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Biomedical subjects

P Leary

Publications and source records attributed to P Leary.

15 recordsLinked to original sources

A prospective controlled study of cognitive function during an amateur boxing tournament.

BACKGROUND: Few studies have reported acute postbout cognitive function in amateur boxers, and none have documented the effects of repeated boxing bouts within a short time frame. OBJECTIVE: To determine whether participation in a 7-day amateur boxing tournament is associated with acute deterioration in cognitive test performance. METHODS: A prospective study was done of 82 collegiate amateur boxers participating in a 7-day single elimination tournament and a group of 30 matched nonboxing control participants. No participants had a history of recent concussion or past history of brain injury. For boxers, cognitive assessment using a computerized test battery was performed before the tournament and within 2 hours of completing each bout. Tests of simple and choice reaction time, working memory, and learning were administered. Analysis of variance was conducted to compare the serial performance of control participants with that of boxers participating in one, two, and three bouts. RESULTS: The 82 boxers fought 159 times. Cognitive testing was performed after 142 of these bouts. On simple reaction time, choice reaction time, and working memory tasks, the serial performance of boxers participating in three bouts (n = 22) was equivalent to that of boxers participating in two bouts (n = 22) and one bout (n = 32) and to nonboxing control participants (n = 30). An improvement in performance was observed on the learning task in boxers participating in three bouts. Boxers whose bout was stopped by the referee (n = 7) displayed significant slowing in simple and choice reaction time. CONCLUSIONS: With the exception of boxers whose contest is stopped by the referee, amateur boxers participating in multiple bouts during a 7-day tournament display no evidence of cognitive dysfunction in the immediate postbout period.

Adult↗

Comparison of accessory cell functions of endothelial cells and monocytes: IL-2 production by T cells and PFC generation.

It has been previously shown that endothelial cells (EC) can modulate T-cell responsiveness by mimicking monocyte (AC) function in several different in vitro systems. We now report that EC and AC differ quantitatively in their ability to provide help for IL-2 generation and T-cell induced B-cell differentiation into immunoglobulin secreting cells (ISC). Equal numbers of EC were deficient when compared to AC for promoting ISC generation, but exceeded AC for IL-2 production. Adding optimal numbers of EC drive non-adherent cell cultures to produce more than twice as much IL-2 as adding any number of AC. Furthermore, small numbers of EC were capable of modulating ongoing immune responses when added to cultures containing AC. IL-2 production by PBM was doubled by the addition of enough EC to comprise only 3% of the total culture. EC do not just mimic monocytes in immune responses, but modulate these responses in unique ways.

Antibody-Producing Cells↗

Interleukin abnormalities in recently active rheumatoid arthritis.

Peripheral blood lymphocytes (PBL) from 14 patients with rheumatoid arthritis (RA) produced increased amounts of interleukin (IL) (p less than 0.05) as measured in a mouse thymocyte assay and showed enhanced proliferation in response to an IL containing supernatant (p less than 0.05) when compared with 9 age matched controls. Both enhanced IL production (p greater than 0.01) and responsiveness (p less than 0.002) were seen exclusively in a subgroup of 7 patients with a recent onset or exacerbation of their disease. PBL from RA patients with equally active disease which had been unchanged for more than 6 months produced and responded to IL normally. There was a direct correlation between IL production and responsiveness (r = 0.69, p less than 0.005). These 2 distinct IL abnormalities appear to reflect disease initiating or exacerbating factors in RA.

Arthritis, Rheumatoid↗

Evidence for activated peripheral blood T-cells in rheumatoid arthritis.

We have previously demonstrated defective antigen specific T-suppressor (Ts) cell function in the peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA). Our study was designed to delineate whether diminished Ts activity is due to impaired interleukin (IL) dependent clonal expansion of Ts cells or to prior in vivo activation. Patients with recent onset of RA, or a disease flare, exhibited enhanced IL generation (IL-1 and /or IL-2). Increased proportions of active E-rosettes, elevated spontaneous production of IgM, and total immunoglobulin in mitogen free cultures were consistent with the concept of prior lymphocyte activation in vivo. Our results do not support defective clonal expansion of Ts cells as the basis of deficient IL generation, but do support the concept of in vivo activation of PBM cells in some patients with RA.

Adult↗

Relationship between the enhanced expression of histocompatibility antigens on interferon-treated L 1210 cells and their position in the cell cycle.

We have determined the cell cycle position of individual mouse leukemia L 1210 cells by cytophotometric and autoradiographic techniques and simultaneously determined the amount of histocompatibility antigens expressed on the surface of individual cells by quantitative immunofluorescence. Interferon treatment of L 1210 cells was accompanied by an enhanced expression of histocompatibility surface antigens. The distribution of interferon-treated cells in the various phases of the cell cycle was similar to that for control cells and the enhanced expression of histocompatibility antigens was observed on interferon-treated cells in all phases of the cell cycle. We conclude, therefore, that this enhancement is not due to a preferential concentration of these cells in any one particular phase of the cell cycle.

Animals↗

Interferon treatment of mice: enhanced expression of histocompatibility antigens on lymphoid cells.

Treatment of young and mature mice with potent mouse interferon preparations results in a marked enhancement of the expression of histocompatibility antigens on the surface of thymocytes and splenic lymphocytes as measured by an enhanced absorption of alloantiserum. We postulate that such modifications of the cell surface may reflect an effect of interferon on lymphocyte maturation and may be relevant to the effect of interferon on lymphocyte function.

Age Factors↗

Enhanced expression of histocompatibility antigens of lymphoid cells in mice treated with interferon.

Treatment of young and mature mice with potent preparations of mouse interferon results in a marked enhancement of the expression of histocompatibility antigens on the surface of thymocytes and splenic lymphocytes, as measured by an enhanced absorption of alloantiserum. These modifications in the expression of cell surface antigens may reflect an effect of interferon on lymphocyte naturation and may be relevant to theffect of interferon on lymphocyte function.

Animals↗

Enhancement by interferon of the expression of surface antigens on murine leukemia L 1210 cells.

Preparations of mouse interferon enhanced the expression of surface antigens of murine leukemia L 1210 cells, as determined by their alloantibody-absorbing capacity. The factor responsible for the enhancement of surface antigen expression could not be dissociated from the antiviral activity of interferon by standard physicochemical means. Likewise, interferon did not increase the antibody-absorbing capacity of an interferon-resistant subline of L 1210 cells. We conclude that interferon treatment of L 1210 cells is accompanied by modifications of the cell surface.

Animals↗

Enhancement by interferon of the specific cytotoxicity of sensitized lymphocytes.

Mouse interferon preparations enhanced the specific cytotoxicity of sensitized lymphocytes for allogeneic target tumor cells. The factor responsible for the enhancement of cytotoxicity could not be dissociated from the antiviral activity of interferon by standard physicochemical means. Thus, in addition to its well-known antiviral activity, and its effect on cell division, interferon also appears to enhance a specialized cellular function. It is suggested that a common mechanism of action underlies these seemingly different biologic phenomena, and that interferon may play a role in the regulation of fundamental cellular processes.

Animals↗