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Biomedical subjects

T Hanson

Publications and source records attributed to T Hanson.

11 recordsLinked to original sources
PubMed1998

Comparison of neutrophil and monocyte function by microbicidal cell-kill assay in patients with cancer receiving granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, or no cytokine after cytotoxic chemotherapy: a phase II trial.

Functional effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) were prospectively measured by harvesting blood samples from 51 oncology patients (21 who were receiving no cytokines, 14 receiving rhGM-CSF, and 16 who were receiving rhG-CSF) just before cytotoxic chemotherapy (baseline) immediately before the last cytokine dose (pre), 2 hours after the last cytokine dose (post), and 48 hours after the pre period (follow-up). Neutrophils and monocytes were separated and functional effects were measured by comparing cell-kill percentages, as determined by a microbial cell-kill assay against Staphylococcus aureus and Candida albicans. Optimal cell concentrations (2 x 10(6) monocytes/ml; 4 x 10(6) neutrophils/ml) and effector-to-cell ratios (1:50) were initially determined with blood samples harvested from 23 healthy volunteers. Results in oncology patients indicated that rhGM-CSF improved monocyte-killing activity against S. aureus at follow-up, compared with controls (p = 0.0094) and compared with monocytes from rhG-CSF-treated patients at the post period (p = 0.014). Cell-killing percentage of the rhGM-CSF-treated patients was also enhanced against C. albicans during the post period, compared with controls (p = 0.011) and rhG-CSF-treated patients (p = 0.067). Neutrophil activity was not altered by either cytokine. In conclusion, monocyte-induced microbial killing was enhanced in oncology patients receiving rhGM-CSF after cytotoxic chemotherapy, compared with patients receiving rhG-CSF or no cytokines. No differences in neutrophil activity were observed between patients receiving either cytokine.

Candida albicans↗
PubMed1994

Anti-CD40 antibody binding modulates human multiple myeloma clonogenicity in vitro.

Ligand binding of the B-cell lineage antigen CD40 enhances growth and interleukin-6 (IL-6) secretion in human B cells (the CD40/IL-6 loop). IL-6 has an autocrine and paracrine role in human multiple myeloma (MM) cell growth. With the use of the CD40 monoclonal antibody (MoAb) G28-5, we examined CD40 expression and the effect of CD40 binding on MM clonogenic colony (MCC) formation to characterize the IL-6/CD40 loop activity in MM. CD40 was expressed on plasmacytoid cells in 21 of 28 plasma cell dyscrasia (PCD) bone marrow (BM) biopsies tested (10 of 14 MM, 2 of 2 Waldenstrom's macroglobulinemia [WM], 2 of 2 plasma cell leukemia [PCL], 6 of 8 monoclonal gammopathy of undetermined significance [MGUS], and 1 of 2 primary amyloidosis [AL]). G28-5 binding increased MCCs by 35% to 150% in 11 of 17 CD40+ PCD BM cultures, but did not affect MCC formation in CD40- specimens or normal BM colony forming units (CFU-GEMM, CFU-GM, BFU-E). Responsive cultures originated from BM of patients with MM (2 of 5 cases tested), WM (2 of 2), PCL (2 of 2), and MGUS (5 of 6). CD40-responsiveness was not significantly inhibited by the presence of an anti-IL-6 MoAb (2 of 2 MGUS cultures tested), and did not correlate with the capacity to respond to IL-6 stimulation (n = 17, P > .05) or a detectable level of endogenous IL-6 (n = 15, P > .05). Additional studies were performed with PCD cell lines to characterize the interrelationship of CD40 activation and IL-6 production. Fifty percent to greater than 95% of cells from the RPMI 8226 and ARH77 lines expressed CD40, whereas 6% of U266 cells were CD40+. For RPMI 8226, ARH-77, and U266 cells, the increased MCC formation after anti-CD40 stimulation was not affected by the presence of an anti-IL-6 neutralizing MoAb and was not accompanied by detectable IL-6 secretion. There was no apparent increase in IL-6 mRNA transcription following G28-5 treatment of U266 or RPMI 8226 cells. Our observations indicate that CD40 is expressed in a subset of human myeloma cells present in various PCDs. Cell-line studies suggest that the CD40+ myeloma cell may regulate MM clonogenic colony formation without activating the IL-6 pathway.

Antigen-Antibody Reactions↗
PubMed1988

Clinical service review--a framework.

Continuous challenge of the way in which healthcare is delivered is one of the features which characterises the current environment for health authorities. As a consequence, managers face the pressure to review their services thoroughly and regularly. Part of the challenge to managers is to examine and define explicitly the role and function of services; to ensure that services are appropriate to the needs of the population; that they are effective in terms of outcome; that they are of high quality; and that they deploy resources in a cost-effective and efficient way. Tracy Hanson and Derek Mowbray show how this can be done.

Efficiency↗
PubMed1980

Effect of sampling intervals and digesta markers on abomasal flow determinations.

Four sampling schedules and three digesta markers were investigated with abomasally-cannulated steers. Nonammonia nitrogen flow through the abomasum was used as the criterion for comparison. A single diet, consisting of ground corn cobs and cane molasses and supplemented with soybean meal to 11.5% crude protein, was used. Each steer was fed hourly to maintain a constant digesta flow. Digesta markers used were: polyethylene glycol (PEG) and chromic oxide (Cr2O3), as external markers for the liquid fraction and the particulate fraction, respectively; and indigestible neutral detergent fiber (INDF) and indigestible acid detergent fiber (IADF), as internal markers for the particulate fraction. Treatments were sampling intervals of 24 hr, 48 hr, 48 hr (sampled twice) and 72 hours. Sampling interval did not alter digesta flow through the abomasum. Extending sampling intervals beyond 24 hr or taking more than one sample per day did not appear advantageous. IADF and Cr2O3 appear to be suitable markers for the particulate fraction. However, IADF is an integral part of the particulate fraction and meets the criteria of an ideal marker.

Abomasum↗
PubMed1975

Elevated serum dopamine-beta-hydroxylase activity in rats with inherited diabetes insipidus.

The activity of dopamine-beta-hydroxylase, the enzyme that catalyzes the conversion of dopamine to norepinephrine, was measured in the serum of a strain of Wistar rats homozygous and heterozygous for a genetic form of hypothalamic diabetes insipidus and in Wistar control rats. Serum dopamine-beta-hydroxylase activity and water intake was highest in the homozygous affected rats and lowest in normal controls. Treatment with pitressin tannate reduced serum enzyme activity and water intake in rats with diabetes insipidus to levels which did not differ from controls. Thus serum dopamine-beta-hydroxylase activity appeared to vary directly with changes in sympathetic nerve activity in response to intravascular volume depletion and repletion.

Animals↗
PubMedDate not supplied

Strain redistribution in the canine femur resulting from hip implants of different stiffnesses.

Bone remodeling adjacent to orthopedic implants has been attributed to bone strain changes. Although many animal studies have assessed bone remodeling near implants, the altered bone strains and even the strains in the intact bone prior to implantation have not been mapped extensively. Instead, bone changes are often correlated with implant stiffnesses. In this study, a benchtop loading system was developed using measurements from in vivo strain analysis to simulate physiologic loading of a canine femur. The effect on bone strains of three different stiffness canine hip implants with the same anatomic shape were compared by taking measurements from the proximal greyhound femur during loading. Peak compressive and tensile strains of the order of 200 to 400 microstrain were measured in the intact and implanted femora. The measurements indicate that during simulated in vivo loading, none of the implants substantially alter the normal strain state of the bone. If initial axial strains significantly affect the remodeling response of bone, the similarity of measurements with the different implants in place suggests that the same remodeling response would be expected to both the stiffest and least stiff implant, as has been noted in animal studies adjacent to the intermediate stiffness implant. It also suggests that this implant shape and initial bone implant interface condition can compensate for strain reductions expected near stiff straight-stemmed implants.

Animals↗