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Abstract Background To determine the effects of supplemental fish oil (FO) on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults. Methods A total of 44 men and women (34 ± 13y, mean+SD) participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO); or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA) and 800 mg/d docosahexaenoic acid (DHA). All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r. Results Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03), a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04), and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08). No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg), RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal) or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05). There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 μg/dL, SO = +0.016 ± 0.272 μg/dL, p = 0.11). There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02) and fat mass (r = 0.661, p = 0.001). Conclusion 6 wk of supplementation with FO significantly increased lean mass and decreased fat mass. These changes were significantly correlated with a reduction in salivary cortisol following FO treatment.

A nonpeptidyl small molecule SB 247464, capable of activating granulocyte-colony-stimulating factor (G-CSF) signal transduction pathways, was identified in a high-throughput assay in cultured cells. Like G-CSF, SB 247464 induced tyrosine phosphorylation of multiple signaling proteins and stimulated primary murine bone marrow cells to form granulocytic colonies in vitro. It also elevated peripheral blood neutrophil counts in mice. The extracellular domain of the murine G-CSF receptor was required for the activity of SB 247464, suggesting that the compound acts by oligomerizing receptor chains. The results indicate that a small molecule can activate a receptor that normally binds a relatively large protein ligand.

These studies were undertaken to examine the in vitro effects of the cysteine pro-drug L-2-oxothiazolidine-4-carboxylic acid (Procysteine) on human immunodeficiency virus expression. Procysteine inhibited HIV expression in human peripheral blood mononuclear cells as detected by measurement of supernatant core antigen. In transient transfection assays, Procysteine inhibited gene expression controlled by the HIV-1 promoter in activated Jurkat cells but not in resting Jurkat cells. Gel-shift assays showed that Procysteine inhibited NF-kappa B DNA binding activity in nuclear extracts. Procysteine did not affect the production of interleukin-2 by peripheral blood mononuclear cells of healthy HIV-seronegative subjects, as measured by bioassay but it decreased the density of cell-surface interleukin-2 receptors detected by flow cytometry after stimulation with phytohemagglutinin (PHA). Thus, Procysteine inhibits HIV expression, HIV promoter activity, and NF-kappa B binding activity in vitro. Procysteine does not affect interleukin-2 production but inhibits interleukin-2 receptor expression in PHA-stimulated peripheral blood mononuclear cells.

The production of transforming growth factor-beta (TGF beta 1) by human monocytes (MN) infected with Mycobacterium tuberculosis and its effects on the intracellular fate of the organism were studied. M. tuberculosis infection of MN induced both expression of mRNA and secretion of tumor necrosis factor-alpha (TNF alpha) and TGF beta 1 protein. Neutralizing antibody to TGF beta 1 reduced the intracellular growth of M. tuberculosis. The growth-enhancing effects of TGF beta 1 could not be explained by increased initial bacterial load. Preculture with TGF beta 1 decreased uptake of M. tuberculosis. Exposure of MN to increasing concentrations of TGF beta 1 before or after infection with M. tuberculosis accelerated intracellular bacterial replication. Both TNF alpha and interferon-gamma (IFN-gamma) limited mycobacterial replication. TGF beta 1 (10 ng/mL) abrogated the bacteriostatic effects of TNF alpha and IFN-gamma. Within the infected focus, TGF beta 1 produced by mononuclear phagocytes may play an important role in the pathogenesis of tuberculosis, in part by modulating the response to potentially protective cytokines such as TNF alpha and IFN-gamma.

We have developed a novel method for screening a Mycobacterium bovis (BCG) cosmid library in Mycobacterium smegmatis for the detection of immunostimulatory T-cell antigens (Ag). Distinctive protein banding patterns were demonstrated in culture filtrates of three of 30 recombinant M. smegmatis clones: pBCCS13 (41 and 73 kDa); pBCCS221 (30, 50 and 68 kDa); pBCCS223 (100 kDa). Western immunoblots indicated that monoclonal antibodies (mAb) directed to the previously characterized 19-, 30-, 38-, 65- and 71-kDa mycobacterial Ag were not reactive with the distinctive recombinant proteins. Furthermore, T-cell Western blots demonstrated that fractions containing the distinctive proteins were immunostimulatory. A given tuberculin-positive donor expressed unique patterns of blastogenic reactivity to protein fractions isolated from each of the three recombinant clones. Restriction enzyme digests of the three recombinant BCG inserts revealed distinctive DNA-banding patterns. The immunostimulatory Ag, therefore, are most likely encoded within different regions of the BCG genome, as contained within three distinct inserts. T-cell Western blots further indicated a heterogeneity in the repertoire of BCG-responsive T cells since tuberculin-positive donors varied in the pattern of reactivity to protein fractions isolated from the same recombinant filtrate. Most likely, immunity to M. tuberculosis results from activation of a heterogeneous array of T cells targeted to multiple immunostimulatory Ag. The method we describe should greatly enhance our ability to define the full spectrum of T-cell Ag encoded by mycobacteria, particularly those which are secreted proteins.

This study demonstrated for the first time that bone marrow is a target of enhanced in vivo monocytopoiesis in hyperlipemia. A significantly greater number of bone marrow cells (BMC) were recovered per femur in swine fed a hyperlipemic (HL) diet compared with swine fed a normal (N) diet. In addition, a significantly elevated number of monocytic precursors proliferated in HL-swine compared with N-swine BMC cultures grown in standardized media in the absence of an exogenous source of colony stimulating factor (CSF). HL-swine sera stimulated a significant enhancement in the number of proliferating monocytic precursor cells, regardless of whether or not the BMC were from HL- or N-swine. In addition, HL-swine compared with N-swine BMC demonstrated an enhanced intrinsic capacity to form monocytic colonies in culture, irrespective of the source of swine sera used to stimulate growth.