ZM 252868 on cell growth and signalling have been evaluated in four ovarian carcinoma cell lines PE01, PE04, SKOV-3 and PE01CDDP. Transforming growth factor α (TGF-α)-stimulated growth was completely inhibited by concentrations ≥ 0.3 μM in the PE01 and PE04 cell lines and by ≥ 0.1 μM in SKOV-3 cells. TGF-α inhibition of PE01CDDP growth was reversed by concentrations ≥ 0.1 μM ZM 252868. TGF-α-stimulated tyrosine phosphorylation of both the EGF receptor and c-erbB2 receptor in all four cell lines. The inhibitor ZM 252868, at concentrations ≥ 0.3 μM, completely inhibited TGF-α-stimulated tyrosine phosphorylation of the EGF receptor and reduced phosphorylation of the c-erbB2 protein. EGF-activated EGF receptor tyrosine kinase activity was completely inhibited by 3 μM ZM 252868 in PE01, SKOV-3 and PE01CDDP cells. These data indicate that the EGF receptor-targeted TK inhibitor ZM 252868 can inhibit growth of ovarian carcinoma cells in vitro consistent with inhibition of tyrosine phosphorylation at the EGF receptor. © 1999 Cancer Research Campaign PMID:10098742

  9. Effect of intestinal ischemia-reperfusion on expressions of endogenous basic fibroblast growth factor and transforming growth factor betain lung and its relation with lung repair.

    PubMed

    Fu, Xiao-Bing; Yang, Yin-Hui; Sun, Tong-Zhu; Gu, Xiao-Man; Jiang, Li-Xian; Sun, Xiao-Qing; Sheng, Zhi-Yong

    2000-06-01

    AIM:To study the changes of endogenous transforming growth factor beta(TGFbeta) and basic fibroblast growth factor (bFGF) in lung following intestinal ischemia and reperfusion injury and their effects on lung injury and repair.METHODS:Sixty Wistar rats were divided into five groups, which underwent sham-operation, ischemia (45 minutes), and reperfusion (6, 24 and 48 hours, respectively) after ischemia (45 minutes). Immunohistochemical method was used to observe the localization and amounts of both growth factors.RESULTS:Positive signals of both growth factors could be found in normal lung, mainly in alveolar cells and endothelial cells of vein. After ischemia and reperfusion insult, expressions of both growth factors were increased and their amounts at 6 hours were larger than those of normal control or of 24 and 48 hours after insult.CONCLUSION:The endogenous bFGF and TGF beta expression appears to be upregulated in the lung following intestinal ischemia and reperfusion, suggesting that both growth factors may be involved in the process of lung injury and repair. PMID:11819596

  10. Comparison of the effect of calcium gluconate and batroxobin on the release of transforming growth factor beta 1 in canine platelet concentrates

    PubMed Central

    2012-01-01

    Background The clinical use of autologous platelet concentrates (also known as platelet-rich plasma) on the field of regenerative therapy, in the last decade has been the subject of several studies especially in equine medicine and surgery. The objectives of this study was: 1) to describe and compare the cellular population in whole blood, lower fraction (A) and upper fraction (B) of platelet concentrates, 2) to measure and compare the transforming growth factor beta 1 (TGF-β1) concentration in plasma and both platelet concentrates after be activated with calcium gluconate or batroxobin plus calcium gluconate and, 3) to determine correlations between cell counts in platelet concentrates and concentrations of TGF-β1. Blood samples were taken from 16 dogs for complete blood count, plasma collection and platelet concentrates preparation. The platelet concentrates (PC) were arbitrarily divided into two fractions, specifically, PC-A (lower fraction) and PC-B (upper fraction). The Platelet concentrates were analyzed by hemogram. After activated with calcium gluconate or batroxobin plus calcium gluconate, TGF-β1 concentration was determined in supernatants of platelet concentrates and plasma. Results There were differences statistically significant (P < 0.05) for the platelet count and leukocyte count and TGF-β1 concentration between whole blood, plasma and both platelet concentrates. A significant correlation was found between the number of platelets in both platelet concentrates and TGF-β1 concentration. Platelet collection efficiency was 46.34% and 28.16% for PC-A and PC-B, respectively. TGF-β1 concentration efficiency for PC activated with calcium gluconate was 47.75% and 31.77%, for PC-A and PC-B, respectively. PC activated with batroxobin plus CG showed 46.87% and 32.24% for PC-A and PC-B, respectively. Conclusions The methodology used in this study allows the concentration of a number of platelets and TGF-β1 that might be acceptable for a biological

  11. Cloning the promoter for transforming growth factor-beta type III receptor. Basal and conditional expression in fetal rat osteoblasts

    NASA Technical Reports Server (NTRS)

    Ji, C.; Chen, Y.; McCarthy, T. L.; Centrella, M.

    1999-01-01

    Transforming growth factor-beta binds to three high affinity cell surface molecules that directly or indirectly regulate its biological effects. The type III receptor (TRIII) is a proteoglycan that lacks significant intracellular signaling or enzymatic motifs but may facilitate transforming growth factor-beta binding to other receptors, stabilize multimeric receptor complexes, or segregate growth factor from activating receptors. Because various agents or events that regulate osteoblast function rapidly modulate TRIII expression, we cloned the 5' region of the rat TRIII gene to assess possible control elements. DNA fragments from this region directed high reporter gene expression in osteoblasts. Sequencing showed no consensus TATA or CCAAT boxes, whereas several nuclear factors binding sequences within the 3' region of the promoter co-mapped with multiple transcription initiation sites, DNase I footprints, gel mobility shift analysis, or loss of activity by deletion or mutation. An upstream enhancer was evident 5' proximal to nucleotide -979, and a silencer region occurred between nucleotides -2014 and -2194. Glucocorticoid sensitivity mapped between nucleotides -687 and -253, whereas bone morphogenetic protein 2 sensitivity co-mapped within the silencer region. Thus, the TRIII promoter contains cooperative basal elements and dispersed growth factor- and hormone-sensitive regulatory regions that can control TRIII expression by osteoblasts.

  12. Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 3; Plasma Analysis Hormone Measurements

    NASA Technical Reports Server (NTRS)

    Grindeland, R. E.; Popova, I. A.; Grossman, E.; Rudolph, I.

    1994-01-01

    Plasma from space flight and tail suspended rats was analyzed for a number of constituents in order to evaluate their metabolic status and endocrine function. The data presented here cover plasma hormone measurements. Corticosterone, thyroxine, and testosterone were measured by radioimmunoassay. Prolactin and growth hormone were measured by double antibody immunoassays using hormones and antisera prepared in house. Data were evaluated by analysis of variance.

  13. Plasma rich in growth factors: preliminary results of use in the preparation of future sites for implants.

    PubMed

    Anitua, E

    1999-01-01

    This article presents preliminary clinical evidence of the beneficial effect of the use of plasma rich in growth factors of autologous origin. The plasma is obtained from the individual patient by plasmapheresis. The macroscopic and microscopic results obtained with bone regeneration using this technique, which uses no membrane or barrier, can be observed. The incorporation of these concepts can introduce several advantages, including the enhancement and acceleration of bone regeneration and more rapid and predictable soft tissue healing.

  14. Prodomains of transforming growth factor beta (TGFbeta) superfamily members specify different functions: extracellular matrix interactions and growth factor bioavailability.

    PubMed

    Sengle, Gerhard; Ono, Robert N; Sasaki, Takako; Sakai, Lynn Y

    2011-02-18

    The specific functions of the prodomains of TGFβ superfamily members are largely unknown. Interactions are known between prodomains of TGFβ-1-3 and latent TGFβ-binding proteins and between prodomains of BMP-2, -4, -7, and -10 and GDF-5 and fibrillins, raising the possibility that latent TGFβ-binding proteins and fibrillins may mediate interactions with all other prodomains of this superfamily. This possibility is tested in this study. Results show that the prodomain of BMP-5 interacts with the N-terminal regions of fibrillin-1 and -2 in a site similar to the binding sites for other bone morphogenetic proteins. However, in contrast, the prodomain of GDF-8 (myostatin) interacts with the glycosaminoglycan side chains of perlecan. The binding site for the GDF-8 prodomain is likely the heparan sulfate chain present on perlecan domain V. These results support and extend the emerging concept that TGFβ superfamily prodomains target their growth factor dimers to extracellular matrix macromolecules. In addition, biochemical studies of prodomain·growth factor complexes were performed to identify inactive complexes. For some members of the superfamily, the prodomain is noncovalently associated with its growth factor dimer in an inactive complex; for others, the prodomain·growth factor complex is active, even though the prodomain is noncovalently associated with its growth factor dimer. Results show that the BMP-10 prodomain, in contrast to BMP-4, -5, and -7 prodomains, can inhibit the bioactivity of the BMP-10 growth factor and suggest that the BMP-10 complex is like TGFβ and GDF-8 complexes, which can be activated by cleavage of the associated prodomain.

  15. Structural Variability of Tropospheric Growth Factors Transforming Mid-latitude Cyclones to Severe Storms over the North Atlantic

    NASA Astrophysics Data System (ADS)

    Wild, Simon; Befort, Daniel J.; Leckebusch, Gregor C.

    2015-04-01

    The development of European surface wind storms out of normal mid-latitude cyclones is substantially influenced by upstream tropospheric growth factors over the Northern Atlantic. The main factors include divergence and vorticity advection in the upper troposphere, latent heat release and the presence of instabilities of short baroclinic waves of suitable wave lengths. In this study we examine a subset of these potential growth factors and their related influences on the transformation of extra-tropical cyclones into severe damage prone surface storm systems. Previous studies have shown links between specific growth factors and surface wind storms related to extreme cyclones. In our study we investigate in further detail spatial and temporal variability patterns of these upstream processes at different vertical levels of the troposphere. The analyses will comprise of the three growth factors baroclinicity, latent heat release and upper tropospheric divergence. Our definition of surface wind storms is based on the Storm Severity Index (SSI) alongside a wind tracking algorithm identifying areas of exceedances of the local 98th percentile of the 10m wind speed. We also make use of a well-established extra-tropical cyclone identification and tracking algorithm. These cyclone tracks form the base for a composite analysis of the aforementioned growth factors using ERA-Interim Reanalysis from 1979 - 2014 for the extended winter season (ONDJFM). Our composite analysis corroborates previous similar studies but extends them by using an impact based algorithm for the identification of strong wind systems. Based on this composite analysis we further identify variability patterns for each growth factor most important for the transformation of a cyclone into a surface wind storm. We thus also address the question whether the link between storm intensity and related growth factor anomaly taking into account its spatial variability is stable and can be quantified. While the

  16. Study of radial growth rate and size control of silicon nanocrystals in square-wave-modulated silane plasmas

    SciTech Connect

    Nguyen-Tran, Th.; Roca i Cabarrocas, P.; Patriarche, G.

    2007-09-10

    The growth of silicon nanocrystals in high pressure and high dilution silane plasmas is investigated by using the temporal evolution of the self-bias on the radio frequency electrode and transmission electron microscopy. A square-wave-modulated plasma was used in order to control the growth of monodispersed nanoparticles with sizes smaller than 12 nm. To this end, the plasma on time was kept below 1 s. The radial growth rate of nanoparticles was varied in the range from 7.5 to 75 nm/s by changing silane partial pressure. Nanoparticles grown in silane-helium discharges have been found amorphous while they are crystalline in silane-hydrogen-argon discharges. Surprisingly, the crystallization in the gaseous phase does not depend on how slow or fast the particles grow but on the presence of atomic hydrogen.

  17. Effect of plasma parameters on growth and field emission of electrons from cylindrical metallic carbon nanotube surfaces

    SciTech Connect

    Sharma, Suresh C.; Tewari, Aarti

    2011-08-15

    The effect of plasma parameters (e.g., electron density and temperature, ion density and temperature, neutral atom density, and temperature) on the growth (without a catalyst), structure, and field emission of electrons from a cylindrical metallic carbon nanotube (CNT) surfaces has been theoretically investigated. A theoretical model of charge neutrality, including the kinetics of electrons, positively charged ions, and neutral atoms, and the energy balance of the various species in plasma, has been developed. Numerical calculations of the radius of the cylindrical CNT for different CNT number densities and plasma parameters have been carried out for the typical glow discharge plasma parameters. It is found that, on increasing the CNT number density and plasma parameters, the radius of cylindrical CNT decreases and consequently, the field emission factor for the metallic cylindrical CNT surfaces increase.

  18. Biocompatible, smooth, plasma-treated nickel-titanium surface--an adequate platform for cell growth.

    PubMed

    Chrzanowski, W; Szade, J; Hart, A D; Knowles, J C; Dalby, M J

    2012-02-01

    High nickel content is believed to reduce the number of biomedical applications of nickel-titanium alloy due to the reported toxicity of nickel. The reduction in nickel release and minimized exposure of the cell to nickel can optimize the biocompatibility of the alloy and increase its use in the application where its shape memory effects and pseudoelasticity are particularly useful, e.g., spinal implants. Many treatments have been tried to improve the biocompatibility of Ni-Ti, and results suggest that a native, smooth surface could provide sufficient tolerance, biologically. We hypothesized that the native surface of nickel-titanium supports cell differentiation and insures good biocompatibility. Three types of surface modifications were investigated: thermal oxidation, alkali treatment, and plasma sputtering, and compared with smooth, ground surface. Thermal oxidation caused a drop in surface nickel content, while negligible chemistry changes were observed for plasma-modified samples when compared with control ground samples. In contrast, alkali treatment caused significant increase in surface nickel concentration and accelerated nickel release. Nickel release was also accelerated in thermally oxidized samples at 600 °C, while in other samples it remained at low level. Both thermal oxidation and alkali treatment increased the roughness of the surface, but mean roughness R(a) was significantly greater for the alkali-treated ones. Ground and plasma-modified samples had 'smooth' surfaces with R(a)=4 nm. Deformability tests showed that the adhesion of the surface layers on samples oxidized at 600 °C and alkali treatment samples was not sufficient; the layer delaminated upon deformation. It was observed that the cell cytoskeletons on the samples with a high nickel content or release were less developed, suggesting some negative effects of nickel on cell growth. These effects were observed primarily during initial cell contact with the surface. The most favorable

  19. Transforming growth factor alpha may be a physiological regulator of liver regeneration by means of an autocrine mechanism.

    PubMed Central

    Mead, J E; Fausto, N

    1989-01-01

    We investigated whether transforming growth factor alpha (TGF-alpha) is involved in hepatocyte growth responses both in vivo and in culture. During liver regeneration after partial hepatectomy in rats, TGF-alpha mRNA increased; it reached a maximum (approximately 9-fold higher than normal) at the peak of DNA synthesis. The message and the peptide were localized in hepatocytes and found in higher amounts in hepatocytes obtained from regenerating liver. TGF-alpha caused a 13-fold elevation of DNA synthesis in hepatocytes in primary culture and was slightly more effective than epidermal growth factor. TGF-beta blocked TGF-alpha stimulation when added either simultaneously with TGF-alpha or a day later. TGF-alpha message increased in hepatocytes stimulated to undergo DNA synthesis by TGF-alpha or epidermal growth factor, and the peptide was detected in the culture medium by RIA. In the regenerating liver, the increase in TGF-alpha mRNA during the first day after partial hepatectomy coincided with an increase in epidermal growth factor/TGF-alpha receptor mRNA and a decrease (already reported) in the number of these receptors. We conclude that TGF-alpha may function as a physiological inducer of hepatocyte DNA synthesis during liver regeneration by means of an autocrine mechanism and that its stimulatory effects in this growth process are balanced by the inhibitory action of TGF-beta 1. Images PMID:2922399

  20. Transforming growth factor type beta specifically stimulates synthesis of proteoglycan in human adult arterial smooth muscle cells.

    PubMed Central

    Chen, J K; Hoshi, H; McKeehan, W L

    1987-01-01

    Myo-intimal proteoglycan metabolism is thought to be important in blood vessel homeostasis, blood clotting, atherogenesis, and atherosclerosis. Human platelet-derived transforming growth factor type beta (TGF-beta) specifically stimulated synthesis of at least two types of chondroitin sulfate proteoglycans in nonproliferating human adult arterial smooth muscle cells in culture. Stimulation of smooth muscle cell proteoglycan synthesis by smooth muscle cell growth promoters (epidermal growth factor, platelet-derived growth factor, and heparin-binding growth factors) was less than 20% of that elicited by TGF-beta. TGF-beta neither significantly stimulated proliferation of quiescent smooth muscle cells nor inhibited proliferating cells. The extent of TGF-beta stimulation of smooth muscle cell proteoglycan synthesis was similar in both nonproliferating and growth-stimulated cells. TGF-beta, which is a reversible inhibitor of endothelial cell proliferation, had no comparable effect on endothelial cell proteoglycan synthesis. These results are consistent with the hypothesis that TGF-beta is a cell-type-specific regulator of proteoglycan synthesis in human blood vessels and may contribute to the myo-intimal accumulation of proteoglycan in atherosclerotic lesions. Images PMID:3474655

  1. Stimulating Effects of Seed Treatment by Magnetized Plasma on Tomato Growth and Yield

    NASA Astrophysics Data System (ADS)

    Yin, Meiqiang; Huang, Mingjing; Ma, Buzhou; Ma, Tengcai

    2005-12-01

    Tomato seeds (Lycopersicon esculentum L. Mill. cv. zhongshu No. 6) were treated by magnetized plasma before being sown to investigate its effect on the growth and yield of tomatoes. Biochemical analysis showed that dehydrogenase activity increased with the increase of the current but decreased when the current was higher than 1.5 A. The activities of peroxidase (POD) isoenzyme changed in the same pattern. There was no difference in germination percentage between treatments and control, which were carried out in laboratory conditions. However, significant (α = 0.01) difference was observed in germination percentage in the pot experiment. In the pot experiment, the sprouting rate for the treatment with a 1.5 A current was 32.75%, whereas the untreated was only 4.75% on the eleventh day. Germination time is more than one day earlier than the control. The 1.5 A treatment increased the tomato yield by 20.7%.

  2. Synthesis and growth mechanism of Fe-catalyzed carbon nanotubes by plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Jiang, Jun; Feng, Tao; Cheng, Xinhong; Dai, Lijuan; Cao, Gongbai; Jiang, Bingyao; Wang, Xi; Liu, Xianghuai; Zou, Shichang

    2006-03-01

    Plasma-enhanced chemical vapor deposition (PECVD) was used to grow Fe-catalyzed carbon nanotubes (CNTs). The nanotubes had a uniform diameter in the range of about 10-20 nm. A base growth mode was responsible for the CNTs growth using a mixture of H 2 (60 sccm) and C 2H 2 (15 sccm). For a mixture of H 2 (100 sccm) and C 2H 2 (25 sccm), a complicated growth mechanism took place involving both the base growth and the tip growth. X-ray photoelectron spectroscopy measurements revealed that the grown CNTs contained C-H covalent bonds and Fe-C bonds located at the interface between them and the substrates. The factors determining the growth mechanism of CNTs are discussed and their growth mechanisms with the different gas ratios are suggested.

  3. Plasma prolactin, growth hormone and progesterone concentrations in pseudopregnant, hysterectomized and pregnant goats.

    PubMed

    Kornalijnslijper, J E; Kemp, B; Bevers, M M; van Oord, H A; Taverne, M A

    1997-12-01

    Jugular plasma prolactin (PRL), growth hormone (GH) and progesterone (P4) levels were estimated in goats under three different conditions with prolonged luteal function (P4 > or = 1 ng/ml): pseudopregnant animals (n = 4), goats hysterectomized during early pregnancy (n = 4) and does with normal pregnancy (n = 4). Mean duration (+/- S.E.M.) of luteal phases were 189 +/- 20, 171 +/- 10, and 147 +/- 2 days in the three groups, respectively. Until day 120, mean PRL levels were below 150 ng/ml in each group. After day 120 of the luteal phase, PRL concentrations were significantly higher than before, but continued to increase up to 800 ng/ml only in pregnant animals around parturition. Mean GH levels varied between 2 and 3 ng/ml in animals of each group during the luteal phase. Only after parturition, a significant elevation occurred. P4 levels in pseudopregnant animals were significantly lower than in the other two groups between days 10 and 55, and showed a gradual but continuous decline towards the end of the luteal phase. After hysterectomy of early pregnant animals, P4 concentrations decreased to levels measured in pseudopregnant animals but were significantly higher again as compared to pseudopregnant animals between days 121 and 150. It is concluded that a pseudopregnant condition, characterized by intrauterine fluid accumulation, is not related to increased plasma PRL and GH concentrations. The low and gradually decreasing plasma progesterone levels in the pseudopregnant animals probably reflect the absence of a luteotrophic stimulus by the conceptus. The progesterone profile in the animals that were hysterectomized during early pregnancy suggests that the corpora lutea of these does have been permanently changed by the presence of the conceptus during the first weeks of the luteal phase. PMID:9505110

  4. Relationship between transforming growth factor β1 and anti-fibrotic effect of interleukin-10

    PubMed Central

    Shi, Mei-Na; Huang, Yue-Hong; Zheng, Wei-Da; Zhang, Li-Juan; Chen, Zhi-Xin; Wang, Xiao-Zhong

    2006-01-01

    AIM: To study the effect of interleukin-10 (IL-10) on the expression of transforming growth factor β1 (TGF-β1) in hepatic fibrosis rats and the anti-fibrotic role of exo-genous IL-10. METHODS: Hepatic fibrosis was induced by carbon tetrachloride administered (CCl4) intraperitoneally. The experiment was performed in two stages. In the first stage, 60 SD rats were divided randomly into normal control group 1(GN1, n = 8), hepatic fibrosis group(GC, n = 28)and IL-10 intervened group(GI, n = 24). At the beginning of the 7th and 11th wk, hepatic stellate cells (HSCs) were isolated, reverse transcription-polymerase chain reation (RT-PCR) and immunocytochemistry were performed to detect the expression of TGF-β1 in HSCs. Histological examination was used to determine the degree of hepatic fibrosis. In the second stage, 47 SD rats were divided randomly into normal control group 2(GN2, n = 6)and CCl4 group(GZ, n = 41). At the end of the 9th week, rats in GZ group were allocated randomly into model group(GM, n = 9), IL-10 treatment group(GT, n = 9)and recovered group(GR, n = 9). At the end of the 12th week, all rats were sacrificed. RT-PCR and immunohistochemistry were performed to detect the expression of TGF-β1 in liver tissue. ELISA was used to assay serum TGF-β1 levels. RESULTS: Hepatic fibrosis developed in rats with the increase of the injection frequency of CCl4. In the first stage, hepatic fibrosis developed and HSCs were isolated successfully. At the 7th and 11th week, TGF-β1 mRNA in GC group increased significantly compared with that in GN1(P = 0.001/0.042)and GI groups(P = 0.001/0.007), whereas there was no significant difference between the two groups. The levels of TGF-β1 at the beginning of the 7th wk was higher than that of the 11th wk(P = 0.049). Immunocytochemistry results of TGF-β1 were consistent with the above findings. In the second stage, TGF-β1 increased significantly in GM group compared to GN2. After treatment with IL-10, TGF-β1 declined

  5. Transforming growth factor-β1 up-regulates connexin43 expression in human granulosa cells

    PubMed Central

    Chen, Yu-Ching; Chang, Hsun-Ming; Cheng, Jung-Chien; Tsai, Horng-Der; Wu, Cheng-Hsuan; Leung, Peter C.K.

    2015-01-01

    STUDY QUESTION Does transforming growth factor-β1 (TGF-β1) up-regulate connexin43 (Cx43) to promote cell–cell communication in human granulosa cells? SUMMARY ANSWER TGF-β1 up-regulates Cx43 and increases gap junction intercellular communication activities (GJIC) in human granulosa cells, and this effect occurs via the activin receptor-like kinase (ALK)5-mediated Sma- and Mad-related protein (SMAD)2/3-SMAD4-dependent pathway. WHAT IS KNOWN ALREADY TGF-β1 and its receptors are expressed in human granulosa cells, and follicular fluid contains TGF-β1 protein. In human granulosa cells, Cx43 gap junctions play an important role in the development of follicles and oocytes. STUDY DESIGN, SIZE, DURATION This is an experimental study which was performed over a 1-year period. PARTICIPANTS/MATERIALS, SETTING, METHODS Immortalized human granulosa cells (SVOG cells) and primary human granulosa-lutein cells obtained from women undergoing IVF in an academic research center were used as the study models. Cx43 mRNA and protein expression levels were examined after exposure of SVOG cells to recombinant human TGF-β1. An activin/TGF-β type I receptor inhibitor, SB431542, and small interfering RNAs targeting ALK4, ALK5, SMAD2, SMAD3 and SMAD4 were used to verify the specificity of the effects and to investigate the molecular mechanisms. Real-time-quantitative PCR and western blot analysis were used to detect the specific mRNA and protein levels, respectively. GJIC between SVOG cells were evaluated using a scrape loading and dye transfer assay. Results were analyzed by one-way analysis of variance. MAIN RESULTS AND THE ROLE OF CHANCE TGF-β1 treatment increased phosphorylation of SMAD2/3 (P < 0.0001) and up-regulated Cx43 mRNA and protein levels (P < 0.001) in SVOG cells and these stimulatory effects were abolished by the TGF-β type I receptor inhibitor SB431542. In addition, the up-regulatory effect of TGF-β1 on Cx43 expression (mRNA and protein) was confirmed in primary

  6. Fast growth of ultrananocrystalline diamond films by bias-enhanced nucleation and growth process in CH{sub 4}/Ar plasma

    SciTech Connect

    Saravanan, A.; Huang, B. R.; Sankaran, K. J.; Tai, N. H.; Dong, C. L.; Lin, I. N.

    2014-05-05

    This letter describes the fast growth of ultrananocrystalline diamond (UNCD) films by bias-enhanced nucleation and growth process in CH{sub 4}/Ar plasma. The UNCD grains were formed at the beginning of the film's growth without the necessity of forming the amorphous carbon interlayer, reaching a thickness of ∼380 nm in 10 min. Transmission electron microscopic investigations revealed that the application of bias voltage induced the formation of graphitic phase both in the interior and at the interface regions of UNCD films that formed interconnected paths, facilitating the transport of electrons and resulting in enhanced electron field emission properties.

  7. Characterization of Differential Protein Tethering at the Plasma Membrane in Response to Epidermal Growth Factor Signaling

    PubMed Central

    Looyenga, Brendan D.; MacKeigan, Jeffrey P.

    2013-01-01

    Physical tethering of membrane proteins to the cortical actin cytoskeleton provides functional organization to the plasma membrane and contributes to diverse cellular processes including cell signaling, vesicular trafficking, endocytosis, and migration. For these processes to occur, membrane protein tethering must be dynamically regulated in response to environmental cues. In this study, we describe a novel biochemical scheme for isolating the complement of plasma membrane proteins that are physically tethered to the actin cytoskeleton. We utilized this method in combination with tandem liquid chromatography/mass spectrometry (LC–MS/MS) to demonstrate that cytoskeletal tethering of membrane proteins is acutely regulated by epidermal growth factor (EGF) in normal human kidney (HK2) cells. Our results indicate that several proteins known to be involved in EGF signaling, as well as other proteins not traditionally associated with this pathway, are tethered to the cytoskeleton in dynamic fashion. Further analysis of one hit from our proteomic survey, the receptor phosphotyrosine phosphatase PTPRS, revealed a correlation between cytoskeletal tethering and endosomal trafficking in response to EGF. This finding parallels previous indications that PTPRS is involved in the desensitization of EGFR and provides a potential mechanism to coordinate localization of these two membrane proteins in the same compartment upon EGFR activation. PMID:22559174

  8. A recessive cellular mutation in v-fes-transformed mink cells restores contact inhibition and anchorage-dependent growth.

    PubMed Central

    Haynes, J R; Downing, J R

    1988-01-01

    A contact-inhibited revertant of mink cells transformed by the Gardner-Arnstein strain of feline sarcoma virus was isolated by fluorescence-activated sorting of cells stained with the mitochondria-specific dye rhodamine 123. The revertant cell line exhibited a decrease in its proliferative rate and saturation density and a complete loss of its capacity for anchorage-independent growth, but it remained tumorigenic when inoculated into nude mice. The revertant cells retained a rescuable Gardner-Arnstein feline sarcoma provirus, expressed high levels of the v-fes oncogene product and its associated tyrosine kinase activity, manifested elevated levels of phosphotyrosine-containing cellular proteins similar to those observed in v-fes-transformed cells, and were refractory to retransformation by retroviruses containing the v-fes, v-fms, and v-ras oncogenes. Fusion of the revertant and parental cells generated somatic cell hybrids which formed colonies in semisolid medium, indicating that the block in transformation was recessive. These data together with the observation that the revertant phenotype is unstable in continuous culture suggest that the loss of transformation is due to the presence of limiting quantities of a gene product which functions downstream of the v-fes-coded kinase in the mitogenic pathway. Images PMID:3261387

  9. Althaea rosea Cavanil and Plantago major L. suppress neoplastic cell transformation through the inhibition of epidermal growth factor receptor kinase.

    PubMed

    Choi, Eun-Sun; Cho, Sung-Dae; Shin, Ji-Ae; Kwon, Ki Han; Cho, Nam-Pyo; Shim, Jung-Hyun

    2012-10-01

    For thousands of years in Asia, Althaea rosea Cavanil (ARC) and Plantago major L. (PML) have been used as powerful non-toxic therapeutic agents that inhibit inflammation. However, the anticancer mechanisms and molecular targets of ARC and PML are poorly understood, particularly in epidermal growth factor (EGF)-induced neoplastic cell transformation. The aim of this study was to evaluate the chemopreventive effects and mechanisms of the methanol extracts from ARC (MARC) and PML (MPML) in EGF-induced neoplastic cell transformation of JB6 P+ mouse epidermal cells using an MTS assay, anchorage-independent cell transformation assay and western blotting. Our results showed that MARC and MPML significantly suppressed neoplastic cell transformation by inhibiting the kinase activity of the EGF receptor (EGFR). The activation of EGFR by EGF was suppressed by MARC and MPML treatment in EGFR(+/+) cells, but not in EGFR(-/-) cells. In addition, MARC and MPML inhibited EGF-induced cell proliferation in EGFR-expressing murine embryonic fibroblasts (EGFR(+/+)). These results strongly indicate that EGFR targeting by MARC and MPML may be a good strategy for chemopreventive or chemotherapeutic applications. PMID:22767187

  10. Althaea rosea Cavanil and Plantago major L. suppress neoplastic cell transformation through the inhibition of epidermal growth factor receptor kinase.

    PubMed

    Choi, Eun-Sun; Cho, Sung-Dae; Shin, Ji-Ae; Kwon, Ki Han; Cho, Nam-Pyo; Shim, Jung-Hyun

    2012-10-01

    For thousands of years in Asia, Althaea rosea Cavanil (ARC) and Plantago major L. (PML) have been used as powerful non-toxic therapeutic agents that inhibit inflammation. However, the anticancer mechanisms and molecular targets of ARC and PML are poorly understood, particularly in epidermal growth factor (EGF)-induced neoplastic cell transformation. The aim of this study was to evaluate the chemopreventive effects and mechanisms of the methanol extracts from ARC (MARC) and PML (MPML) in EGF-induced neoplastic cell transformation of JB6 P+ mouse epidermal cells using an MTS assay, anchorage-independent cell transformation assay and western blotting. Our results showed that MARC and MPML significantly suppressed neoplastic cell transformation by inhibiting the kinase activity of the EGF receptor (EGFR). The activation of EGFR by EGF was suppressed by MARC and MPML treatment in EGFR(+/+) cells, but not in EGFR(-/-) cells. In addition, MARC and MPML inhibited EGF-induced cell proliferation in EGFR-expressing murine embryonic fibroblasts (EGFR(+/+)). These results strongly indicate that EGFR targeting by MARC and MPML may be a good strategy for chemopreventive or chemotherapeutic applications.

  11. Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements

    SciTech Connect

    Niemi, K.; O'Connell, D.; Gans, T.; Oliveira, N. de; Joyeux, D.; Nahon, L.; Booth, J. P.

    2013-07-15

    Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

  12. Transformation phenotype of polyoma virus-transformed rat fibroblasts: plasminogen activator production is modulated by the growth state of the cells and regulated by the expression of an early viral gene function.

    PubMed Central

    Perbal, B

    1980-01-01

    The expression of two transformation parameters, namely, ability to grow in agar and plasminogen activator production, was studied in several rat fibroblasts transformed by either wild-type or thermo-sensitive (tsa and ts25) polyoma viruses. The production of plasminogen activator was found to be dependent upon the growth state of the infected cells during a period of several days after infection. The analysis of the transformed phenotype of 25 tsa transformants and of 19 ts25 transformants independently isolated under various growth conditions led to the conclusion that there is no correlation between the regulation processes involved in plasminogen activator production and ability to grow without anchorage. The results obtained also suggested that the production of plasminogen activator is under the control of a functional large T antigen. PMID:6255182

  13. Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation.

    PubMed

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-01-01

    Smooth muscle cells (SMCs) in normal blood vessels exist in a highly differentiate state characterized by expression of SMC-specific contractile proteins ("contractile phenotype"). Following blood vessel injury in vivo or when cultured in vitro in the presence of multiple growth factors, SMC undergo a phenotype switch characterized by the loss of contractile markers and appearance of expression of non-muscle proteins ("proliferative phenotype"). While a number of factors have been reported to modulate this process, its regulation remains uncertain. Here we show that induction of SMC FGF signaling inhibits TGFβ signaling and converts contractile SMCs to the proliferative phenotype. Conversely, inhibition of SMC FGF signaling induces TGFβ signaling converting proliferating SMCs to the contractile phenotype, even in the presence of various growth factors in vitro or vascular injury in vivo. The importance of this signaling cross-talk is supported by in vivo data that show that an SMC deletion of a pan-FGF receptor adaptor Frs2α (fibroblast growth factor receptor substrate 2 alpha) in mice profoundly reduces neointima formation and vascular remodelling following carotid artery ligation. These results demonstrate that FGF-TGFβ signaling antagonism is the primary regulator of the SMC phenotype switch. Manipulation of this cross-talk may be an effective strategy for treatment of SMC-proliferation related diseases. PMID:27634335

  14. Protopanaxatirol type ginsenoside Re promotes cyclic growth of hair follicles via inhibiting transforming growth factor β signaling cascades.

    PubMed

    Li, Zheng; Ryu, Seung-Wook; Lee, Jungsul; Choi, Kyungsun; Kim, Sunchang; Choi, Chulhee

    2016-02-19

    Ginsenosides, the major bio-active ingredients included in Panax ginseng, have been known for the hair growth activity and used to treat patients who suffer from hair loss; however, the detailed mechanisms of this action are still largely unknown. This study was conducted to investigate the molecular and cellular mechanisms responsible for hair growth promoting effect of ginsenoside Re (GRe) in vitro and in vivo. Different doses of minoxidil and GRe were administered topically to the back regions of nude mice for up to 45 days, and hair shaft length and hair cycles were determined for hair promoting activities. Topical treatment of GRe significantly increased the hair shaft length and hair existent time, which was comparable to the action of minoxidil. We also demonstrated that GRe stimulated hair shaft elongation in the ex vivo cultures of vibrissa hair follicles isolated from C57BL/6 mouse. Systemic transcriptome analysis by next generation sequencing demonstrated that TGF-β-pathway related genes were selectively down-regulated by treatment of GRe in vivo, and the same treatment suppressed TGF-β-induced phosphorylation of ERK in HeLa cells. The results clearly indicated that GRe is the effective constituent in the ginseng on hair promotion via selective inhibition of the hair growth phase transition related signaling pathways, TGF-β signaling cascades.

  15. Fibroblast growth factor (FGF) signaling regulates transforming growth factor beta (TGFβ)-dependent smooth muscle cell phenotype modulation

    PubMed Central

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-01-01

    Smooth muscle cells (SMCs) in normal blood vessels exist in a highly differentiate state characterized by expression of SMC-specific contractile proteins (“contractile phenotype”). Following blood vessel injury in vivo or when cultured in vitro in the presence of multiple growth factors, SMC undergo a phenotype switch characterized by the loss of contractile markers and appearance of expression of non-muscle proteins (“proliferative phenotype”). While a number of factors have been reported to modulate this process, its regulation remains uncertain. Here we show that induction of SMC FGF signaling inhibits TGFβ signaling and converts contractile SMCs to the proliferative phenotype. Conversely, inhibition of SMC FGF signaling induces TGFβ signaling converting proliferating SMCs to the contractile phenotype, even in the presence of various growth factors in vitro or vascular injury in vivo. The importance of this signaling cross-talk is supported by in vivo data that show that an SMC deletion of a pan-FGF receptor adaptor Frs2α (fibroblast growth factor receptor substrate 2 alpha) in mice profoundly reduces neointima formation and vascular remodelling following carotid artery ligation. These results demonstrate that FGF-TGFβ signaling antagonism is the primary regulator of the SMC phenotype switch. Manipulation of this cross-talk may be an effective strategy for treatment of SMC-proliferation related diseases. PMID:27634335

  16. Synergistic Action of Fibroblast Growth Factor-2 and Transforming Growth Factor-beta1 Enhances Bioprinted Human Neocartilage Formation

    PubMed Central

    Cui, Xiaofeng; Breitenkamp, Kurt; Lotz, Martin; D’Lima, Darryl

    2012-01-01

    Bioprinting as a promising but unexplored approach for cartilage tissue engineering has the advantages of high throughput, digital control, and highly accurate placement of cells and biomaterial scaffold to the targeted 3D locations with simultaneous polymerization. This study tested feasibility of using bioprinting for cartilage engineering and examined the influence of cell density, growth and differentiation factors. Human articular chondrocytes were printed at various densities, stimulated transiently with growth factors and subsequently with chondrogenic factors. Samples were cultured for up to 4 weeks to evaluate cell proliferation and viability, mechanical properties, mass swelling ratio, water content, gene expression, ECM production, DNA content, and histology. Bioprinted samples treated with FGF-2/TGF-β1 had the best chondrogenic properties among all groups apparently due to synergistic stimulation of cell proliferation and chondrogenic phenotype. ECM production per chondrocyte in low cell density was much higher than that in high cell seeding density. This finding was also verified by mechanical testing and histology. In conclusion, cell seeding density that is feasible for bioprinting also appears optimal for human neocartilage formation when combined with appropriate growth and differentiation factors. PMID:22508498

  17. Protopanaxatirol type ginsenoside Re promotes cyclic growth of hair follicles via inhibiting transforming growth factor β signaling cascades.

    PubMed

    Li, Zheng; Ryu, Seung-Wook; Lee, Jungsul; Choi, Kyungsun; Kim, Sunchang; Choi, Chulhee

    2016-02-19

    Ginsenosides, the major bio-active ingredients included in Panax ginseng, have been known for the hair growth activity and used to treat patients who suffer from hair loss; however, the detailed mechanisms of this action are still largely unknown. This study was conducted to investigate the molecular and cellular mechanisms responsible for hair growth promoting effect of ginsenoside Re (GRe) in vitro and in vivo. Different doses of minoxidil and GRe were administered topically to the back regions of nude mice for up to 45 days, and hair shaft length and hair cycles were determined for hair promoting activities. Topical treatment of GRe significantly increased the hair shaft length and hair existent time, which was comparable to the action of minoxidil. We also demonstrated that GRe stimulated hair shaft elongation in the ex vivo cultures of vibrissa hair follicles isolated from C57BL/6 mouse. Systemic transcriptome analysis by next generation sequencing demonstrated that TGF-β-pathway related genes were selectively down-regulated by treatment of GRe in vivo, and the same treatment suppressed TGF-β-induced phosphorylation of ERK in HeLa cells. The results clearly indicated that GRe is the effective constituent in the ginseng on hair promotion via selective inhibition of the hair growth phase transition related signaling pathways, TGF-β signaling cascades. PMID:26820528

  18. Co-stimulation of gastrointestinal tumour cell growth by gastrin, transforming growth factor alpha and insulin like growth factor-I.

    PubMed Central

    Durrant, L. G.; Watson, S. A.; Hall, A.; Morris, D. L.

    1991-01-01

    Epidermal growth factor receptors and insulin like growth factor-I receptors were co-expressed on two gastric and three colorectal tumour cell lines. Previous studies have shown that gastrin receptors were also expressed at a low level or two of these cell lines. Both TGF alpha and IGF-I promoted cell growth in all of the cell lines tested. The cell doubling time of a colorectal cell line was reduced from 48 to 30-34 h. Furthermore the effects of the growth factors were additive. Each growth factor also increased the response of the cells to gastrin, but a combination of both growth factors and gastrin did not further increase growth. PMID:1846553

  19. Plasma binding proteins for platelet-derived growth factor that inhibit its binding to cell-surface receptors.

    PubMed Central

    Raines, E W; Bowen-Pope, D F; Ross, R

    1984-01-01

    Evidence is presented that the binding of platelet-derived growth factor (PDGF) to plasma constituents inhibits the binding of PDGF to its cell-surface mitogen receptor. Approximately equivalent amounts of PDGF-binding activity were found in plasma from a number of different species known by radioreceptor assay to contain PDGF homologues in their clotted blood. Activation of the coagulation cascade did not significantly alter the PDGF-binding activity of the plasma components. Three molecular weight classes of plasma fractions that inhibit PDGF binding to its cell-surface receptor were defined by gel filtration: approximately equal to 40,000, 150,000, and greater than 500,000. Specific binding of 125I-labeled PDGF to the highest molecular weight plasma fraction could also be demonstrated by gel filtration. The binding of PDGF to these plasma components was reversible under conditions of low pH or with guanidine X HCl, and active PDGF could be recovered from the higher molecular weight fractions. Immunologic and functional evidence is presented that the highest molecular weight plasma fraction may be alpha 2-macroglobulin. A model is proposed in which the activity of PDGF released in vivo may be regulated by association with these plasma binding components and by high-affinity binding to cell-surface PDGF receptors. PMID:6203121

  20. Assessing spiritual growth and spiritual decline following a diagnosis of cancer: reliability and validity of the spiritual transformation scale.

    PubMed

    Cole, Brenda S; Hopkins, Clare M; Tisak, John; Steel, Jennifer L; Carr, Brian I

    2008-02-01

    This study assessed the factor structure, reliability, and validity of an instrument designed to assess spiritual transformations following a diagnosis of cancer-the Spiritual Transformation Scale (STS). The instrument was administering to 253 people diagnosed with cancer within the previous 2 years. Two underlying factors emerged (spiritual growth (SG) and spiritual decline (SD)) with adequate internal reliability (alpha = 0.98 and 0.86, respectively) and test-retest reliability (r = 0.85 and 0.73, respectively). Validity was supported by correlations between SG and the Positive and Negative Affect Scale (PANAS) Positive Affect Subscale (r = 0.23, p < 0.001), the Daily Spiritual Experiences Scale (r = 0.57, p < 0.001), and the Post-traumatic Growth Inventory (r = 0.68, p < 0.001). SD was associated with higher scores on the Center for Epidemiological Studies Depression scale (r = 0.38, p < 0.001) and PANAS-Negative Affect Subscale (r = 0.40, p < 0.001), and lower scores on the PANAS-Positive Affect Subscale (r = -0.23, p < 0.001), and the Daily Spiritual Experiences Scale (r = -0.30, p < 0.001). Hierarchical regression analyses indicated that the subscales uniquely predicted adjustment beyond related constructs (intrinsic religiousness, spiritual coping, and general post-traumatic growth). The results indicate that the STS is psychometrically sound, with SG predicting better, and SD predicting poorer, mental and spiritual well-being following a diagnosis of cancer. PMID:17458862

  1. Loss of Tumor Necrosis Factor α Potentiates Transforming Growth Factor β-mediated Pathogenic Tissue Response during Wound Healing

    PubMed Central

    Saika, Shizuya; Ikeda, Kazuo; Yamanaka, Osamu; Flanders, Kathleen C.; Okada, Yuka; Miyamoto, Takeshi; Kitano, Ai; Ooshima, Akira; Nakajima, Yuji; Ohnishi, Yoshitaka; Kao, Winston W.-Y.

    2006-01-01

    Animal cornea is an avascular transparent tissue that is suitable for research on wound healing-related scarring and neovascularization. Here we show that loss of tumor necrosis factor α (TNFα) potentiates the undesirable, pathogenic response of wound healing in an alkali-burned cornea in mice. Excessive invasion of macrophages and subsequent formation of a vascularized scar tissue were much more marked in TNFα-null knockout (KO) mice than in wild-type mice. Such an unfavorable outcome in KO mice was abolished by Smad7 gene introduction, indicating the involvement of transforming growth factor β or activin/Smad signaling. Bone marrow transplantation from wild-type mice normalized healing of the KO mice, suggesting the involvement of bone marrow-derived inflammatory cells in this phenomenon. Co-culture experiments showed that loss of TNFα in macrophages, but not in fibroblasts, augmented the fibroblast activation as determined by detection of α-smooth muscle actin, the hallmark of myofibroblast generation, mRNA expression of collagen Iα2 and connective tissue growth factor, and detection of collagen protein. TNFα in macrophages may be required to suppress undesirable excessive inflammation and scarring, both of which are promoted by transforming growth factor β, and for restoration of tissue architecture in a healing alkali-burned cornea in mice. PMID:16723700

  2. UV/visible Fourier transform spectroscopy using an inductively-coupled plasma: dual-channel noise cancellation

    NASA Astrophysics Data System (ADS)

    Travis, J. C.; Winchester, M. R.; Salit, M. L.; Wythoff, B. J.; Scheeline, A.

    1993-04-01

    Although technological advances have extended the range of Fourier transform spectroscopy (FTS) into the UV/visible spectral domain, its application to spectroscopic and spectrometric problems has been hampered-relative to such applications in the infrared domain-by noise considerations. Although the technique retains high resolution, accurate wavelength registration, and simultaneous broad band coverage, the multiplex advantage present in the IR is severely compromised in the UV/visible due to the relative insignificance of detector noise. In particular, signal-carried noise distributes widely through the spectrum, degrading the dynamic range needed for many spectroscopic and analytical applications. This study demonstrates the use of complementary optical output channels in a commercial FTS to achieve up to ten-fold noise reductions for spectra acquired from an analytical inductively-coupled plasma with conventional pneumatic sample aspiration. The study also demonstrates the advisability of increasing the sampling rate of future instruments to exceed the maximum noise frequency characteristic of droplet evaporation effects.

  3. Creating Sacred Experiences for Children as Pathways to Healing, Growth and Transformation

    ERIC Educational Resources Information Center

    Bhagwan, Raisuyah

    2009-01-01

    Spiritual well-being forms an important dimension of children's lives globally. They are vulnerable to a range of difficulties as they grow and develop. Recently there has been a strong awareness that spirituality not only enables their healing but is critical to spiritual transformation. This paper briefly explores children's spirituality and…

  4. Arsenic transformation and plant growth promotion characteristics of As-resistant endophytic bacteria from As-hyperaccumulator Pteris vittata.

    PubMed

    Xu, Jia-Yi; Han, Yong-He; Chen, Yanshan; Zhu, Ling-Jia; Ma, Lena Q

    2016-02-01

    The ability of As-resistant endophytic bacteria in As transformation and plant growth promotion was determined. The endophytes were isolated from As-hyperaccumulator Pteris vittata (PV) after growing for 60 d in a soil containing 200 mg kg(-1) arsenate (AsV). They were isolated in presence of 10 mM AsV from PV roots, stems, and leaflets, representing 4 phyla and 17 genera. All endophytes showed at least one plant growth promoting characteristics including IAA synthesis, siderophore production and P solubilization. The root endophytes had higher P solubilization ability than the leaflet (60.0 vs. 18.3 mg L(-1)). In presence of 10 mM AsV, 6 endophytes had greater growth than the control, suggesting As-stimulated growth. Furthermore, root endophytes were more resistant to AsV while the leaflet endophytes were more tolerant to arsenite (AsIII), which corresponded to the dominant As species in PV tissues. Bacterial As resistance was positively correlated to their ability in AsV reduction but not AsIII oxidation. The roles of those endophytes in promoting plant growth and As resistance in P. vittata warrant further investigation.

  5. Arsenic transformation and plant growth promotion characteristics of As-resistant endophytic bacteria from As-hyperaccumulator Pteris vittata.

    PubMed

    Xu, Jia-Yi; Han, Yong-He; Chen, Yanshan; Zhu, Ling-Jia; Ma, Lena Q

    2016-02-01

    The ability of As-resistant endophytic bacteria in As transformation and plant growth promotion was determined. The endophytes were isolated from As-hyperaccumulator Pteris vittata (PV) after growing for 60 d in a soil containing 200 mg kg(-1) arsenate (AsV). They were isolated in presence of 10 mM AsV from PV roots, stems, and leaflets, representing 4 phyla and 17 genera. All endophytes showed at least one plant growth promoting characteristics including IAA synthesis, siderophore production and P solubilization. The root endophytes had higher P solubilization ability than the leaflet (60.0 vs. 18.3 mg L(-1)). In presence of 10 mM AsV, 6 endophytes had greater growth than the control, suggesting As-stimulated growth. Furthermore, root endophytes were more resistant to AsV while the leaflet endophytes were more tolerant to arsenite (AsIII), which corresponded to the dominant As species in PV tissues. Bacterial As resistance was positively correlated to their ability in AsV reduction but not AsIII oxidation. The roles of those endophytes in promoting plant growth and As resistance in P. vittata warrant further investigation. PMID:26469935

  6. Ca-alginate hydrogel mechanical transformations--the influence on yeast cell growth dynamics.

    PubMed

    Pajić-Lijaković, Ivana; Plavsić, Milenko; Bugarski, Branko; Nedović, Viktor

    2007-05-01

    A mathematical model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for the intra-bead cell concentration profile, after reached the equilibrium state, as well as, total yeast cell concentration per microbed and microbead volume as function of time. Relatively uniform cell concentration in the carrier matrix indicated that no internal nutrient diffusion limitations, but microenvironmental restriction, affected dominantly the dynamics of cell growth. Also interesting phenomenon of very different rates of cell number growth during cultivation is observed. After some critical time, the growth rate of cell colonies decreased drastically, but than suddenly increased again under all other experimental condition been the same. It is interpreted as disintegration of gel network and opening new free space for growth of cell clusters. These complex phenomena are modeled using the thermodynamical, free energy formalism. The particular form of free energy functional is proposed to describe various kinds of interactions, which affected the dynamics of cell growth and cause pseudo-phase transition of hydrogel. The good agreement of experimentally obtained data and model predictions are obtained. In that way the model provides both, the quantitative tools for further technological optimization of the process and deeper insight into dynamics of cell growth mechanism.

  7. Cold atmospheric plasma in combination with mechanical treatment improves osteoblast growth on biofilm covered titanium discs.

    PubMed

    Duske, Kathrin; Jablonowski, Lukasz; Koban, Ina; Matthes, Rutger; Holtfreter, Birte; Sckell, Axel; Nebe, J Barbara; von Woedtke, Thomas; Weltmann, Klaus Dieter; Kocher, Thomas

    2015-06-01

    Treatment of implants with peri-implantitis is often unsuccessful, because an instrumented implant surface and residual microbial biofilm impedes re-osseointegration. The application of cold atmospheric plasma (CAP) could be a simple and effective strategy to overcome the inherent problems of peri-implantitis treatment. CAP is able to destroy and eliminate bacterial biofilms. Additionally, it increases the wettability of titanium, which supports cellular attachment. In this study, the behaviour of osteoblasts on titanium discs was analysed after treatment of bacterial biofilms with CAP, brushing, or a combination of both. A human plaque biofilm was cultured on titanium discs. Treatment with a brush (BR), 1% oxygen/argon CAP (PL), or brushing combined with CAP (BR+PL) was used to eliminate the biofilm. Discs without biofilm (C), autoclaved biofilm (AUTO) and untreated biofilm (BIO) served as controls. Subsequently, human osteoblastic cell growth (MG-63) was observed after 1 and 24 h. Biofilm remnants on BR and PL impaired osteoblastic cell development, whereas the BR+PL provided an increased area of osteoblastic cells. A five-day cell growth was only detectable on BR+PL treated discs. The combination of established brushing and CAP application may be a promising strategy to treat peri-implantitis.

  8. Plasma membrane H⁺ -ATPase regulation is required for auxin gradient formation preceding phototropic growth.

    PubMed

    Hohm, Tim; Demarsy, Emilie; Quan, Clément; Allenbach Petrolati, Laure; Preuten, Tobias; Vernoux, Teva; Bergmann, Sven; Fankhauser, Christian

    2014-01-01

    Phototropism is a growth response allowing plants to align their photosynthetic organs toward incoming light and thereby to optimize photosynthetic activity. Formation of a lateral gradient of the phytohormone auxin is a key step to trigger asymmetric growth of the shoot leading to phototropic reorientation. To identify important regulators of auxin gradient formation, we developed an auxin flux model that enabled us to test in silico the impact of different morphological and biophysical parameters on gradient formation, including the contribution of the extracellular space (cell wall) or apoplast. Our model indicates that cell size, cell distributions, and apoplast thickness are all important factors affecting gradient formation. Among all tested variables, regulation of apoplastic pH was the most important to enable the formation of a lateral auxin gradient. To test this prediction, we interfered with the activity of plasma membrane H⁺ -ATPases that are required to control apoplastic pH. Our results show that H⁺ -ATPases are indeed important for the establishment of a lateral auxin gradient and phototropism. Moreover, we show that during phototropism, H⁺ -ATPase activity is regulated by the phototropin photoreceptors, providing a mechanism by which light influences apoplastic pH. PMID:25261457

  9. Plasma nitriding induced growth of Pt-nanowire arrays as high performance electrocatalysts for fuel cells

    NASA Astrophysics Data System (ADS)

    Du, Shangfeng; Lin, Kaijie; Malladi, Sairam K.; Lu, Yaxiang; Sun, Shuhui; Xu, Qiang; Steinberger-Wilckens, Robert; Dong, Hanshan

    2014-09-01

    In this work, we demonstrate an innovative approach, combing a novel active screen plasma (ASP) technique with green chemical synthesis, for a direct fabrication of uniform Pt nanowire arrays on large-area supports. The ASP treatment enables in-situ N-doping and surface modification to the support surface, significantly promoting the uniform growth of tiny Pt nuclei which directs the growth of ultrathin single-crystal Pt nanowire (2.5-3 nm in diameter) arrays, forming a three-dimensional (3D) nano-architecture. Pt nanowire arrays in-situ grown on the large-area gas diffusion layer (GDL) (5 cm2) can be directly used as the catalyst electrode in fuel cells. The unique design brings in an extremely thin electrocatalyst layer, facilitating the charge transfer and mass transfer properties, leading to over two times higher power density than the conventional Pt nanoparticle catalyst electrode in real fuel cell environment. Due to the similar challenges faced with other nanostructures and the high availability of ASP for other material surfaces, this work will provide valuable insights and guidance towards the development of other new nano-architectures for various practical applications.

  10. Influence of platelet-derived growth factor-AB on tissue development in autologous platelet-rich plasma gels.

    PubMed

    Wirz, Simone; Dietrich, Maren; Flanagan, Thomas C; Bokermann, Gudrun; Wagner, Wolfgang; Schmitz-Rode, Thomas; Jockenhoevel, Stefan

    2011-07-01

    Fibrin-based scaffolds are widely used in tissue engineering. We postulated that the use of platelet-rich plasma (PRP) in contrast to platelet-poor plasma and pure fibrinogen as the basic material leads to an increased release of autologous platelet-derived growth factor (PDGF)-AB, which may have a consequent positive effect on tissue development. Therefore, we evaluated the release of PDGF-AB during the production process and the course of PDGF release during cultivation of plasma gels with and w/o platelets. The influence of PDGF-AB on the proliferation rate of human umbilical cord artery smooth muscle cells (HUASMCs) was studied using XTT assay. The synthesis of extracellular matrix by HUASMCs in plasma- and fibrin gels was measured using hydroxyproline assay. The use of PRP led to an increase in autologous PDGF-AB release. Further, the platelet-containing plasma gels showed a prolonged release of growth factor during cultivation. Both PRP and platelet-poor plasma gels had a positive effect on the production of collagen. However, PDGF-AB as a supplement in medium and in pure fibrin gel had neither an effect on cell proliferation nor on the collagen synthesis rate. This observation may be due to an absence of PDGF receptors in HUASMCs as determined by flow cytometry. In conclusion, although the prolonged autologous production of PDGF-AB in PRP gels is possible, the enhanced tissue development by HUASMCs within such gels is not PDGF related.

  11. Transforming Growth Factor Beta Family: Insight into the Role of Growth Factors in Regulation of Fracture Healing Biology and Potential Clinical Applications

    PubMed Central

    Poniatowski, Łukasz A.; Gasik, Robert

    2015-01-01

    The transforming growth factor beta (TGF-β) family forms a group of three isoforms, TGF-β1, TGF-β2, and TGF-β3, with their structure formed by interrelated dimeric polypeptide chains. Pleiotropic and redundant functions of the TGF-β family concern control of numerous aspects and effects of cell functions, including proliferation, differentiation, and migration, in all tissues of the human body. Amongst many cytokines and growth factors, the TGF-β family is considered a group playing one of numerous key roles in control of physiological phenomena concerning maintenance of metabolic homeostasis in the bone tissue. By breaking the continuity of bone tissue, a spread-over-time and complex bone healing process is initiated, considered a recapitulation of embryonic intracartilaginous ossification. This process is a cascade of local and systemic phenomena spread over time, involving whole cell lineages and various cytokines and growth factors. Numerous in vivo and in vitro studies in various models analysing cytokines and growth factors' involvement have shown that TGF-β has a leading role in the fracture healing process. This paper sums up current knowledge on the basis of available literature concerning the role of the TGF-β family in the fracture healing process. PMID:25709154

  12. Transforming growth factor Beta family: insight into the role of growth factors in regulation of fracture healing biology and potential clinical applications.

    PubMed

    Poniatowski, Łukasz A; Wojdasiewicz, Piotr; Gasik, Robert; Szukiewicz, Dariusz

    2015-01-01

    The transforming growth factor beta (TGF-β) family forms a group of three isoforms, TGF-β1, TGF-β2, and TGF-β3, with their structure formed by interrelated dimeric polypeptide chains. Pleiotropic and redundant functions of the TGF-β family concern control of numerous aspects and effects of cell functions, including proliferation, differentiation, and migration, in all tissues of the human body. Amongst many cytokines and growth factors, the TGF-β family is considered a group playing one of numerous key roles in control of physiological phenomena concerning maintenance of metabolic homeostasis in the bone tissue. By breaking the continuity of bone tissue, a spread-over-time and complex bone healing process is initiated, considered a recapitulation of embryonic intracartilaginous ossification. This process is a cascade of local and systemic phenomena spread over time, involving whole cell lineages and various cytokines and growth factors. Numerous in vivo and in vitro studies in various models analysing cytokines and growth factors' involvement have shown that TGF-β has a leading role in the fracture healing process. This paper sums up current knowledge on the basis of available literature concerning the role of the TGF-β family in the fracture healing process.

  13. The combination of epidermal growth factor and transforming growth factor-beta induces novel phenotypic changes in mouse liver stem cell lines.

    PubMed

    Isfort, R J; Cody, D B; Stuard, S B; Randall, C J; Miller, C; Ridder, G M; Doersen, C J; Richards, W G; Yoder, B K; Wilkinson, J E; Woychik, R P

    1997-12-01

    Mouse liver stem cell (oval cell) lines were investigated in order to determine the role which two families of growth and differentiation factors (GDFs), epidermal growth factor (EGF) family and transforming growth factor beta (TGF-beta) family, play in liver regeneration. EGF family members, including EGF, amphiregulin, betacellulin, heparin-binding epidermal growth factor, and TGF-alpha, were mitogenic for oval cell lines while TGF-beta family members, including TGF-beta1, TGF-beta2 and TGF-beta3, inhibited mitogenesis and induced apoptosis in oval cell lines. Surprisingly, the combination of EGF family members and TGF-ss family members resulted in neither proliferation nor apoptosis but instead in a novel cellular response, cellular scattering in tissue culture and morphological differentiation in Matrigel. Analysis of the signal transduction pathways activated by exposure of oval cell lines to either EGF, EGF+TGF-beta, or TGF-beta indicated that novel combinations of intracellular signals result following stimulation of the cells with the combination of EGF+TGF-beta. These data reveal that the dynamics of synergistic GDF action following tissue injury and regeneration results in a new level of complexity not obvious from the study of individual GDFs.

  14. Relation of soya bean meal level to the concentration of plasma free amino acids and body growth in white rats.

    PubMed

    Mandal, Tapas K; Parvin, Nargish; Mondal, Santanu; Saxena, Vijaylaxmi; Saxena, Ashok K; Sarkar, Sabyasachi; Saha, Mitali

    2012-04-01

    Amino acid (AA) levels in plasma and body growth were determined in rats (n20) fed diets with different soya bean meal levels. Free AA in plasma was determined by reversed-phase high-pressure liquid chromatography. We have used four levels of protein diets like 8%, 15%, 23% and 35% in this trial. Rats which were fed the low-protein (8%) diet with low percentage of soya bean meal were found to be growth-retarded. The body weight gain of high protein group (35%) was lower than that of the 23% groups. In the rats fed with the low-soya bean meal diet, some nonessential AA (NEAA) in plasma like asparagine, aspartic acid, cysteine, glutamic acid and serine increased, whereas the essential AA (EAA), with the exception of arginine, methionine and valine decreased. Here, plasma EAA-to-NEAA ratios were not correlated to growth and experimental diet. We hypothesize that AA metabolism is associated to changes in growth in rats on different protein intake. This study has showed the sensitivity of body mass gain, feed intake, feed conversion rate of rats to four levels of protein in the diet under controlled experimental conditions.

  15. Crystalline phase transition information induced by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ

    NASA Astrophysics Data System (ADS)

    Zhang, C. P.; Chaud, X.; Beaugnon, E.; Zhou, L.

    2015-01-01

    The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the crystalline phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu2O reciprocally as well as the copper ion valence changed between divalent Cu2+ and trivalent Cu1+ each other. It was essential to keep quantities of CuO phase instead of the Cu2O for Y123 crystal solidification.

  16. Identification and subcellular localization of a 21-kilodalton molecule using affinity-purified antibodies against. cap alpha. -transforming growth factor

    SciTech Connect

    Hazarika, P.; Pardue, R.L.; Earls, R.; Dedman, J.R.

    1987-04-07

    Monospecific antibodies were generated against each of six different peptide sequences derived from rat and human ..cap alpha..-transforming growth factor (..cap alpha..-TGF). The affinity-purified antibody to the 17 amino acid carboxyl-terminal portion of the molecule proved most useful in detecting ..cap alpha..-TGF. When used in a peptide-based radioimmunoassay, it was possible to measure nanogram quantities of native ..cap alpha..-TGF in conditioned cell culture media. When used to analyze cell lysate, these antibodies specifically recognized a 21-kilodalton protein species. Indirect immunofluorescence localization procedures revealed a high concentration of ..cap alpha..-TCF in a perinuclear ring with a diffuse cytoplasmic distribution. These results suggest that a precursor form of ..cap alpha..-TGF has a cellular role beyond that of an autocrine growth factor.

  17. An improved Γ-Riccati Bäcklund transformation and its applications for the inhomogeneous nonlinear Schrödinger model from plasma physics and nonlinear optics

    NASA Astrophysics Data System (ADS)

    Liu, Yu-Ping; Gao, Yi-Tian; Wei, Guang-Mei

    2012-02-01

    The inhomogeneous nonlinear Schrödinger-type (NLS) model from certain plasmas and optical fibers is investigated with symbolic computation. An improved Γ-Riccati Bäcklund transformation (Γ-R BT) is presented, which can generate successively a hierarchy of solutions through algebraic manipulations. Based on the improved Γ-R BT, the Darboux transformation is obtained, the analytic one/two-soliton-like solutions are presented, and the physical characteristics of the influences of the coefficient parameters on the propagation of the soliton pulses are discussed graphically.

  18. OSCILLATOR: A system for analysis of diurnal leaf growth using infrared photography combined with wavelet transformation

    PubMed Central

    2012-01-01

    Background Quantification of leaf movement is an important tool for characterising the effects of environmental signals and the circadian clock on plant development. Analysis of leaf movement is currently restricted by the attachment of sensors to the plant or dependent upon visible light for time-lapse photography. The study of leaf growth movement rhythms in mature plants under biological relevant conditions, e.g. diurnal light and dark conditions, is therefore problematic. Results Here we present OSCILLATOR, an affordable system for the analysis of rhythmic leaf growth movement in mature plants. The system contains three modules: (1) Infrared time-lapse imaging of growing mature plants (2) measurement of projected distances between leaf tip and plant apex (leaf tip tracking growth-curves) and (3) extraction of phase, period and amplitude of leaf growth oscillations using wavelet analysis. A proof-of-principle is provided by characterising parameters of rhythmic leaf growth movement of different Arabidopsis thaliana accessions as well as of Petunia hybrida and Solanum lycopersicum plants under diurnal conditions. The amplitude of leaf oscillations correlated to published data on leaf angles, while amplitude and leaf length did not correlate, suggesting a distinct leaf growth profile for each accession. Arabidopsis mutant accession Landsberg erecta displayed a late phase (timing of peak oscillation) compared to other accessions and this trait appears unrelated to the ERECTA locus. Conclusions OSCILLATOR is a low cost and easy to implement system that can accurately and reproducibly quantify rhythmic growth of mature plants for different species under diurnal light/dark cycling. PMID:22867627

  19. Evaluation of the effect of calcium gluconate and bovine thrombin on the temporal release of transforming growth factor beta 1 and platelet-derived growth factor isoform BB from feline platelet concentrates

    PubMed Central

    2012-01-01

    Background There are not reported regarding the protocols for obtaining platelet concentrates (PC) in cats for medical purposes. The objectives of this study were: 1) to describe a manual method for producing two kinds of PC in cats (PC-A and PC-B), 2) to describe the cellular population of the PC, 3) to measure and compare the effect of calcium gluconate (CG) and bovine thrombin (BT) on the temporal release of transforming growth factor beta 1 (TGF-β1) and platelet-derived growth factor type BB (PDGF-BB) at 3 and 12 hours post-activation and 4) to establish correlations between the cellular population of both PCs and the concentration of growth factors (GF). Blood samples were taken from 16 cats for complete blood count, plasma collection and PC preparation. The PC were arbitrarily divided into two fractions, specifically, PC-A (lower fraction) and PC-B (upper fraction). Results The platelet counts were significantly different (P<0.05) between the PC and whole blood but not between the PC fractions. The TGF-β1 concentration efficiencies for PC-A and PC-B activated with CG were 42.86% and 46.54%, and activated with BT were 42.88% and 54.64%, respectively. The PDGF-BB concentration efficiencies for PC-A and PC-B activated with CG were 61.36% and 60.61%, and activated with BT were 65.64% and 72.12%, respectively. The temporal release of GFs showed no statistically significant difference (P>0.05) between the activating substances at the time or for any PC fraction. Conclusions Whatever the activation means, these preparations of cat PC provide significant concentrations of platelets and GFs for possible clinical or experimental use. PMID:23131192

  20. Interleukin 1 beta suppresses transforming growth factor-induced inorganic pyrophosphate (PPi) production and expression of the PPi-generating enzyme PC-1 in human chondrocytes.

    PubMed Central

    Lotz, M; Rosen, F; McCabe, G; Quach, J; Blanco, F; Dudler, J; Solan, J; Goding, J; Seegmiller, J E; Terkeltaub, R

    1995-01-01

    Articular cartilage chondrocytes have the unique ability to elaborate large amounts of extracellular pyrophosphate (PPi), and transforming growth factor beta (TGF beta) appears singular among cartilage regulatory factors in stimulating PPi production. TGF beta caused a time and dose-dependent increase in intracellular and extracellular PPi in human articular chondrocyte cultures. TGF beta and interleukin 1 beta (IL-1 beta) antagonistically regulate certain chondrocyte functions. IL-1 beta profoundly inhibited basal and TGF beta-induced PPi elaboration. To address mechanisms involved with the regulation of PPi synthesis by IL-1 beta and TGF beta, we analyzed the activity of the PPi-generating enzyme NTP pyrophosphohydrolase (NTPPPH) and the PPi-hydrolyzing enzyme alkaline phosphatase. Human chondrocyte NTPPPH activity was largely attributable to plasma cell membrane glycoprotein 1, PC-1. Furthermore, TGF beta induced comparable increases in the activity of extracellular PPi, intracellular PPi, and cellular NTPPPH and in the levels of PC-1 protein and mRNA in chondrocytes as well as a decrease in alkaline phosphatase. All of these TGF beta-induced responses were completely blocked by IL-1 beta. Thus, IL-1 beta may be an important regulator of mineralization in chondrocytes by inhibiting TGF beta-induced PPi production and PC-1 expression. Images Fig. 4 Fig. 5 PMID:7479785

  1. Transforming Growth Factor-β1 Gene Polymorphism (T29C) in Egyptian Patients with Hepatitis B Virus Infection: A Preliminary Study

    PubMed Central

    Talaat, Roba M.; Dondeti, Mahmoud F.; El-Shenawy, Soha Z.; Khamiss, Omaima A.

    2013-01-01

    The interindividual variations in the capacity of transforming growth factor-β1 (TGF-β1) production have been ascribed to genetic polymorphisms in TGF-β1 gene. As pathogenesis of HBV has a genetic background, this preliminary study was designed to assess the impact of TGF-β1 (T29C) on the susceptibility of Egyptians to HBV infection. Genotyping was performed using single stranded polymorphism-polymerase chain reaction (SSP-PCR) in 65 Egyptian hepatitis B patients and 50 healthy controls. TGF-β1 plasma levels were measured using Enzyme-linked immunosorbent assay (ELISA). The frequency of CC genotype was significantly higher (P < 0.05) in HBV patients compared to controls. On the contrary, TC genotype did not show significant difference in both groups. TT genotype was significantly higher (P < 0.01) in controls than HBV patients. Our current preliminary data revealed that the frequency of the genotypes in the controls were within Hardy-Weinberg equilibrium (HWE) while the patients group was out of HWE (P < 0.01). TGF-β1 was significantly (r = −0.684; P < 0.001) deceased in the sera of patients as compared to normal subjects. Depending on our preliminary work, CC genotype may act as a host genetic factor in the susceptibility to HBV infection in Egyptians. Taken together, the current data pointed to the importance of polymorphism of TGF-β1 gene (T29C) in HBV infection. PMID:24455227

  2. Relationships among growth mechanism, structure and morphology of PEALD TiO2 films: the influence of O2 plasma power, precursor chemistry and plasma exposure mode.

    PubMed

    Chiappim, W; Testoni, G E; Doria, A C O C; Pessoa, R S; Fraga, M A; Galvão, N K A M; Grigorov, K G; Vieira, L; Maciel, H S

    2016-07-29

    Titanium dioxide (TiO2) thin films have generated considerable interest over recent years, because they are functional materials suitable for a wide range of applications. The efficient use of the outstanding functional properties of these films relies strongly on their basic characteristics, such as structure and morphology, which are affected by deposition parameters. Here, we report on the influence of plasma power and precursor chemistry on the growth kinetics, structure and morphology of TiO2 thin films grown on Si(100) by plasma-enhanced atomic layer deposition (PEALD). For this, remote capacitively coupled 13.56 MHz oxygen plasma was used to act as a co-reactant during the ALD process using two different metal precursors: titanium tetrachloride (TiCl4) and titanium tetraisopropoxide (TTIP). Furthermore, we investigate the effect of direct plasma exposure during the co-reactant pulse on the aforementioned material properties. The extensive characterization of TiO2 films using Rutherford backscattering spectroscopy, ellipsometry, x-ray diffraction (XRD), field-emission scanning electron microscopy, and atomic force microscopy (AFM) have revealed how the investigated process parameters affect their growth per cycle (GPC), crystallization and morphology. The GPC tends to increase with plasma power for both precursors, however, for the TTIP precursor, it starts decreasing when the plasma power is greater than 100 W. From XRD analysis, we found a good correlation between film crystallinity and GPC behavior, mainly for the TTIP process. The A