Growth Of RD Research Articles

Influence of EHD on transportation of ferric water nanofluid within permeable space

This modeling article incorporated the CVFEM in demonstrating EHD forced convection of ferrofluid within a tank assuming variable permeability. Although this method has good accuracy in various approaches of modeling nanomaterial, the homogeneous model was selected in current effort. Plots, contours and formulas were exhibited as outputs. Rise of permeability guides to the augmentation of Nu which is related to higher speed of nano powders in media with higher Da. Thinner boundary is appeared with rise of Δφ and more complex isotherms can be seen which guides to higher Nu. If radiation term added in energy transportation, greater magnitude of Nu will be obtained. Additionally, augmenting Rd, make the influence of Da more sensible. Slope of changing Nu with altering Δφ augments for region with higher permeability. Growth of Rd yields to higher Nu and the slop of profile is unchanged with impose of EHD.

Mitochondria-targeted antioxidant SkQ1 suppresses fibrosarcoma and rhabdomyosarcoma tumour cell growth

ABSTRACT Mitochondria are important regulators of tumour growth and progression due to their specific role in cancer metabolism and modulation of apoptotic pathways. In this paper we describe that mitochondria-targeted antioxidant SkQ1 designed as a conjugate of decyl-triphenylphosphonium cation (TPP+) with plastoquinone, suppressed the growth of fibrosarcoma HT1080 and rhabdomyosarcoma RD tumour cells in culture and tumour growth of RD in xenograft nude mouse model. Under the same conditions, no detrimental effect of SkQ1 on cell growth of primary human subcutaneous fibroblasts was observed. The tumour growth suppression was shown to be a result of the antioxidant action of low nanomolar concentrations of SkQ1. We have revealed significant prolongation of mitosis induced by SkQ1 in both tumour cell cultures. Prolonged mitosis and apoptosis could be responsible for growth suppression after SkQ1 treatment in RD cells. Growth suppression in HT1080 cells was accompanied by the delay of telophase and cytokinesis, followed by multinuclear cells formation. The effects of SkQ1 on the cell cycle were proved to be at least partially mediated by inactivation of Aurora family kinases. Abbreviations: TPP+: Triphenylphosphonium cation; ROS: Reactive oxygen species; mtROS: Mitochondrial reactive oxygen species; NAC: N-acetyl-L-cysteine; DCFH-DA: Dichlorodihydrofluorescein diacetate; APC: Anaphase promoting complex; ABPs: Actin-binding proteins; DMEM: Dulbecco’s modified Eagle media; SDS: sodium dodecyl sulfate; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid

Physiological assessment of the mariculture potential of a Gracilaria caudata (Gracilariales, Rhodophyta) variant

On the Brazilian coast, the red alga Gracilaria caudata is exploited for agar production. Recently, among the common red wild type (RD), a greenish-brown variant (GB) was collected from a natural population. The aim of this work was to compare the growth (GR), photosynthesis, and pigment content of GB and RD tetrasporophytes cultivated under two irradiances, 70 and 150 μmol photons m−2 s−1, for a period of 28 days. The GB variant is deficient in phycoerythrin, but it produced higher levels of allophycocyanin (APC) and phycocyanin (PC) at 150 μmol photons m−2 s−1. At this irradiance, no difference of phycoerythrin content was observed between strains, suggesting that RD could be using this pigment as a nitrogen source. RD growth rates, irrespective of irradiance, were higher when compared to GB up to 14 days, although no differences were observed in photosynthesis. During the 14-day period, both color strains showed higher GR, maximum electron transport rate, and effective quantum yield at 150 μmol photons m−2 s−1 when compared to 70 μmol photons m−2 s−1. After that, although no differences were observed in the photosynthetic properties, a decrease in GR was seen at both irradiances when RD and GB simultaneously differentiated tetrasporangia. The GB, although fertile, was better able to maintain its growth and even exceed the growth rates of RD in the last week (150 μmol photons m−2 s−1). This characteristic could be advantageous to the species, favoring GB in natural populations, since G. caudata is normally found in the fertile state along the Brazilian coast, and most individuals are tetrasporophytes. This feature could also be important to the selection of this GB strain for future mariculture in Brazil. In addition, their higher concentration of PC and APC could open prospects for a possible use as source of material for pharmaceuticals and fluorescent applications.

Newcastle Disease Virus (NDV) Iraqi Strain AD2141 Induces DNA Damage and FasL in Cancer Cell Lines

The oncolytic viruses are promising form of cancer therapy which is based on the selectively killing of the cancer cells. This study was aimed to investigate the role of Newcastle disease virus (NDV) Iraqi strain AD2141 in apoptosis. Firstly, the virulence of AD2141 was detected in embryonated chicken eggs after 48hrs of infection. It was observed a hemorrhage in the skin of infected embryos that led to death. Then, the ability of this strain for regression cancer cell lines was examined. By using cytotoxicity test, it was found 128 HAU/ml of AD2141 had a potent inhibition against growth of RD and AMN3 after 72hrs of exposure time; the inhibition rate was 86.8% and 86.98% respectively. Moreover, the a poptotic activity of AD2141 was examined by comet assay. A significant induction of DNA damage in cancer cells was determined after 48hrs of exposure time; the average DNA tail length in RD, AMN3, and AMGM was 55.46, 79.1, and 84.4 respectively, and the percentage of apoptosis in treated RD, AMN-3, and AMGM was 78%, 92%, and 94% respectively. Furthermore, the concentration of FasL in treated and untreated cells was measured by immunofluoresent technique. FasL was elevated particularly in treated human cancer cell lines, RD and AMGM; it was 62.5pg/ml and 31.25pg/ml respectively. From these results, it can be concluded that NDV Iraqi strain AD2141 is a velogenic type; it caused death in infected chicken embryos. In addition it is an oncolytic virus due to induced apoptosis by damaging DNA and elevating FasL concentration in human cancer cells.

Does Business Strategy Impact a Firm's Information Environment?

This study examines whether a firm’s business strategy affects their information environment. Organizational theory suggests that firms following an innovative “prospector” strategy have greater incentives to provide more frequent voluntary disclosures than firms following an efficient “defender” strategy. Furthermore, prospectors are more likely to attract greater coverage by external information intermediaries. We find that prospectors engage in more frequent management earnings guidance, issue more press releases and are followed by more financial analysts compared to defenders. Next, we examine the association between business strategy and information asymmetry. We find that despite prospectors having attributes associated with information asymmetry (RD growth options), prospectors appear to have lower information asymmetry than defenders. We attribute this finding to prospectors’ greater access to both internal and external sources of disclosure compared to defender firms. Collectively, our results suggest that business strategy does affect firms’ information environments, incremental to known determinants, and that strategy serves as a useful context for understanding a firm’s underlying information environment.

Effects of transforming growth factor-beta/Smad signaling on the growth and apoptosis of human rhabdomyosarcoma cell line RD

To study the effects of TGF-beta/Smad signaling on the growth and apoptosis of human rhabdomyosarcoma cell line RD. Biosynthesized short hairpin RNA (shRNA) was transfected into RD cells by cation liposome vector to suppress Smad4 expression. The mRNA and protein expression of Smad4 in RD after shRNA-transfection were examined by RT-PCR and Western blot respectively. Immunofluorescent staining was used to detect the location of Smad2/3 in RD by laser scanning confocal microscopy. The viability of RD cells was examined by MTT method and (3)H-thymidine incorporation assay. The apoptosis of RD was examined by flow cytometry analysis and fluorescent staining. The expression of mRNA and protein of Smad4 in RD were effectively suppressed by shRNA interference. Such suppression effectively interrupted the endogenous TGF-beta/Smad signaling and consequently blocked the translocation of Smad2/3. The interruption of endogenous TGF-beta/Smad signaling not only inhibited the growth of RD but also induced apoptosis of RD. Exogenous TGF-beta1 inhibited the growth of RD but did not influence the apoptosis of RD. shRNA interference can effectively interrupt the TGF-beta/Smad signaling by suppressing the expression of Smad4. TGF-beta/Smad signaling subtly regulates the growth and apoptosis of RD.

Overexpression of insulin-like growth factor binding protein-6 inhibits rhabdomyosarcoma growth in vivo.

Rhabdomyosarcoma is the most common soft-tissue sarcoma of childhood. Rhabdomyosarcoma cell lines overexpress insulin-like growth factor-II (IGF-II), an autocrine growth factor that is inhibited by insulin-like growth factor binding protein-6 (IGFBP-6). IGFBP-6 is associated with myoblast quiescence, and expression in rhabdomyosarcoma cells is low. The effect of IGFBP-6 on 2 rhabdomyosarcoma cell lines, RD and Rh30, was studied. IGFBP-6 inhibited anchorage-dependent growth of RD and Rh30 cells in a dose-dependent manner (p < 0.0001). IGFBP-6 also inhibited anchorage-independent growth of RD cells in soft agar in a dose-dependent manner (p < 0.01). Anchorage-independent growth of RD cells on polyhydroxyethylmethacrylate-coated plates was decreased to a minimum of 48% of control after treatment with IGFBP-6 (p < 0.001). In this system, IGFBP-6 increased apoptosis 4-fold (p < 0.001). IGF-II partially reversed the IGFBP-6-induced decrease in growth and increase in apoptosis. Rh30 cells were stably transfected with an IGFBP-6 cDNA and subcutaneous xenografts established in BALB/c nude mice. After 18 days, sizes of 2 independent clones of IGFBP-6-overexpressing Rh30 cells were reduced to 12% and 26% of vector control-transfected tumors (p = 0.0006 and 0.002, respectively). IGFBP-6 therefore inhibits proliferation and promotes apoptosis of rhabdomyosarcoma in vitro and dramatically inhibits xenograft growth in vivo, at least in part by inhibiting IGF-II. Low expression of IGFBP-6 may therefore contribute to rhabdomyosarcoma growth and metastasis.