Factors affecting body temperatures of toads

Factors influencing levels and rates of variation of body temperature ( T b ) in montane Bufo boreas boreas and in lowland Bufo boreas halophilus were investigated as an initial step toward understanding the role of natural thermal variation in the physiology and energetics of these ectothermic animals. Body temperatures of boreas can vary 25–30° C over 24-h periods. Such variation is primarily due to both nocturnal and diurnal activity and the physical characteristics of the montane environment. Bufo boreas halophilus are primarily nocturnal except during breeding and are voluntarily active at body temperatures ranging between 10 and 25° C. Despite variation in T b encountered in the field, boreas select a narrow range of T b in a thermal gradient, averaging 23.5 and 26.2° C for fasted individuals maintained under field conditions or acclimated to 20° C, respectively. In a thermal gradient the mean T b of fasted halophilus acclimated to 20° C is 23.9° C. Skin color of boreas varies in the field from very dark to light. The dark skins absorb approximately 4% more radiation than the light ones. Light colored boreas should absorb approximately 5% more radiation than similarly colored halophilus . Evaporative water losses increase directly with skin temperatures and vapor pressure deficit in both subspecies. Larger individuals heat and cool more slowly than smaller ones. Calculation of an enery budget for boreal toads suggests that they could sit in direct sunlight for long periods without fatally overheating, providing the skin was continually moist.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47722/1/442_2004_Article_BF00344732.pd

Hematopoietic growth factors after HLA-identical allogeneic bone marrow transplantation in patients treated with methotrexate-containing graft-vs.-host disease prophylaxis

The use of hematopoietic growth factors (HGFs) in the allogeneic transplant setting has sometimes been avoided for fear of stimulating leukemic cell growth and intensifying graft-vs.- host disease (GVHD). However, neither an increase in relapse rate nor an aggravation of GVHD has been routinely described when HGFs are used after allogeneic bone marrow transplantation (allo-BMT). Early outcomes after HLAmatched allo-BMT in 26 patients with hematologic malignancies treated with recombinant human granulocyte colonystimulating factor (rhG-CSF) or recombinant human granulocyte-macrophage colony-stimulating factor (rhGMCSF) from the day of transplantation were analyzed. Results were compared to those from a series of 38 patients treated earlier with an identical approach, but not scheduled to receive HGFs after transplantation. All patients received a preparative regimen consisting of etoposide, cyclophosphamide, and total-body irradiation and GVHD prophylaxis with cyclosporine and a short course of methotrexate (MTX). The analysis has shown that the duration of neutropenia was significantly decreased in the group of patients treated routinely with HGFs (median 17 vs. 20 days; p < 0.001). These patients also required fewer days of intravenous antibiotic therapy (median 20 vs. 34 days; p < 0.001), had fewer positive blood and tissue cultures (median 2 vs. 12 and 13 vs. 28; p = 0.02 and p = 0.05, respectively), needed fewer packed red blood cell transfusions (median 7 vs. 11; p < 0.03), and were discharged earlier from the hospital (median 33.5 vs. 39 days; p < 0.001). The use of HGFs was not associated with an increase in acute GVHD or early leukemic relapse. No side effects were attributable to the simultaneous administration of MTX and HGF during the neutropenic period. A trend toward better 100-day actuarial survival for patients treated with rhG-CSF or rhGM-CSF did not reach statistical significance. A decrease in the number of early deaths from fungal or bacterial infections was found in the cytokine-treated group (p = 0.05). These data suggest that the early use of rhGCSF or rhGM-CSF after HLA-matched allo-BMT in hematologic malignancies accelerates engraftment, reduces hospitalization time, and improves outcome, without increasing acute GVHD or early relapse. Because MTX-based prophylaxis regimens are associated with prolonged neutropenia, the routine use of HGFs after transplantation may be particularly useful in regimens including MTX