[Acceptance of killing of animals: survey among veterinarians and other professions]. / Akzeptanz des Tötens von Tieren: Umfrage bei Tierärzten und anderen Berufsgruppen.

Professional veterinarians are one of the most affected professions when it comes to killing animals. However, in some situations the opinion about the acceptance of killing of animals differs between people, which can cause a dilemma for the executing person. In a pilot study based on questionnaires, veterinarians from different working fields and students of different branches stated their acceptance of killing of animals in diverse concrete situations. The result clearly demonstrates a higher acceptance of killing of animals among veterinarians with longtime experience in contrast to other groups and the almost same acceptance among agricultural students. The acceptance increased with age, however, we could not find a gender specific difference except of within a narrow age interval. The variability of acceptance within the same profession group differs between the situations. Veterinarians should be aware of their different thinking about killing of animals in some situations compared to other people and should know the reason of such differences. This is important not least to protect themselves and their opinion and to contribute to their societal responsibility by their veterinarian activity.

Methodologies for Quantitative Systems Pharmacology (QSP) Models: Design and Estimation.

With the increased interest in the application of quantitative systems pharmacology (QSP) models within medicine research and development, there is an increasing need to formalize model development and verification aspects. In February 2016, a workshop was held at Roche Pharma Research and Early Development to focus discussions on two critical methodological aspects of QSP model development: optimal structural granularity and parameter estimation. We here report in a perspective article a summary of presentations and discussions.

Altered membrane fluidity and lipid raft composition in presenilin-deficient cells.

The pathology of Alzheimer's disease is closely connected with lipid metabolism. Processing of amyloid precursor protein (APP) is sensitive to membrane alterations in levels of cholesterol and gangliosides. As cholesterol and gangliosides are major components of rafts and BACE I and gamma-secretase are supposed to be localized to rafts there might be a yet unknown biological function underlying this connection. Increasing evidence shows a close connection between cholesterol homeostasis and APP processing and Abeta production respectively. We measured membrane fluidity by anisotropy determination, isolated detergent resistant membrane (DRM) fractions from membrane preparations and determined cholesterol content of these fractions by a coupled enzymatic assay. We found membrane fluidity to be changed in mouse embryonic fibroblasts (MEF) PS1/2 -/- along with altered cholesterol content in DRM fraction of these cells. In addition, total ganglioside levels were enhanced in absence of presenilin (PS).

Phonon dispersion of oriented DNA by inelastic x-ray scattering.

Films of oriented deoxyribonucleic acid (DNA), prepared by the wet spinning method, have been studied using inelastic x-ray scattering. Spectra were recorded within the range of energy transfers -30< homega <30 meV at momentum transfers homegaQ ranging from 2.5 to 30 nm(-1) whereby the direction of Q essentially coincided with the helical axis. Measurements at ambient temperature cover samples in the A, B, C, and D conformations of DNA. Within the limits of the instrumental resolution, the spectra were analyzed by the response of a damped harmonic oscillator delivering dispersion and damping of modes having displacements with nonzero projections onto Q, i.e., essentially the compression waves traveling along the helical axis. The longitudinal speed of sound resulting from the sinusoidal dispersion varies only weakly with conformation. Our sound speed values are compared to results from Brillouin spectroscopy. The dispersion curves exhibit a minimum at about the inverse rise per residue, which -- together with strong elastic scattering -- reflect the large degree of disorder. Overdamping of the modes is observed for Q>5 nm(-1). The possibility that the observed large damping parameters are due to several contributing modes is discussed in terms of a simple model calculation for an idealized double helix. Whereas the quasicrystalline approximation for an effective disordered chain could well describe the sinusoidal dispersion, it fails to reproduce the observed damping by one order of magnitude. Our results indicate that the high-frequency dynamics of DNA is liquidlike and is most appropriately described by instantaneous normal modes of short correlation length.

Prostate cancer and other xenografts from cells in peripheral blood of patients.

Good models for the investigation of human prostate cancer are few. Cells from approximately 9.2-21 ml of peripheral blood from patients with metastatic prostate cancer or metastatic colon cancer were injected s.c. into nude mice. Prostate cancer from 2 of 11 patients and colon cancer from 1 of 3 patients were found to be growing as metastases in the lungs of the nude mice. To our knowledge, this is the first report of the formation of xenografts from carcinoma cells taken directly from the peripheral blood of patients. Expanding circulating cancer cells with this approach may have important translational applications including: (a) development of models of human cancers; and (b) sampling of cancers from specific patients for novel molecular and therapeutic approaches.

Hirudin reduces tissue factor expression and attenuates graft arteriosclerosis in rat cardiac allografts.

BACKGROUND-Intravascular clotting has been implicated in the pathogenesis of cardiac allograft vasculopathy (CAV). We previously identified the expression of tissue factor (TF), the primary cellular initiator of blood coagulation, within the coronary intima, which was associated with neointimal thickening. In the present study, the effect of recombinant hirudin on CAV was assessed in Lewis to Fisher rat heterotopic cardiac allografts. METHODS AND RESULTS-Transplant recipients were randomized to a control group (n=10) and a hirudin-treated group (n=12; 2 mg. kg(-1). d(-1) SC). Histological evaluations of rejection, CAV, and TF staining were performed 120 days after transplantation. No significant differences were observed between the 2 groups with respect to the degree of rejection. Hirudin significantly (P<0.05) suppressed the development of CAV in the graft microvessels, but it was less effective in large coronary arteries. Graft intimal cells, isolated by laser-assisted cell picking, showed a marked upregulation of TF gene transcription, which was prevented by hirudin (P<0.01). As demonstrated by immunohistochemistry and quantitative analyses of TF mRNA levels by real-time polymerase chain reaction, hirudin treatment resulted in a significant reduction of TF protein and mRNA expression (P<0.001). CONCLUSIONS-Treatment with hirudin in this rat cardiac transplant model inhibited TF expression and decreased neointimal hyperplasia. These results suggest that TF inhibition by hirudin, in addition to its direct effect on thrombin, may attenuate the hypercoagulable state and prevent the development of CAV at least in restricted sites of the graft coronary vasculature.

Vitamin E: Curse or Benefit in Alzheimer's Disease? A Systematic Investigation of the Impact of α-, γ- and δ-Tocopherol on Aß Generation and Degradation in Neuroblastoma Cells.

OBJECTIVES: The E vitamins are a class of lipophilic compounds including tocopherols, which have high antioxidative properties. Because of the elevated lipid peroxidation and increased reactive oxidative species in Alzheimer's disease (AD) many attempts have been made to slow down the progression of AD by utilizing the antioxidative action of vitamin E. Beside the mixed results of these studies nothing is known about the impact of vitamin E on the mechanisms leading to amyloid-ß production and degradation being responsible for the plaque formation, one of the characteristic pathological hallmarks in AD. Here we systematically investigate the influence of different tocopherols on Aß production and degradation in neuronal cell lines. MEASUREMENTS: Beside amyloid-ß level the mechanisms leading to Aß production and degradation are examined. RESULTS: Surprisingly, all tocopherols have shown to increase Aß level by enhancing the Aß production and decreasing the Aß degradation. Aß production is enhanced by an elevated activity of the involved enzymes, the ß- and γ-secretase. These secretases are not directly affected, but tocopherols increase their protein level and expression. We could identify significant differences between the single tocopherols; whereas α-tocopherol had only minor effects on Aß production, δ-tocopherol showed the highest potency to increase Aß generation. Beside Aß production, Aß clearance was decreased by affecting IDE, one of the major Aß degrading enzymes. CONCLUSIONS: Our results suggest that beside the beneficial antioxidative effects of vitamin E, tocopherol has in respect to AD also a potency to increase the amyloid-ß level, which differ for the analysed tocopherols. We therefore recommend that further studies are needed to clarify the potential role of these various vitamin E species in respect to AD and to identify the form which comprises an antioxidative property without having an amyloidogenic potential.

In vitro study with ciprofloxacin: interpretive criteria of agar diffusion test according to standards of the NCCLS and DIN.

Regression analyses to determine the correlation between minimal inhibitory concentrations (MICs) and inhibition zones produced by ciprofloxacin disks were carried out using 400 freshly isolated cultures of infective organisms (approximately 20 strains from each of 22 species). It was found in pilot studies that the correlation becomes weaker with increasing disk loads (1, 5, 10, and 30 micrograms). Disks containing 5 micrograms of ciprofloxacin were chosen for comparative studies using Mueller-Hinton agar and methods of the National Committee for Clinical and Laboratory Standards (NCCLS) as well as of the Deutsches Institut für Normung (DIN 58940). Based on preliminary MIC breakpoints (susceptible, 1 microgram/ml or less; intermediate, 2 micrograms/ml; and resistant, 4 micrograms/ml or more) and calculations from regression equations (limited to the MIC range of 0.25 to 32 micrograms/ml), the following zone interpretations using the NCCLS method are recommended: resistant, 15 mm or less; intermediate, 16 to 20 mm; and susceptible, 21 mm or more. The respective values with the DIN method are resistant, 18 mm or less; intermediate, 19 to 22 mm; and susceptible, 23 mm or more.

Altered mitogen-activated protein kinase signaling, tau hyperphosphorylation and mild spatial learning dysfunction in transgenic rats expressing the beta-amyloid peptide intracellularly in hippocampal and cortical neurons.

The pathological significance of intracellular Abeta accumulation in vivo is not yet fully understood. To address this, we have studied transgenic rats expressing Alzheimer's-related transgenes that accumulate Abeta intraneuronally in the cerebral and hippocampal cortices but do not develop extracellular amyloid plaques. In these rats, the presence of intraneuronal Abeta is sufficient to provoke up-regulation of the phosphorylated form of extracellular-regulated kinase (ERK) 2 and its enzymatic activity in the hippocampus while no changes were observed in the activity or phosphorylation status of other putative tau kinases such as p38, glycogen synthase kinase 3, and cycline-dependent kinase 5. The increase in active phospho-ERK2 was accompanied by increased levels of tau phosphorylation at S396 and S404 ERK2 sites and a decrease in the phosphorylation of the CREB kinase p90RSK. In a water maze paradigm, male transgenic rats displayed a mild spatial learning deficit relative to control littermates. Our results suggest that in the absence of plaques, intraneuronal accumulation of Abeta peptide correlates with the initial steps in the tau-phosphorylation cascade, alterations in ERK2 signaling and impairment of higher CNS functions in male rats.

Interpretive criteria for the agar diffusion susceptibility test with ofloxacin.

Regression analyses to determine the correlation of minimal inhibitory concentrations (MICs) and inhibition zones produced by ofloxacin discs were carried out with 300 freshly isolated cultures of infective organisms (20 strains from each of 15 species). After pilot studies, 5 micrograms loaded discs were chosen. Studies were performed simultaneously by using ICS/DIN and Kirby-Bauer/NCCLS methods on Mueller-Hinton agar. It was found that the correlation becomes poorer with increasing disc loads and when the Kirby-Bauer method is used. Based on preliminary MIC breakpoints of greater than or equal to 2 mg/L and greater than or equal to 8 mg/L and by calculations from regression equations, the following zone interpretations using the NCCLS method are recommended: resistant up to 12mm, intermediate 13 to 15mm, susceptible 16mm or more. The values for the DIN method are: resistant up to 13mm, intermediate 14 to 17mm, susceptible 18mm or more. No major errors were found in zone interpretations. Minor errors were observed in 0.7% when the NCCLS method was used, and in 1.3% with the DIN method.

Evidence against a pivotal role of preformed antibodies in delayed rejection of a guinea pig-to-rat heart xenograft.

INTRODUCTION: Whereas the involvement of elicited xenoantibodies in delayed xenograft rejection is currently being substantiated, this study focuses on the role of the preformed fraction of xenoantibodies. METHODS: To check the influence of the latter, we combined pretransplant complement inactivation (cobra venom factor) and antibody reduction (plasmapheresis) in a guinea pig-to-rat heart transplant model. RESULTS: Antibody reduction on plasmapheresis before xenografting did not prolong delayed xenorejection in decomplemented rats, although the immunohistologic pattern lacked the immunoglobulin deposits along endothelial walls found in xenografts of merely decomplemented recipients. Astonishingly, plasmapheresis, if carried out 2 days before transplantation, almost tripled xenograft survival, although preformed antibody levels were completely restored and even rebounding at the time of grafting. The pattern and number of infiltrating cells did not differ in dependence of the timing of plasmapheresis nor did the proliferative response of lymphocytes in the mixed lymphocyte reaction differ. However, plasmapheresis led to a retarded decrease of the mononuclear cell tumor necrosis factor alpha secretory potential, which correlated well with a diminished immunohistologic staining of tumor necrosis factor alpha secreted by graft-infiltrating mononuclear cells. CONCLUSION: These findings argue against a pivotal role of preformed xenoantibodies in the pathomechanistic process of delayed xenograft rejection and challenge the therapeutic strategy to reduce preformed xenoantibody levels before xenotransplantation in complement-inactivated recipients.

Nutrition and allorejection impact of lipids.

Polyene n-3 and n-6 fatty acids are claimed to have immunomodulating properties. The impact of nutritional variations on transplant rejection was therefore studied in the heterotopic rat heart allotransplant model with particular focus on lipids. Twenty per cent fat emulsions with differing n-3/n-6 fatty acid ratios were continuously infused (9 g fat per kg bodyweight per day; n = 10 in each group) after transplantation until rejection: safflower oil (n-3/n-6 = 1/370), fish oil (7.6/1), soybean oil (1/6.5) and a 1:1 mixture of safflower and fish oil (1/2.1; oil control group). Graft survival time, subpopulations of infiltrating and circulating immunocompetent cells and interleukin-6 release by circulating mononuclear cells were analysed. In the safflower oil, fish oil and soybean oil groups graft survival was prolonged to 13.3, 12.3 and 10.4 days vs. 6.7 days in the oil control group and 7.8 days in the saline control group (p < 0.01). In the two groups with the highest prolongation of graft survival the number of infiltrating cells was reduced by up to 50% and the peripheral blood mononuclear cell interleukin-6 release by up to 45%. Beyond that, circulating T-cells were reduced in the fish oil group. The n-3/n-6 fatty acid ratio determines the immunomodulating effect of lipids. Both n-6 and n-3 fatty acids, if applied as the main fatty acid source, exert immunosuppressive effects by diminished infiltration, mobilization and cytokine release by immunocompetent cells. A n-3/n-6 fatty acid ratio of 1/2 proved to be immunologically neutral. The recipient's disposition to reject an allotransplant is influenced by the fatty acid composition of exogenously supplied lipids.

Antimicrobial interactions (synergy) of teicoplanin with two broad-spectrum drugs (cefotaxime, ofloxacin) tested against gram-positive isolates from Germany and the United States.

Teicoplanin, a glycopeptide, has been widely used in some nations alone and in empiric therapy combinations to address infections caused by Gram-positive cocci. However, glycopeptide resistance and the increasing incidence of oxacillin-resistant staphylococci have compromised contemporary chemotherapy. In this study, teicoplanin was tested in combinations with ampicillin, cefotaxime with and without desacetylcefotaxime, and ofloxacin against 151 Gram-positive cocci to assess the potential for enhanced action. The strains included recent isolates from the United States and Germany having well-characterized resistance mechanisms (oxacillin-resistant staphylococci, vancomycin-resistant enterococci), each tested by NCCLS methods, checkerboard synergy tests, and kill-curves. Teicoplanin alone was active (MIC90s, 0.25-2 micrograms/mL) against all species except vanA enterococci. Drug interactions of teicoplanin with beta-lactams revealed synergy and partial synergy versus oxacillin-resistant Staphylococcus spp. (67-100%) and vancomycin-resistant enterococci (70-100%), many at clinically achievable drug concentrations. However, confirming kill-curve experiments showed static action and no significant bactericidal effect. Combinations of ofloxacin with teicoplanin or cefotaxime plus desacetylcefotaxime showed a dominant additive and indifferent interaction. Teicoplanin continues to be a viable alternative to vancomycin, especially in combination therapy with selected broad-spectrum cephalosporins or fluoroquinolones. Many emerging pathogens that test resistant to individual drugs appear to be inhibited by tested combinations, extending their potential clinical utility.

Elevated sister chromatid exchange rate in lymphocytes of the European eel (Anguilla anguilla) with cauliflower tumor.

Sister chromatid exchange (SCE) frequency and chromosomal aberration were studied in cultured lymphocytes from the European eel (Anguilla anguilla) with cauliflower tumors. SCE was significantly increased in the affected fishes compared with normal controls, whereas chromosomal aberration did not. In comparison to normal cells, the lymphocytes responding to phytohemagglutinin M (PHA-M) in cultures from tumorous eels showed no evidence of cell cycle retardation. A possible mechanism for elevation of SCE and the significance of this finding relation to the etiology were discussed.

Comparative in vitro studies on the beta-lactamase-inhibiting effect of clavulanic acid and sulbactam on ampicillin-resistant Enterobacteriaceae.

Clavulanic acid and sulbactam alone are ineffective against Pseudomonas and enterococci. Staphylococci and Enterobacteriaceae are inhibited by high concentrations not attainable under clinical conditions. Strains of Acinetobacter, especially A. lwoffii are susceptible to clavulanic acid and highly susceptible to sulbactam. The ampicillin/sulbactam combination is superior to ampicillin/clavulanic acid against Citrobacter freundii, Enterobacter spp. and Morganella morganii. The latter combination is superior against Klebsiella spp. and Escherichia coli. Antagonistic effects are more frequent with the clavulanic acid combination (Enterobacter spp. and C. freundii) but are rarely observed with the sulbactam combination (Providencia spp. and P. rettgeri).

The influence of sulbactam on the in vitro activity of mezlocillin, piperacillin and cefotaxime.

In a multicentre study, the in-vitro activity of mezlocillin (MEZ, Chemical Abstract Service [CAS] 51481-65-3), piperacillin (PIP, CAS 61477-96-1) and cefotaxime (CTX, CAS 63527-52-6) against mezlocillin-resistant organisms was determined alone and in combination with the beta-lactamase inhibitor sulbactam (SBT, CAS 68373-14-8). A total of 870 strains were investigated (481 Enterobacteriaceae, 57 Pseudomonas aeruginosa, 41 Acinetobacter spp., 194 Bacteroides fragilis and 97 Staphylococcus spp.). MIC values were determined using the agar dilution test (aerobic organisms) or the microbroth dilution test (Bacteroides spp.) in accordance with Deutsche Industrie für Normung 58 940. SBT was added in fixed concentrations of 5 mg/l and 10 mg/l. For all combinations with SBT investigated, the geometric mean of the MIC and the MIC(50) and MIC(90) values were reduced as compared with the antibiotic alone (without SBT). Consequently, the proportion of sensitive strains was appreciably increased, for example in the Enterobacteriaceae: MEZ 1%, MEZ + 10 mg/l SBT 53%; PIP 4%, PIP + 10 mg/l SBT 54%; CTX 52%, CTX + 10 mg/l SBT 68%. The effect of SBT was especially pronounced on Bacteroides spp. For this organism, the proportion of sensitive strain rose from 2% to 97% (MEZ), 6% to 95% (PIP) and from 7% to 98% (CTX). The results show that adding SBT appreciably enhances the activity of MEZ, PIP and CTX against resistant strains of microorganism, and extends the activity spectrum to include anaerobic organisms. Thus the availability of SBT as a single-agent preparation for use in combination with various beta-lacta antibiotics represents a worthwhile enlargement of the therapeutic armamentarium for treating bacterial infections.

Metabolic characteristics of different malignant cancer cell lines.

Extracellular AMP inhibits cell proliferation of MCF-7 and MDA-MB-453 whereas cell proliferation of the highly malignant Novikoff cell line is not affected. In medium with low glucose supply MDA-MB-453 cells grow well, Novikoff cells are slightly inhibited and MCF-7 cells are totally unable to grow. Isoelectric focusing revealed that a glyclytic enzyme complex exists in all three cell lines. In addition to the glycolytic enzymes, c-Raf-kinase, adenylate kinase, and nucleoside diphosphate kinase are also found within the complex. The differences in glucose in dependence of the three cell lines can be explained by the different constitutions of shuttle enzymes. MDA-MB-453 and Novikoff cells contain cytsolic glycerol 3-phosphate dehydrogenase which is associated with glyceraldehyde 3-phosphate dehydrogenase within the glycolytic enzyme complex and which is responsible for the transport of cytoslic hydrogen in the mitochondria. MCF-7 and Novikoff cells contain the pI 7.8 form of malate dehydrogenase which couples glycolysis with glutaminolysis.

Tumor M2-PK and glutaminolytic enzymes in the metabolic shift of tumor cells.

The pyruvate kinase isoenzyme M2-PK is known to be associated with a metabolic shift that is characteristic for tumor cells. Meanwhile, the universal expression of this isoenzyme is the basis for the detection of various tumor diseases in human clinical diagnosis. Other enzymes which are known to be essential for this tumor specific metabolic shift in rat chemical carcinogenesis are the NADP-dependent enzymes malic enzyme, isocitrate dehydrogenase and glucose 6-phosphate dehydrogenase. To evaluate the role of these enzymes in human carcinogenesis, we compared their enzymatic activities in normal colon mucosa and tissues derived from primary colon tumors. Histochemical staining showed that the enzyme activities were restricted to mucosal colon cells and colon cancer cells. The enzymes were strongly but heterogeneously expressed in the tumor tissues, whereas staining of normal mucosa was weak. Tumor M2-PK showed the most prominent differences in normal colon mucosa and colon cancer cells.

Effect of selective ultraviolet phototherapy on DNA and antinuclear antibody titers in psoriatic patients.

The sera of 21 psoriatics treated by selective ultraviolet phototherapy (SUP) for 1-7 months were screened for IgG- and IgM-anti-DNA antibodies and antinuclear antibodies (ANAs) by standardized ELISA and the indirect immunofluorescence technique. No patients developed IgG-antibodies against native DNA under SUP, but two patients increased their IgM-antibody titers five- and tenfold, respectively. The IgG- and IgM-anti-single-stranded-(ss)DNA antibody titers remained unaltered in 38% and 57% of the patients. In 43% and 24%, respectively, they rose to a maximum of three times their original; and in 20% they decreased to a minimum of 40% of their pretherapeutic titers. After 1 month therapy no patient had produced ANAs, but all three patients showing ANAs before therapy had increased titers (one titer step). These remained on the elevated level or were even further increased by one-titer step during progressive therapy. Two patients out of 14 developed low titers of IgM-(1:20) or IgA-(1:40)ANAs against deoxyribonucleoprotein (DNP), initially after 3 months of irradiation; in one of them IgG-ANAs (titer 1:10) against DNP were additionally formed after 6 months of therapy. Our results suggest that lesions in DNA and DNP generated by SUP trigger an immune response to nuclear antigens.

Immunoregulation by parenteral lipids: impact of the n-3 to n-6 fatty acid ratio.

BACKGROUND: The immune system is reported to be influenced by polyunsaturated fatty acids. Therefore, immunoregulation caused by intravenous fat emulsions with different n-3 to n-6 fatty acid ratios was studied in an in vivo model. METHODS: Experimental rat heart allotransplantation served as a defined immunologic challenge. Twenty percent emulsions of safflower oil (n-3 to n-6 = 1:370), fish oil (n-3 to n-6 = 7.6:1), and soybean oil (n-3 to n-6 = 1:6.5), and a 1:1 mixture of safflower oil and fish oil (n-3 to n-6 = 1:2.1) were continuously infused (9 g of fat per kg of body weight per day) after transplantation until complete rejection. The prolongation of graft survival, an accepted parameter of immunosuppression, was assessed. Beyond that, cytokine release by mitogen-stimulated peripheral-blood mononuclear cells (PBMCs) from animals exsanguinated on day 4 after transplantation was evaluated. RESULTS: The mean rejection time was 7.8 days in the sham-infused saline control group and 6.7 days in the safflower- and fish-oil-mixture group (oil control group). Continuous infusion of soybean oil prolonged the graft survival time to 10.4 days, fish oil to 12.3 days, and safflower oil to 13.3 days. PBMC alpha-tumor necrosis factor release was significantly reduced in the fish-oil group (51.9 +/- 13.0 pg/10(6) PBMCs vs 70.8 +/- 10.9 pg/10(6) PBMCs [controls], p < .004). Interleukin-6 release was diminished in both the fish-oil group (22.2 +/- 13.6 pg/10(6) PBMCs vs 40.7 +/- 8.3 pg/10(6) PBMCs [controls], p < .002) and the safflower-oil group (28.4 +/- 6.9 pg/10(6) PBMCs, p < .002). CONCLUSIONS: The n-3 to n-6 fatty acid ratio determined the immunoregulatory potential of intravenous fat emulsions in vivo. Both n-3 and n-6 fatty acids were immunosuppressive when applied as the main polyunsaturated fatty acid sources. PBMC cytokine release was significantly reduced in these groups. The more balanced the n-3 to n-6 ratios, the less immunosuppressive the fat emulsion. There was no immunosuppressive effect at an n-3 to n-6 ratio of 1:2.1.