996 resultados para TISSUE CULTURES
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We characterised the effects of selective oestrogen receptor modulators (SERM) in explant cultures of human endometrium tissue. Endometrium tissues were cultured for 24 h in Millicell-CM culture inserts in serum-free medium in the presence of vehicle,17 beta-estradiol (17 beta-E2,1 nM), oestrogen receptor (ER) antagonist ICI 164.384 (40 nM), and 4-OH-tamoxifen (40 nM), raloxifene (4 nM), lasofoxifene (4 nM)and acolbifene (4 nM). Protein expression of ER alpha, ER beta 1 and Ki-67 were evaluated by immunohistochemistry (IHC). The proliferative fraction was assessed by counting the number of Ki-67 positive cells. Nuclear staining of ER( and ER(1 was observed in the glandular epithelium and stroma of pre- and postmenopausal endometrium. ER(1 protein was also localized in the endothelial cells of blood vessels. Treating premenopausal endometrium tissue with 17 beta-E2 increased the fraction of Ki-67 positive cells (p < 0.001) by 55% in glands compared to the control. Raloxifene (4 nM) increased (p < 0.05) the Ki-67 positive fraction. All other SERMS did not affect proliferation in this model. Treating postmenopausal endometrium with 17(-E2 increased (p < 0.001) the fraction of Ki-67 positive cells by 250% in glands compared to the control. A similar effect was also seen for 4-OH-tamoxifen, whereas the rest of SERMs did not stimulate proliferation. We demonstrated that oestradiol increases the fraction of proliferating cells in short term explant cultures of postmenopausal endometrium. In addition, we were able to reveal the agonistic properties of 4-OH-tamoxifen and confirm that raloxifene and next-generation SERMs acolbifene and lasofoxifene were neutral on the human postmenopausal endometrium. (C) 2008 Elsevier Ltd. All rights reserved.
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Tissue culture in the oil palm business is generally concerned with the multiplication (clonal production) of dura, pisifera and tenera palms. These are all normal diploids (2n=2x=36). Sumatra Bioscience has pioneered haploid tissue culture of oil palm (n=x=18). Haploid oil palm is the first step in producing doubled haploid palms which in turn provide parental lines for F1 hybrid production. Chromosome doubling is known to occur during embryogenesis in other haploid cultures, e.g. barley anther culture. Haploid tissue cultures in oil palm were therefore set up to investigate and exploit spontaneous chromosome doubling during embryogenesis. Flow cytometry of embryogenic tissue showed the presence of both haploid (n) and doubled haploid (2n) cells indicating spontaneous doubling. Completely doubled haploid ramets were regenerated suggesting that doubling occurred during the first mitoses of embryogenesis. This is the first report of doubled haploid production in oil palm via haploid tissue culture. The method provides a means of producing a range of doubled haploids in oil palm from the 1,000 plus haploids available at Sumatra Bioscience, in addition the method also produced doubled haploid (and haploid) clones. 1.
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Cancer is caused by a complex pattern of molecular perturbations. To understand the biology of cancer, it is thus important to look at the activation state of key proteins and signaling networks. The limited amount of available sample material from patients and the complexity of protein expression patterns make the use of traditional protein analysis methods particularly difficult. In addition, the only approach that is currently available for performing functional studies is the use of serial biopsies, which is limited by ethical constraints and patient acceptance. The goal of this work was to establish a 3-D ex vivo culture technique in combination with reverse-phase protein microarrays (RPPM) as a novel experimental tool for use in cancer research. The RPPM platform allows the parallel profiling of large numbers of protein analytes to determine their relative abundance and activation level. Cancer tissue and the respective corresponding normal tissue controls from patients with colorectal cancer were cultured ex vivo. At various time points, the cultured samples were processed into lysates and analyzed on RPPM to assess the expression of carcinoembryonic antigen (CEA) and 24 proteins involved in the regulation of apoptosis. The methodology displayed good robustness and low system noise. As a proof of concept, CEA expression was significantly higher in tumor compared with normal tissue (p<0.0001). The caspase 9 expression signal was lower in tumor tissue than in normal tissue (p<0.001). Cleaved Caspase 8 (p=0.014), Bad (p=0.007), Bim (p=0.007), p73 (p=0.005), PARP (p<0.001), and cleaved PARP (p=0.007) were differentially expressed in normal liver and normal colon tissue. We demonstrate here the feasibility of using RPPM technology with 3-D ex vivo cultured samples. This approach is useful for investigating complex patterns of protein expression and modification over time. It should allow functional proteomics in patient samples with various applications such as pharmacodynamic analyses in drug development.
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Experience with anidulafungin against Candida krusei is limited. Immunosuppressed mice were injected with 1.3 x 10(7) to 1.5 x 10(7) CFU of C. krusei. Animals were treated with saline, 40 mg/kg fluconazole, 1 mg/kg amphotericin B, or 10 and 20 mg/kg anidulafungin for 5 days. Anidulafungin improved survival and significantly reduced the number of CFU/g in kidneys and serum beta-glucan levels.
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Five retrotransposon families of rice (Tos1-Tos5) have been reported previously. Here we report 15 new retrotransposon families of rice (Tos6-Tos20). In contrast to yeast and Drosophila retrotransposons, all of the rice retrotransposons examined appear inactive (or almost inactive) under normal growth conditions. Three of the rice retrotransposons (Tos10, Tos17, and Tos19) are activated under tissue culture conditions. The most active one, Tos17, was studied in detail. The copy number of Tos17 increased with prolonged culture period. In all of the plants regenerated from tissue cultures, including transgenic plants, 5 to 30 transposed Tos17 copies were detected. The transcript of Tos17 was only detected under tissue culture conditions, indicating that the transposition of Tos17 is mainly regulated at the transcriptional level. To examine the target-site specificity of Tos17 transposition, sequences flanking transposed Tos17 copies were analyzed. At least four out of eight target sites examined are coding regions. Other target sites may also be in genes because two out of four were transcribed. The regenerated plants with Tos17-insertions in the phytochrome A gene and the S-receptor kinase-related gene were identified. These results indicate that activation of Tos17 is an important cause of tissue culture-induced mutations. Tissue culture-induced activation of Tos17 may be a useful tool for insertional mutagenesis and functional analysis of genes.
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Catharanthlls rosellS (L.) G Don is a commercially significant flower species and in addition is the only source of the monoterpenoid indole alkaloids (MIA) vinblastine and vincristine, which are key pharmaceutical compounds that are used to combat a number of different cancers. Therefore, procurement of the antineoplastic agents is difficult but essential procedure. Alternatively, CatharanthllS tissue cultures have been investigated as a source of these agents; however they do not produce vindoline, which is an obligate precursor to vinblastine and vincristine. The interest in developing high MIA cultivars of Catharantlws rosellS has prompted metabolic profiling studies to determine the variability of MIA accumulation of existing flowering cultivars, with particular focus on the vindoline component ofthe pathway. Metabolic profiling studies that used high performance liquid chromatography of MIAs from seedlings and young leaf extracts from 50 different flowering cultivars showed that, except for a single low vindoline cultivar (Vinca Mediterranean DP Orchid), they all accumulate similar levels of MIAs. Further enzymatic studies with extracts from young leaves and from developing seedlings showed that the low vindoline cultivar has a IO-fold lower tabersonine-16-hydroxylase activity than those of CatharanthllS rosellS cv Little Delicata. Additionally, studies aimed at metabolic engineering ofvindoline bios}l1thesis in Catharanthus rosellS hairy root cultures have been performed by expressing the last step in vindoline biosynthesis [Dcacetylvindoline-4-0- acetyltransferase (DAT)]. Enzymatic profiling studies with transformed hairy roots have confirmed that over-expressing DAT leads to lines with high levels of O-acetyltransferase activity when compared to non-expressing hairy roots. One particular DA T over111 expressing hairy root culture (line 7) contained 200 times the OAT activity than leaves of control lines. Additional MIA analyses revealed that DAT over-expressing hairy roots have an altered alkaloid profile with significant variation in the accumulation of h6rhammericine. Further analysis of transformed hairy root line 7 suggests a correlation between the expression of OAT activity and h6rhammericine accumulation with root maturation. These studies show that metabolic and selective enzymatic profiling can enhance our ability to search for relevant MIA pathway mutants and that genetic engineering with appropriate pathway genes shows promise as a tool to modify the MIA profile of Catharanthus roseus.
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The present work deals with the development of primary cell culture and diploid cell lines from two fishes, such as Poecilia reticulata and Clarias gariepinus. The greatest difficulty experienced was the avoidance of bacterial and fungi contamination. Three types of cell cultures are commonly developed, primary cell culture, diploid cell lines and heteroploid cell lines. Primary cell culture obtained from the animal tissues that have been cultivated in vitro for the first time. They are characterized by the same chromosome number as parent tissue, cultivated in vitro for the first time, have wide range of virus susceptibility, usually not malignant, six chromatin retarded and do not grow as suspension cultures. Diploid cell lines arise from a primary cell culture at the time of subculturing. Diploid cell lines commercially used in virology are W1-38 (human embryonic lung), W1-26 (human embryonic lung) and HEX (Human embryonic kidney). Heteroploid cell lines have been subcultivated with less than 75% of the cells in the population having a diploid chromosome constitution. Tissue cultures have been extensively used in biomedical research. The main applications are in three areas, Karyological studies, Identification and study of hereditary metabolic disorders and Somatic cell genetics. Other applications are in virology and host-parasite relationships. In this study an attempt was made to preserve the ovarian tissue at low temperature in the presence of cryoprotectants so that the tissue can be retrieved at any time and a cell culture could be developed.
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In vitro morphogenesis and cell suspension culture establishment in Piper solmsianum C. DC. (Piperaceae)). Piper solmsianum is a shrub from Southeast Brazil in which many biologically active compounds were identified. The aim of this work was to establish a cell suspension culture system for this species. With this in mind, petiole and leaf explants obtained from in vitro plantlets were cultured in the presence of different plant growth regulator combinations (IAA, NAA, 2,4-D and BA). Root and indirect shoot adventitious formation, detected by histological analysis, was observed. Besides the different combinations of plant growth regulators, light regime and the supplement of activated charcoal (1.5 mg.l(-1)) were tested for callus induction and growth. Cultures maintained in light, on a 0.2 mg.l(-1) 2,4-D and 2 mg.l(-1) BA supplemented medium, and in the absence of activated charcoal, showed the highest calli fresh matter increment. From a callus culture, cell suspension cultures were established and their growth and metabolite accumulation studied. The achieved results may be useful for further characterization of the activated secondary metabolites pathways in in vitro systems of P. solmsianum.
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As all herbicides act on pathways or processes crucial to plants, in an inhibitory or stimulatory way, low doses of any herbicide might be used to beneficially modulate plant growth, development, or composition. Glyphosate, the most used herbicide in the world, is widely applied at low rates to ripen sugarcane. Low rates of glyphosate also can stimulate plant growth (this effect is called hormesis). When applied at recommended rates for weed control, glyphosate can inhibit rust diseases in glyphosate-resistant wheat and soybean. Fluridone blocks carotenoid biosynthesis by inhibition of phytoene desaturase and is effective in reducing the production of abscisic acid in drought-stressed plants. Among the acetolactate synthase inhibitors, sulfometuron-methyl is widely used to ripen sugarcane and imidazolinones can be used to suppress turf species growth. The application of protoporphyrinogen oxidase inhibitors can trigger plant defenses against pathogens. Glufosinate, a glutamine syntherase inhibitor, is also known to improve the control of plant diseases. Auxin agonists (i.e., dicamba and 2,4-D) are effective, low-cost plant growth regulators. Currently, auxin agonists are still used in tissue cultures to induce somatic embryogenesis and to control fruit ripening, to reduce drop of fruits, to enlarge fruit size, or to extend the harvest period in citrus orchards. At low doses, triazine herbicides stimulate growth through beneficial effects on nitrogen metabolism and through auxin-like effects. Thus, sublethal doses of several herbicides have applications other than weed control.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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We investigated thyroid hormone levels in menopausal BrC patients and verified the action of triiodothyronine on genes regulated by estrogen and by triiodothyronine itself in BrC tissues. We selected 15 postmenopausal BrC patients and a control group of 18 postmenopausal women without BrC. We measured serum TPO-AB, TSH, FT4, and estradiol, before and after surgery, and used immunohistochemistry to examine estrogen and progesterone receptors. BrC primary tissue cultures received the following treatments: ethanol, triiodothyronine, triiodothyronine plus 4-hydroxytamoxifen, 4-hydroxytamoxifen, estrogen, or estrogen plus 4-hydroxytamoxifen. Genes regulated by estrogen (TGFA, TGFB1, and PGR) and by triiodothyronine (TNFRSF9, BMP-6, and THRA) in vitro were evaluated. TSH levels in BrC patients did not differ from those of the control group (1.34 ± 0.60 versus 2.41 ± 1.10 μ U/mL), but FT4 levels of BrC patients were statistically higher than controls (1.78 ± 0.20 versus 0.95 ± 0.16 ng/dL). TGFA was upregulated and downregulated after estrogen and triiodothyronine treatment, respectively. Triiodothyronine increased PGR expression; however 4-hydroxytamoxifen did not block triiodothyronine action on PGR expression. 4-Hydroxytamoxifen, alone or associated with triiodothyronine, modulated gene expression of TNFRSF9, BMP-6, and THRA, similar to triiodothyronine treatment. Thus, our work highlights the importance of thyroid hormone status evaluation and its ability to interfere with estrogen target gene expression in BrC samples in menopausal women.
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The larvicidal activity of the neotropical "matico" Piper tuberculatum was evaluated. The secondary compounds were extracted of leaves, stems and mature spikes with fruits and seeds from wild plants and in vitro plants of Piper tuberculatum. The acute toxicities to the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), of extracts of spikes with fruits and seeds and in vitro plants of P tuberculatum were evaluated by means of contact bioassays. Only CH2Cl2:MeOH (2:1) and EtOH extracts of mature spikes and CH2C12:MeOH (2:1) extract from in vitro plants showed significant levels of larval mortality. The CH2Cl2:MeOH (2:1) and EtOH extracts of mature spikes caused 90% mortality when doses of 0.1850 mg/mu L were applied to the S. frugiperda in 24 and 48 h of exposure, respectively. The CH2Cl2:MeOH (2:1) extract from in vitro plants caused 95% mortality when doses of 0.1850 mg/mu L were too applied in 48 h of exposure. The mature spikes test best results were: LD50 0.001 mg/mu L with EtOH and 0.007 mg/mu L with CH2Cl2:MeOH (2:1) and LD90 0.027 mg/mu L with EtOH and 0.103 mg/mu L with CH2Cl2:MeOH (2:1); and, in the case of in vitro plants, only CH2Cl2:MeOH (2:1) extract was: LD50 0.003 mg/mu L and LD90 0.060 mg/mu L. The potential value of extracts derived from P. tuberculatum as efficient insecticides against S.frugiperda is discussed.