1,721,003 research outputs found

    Evaluation of vegetation and stream health within sites supported by the Hamilton City Council Plants for Gullies Programme

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    Between August 2012 and March 2013, the Environmental Research Institute, University of Waikato, conducted a survey of randomly selected Hamilton gully sites which had received plants from the Hamilton City Council’s Plants for Gullies Programme. This survey assessed recent plantings, existing gully vegetation and stream health, along with property owner awareness and engagement with the key restoration principles. The Plants for Gullies Programme has been extremely well received by the Hamilton community and gully owners. Survey participants were actively restoring their gully sites with the most common goal (c. 40%) being the establishment of native plant dominance within 10 years. Gully owners have a good understanding of restoration theory and practise; on average, plant placement in the gullies scored 15.7 out of 20 with consideration of plant environmental requirements and the concept of ecosourcing was understood by c. 76% of landowners surveyed. Also, most of the interviewed participants (c. 80%) were active in seeking guidance from other gullies, often through organised tours. Current stream health was qualitatively assessed and characterised at each of the gully sites. Results provide baseline data for future monitoring. The majority of surveyed sites (c. 50%) had sand or silt substrate and the Bankwood gully had the best features for fauna habitat (e.g. debris and areas of low flow). At the time of visit, c. 60% of surveyed streams had clear water clarity. The poorest water clarity scores were in the Waitawhiriwhiri gully. When assessed on width, length and density, the average riparian buffer score was 12.8 out of 20 while the average stream shading score was 12.7 out of 20. The average bank stability score was 13.1 out of 20, reflecting an erosion problem that many gully owners talked about. Surveyed gullies were diverse in terms of native and exotic vegetation structure and composition; native species contributed between c. 30% to 100% of surveyed trees and shrubs, whereas groundcovers were predominantly exotic. This assessment of gully sites has shown that the Plants for Gullies Programme improves native species diversity through the re-introduction of species that are not naturally regenerating. The Plants for Gullies programme is a powerful tool for engaging private landowners and making cost-effective change to Hamilton City’s native biodiversity. There is now a community of willing gully owners who will continue to restore their gullies with the support of a programme or network. It is our recommendation that the Plants for Gullies Programme is reinstated before this community loses momentum

    Proliferation of human hematopoietic progenitors in long-term bone marrow cultures in gas permeable plastic bags is enhanced by colony-stimulating factors.

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    We compared the recovery of human hematopoietic progenitors in long-term bone marrow culture (LTBMC) initiated in tissue culture (TC) flasks to that in "Lifecell" bags, which are gas-permeable plastic bags in which feeder-layer cells cannot adhere. Our results showed that granulocyte-macrophage colony-forming unit (CFU-GM) and erythroid burst-forming unit (BFU-E) cumulative recovery in cultures from normal donor marrow, expressed as a percent of the initial inoculum, was not statistically different in the two culture systems up to week 8, when the cultures were terminated: 31.5 +/- 19 (flask) vs 30 +/- 14 (bag) and 15.5 +/- 12 (flask) vs 11.5 +/- 8 (bag), respectively. The effects of weekly addition of recombinant human (r-hu)-interleukin 1 (IL1) and r-hu-interleukin 3 (IL3) were then studied, alone and combined, at two different concentrations. Addition of IL1, either alone or combined with IL3, in LTBMC established in flasks induced an increase of hematopoietic progenitors for the first week, but BFU-E and CFU-GM were no longer detectable at weeks 4 and 6, respectively. Analysis of adherent layer cells showed a decreased cellularity, no adipogenesis, and early disappearance of bone marrow (BM) progenitors, whereas the cycling rate of myeloid precursors, by cytosine arabinoside (Ara-C) suicide assay, was similar to that of untreated cultures. Conversely, IL3 alone (5 ng/ml) resulted in 3.6- and 5.4-fold peak increases for CFU-GM and BFU-E, respectively, at week 1 (adherent plus nonadherent cells), and the recovery of BM cells was still higher than that of control flasks at week 8. By comparison, stimulation with colony-stimulating factors (CSFs) of BM cells grown in bags never affected the longevity of the culture. Addition of IL3 (5 ng/ml) induced a higher recovery of total cells, CFU-GM (range: 1.6- to 15-fold peak increase during the culture), and BFU-E (1.2- to 3-fold) compared to the untreated controls. Bags treated with IL1 alone demonstrated only transient beneficial effects, and the number of hematopoietic precursors fell below the level of control bags during the culture. IL1 and IL3 induced 1.8- and 5.3-fold peak increases in BFU-E and CFU-GM at weeks 1 and 4, respectively. Simultaneous flow cytometric analysis of CD34+/CD33+ cells and DNA content showed increased numbers and proliferation of the committed BM progenitors when CSFs were added to the ba

    Combination of hematopoietic growth factors containing IL-3 induce Acute Myeloid Leukemia Cell Sensitization to cycle specific and cycle non-specific drugs.

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    Laboratory studies have suggested that hematopoietic growth factors (GF), combined with cytosine-arabinoside (Ara-C) can enhance cytotoxic effects of this agent against acute myeloid leukemia (AML) cells. While clinical trials based on this growth factor/chemotherapy combination (GF/CT) are progressing with discordant results, further information regarding the underlying mechanisms have been reported supporting this rationale and requiring additional investigation. To assess the role of cytokinetic changes in the GF/CT strategy and to evaluate if chemotherapeutic agents regimens other than Ara-C, when combined with GF, can enhance their cytotoxic effects, we have primed AML blasts with two cytokine combinations and then exposed these cells to the S-phase specific agent Ara-C as well as to the phase non-specific drug daunorubicin (DNR) and to the alkylating agent 4-hydroperoxycyclophosphamide (4-HC). The two cytokine combinations used for priming AML blasts were: (i) interleukin-3 (IL-3) + granulocyte-macrophage colony-stimulating factor (GM-CSF) + granulocyte colony-stimulating factor (G-CSF); and (ii) GM + G-CSF. Cytokinetic analysis in ten AML samples and clonogenic growth of leukemic colonies (CFU-L) in methylcellulose were used to detect proliferative and cytotoxic effects on AML samples. We report that in AML clonogenic cell growth can be stimulated by cytokines in 50% of the samples (4/8), and that Ara-C sensitization clearly occurs in two out of these four samples. Among the different cytokine combinations tested, the one containing IL-3 was the most effective through a cytokinetic mechanism consistent with recruitment (averaged G0 decrease p = 0.04; S-phase increase p = 0.005). Furthermore we observed increased cytotoxicity also to the phase non-specific drugs DNR and 4-HC, which may be mediated by other mechanisms recently described. We conclude that GF/CT combinations may also be beneficial in regimens containing drugs other than Ara-C, used for AML treatment, including bone marrow transplantation conditioning regimens
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