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Biomedical subjects

J D Weaver

Publications and source records attributed to J D Weaver.

15 recordsLinked to original sources

Incubation of European yew (Taxus baccata) with white-tailed deer (Odocoileus virginianus) rumen fluid reduces taxine A concentrations.

Yew ( Taxus baccata) foliage was co-incubated with rumen fluid (RF) taken from fistulated cattle (Bos taurus), anesthetized white-tailed deer (Odocoileus virginianus) and O. virginianus killed by bow hunters. The first trial with live deer resulted in statistically significant 59% reduction of taxine A by deer RF and no reduction by cattle RF. The second intubation trial, in which half the samples were stopped after 12 h, resulted in slightly less taxine A reduction by deer (46%) and 12% reduction by cattle RF. RF obtained by hunters eQuipped with thermos bottles and trained to collect RF immediatey upon field dressing their deer caused the most (88-96%) taxine A destruction: cattle RF reduced 68-88% the toxin. Obtaining RF from freshly killed deer was less expensive and more consistently successful than taking RF by intubation of anesthetized deer. The greater ability of white-tailed deer RF to detoxify yew taxines may not entirely explain the advantage white-tailed deer have over cattle to surviveyew ingestions without toxic effects.

Alkaloids↗

Interleukin-6 and risk of cognitive decline: MacArthur studies of successful aging.

OBJECTIVE: To investigate whether plasma interleukin-6 (IL-6) is cross-sectionally related to poorer cognitive function and whether a baseline plasma IL-6 measurement can predict risk for decline in cognitive function in longitudinal follow-up of a population-based sample of nondisabled elderly people. METHODS: A prospective cohort study of 779 high-functioning men and women aged 70 to 79 from the MacArthur Study of Successful Aging was conducted. Regression modeling was used to investigate whether baseline IL-6 levels (classified by tertiles) were associated with initial cognitive function and whether IL-6 levels predicted subsequent declines in cognitive function from 1988 to 1991 (2.5-year follow-up) and from 1988 to 1995 (7-year follow-up). RESULTS: Subjects in the highest tertile for plasma IL-6 were marginally more likely to exhibit poorer baseline cognitive function (i.e., scores below the median), independent of demographic status, social status, health and health behaviors, and other physiologic variables (odds ratio [OR] = 1.46; 95% CI: 0.97, 2.20). At 2.5 years, those in both the second tertile of IL-6 (OR = 2.21; 95% CI: 1.44, 3.42) and the third tertile (OR = 2.03; 95% CI: 1.30, 3.19) were at increased risk of cognitive decline even after adjusting for all confounders. At 7 years of follow-up, only those in the highest IL-6 tertile were significantly more likely to exhibit declines in cognition (OR = 1.90; 95% CI: 1.14, 3.18) after adjustment for all confounders. CONCLUSIONS: The results suggest a relationship between elevated baseline plasma IL-6 and risk for subsequent decline in cognitive function. These findings are consistent with the hypothesized relationship between brain inflammation, as measured here by elevated plasma IL-6, and neuropathologic disorders.

Aged↗

The American Red Cross disaster mental health services: development of a cooperative, single function, multidisciplinary service model.

Not until 1989 did the Red Cross officially recognize a need for a systematic and organized plan for the mental health needs of disaster survivors. Over the next decade, the Red Cross Disaster Mental Health Services program has developed and evolved to assist both disaster victims and the Red Cross workers who serve them to cope with the overwhelming stresses encountered by both groups in the aftermath of disasters. The Red Cross now coordinates a large and diverse group of mental health professionals from fields of psychology, psychiatry, nursing, social work, marriage and family therapy, and counseling who work together cooperatively. Cross-disciplinary conflicts are minimized by the Red Cross' generic approach to the various mental health professional specialties as functionally interchangeable in performing Red Cross duties. This article reviews the development of this process and describes one local Red Cross chapter's early experience as part of this effort.

Crisis Intervention↗

Murine dendritic cells infected with adenovirus vectors show signs of activation.

Dendritic cells (DC) are highly efficient antigen presenting cells being actively evaluated as vaccine components. A number of studies have shown adenovirus-mediated gene transfer to cultured DCs is feasible and that Ad-modified DCs are effective at inducing T cell immunity in vitro and establishing antitumor immunity in experimental tumor models in vivo. The current study evaluates the biologic effects of Ad infection on murine bone marrow-derived DCs (BMDC) in primary culture. Ad infection (MOI 200) of BMDC induced significant increases in IL 12 p40 protein in culture supernatants (6 x that of uninfected BMDC and similar to that observed with addition of LPS and CD40 crosslinking antibody). Supernatants from Ad infected BMDCs induced appreciable increases in IFNgamma from naive splenocytes in culture. Consistent with DC activation, FACs analysis showed BMDC infected with Ad vectors up-regulated the surface expression of B7-2, ICAM-1 and MHC II. Additional experiments evaluated the role of virus attachment, internalization and gene expression using IL-12 p40 production as a marker of DC activation. Neither heat-inactivated Ad nor peptides containing the RGD sequence (the primary component of Ad penton base which interacts with cell surface integrins) induced significant amounts of IL12 p40. In contrast, psoralen/UV-inactivated Ad showed similar levels of IL12 p40 production compared with intact Ad. These data suggest this phenomenon is dependent on viral entry into the cell and/or translocation to the nucleus, and is independent of either viral gene or transgene expression.

Adenoviridae↗

Partial trisomies in two spontaneously arising long-lived human keratinocyte lines.

During experiments concerning the introduction of oncogenes into normal human keratinocytes, we observed long-lived colonies arising spontaneously at the same low frequency in control cultures as in those transfected with Ha-rasEJ or activated c-myc or both. Two of these were karyotyped early in their life span and showed additional chromosomal material on the short arm of chromosome 9 in one case and of chromosome 18 in the other, whereas the parental cells had a normal karyotype. This indicates the presence of a partial trisomy in each line, although the origin of the extra chromosomal material is not known. A similarly long-lived human keratinocyte line containing an isochromosome of the long arm of chromosome 8 has been described elsewhere. Together these results suggest that the spontaneous occurrence of long-lived lines is more common in human keratinocytes than in fibroblasts and that a triple dose of one or more genes may be the initial event in this process.

Adult↗

Marginal adaptation of castable ceramic crowns.

Tooth preparations and seating techniques of castable ceramic crowns differ from metal ceramic crowns. This study evaluated the variable effects of cementation on the marginal adaptation of Dicor, Cerestore, and porcelain-fused-to-metal crowns. The shoulder preparation was maintained for ceramic crowns, and a cavosurface bevel was designed for metal ceramic crowns. Crowns were made with a replication size of 10, placed on master dies, and the marginal openings measured with a Nikon Measurescope 20 instrument. Thirty crowns were cemented with zinc phosphate cement and the recommended clinical force. Marginal adaptation was not improved with a gingival bevel preparation or an increased seating force. The best marginal adaptation was recorded for Cerestore crowns.

Aluminum Oxide↗

Telescopic copings in restorative dentistry.

The complete mouth reconstruction of a periodontally compromised dentition is a tremendous challenge. Although the treatment is complex, the rewards can be satisfying. In some cases, the use of telescopic copings overcomes several of the problems associated with periodontal prosthetic treatment. This article reviews the advantages and disadvantages in the use of telescopic copings in restorative dentistry.

Cementation↗

Consultation and education in rural mental health: core elements for the (lean) 1980's.

The consultation and educational components of local mental health centers, which flourished in the 1970's, now find themselves being cut back, either along with or instead of direct services. This article examines some core ingredients of rural mental health consultation and education which can continue even with low levels of funding.

Community Mental Health Services↗