Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA).

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Interest and informational preferences regarding genomic testing for modest increases in colorectal cancer risk.

BACKGROUND/AIMS: This study explored the interest in genomic testing for modest changes in colorectal cancer risk and preferences for receiving genomic risk communications among individuals with intermediate disease risk due to a family history of colorectal cancer. METHODS: Surveys were conducted on 272 men and women at intermediate risk for colorectal cancer enrolled in a randomized trial comparing a remote personalized risk communication intervention (TeleCARE) aimed at promoting colonoscopy to a generic print control condition. Guided by Leventhal's Common Sense Model of Self-Regulation, we examined demographic and psychosocial factors possibly associated with interest in SNP testing. Descriptive statistics and logistic regression models were used to identify factors associated with interest in SNP testing and preferences for receiving genomic risk communications. RESULTS: Three-fourths of participants expressed interest in SNP testing for colorectal cancer risk. Testing interest did not markedly change across behavior modifier scenarios. Participants preferred to receive genomic risk communications from a variety of sources: printed materials (69.5%), oncologists (54.8%), primary-care physicians (58.4%), and the web (58.1%). Overall, persons who were unmarried (p = 0.029), younger (p = 0.003) and with greater cancer-related fear (p = 0.019) were more likely to express interest in predictive genomic testing for colorectal cancer risk. In a stratified analysis, cancer-related fear was associated with the interest in predictive genomic testing in the intervention group (p = 0.017), but not the control group. CONCLUSIONS: Individuals with intermediate familial risk for colorectal cancer are highly interested in genomic testing for modest increases in disease risk, specifically unmarried persons, younger age groups and those with greater cancer fear.

Impairment of human lymphocyte function by bile salts.

Since there appears to be an association between depressed lymphocyte function and liver disease, the effect of bile salts on lymphocyte function was determined in vitro. Peripheral lymphocytes from normal volunteers were incubated with varying concentrations of three bile salts (chenodeoxycholate, deoxycholate, or ursodeoxycholate) and stimulated by the mitogens phytohemagglutinin or concanavalin. The three bile salt concentrations used in these experiments were 75, 100, and 250, mumol/L, which are similar to serum levels found in various types of liver disease. Blast transformation, as measured by tritiated thymidine incorporation, was significantly depressed by all three bile salts at all concentrations and with both mitogens. Suppression increased with the higher bile salt concentrations. However, ursodeoxycholate suppressed lymphocyte function significantly less than did either chenodeoxycholate or deoxycholate. These data suggest that elevated serum bile levels associated with liver disease may contribute to immunosuppression and that ursodeoxycholate, an epimer of chenodeoxycholate that is used for gallstone dissolution, depresses lymphocyte function significantly less than does chenodeoxycholate.

A model of psychological dependence in adolescent substance abusers.

Adolescent substance abuse appears to have its foundations in a distortion of perceived events at an age prior to involvement with substances. Substances are used as a compromise in an attempt to establish a lifestyle which has meaning to the individual. Because the individual's involvement with a substance has taken place during the crucial developmental phase of adolescence, and because the use of drugs alters one's perception of one's social, emotional and cognitive state, any experience during this time must, by necessity, be distorted. At the same time, other experiences, necessary for natural development into adulthood, are forsaken . Thus, certain learned skills are replaced by those learned whilst under the influence of substances or as a reaction to the substance abusing lifestyle. The latter two often being inappropriate in drug-free situations. As the abuse of substances severely hampers the individual's natural development, a model of Developmental Habilitation is the essence of change.

The preparation of stable phosphorylcholine-erythrocyte conjugates for use in plaque assays.

A method for the preparation of stable phosphorylcholine-conjugated erythrocytes is described. This method employs the formation of active esters of phosphorylcholine hydroxyphenylacetic acid (PC-HPA) and results in coupled red cells which are completely stable for 2-3 weeks. Using this procedure up to 80% of the activity was demonstrable after 6 weeks. Cells coupled with PC-HPA are suitable for the demonstration of anti-idiotype effects in a plaquing assay.

Prediction of sepsis in the multitraumatic patient by assays of lymphocyte responsiveness.

In vitro lymphocyte response to antigens, mitogens and in mixed lymphocyte culture were studied at intervals after injury in 31 patients with extensive trauma. Mean responses were significantly depressed up to 15 to 20 days. Responses were lower and the duration of suppression longer in those patients who become infected, and the suppression of response preceded the onset of infection. Extremely low responses were found in three patients who later died. This in vitro system is suitable for the serial monitoring of patients, as it reflects the extent of injury, infectious sequelae and prognosis. Its results are quantifiable and avoid the problems associated with repeated skin testing.

Suppression of lymphocyte function after aortic reconstruction. Use of nonimmunosuppressive anesthesia.

Serial estimations of lymphocyte responses to antigens and mitogens and in mixed lymphocyte culture in 13 major vascular surgical patients were carried out before and after operation, which was performed using anesthetic agents that have been shown not to depress lymphocyte function. All responses were significantly depressed up to five to eight days, and some up to nine to 11 days. Such depression, attributable to surgical trauma, may underline the vulnerability to infection of these patients who are having prostheses inserted.

Suppressor cell activity after major injury: indirect and direct functional assays.

In vitro responses to streptokinase-streptodornase (SKSD), mumps, and mixed lymphocyte culture (MLC) in 19 burned and 13 multitrauma patients were studied sequentially by lymphocyte tritiated thymidine incorporation and compared to responses of 28 normals. Mean responses to SKSD remained significantly depressed from normal for up to 14 to 28 days following injury: MLC responses, significantly depressed at 48 hours, recovered promptly to normal levels. Because of evidence that the proliferative capacity of the T-cell population to soluble antigens is contained within the inducer subpopulation while both inducer and suppressor subpopulations respond in MLC, the observed increase in MLC responses, coupled with a sustained depression of SKSD and mumps responses, suggests activation of a population of suppressor cells. In a direct assay of suppressor cell function, lymphocytes from three or four multitrauma patients incubated in a two-way MLC with normal lymphocytes significantly suppressed PHA responsiveness, confirming the findings of the direct assay.

Inhibition of graft rejection by LPS: further evidence for effects on T lymphocytes.

The effects of bacterial lipopolysaccharides (LPS) on the growth of allografted lymphoma cells in Balb/c mice were studied. It was determined that the injection of LPS at the time of graft implantation resulted in a transient proliferation and a delay in the rejection of the graft. This effect was not attributable to any enhancement of proliferation of the lymphoma cells by LPS nor to any activity of LPS as a competing antigen or as a polyclonal activator of antibody formation. The in vitro cytotoxicity of peritoneal macrophages from LPS-treated animals against allogeneic lymphoma cells was equal to that of mice not treated with LPS. In vitro proliferation responses of splenic lymphocytes from LPS-treated animals indicated that LPS treatment produced a differential depression of Concanavalin A (Con A) responses but phytohemagglutinin (PHA)-induced responses were elevated significantly. These results suggest that the LPS-induced impairment of cell-mediated immunity involves a subset of Con A reactive T cells whose function is important in allograft rejection.

Lipopolysaccharide-induced activation of suppressor cells: reversal by an agent which alters cyclic nucleotide metabolism.

The effects of bacterial lipopolysaccharides (LPS) on the suppressor activity of mouse spleen cells were examined. Pretreatment with LPS was shown to induce suppressor activity in vivo and in vitro. Concurrent treatment of spleen cells with LPS and imidazole, an agent which increases the activity of cyclic nucleotide phosphodiesterases and hastens the degradation of cyclic AMP, reversed the suppressor-inducing effects of LPS. In vitro treatment of spleen cells with aminophylline, an agent which inhibits phosphodiesterase activity, had no effect on suppressor activity. The reversal of LPS-induced suppressor activity by imidazole was time-dependent and addition of this agent 20 hr after LPS treatment did not reverse suppression. These data are consistent with the hypothesis that LPS-induced suppressor activity may be mediated via cyclic AMP-dependent pathways.

Longitudinal assay of lymphocyte responsiveness in patients with major burns.

Serial blast transformation in vitro was measured in peripheral lymphocytes from 38 patients with major thermal injury. Lymphocytes were tested with the antigens streptokinase-streptodornase (SKSD), mumps and purified protein derivative (PPD), the mitogens concanavalin A (Con A) and phytohemagglutinin (PHA), and in the one-way mixed lymphocyte reaction. Statistically significant suppression by the burn injury was noticed in all measurements except response to PHA. One-time measurements were not significantly different between the patients who survived and the patients who did not survive their burn injuries. However, serial determinations of responsiveness to the three natural antigens SKSD, mumps and PPD, as well as the mixed lymphocyte reaction accurately reflected prognosis.