209 research outputs found

    Energetics Among Collegiate Cross-Country Runners

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    The purpose of this study is to determine the energy expenditure of collegiate long distance runners in practice sessions and determine how energetics differ between six male and six female runners. Previous research has looked at aerobic capacity, injury risk, and dietary adequacy. Currently, there is little research on energetics (calories expended during a given running period) throughout a season. Energy expenditure was measured during nine practice sessions by using heart rate monitors. From this data we calculated mean submaximal heart rate (SHR) and used the Flex-Heart Rate method to estimate total energy expenditure (TEE) of the runners. We compared mean SHR and energy expenditure between males and females and within each runner throughout the cross-country season to determine if there were any adaptive changes in endurance ability. The results of this study are advantageous to coaches and athletes, who can utilize the results to create more effective training strategies. Results show an overall decrease in mean SHR and TEE by the end of the season compared to the beginning. Although males appear to show greater energy expenditure in endurance activity compared to females, there is no difference in energy costs when body mass is taken into account. These findings suggest that through daily endurance exercise, individuals are able to adapt to a given level of activity by becoming more physiologically efficient

    Going Beyond Grantmaking: Using External Help to Extend a Foundation’s Core Competencies and Increase Its Impact

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    The drive to achieve impact beyond grantmaking represents a paradigm shift in the way foundations seek to make social change. By bringing to bear new resources and thinking, this shift has the potential to amplify the impact of the philanthropic sector. Consultants and other intermediaries have critical roles to play in extending and enhancing this impact. This article explores the opportunities and challenges inherent in foundations’ efforts to go beyond grantmaking and examines how they can – and cannot – effectively use consultants and other intermediaries to enhance such efforts. It presents three cases: incubating and launching a new organization, effectively deploying impact investments, and collaborating to advocate for policy change. Using these cases and other experience as a reference base, the article then identifies five ways funders can use consultants and other intermediaries to pursue impact beyond grantmaking, and explores several common pitfalls

    Advances in bio-derived cosmetic ingredients

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    Nature is rich in biologically active molecules of interest to the cosmetics industry. Brands are leveraging these “natural” chemicals to tap into the growing market for organic and “natural” products. Advances in chemical analysis and extraction technology were recently discussed in a symposium organized by Dr. Richard Blackburn, University of Leeds, at the 21st Annual Green Chemistry & Engineering Conference

    Umbilical Cord Tissue-Derived Mesenchymal Stem Cells Inhibit T Cell Response to Peptide

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    Mesenchymal stem cells (MSC) have been shown to possess immunomodulatory properties that highlight their potential as a cellular therapy for autoimmune disease. We propose to examine the in vitro potential of stem cells derived from umbilical cord tissue to suppress the effector functions of human auto-reactive T cells. While the mechanism(s) of suppression of T cell function are not fully understood, it has been hypothesized that MSC-derived immunosuppressive soluble factors and cell-to-cell contact are important. We developed an in vitro culture assay to assess the effects of umbilical cord derived MSC (TC-MSC) on T cell function. Various doses of low-passage TC-MSCs were adhered to collagen-coated 96 well plates or in the lower chamber wells of transwell plates. HLA-matched EBV transformed B cells were pulsed +/- with appropriate autoantigenic peptide and cultured with adherent MSC or in the upper transwell chambers with the appropriate T cell clone. After 48 hours, cells were stained for CD4 and stained intracellularly for IFN-γ and analyzed by flow cytometry. We observed decreased T cell effector function with MSC co-culture and this was partially restored by separation of MSC and T cell+B cell+peptide in the transwell. We examined if prostaglandin E2 derived from the MSC also contributed to decreased T cell effector function. The inclusion of a COX-2 inhibitor in the culture system led to partially restored T cell effector function. We conclude that TC-MSC-derived soluble factor(s) and TC-MSC:T cell contact both contribute to the TC-MSC’s immunosuppressive effects. Primary TC-MSC isolates (with no prior cell culture) will also be tested in this system to determine if they possess similar immunosuppressive effects as adherent, cultured TC-MSC. These studies will pinpoint the functional mechanisms of the TC-MSC immunomodulatory properties on T cell effector function and may suggest avenues of enhancing MSC function in the treatment of autoimmune disease

    Stem Cells Expressing Homing Receptors Could be Expanded From Cryopreserved and Unselected Cord Blood

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    We assessed the cytokine combinations that are best for ex vivo expansion of cord blood (CB) and the increment for cell numbers of nucleated cells, as well as stem cells expressing homing receptors, by an ex vivo expansion of cryopreserved and unselected CB. Frozen leukocyte concentrates (LC) from CB were thawed and cultured at a concentration of 1×105/mL in media supplemented with a combination of SCF (20 ng/mL)+TPO (50 ng/mL)+FL (50 ng/mL)±IL-6 (20 ng/mL)±G-CSF (20 ng/mL). After culturing for 14 days, the expansion folds of cell numbers were as follows: TNC 22.3±7.8~26.3±4.9, CFU-GM 4.7±5.1~11.7±2.6, CD34+CD38- cell 214.0±251.9~464.1±566.1, CD34+CXCR4+ cell 4384.5±1664.7~7087.2±4669.3, CD34+VLA4+ cell 1444.3±1264.0~2074.9±1537.0, CD34+VLA5+ cell 86.2±50.9~113.2±57.1. These results revealed that the number of stem cells expressing homing receptors could be increased by an ex vivo expansion of cryopreserved and unselected CB using 3 cytokines (SCF, TPO, FL) only. Further in vivo studies regarding the engraftment after expansion of the nucleated cells, as well as the stem cells expressing homing receptors will be required

    Striking augmentation of hematopoietic cell chimerism in noncytoablated allogeneic bone marrow recipients by flt3 ligand and tacrolimus

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    The influence of granulocyte-macrophage colony-stimulating factor (GM- CSF) and the recently identified hematopoietic stem-progenitor cell mobilizing factor flt3 ligand (FL) on donor leukocyte microchimerism in noncytodepleted recipients of allogeneic bone marrow (BM) was compared. B10 mice (H2b) given 50 x 106 allogeneic (B10.BR [H2(k)]) BM cells also received either GM-CSF (4 ÎĽg/day s.c.), FL (10 ÎĽg/day i.p.), or no cytokine, with or without concomitant tacrolimus (formerly FK506; 2 mg/kg) from day 0. Chimerism was quantitated in the spleen 7 days after transplantation by both polymerase chain reaction (donor DNA [major histocompatibility complex class II; I-E(k)]) and immunohistochemical (donor [I-E(k+)] cell) analyses. Whereas GM-CSF alone significantly augmented (fivefold) the level of donor DNA in recipients' spleens, FL alone caused a significant (60%) reduction. Donor DNA was increased 10-fold by tacrolimus alone, whereas coadministration of GM-CSF and tacrolimus resulted in a greater than additive effect (28-fold increase). A much more striking effect was observed with FL + tacrolimus (>125-fold increase in donor DNA compared with BM alone). These findings were reflected in the relative numbers of donor major histocompatibility complex class II+ cells (many resembling dendritic cells) detected in spleens, although quantitative differences among the groups were less pronounced. Evaluation of cytotoxic T lymphocyte generation by BM recipients' spleen cells revealed that FL alone augmented antidonor immunity and that this was reversed by tacrolimus. Thus, although FL may potentiate antidonor reactivity in nonimmunosuppressed, allogeneic BM recipients, it exhibits potent chimerism-enhancing activity when coadministered with recipient immunosuppressive therapy. This property of FL may offer considerable potential for the augmentation of microchimerism, with therapeutic implications for organ allograft survival and tolerance induction

    High susceptibility of c-KIT+CD34+ precursors to prolonged doxorubicin exposure interferes with Langerhans cell differentiation in a human cell line model

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    As neoadjuvant and adjuvant chemotherapy schedules often consist of multiple treatment cycles over relatively long periods of time, it is important to know what effects protracted drug administration can have on the immune system. Here, we studied the long-term effects of doxorubicin on the capacity of dendritic cell (DC) precursors to differentiate into a particular DC subset, the Langerhans cells (LC). In order to achieve high telomerase activity as detected in hematological stem cells, precursor cells from the acute-myeloid leukemia (AML)-derived cell line MUTZ3 were stably transduced with human telomerase reverse transcriptase (hTERT) to facilitate their growth potential, while preventing growth, and drug-induced senescence, and preserving their unique capacity for cytokine-dependent DC and LC differentiation. The hTERT-MUTZ3 cells were selected with increasing concentrations of the anthracyclin doxorubicin. After 1–2 months of selection with 30–90 nM doxorubicin, the cells completely lost their capacity to differentiate into LC. This inhibition turned out to be reversible, as the cells slowly regained their capacity to differentiate after a 3- to 4-month drug-free period and with this became capable again of priming allogeneic T cells. Of note, the loss and gain of this capacity to differentiate coincided with the loss and gain of a subpopulation within the CD34+ proliferative compartment with surface expression of the stem cell factor receptor (SCF-R/CD117/c-Kit). These data are in favor of cytostatic drug-free intervals before applying autologous DC-based vaccination protocols, as specific DC precursors may need time to recover from protracted chemotherapy treatment and re-emerge among the circulating CD34+ hematopoietic stem and precursor cells
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