University of Kansas

About: University of Kansas is a education organization based out in Lawrence, Kansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 38183 authors who have published 81381 publications receiving 2986312 citations. The organization is also known as: KU & Univ of Kansas.

Detection of functional haematopoietic stem cell niche using real-time imaging

Abstract: Haematopoietic stem cells are found in a specialized regulatory environment or niche in bone marrow. The precise location and characteristics of this niche are now made clearer by two sophisticated imaging studies. Lo Celso et al. performed live-animal tracking of individual haematopoietic cells and find that osteoblasts are enmeshed in microvessels and that different haematopoietic cell populations are localized in different areas according to their stage of differentiation. Xie et al. used newly developed ex vivo real-time imaging technology and immunoassays to trace the homing of fluorescently labelled haematopoietic stem cells in response to irradiation. They report that the membrane lining the medullary cavity of bone forms a special zone that normally maintains haematopoietic stem cells, but promotes their expansion in response to bone marrow damage. Recently haematopoietic stem cell niches have been shown to comprise osteoblastic and vascular microenvironments. This study describes a newly developed ex vivo real-time imaging technology and immunoassaying to trace the homing of highly purified GFP-expressing haematopoietic stem cells in response to irradiation. Haematopoietic stem cell (HSC) niches, although proposed decades ago1, have only recently been identified as separate osteoblastic and vascular microenvironments2,3,4,5,6. Their interrelationships and interactions with HSCs in vivo remain largely unknown. Here we report the use of a newly developed ex vivo real-time imaging technology and immunoassaying to trace the homing of purified green-fluorescent-protein-expressing (GFP+) HSCs. We found that transplanted HSCs tended to home to the endosteum (an inner bone surface) in irradiated mice, but were randomly distributed and unstable in non-irradiated mice. Moreover, GFP+ HSCs were more frequently detected in the trabecular bone area compared with compact bone area, and this was validated by live imaging bioluminescence driven by the stem-cell-leukaemia (Scl) promoter–enhancer7. HSCs home to bone marrow through the vascular system. We found that the endosteum is well vascularized and that vasculature is frequently localized near N-cadherin+ pre-osteoblastic cells, a known niche component. By monitoring individual HSC behaviour using real-time imaging, we found that a portion of the homed HSCs underwent active division in the irradiated mice, coinciding with their expansion as measured by flow assay. Thus, in contrast to central marrow, the endosteum formed a special zone, which normally maintains HSCs but promotes their expansion in response to bone marrow damage.

Stereotypes of the elderly held by young, middle-aged, and elderly adults.

Abstract: This two-part study extended the research on multiple stereotypes of elderly adults by examining the perceptions of young, middle-aged, and elderly adults. First, one set of participants engaged in a trait generation task which yielded a trait list for use in the second part of the study. Second, other participants sorted the set of traits into groups representing different types of elderly individuals. Trait groupings were analyzed with hierarchical cluster analysis. Results supported the hypothesis that older adults have more complex representations of aging than do middle-aged and young ones, and that middle-aged adults have more complex representations than do young ones. For example, middle-aged and elderly adults reported more stereotypes of the elderly than did young adults, and elderly adults reported more stereotypes than did middle-aged adults. Results also showed, as expected, that these differences in complexity exist against a background of general agreement about the nature of aging: Trait lists produced by those in the three age groups were significantly correlated, and the stereotype sets of the three age groups included seven shared stereotypes. Results are interpreted in terms of their support for two alternative explanations of the complexity differences: ingroup/outgroup and developmental.

Design and in vitro studies of a needle-type glucose sensor for subcutaneous monitoring.

Abstract: A new miniaturized glucose oxidase based needle-type glucose microsensor has been developed for subcutaneous glucose monitoring. The sensor is equivalent in shape and size to a 26-guage needle (0.45-mm o.d.) and can be implanted with ease without any incision. The novel configuration greatly facilitates the deposition of enzyme and polymer films so that sensors with characteristics suitable for in vivo use (upper limit of linear range greater than 15 mM, response time less than 5 min, and sensitivity yielding a 5:1 signal-to-background ratio at normal basal glucose levels) can be prepared in high yield (greater than 60%). The sensor response is largely independent of oxygen tension in the normal physiological range. It also exhibits good selectivity against common interferences except for the exogenous drug acetaminophen.

The human type-C retrovirus, HTLV, in blacks from the Caribbean region, and relationship to adult T-cell leukemia/lymphoma

Abstract: Type-C RNA tumor viruses have been implicated in the etiology of naturally occurring leukemias and lymphomas of animals. Human T-cell leukemia/lymphoma virus (HTLV) is the first human virus of this class consistently identified in association with a specific type of human leukemia/lymphoma. The isolation of HTLV was made possible by the ability to grow mature T-cells in tissue culture usually with T-cell growth factor (TCGF). We now report a cluster of adult T-cell leukemia/lymphoma among Blacks from the Caribbean in which all eight cases are positive for HTLV virus and/or antibody. These patients have disease that appears indistinguishable from Japanese adult T-cell leukemia/lymphoma which, as we have also reported, is associated with HTLV in over 90% of cases. The finding of HTLV antibodies in some of the normal population in the Caribbean and Japan, and the clustering of a specific form of T-cell leukemia/lymphoma in these virus-endemic areas, suggest that HTLV infection may be associated with the occurrence of a distinctive clinico-pathologic entity.