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Biomedical subjects

R Pope

Publications and source records attributed to R Pope.

At least 37 records · Page 2Linked to original sources
PubMed1985

[Regulation of natural killer activity by adherent cells in synovial rheumatoid medium].

The activity of natural killer cells in the synovial fluid, the synovial tissue and the peripheral blood was studied in 23 patients with active rheumatoid arthritis and was found to be significantly lower than that in the blood of 28 controls. This decrease was inversely related to the erythrocyte sedimentation rate. The preincubation of mononuclear cells with indomethacin significantly increased the natural killer activity in the blood of the controls and the patients with rheumatoid arthritis, but did not have any effect in the synovial compartment. The elimination of the adherent cells increased the natural killer activity in the blood of the controls and the patients with rheumatoid arthritis, but decreased this activity in the synovium. The stimulatory effect of synovial macrophages and the suppressor effect of the blood macrophages on the natural killer activity were confirmed when the adherent and non-adherent populations were mixed and these effects were reproduced by using supernatants of total mononuclear cells. The stimulation of the natural killer activity by interleukin 2 and poly-I:C, an interferon inducer, is independent of the macrophages in rheumatoid arthritis. These results suggest a deficient natural killer activity in active rheumatoid arthritis and a difference in the modulation of these natural killer cells by macrophages in rheumatoid synovium and normal or rheumatoid arthritis blood.

Adult↗
PubMed1984

Modulation of natural killer cell activity in the rheumatoid joint and peripheral blood.

Natural killer (NK) cell activity and its regulation in synovial fluid (SF), synovial tissue (ST), and peripheral blood (PB) was studied in 23 patients with active rheumatoid arthritis (RA). NK activity was reduced in PB (P less than 0.005), SF (P less than 0.002), and ST of patients with RA compared to the PB of 28 healthy controls. NK activity in SF was inversely correlated with disease activity as measured by erythrocyte sedimentation rate (r = -0.561; P less than 0.02). Poly I:C, an interferon inducer, stimulated NK activity in RA patients' PB and SF and control subjects' PB to similar extents. However, augmentation of NK activity by interleukin-2 was significantly greater in SF than in PB of RA (P less than 0.02). Preincubation of mononuclear cells with indomethacin significantly increased the NK activity of normal and RA PB but had no effect on that of SF. These observations suggest that the NK activity may be reduced in both PB and SF of RA and that functional differences between populations of cells with NK-like activity and/or differences in the control or modulation of NK activity exist between PB and SF.

Adult↗
PubMed1984

Regulation of natural killer cell activity by macrophages in the rheumatoid joint and peripheral blood.

Recently, in another study, we observed that indomethacin, a prostaglandin synthetase inhibitor, significantly increased NK activity in both normal and rheumatoid arthritis (RA) peripheral blood (PB) but not in RA synovial fluid (SF). Because macrophages are a major source of prostaglandins, we examined the effect of macrophage-enriched adherent cells (AC) on NK activity as measured by a 3-hr Cr-release assay with K 562 cells. The removal of AC resulted in increased (p less than 0.01) NK activity in both normal and RA PB. In contrast, the removal of AC from RA SF resulted in a significant decrease (p less than 0.001) of NK activity. By using only nonadherent cells (NAC), NK activity in RA SF and synovial tissue (ST) was significantly reduced when compared to autologous RA PB (p less than 0.001). Enhancement of NK activity of SF NAC by both poly I:C and IL 2 was not dependent on AC. Mixing experiments demonstrated that the addition of synovial AC for 16 hr increased NK activity of synovial NAC to a level similar to that of unseparated mononuclear cells, whereas autologous PB AC suppressed NK activity of PB NAC. PB AC, when added to SF NAC, also increased NK activity. Supernatants from synovial mononuclear cells were stimulatory of synovial NAC NK activity, whereas normal PB mononuclear supernatants were suppressive. These observations document 1) a significant reduction of NAC-mediated NK activity in the rheumatoid joint as compared to PB from the same patient, and 2) that AC modulate NK activity differently in the rheumatoid joint as compared to RA or normal PB.

Adult↗
PubMed1983

Natural killing activity in Sjögren's syndrome. An analysis of defective mechanisms.

Natural killing (NK) by peripheral blood mononuclear cells (PBMC) against K562 cells was examined in 27 patients with Sjögren's syndrome and 17 normal controls. NK activity in the patients was significantly reduced compared with normal controls (34.6 +/- 3.4% versus 52.2 +/- 3.4%, P less than 0.001). Patients with secondary Sjögren's had lower cytotoxicity compared with those who had primary Sjögren's (28.5 +/- 5.5% versus 37.3 +/- 4.2%, P less than 0.01). The proportion of PBMC with characteristics of NK cells was not decreased in the patients. NK by normal PBMC was diminished both in the presence of sera from patients with reduced NK and when the effector cells were pretreated with the sera. Pretreatment of target K562 cells did not alter NK activity. Suppression of NK by sera from patients did not correlate with levels of immune complexes or with antilymphocyte antibodies. Some patients had adherent cells which inhibited NK function. Addition of either indomethacin or catalase partially restored NK activity in such patients, indicating that both prostaglandins and hydrogen peroxide play a role in suppression. These data suggest that multiple mechanisms are involved in the defective NK activity seen in patients with Sjögren's syndrome. The reduction of NK activity in Sjögren's syndrome may contribute to the increased incidence of lymphoid malignancy.

Adult↗
PubMed1978

A new form of automatic watering system for laboratory animals.

During a 2 1/2 year trial of this new system no algal or bacterial build-up occurred, and filters were changed only at infrequent intervals. Among the labour-saving advantages of it is that cleaning of the system can be done when cage racks are changed, normally monthly.

Animals↗
PubMed1977

Plasticity in mammalian skeletal muscle.

While it has been recognized for many years that different limb muscles belonging to the same mammal may have markedly differing contractile characteristics, it is only comparatively recently that it has been demonstrated that these differences depend upon the motor innervation. By appropriately changing the peripheral nerve innervating a mammalian skeletal muscle, it is possible to change dramatically the contractile behaviour of the reinnervated muscle. The manner by which the motor innervation determines the nature of a muscle fibre's contractile machinery is not completely understood, but it appears that the number and pattern of motor nerve impulses reaching the muscle play an important role. The biochemical changes occurring within muscle fibres whose contractile properties have been modified by altered motor innervation include the synthesis of different contractile proteins.

Animals↗
PubMedDate not supplied

Collaboration: an innovative education/business partnership.

Healthy People 2010 initiatives encourage the collaborative partnership goals described in this article. The partnership developed between a UB School of Nursing faculty member, her students, and several case managers at Health-Now Now has been a richly rewarding experience. The opportunities afforded by this partnership have expanded experiences for faculty, students, and case managers in a managed care environment. This partnership has enabled participants to initiate practical, cost-effective methods for improving community-based services. These partnerships should yield significant changes in health behaviors and health outcomes among the American public. Valanis states it most succinctly: "The nurse of the 21st century must innovate, coordinate, and monitor services for populations within the health care system in which she works and interacts with crucial services outside the system. Her or his patient is not only an individual or even the family but the entire community."

Case Management↗