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Cytokine production by peripheral blood mononuclear cells (PBMC) is a sensitive indicator of cytokine-inducing substances which may cross from contaminated dialysate into the blood compartment. The objective of this study was to compare the transfer of cytokine-inducing substances from dialysate contaminated with a culture filtrate from Pseudomonas aeruginosa across dialyzers with low (hemophan) or intermediate ultrafiltration coefficients (modified cellulose triacetate, CTA), under conditions where either 10% plasma or whole blood was circulated in the blood compartment. Eight paired experiments of in vitro dialysis were carried out at 37 degrees C using a countercurrent recirculating loop dialysis circuit with either a new CTA or hemophan dialyzer. 10% plasma in standard tissue culture medium was circulated through the blood compartment and bicarbonate dialysate was circulated in the dialysate compartment. The dialysate was challenged sequentially by log-fold dilutions (10(2), 10(3) or 10(4)) of a Ps. aeruginosa culture filtrate. Samples were drawn from the blood compartment 5 and 15 minutes after each challenge and incubated with suspensions of PBMC in the absence or presence of polymyxin B, in order to block endotoxin. After 24 h at 37 degrees C, total interleukin-1 alpha (IL-1 alpha) was measured by RIA. Although the dialysate contained potent cytokine-inducing substances, there was no significant IL-1 alpha production by PBMC incubated with the plasma mixture from the blood compartment in the majority of experiments with both dialyzers and with each of the three dilutions of the bacterial challenge. Eight experiments were also performed with CTA dialzyers using heparinized whole blood in the blood compartment. Samples of whole blood and dialysate were drawn at baseline, after one hour of dialysis with uncontaminated dialysate and 15 minutes and three hours after dialysis with dialysate contaminated with Ps. aeruginosa filtrate. There was no significant IL-1 alpha production by PBMC isolated from the whole blood 1 h after dialysis with uncontaminated dialysate, and 15 min and 2 h after adding the Ps. aeruginosa filtrate to the dialysate side. In contrast, production of IL-1 alpha by PBMC from the same donors incubated with samples from the dialysate were 263 +/- 50, 1074 +/- 306, 2333 +/- 774 and 2602 +/- 702 pg/2.5 x 10(6) PBMC, respectively at the same four time points. These data suggest that although the Ps. aeruginosa culture filtrate present in the dialysate was a potent inducer of IL-1 alpha, neither dialyzer permitted transfer of cytokine inducing substances from the dialysate into the blood compartment.

The lack of consensus regarding the significance of transmembrane passage of bacterial products across hemodialysis membranes can be related to several methodological differences in the various studies, including the choice of circulating fluid in the blood compartment of the model, nature and concentration of the bacterial products employed to challenge the dialysate compartment and whether cytokine production by PMBC or the limulus amebocyte lysate (LAL) assay was used as the index of transfer and the cytokine used as the read-out. In this study, we examined the production of interleukin-1 alpha (IL-1 alpha), interleukin-1 receptor antagonist (IL-1Ra) and interleukin-8 (IL-8) by peripheral blood mononuclear cells (PBMC) incubated with a Pseudomonas aeruginosa culture filtrate. Further, the effects of 10% autologous human plasma and Polymyxin B sulfate (PmB) on cytokine production by PBMC were also characterized. The results of our study indicate that the Ps. aeruginosa culture filtrate had both PmB suppressible and PmB non-suppressible components and that the addition of 10% human plasma significantly enhanced cytokine production by both PmB suppressible and PmB non-suppressible components. The enhancing effect of plasma was most evident at low concentrations of the filtrate. The inhibitory effect of PmB was most evident in samples cultured in the presence of 10% plasma. There was a direct correlation between the production of IL-1 alpha and IL-1Ra suggesting that both pro-inflammatory cytokines and cytokine-specific inhibitory proteins are concurrently produced. There results have direct relevance to selection of study conditions for in vitro models used to study the transmembrane passage of bacterial products across hemodialysis membranes.

This study compared bereavement experiences of suicide survivors with those of other survivors. The primary focus of investigation was upon grief reactions suggested to be unique to suicide bereavement and upon quality of grief resolution 2-4 years after death. Fifty-seven women and men, between the ages of 24 and 48, who had experienced the death of a marital partner were interviewed. Subjects were assigned to one of four groups by mode of death (suicide, accident, unanticipated natural, and expected natural). Analyses of variance and Scheffe procedures indicated no significant differences among survivors on frequencies of grief reactions considered common to all bereavements. The suicide survivors were significantly different from all others on certain grief measures, including rejection and unique grief reactions. On various other grief measures, significant differences were indicated among the groups of survivors. Four primary conclusions, implications of the findings, and limitations of the study are discussed.

An electrical potential develops between the ends of a column of hyaluronic salt solution displaced from a resting position by gentle pressure. A previous study demonstrated that such displacement changes the optical rotary dispersion properties of the salt, either increasing the rotation in the direction already shown by the salt before displacement or changing and increasing the rotation in the opposite direction, depending on the direction of the displacement. The present investigation demonstrates that the loss of bound water component across a membrane separating the solution and water is corelated with the extent of the column displacement. In addition, a return of the column to the position before displacement is correlated with a return of the water component across the membrane-but not at the same rate as the exodus. The data seem consistent with the hypothesis that the hyaluronic acid salt, when strained, adopts a less entropic configuration, releasing bound water and thus increasing the entropy of water component. This change in the distribution of entropy is reversible; i.e., Eddington's "time's arrow" is reversible with respect to the water component of the solution.

A sinusoidal signal is generally considered the simplest auditory signal. It is, indeed, a simple signal. However, it does not follow that a complex analysing device, like the cochlea, should treat a simple signal in a simple way. Indeed, a simple signal may appear to be complex when viewed from the standpoint of the device considered. Such an observation becomes cogent when one is attempting to discover the analysing capabilities of a device such as the cochlea, which appears designed to handle signals more complex than a sinusoid or multiple sinusoids.

The theory of cancer induction of ultimate carcinogens by parametric excitation is presented. Attention is drawn to the requirement of an energy transfer in perturbing DNA. The concept of energy transfer by resonance is rejected in favor of energy transfer by parametric excitation of which resonance is a special case. The result, reported here, is a remarkable agreement between the Raman vibrational bands of these ultimate carcinogens, various hypochromic bands of DNA and the predictions of parametric excitation theory. This result suggests that the peculiar relation of an ultimate carcinogen and DNA results in parametrically induced energy transfer in the vibrational mode. The problem, then, of cancer induction becomes one of analytical mechanics.