Postprandial chylomicrons and VLDLs in severe hypertriacylglycerolemia are lowered more effectively than are chylomicron remnants after treatment with n-3 fatty acids.

BACKGROUND: n-3 Fatty acids lower plasma triacylglycerols not only in the fasting state but also in the postprandial state. However, it is not known whether chylomicrons, chylomicron remnants, and VLDLs are all affected equally or whether some lipoprotein species are lowered preferentially. OBJECTIVE: Lipoproteins, including large and small chylomicron remnants, were determined specifically with the aid of a newly developed method involving a combination of size-exclusion chromatography and fluorometric determination of retinyl palmitate, which served as a marker for exogenous fat. DESIGN: Twelve hypertriacylglycerolemic men were treated for 6 wk with 4 capsules containing 85% fish-oil concentrate/d; each capsule contained 850 mg n-3 fatty acid ethyl esters (49.1% eicosapentaenoic acid by wt and 32.2% docosahexaenoic acid by wt). Oral-fat-tolerance tests were performed before and after the treatment. Blood samples were drawn in the fasting state and until 8 h postprandially. RESULTS: Treatment with n-3 fatty acids reduced the fasting VLDL-triacylglycerol concentration by 44% (P < 0.05) and postprandial chylomicrons and VLDLs at 4, 6, and 8 h (P < 0.05) by 49-64% and 36-43%, respectively. Chylomicron remnants were reduced only in the late postprandial phase: large chylomicron remnants by 19% at 6 h and by 43% at 8 h (P < 0.05) and small chylomicron remnants by 31% at 8 h (P < 0.05). CONCLUSION: n-3 Fatty acids effectively lower chylomicrons and VLDLs, but their effect on chylomicron remnants was observed only in the late postprandial phase.

Correlation of serum triglyceride and its reduction by omega-3 fatty acids with lipid transfer activity and the neutral lipid compositions of high-density and low-density lipoproteins.

Serum triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) concentrations are inversely correlated and mechanistically linked by means of lipid transfer activities. Phospholipid transfer activity (PLTA) moves phospholipids among serum lipoproteins; cholesteryl ester transfer activity (CETA), which exchanges cholesteryl esters (CE) and TG among lipoproteins, is stimulated by nonesterified fatty acids (NEFA). The aims of this study were (a) to develop a quantitative model that correlates the neutral lipid (NL = CE + TG) compositions of HDL and LDL with serum TG concentration; (b) identify the serum lipid determinants of CETA and PLTA, and; (c) identify the effects of serum TG reductions on the neutral lipid compositions of HDL and LDL, serum NEFA concentrations, and on PLTA and CETA. These aims were addressed in 40 hypertriglyceridemic subjects before and after treatment with an 85% concentrate of omega-3 fatty acids (Omacor) and in 16 untreated normolipidemic subjects. In vivo, the NL compositions of LDL and HDL were described by a mathematical model having the form of adsorption isotherms: HDL - (TG/NL) = (0.90 +/- 0.07) serum TG/(7.0 +/- 1.2 mmol/l + serum TG) and LDL - (TG/NL) = (0.65 +/- 0.08) serum TG/(4.9 +/- 1.5 mmol/l + serum TG). Reduction of serum TG was associated with reductions in HDL - (TG/NL), serum NEFA concentration, and serum CETA but not PLTA. These data suggest that both hypertriglyceridemia and the attendant elevated serum CETA but not PLTA are determinants of HDL and LDL composition and structure and that serum TG concentrations are good predictors of the NL compositions of HDL and LDL.

Zilascorb(2H), a low-toxicity protein synthesis inhibitor that exhibits signs of anticancer activity in malignant melanoma.

Zilascorb(2H) is a benzaldehyde derivative giving rise to strong protein synthesis inhibition. It has shown antitumor activity against human malignant melanoma grown as xenografts in nude mice. The effect was manifest only after prolonged daily treatment and was quickly reversible when treatment was stopped. Drug-induced fever was the dose-limiting toxicity observed during clinical phase I studies of zilascorb(2H). The object of the present study was to assess antitumor activity, safety and tolerability of the drug in melanoma patients. Sixteen patients with disseminated malignant melanoma were included, all presenting with WHO performance status 0-2 and adequate organ functions. Previous chemo- or radiotherapy was accepted, while patients with known CNS metastases were excluded. Due to its low solubility and quickly reversible activity, zilascorb(2H) 1400 mg was infused by the patients twice daily through a venous access port for up to 12 weeks. Induction of tumor regression was demonstrated in one patient, who was, however, withdrawn from treatment after 2 weeks because of recurrent fever and fatigue. All the 12 patients evaluable for antitumor activity had progressive disease. Zilascorb(2H) was well tolerated, except for fever reactions and reversible liver toxicity. Most patients learned quickly how to handle a venous access port, but daily self-administration of i.v. infusions became too cumbersome to justify further patient inclusion despite the tumor regression observed. We conclude that zilascorb(2H) seems to have the potential for antitumor activity in metastatic malignant melanoma and is well tolerated. Daily self-administration of drug infusions is not desirable for long periods and zilascorb(2H) tablets have been developed. Because of its favorable toxicity profile, especially compared to other protein synthesis inhibitors, zilascorb(2H) may be particularly interesting for combinations with other anticancer drugs.

Soluble cell adhesion molecules in hypertriglyceridemia and potential significance on monocyte adhesion.

Hypertriglyceridemia may contribute to the development of atherosclerosis by increasing expression of cell adhesion molecules (CAMs). Although the cellular expression of CAMs is difficult to assess clinically, soluble forms of CAMs (sCAMs) are present in the circulation and may serve as markers for CAMs. In this study, we examined the association between sCAMs and other risk factors occurring with hypertriglyceridemia, the effect of triglyceride reduction on sCAM levels, and the role of soluble vascular cell adhesion molecule-1 (sVCAM-1) in monocyte adhesion in vitro. Compared with normal control subjects (n=20), patients with hypertriglyceridemia and low HDL (n=39) had significantly increased levels of soluble intercellular adhesion molecule-1 (sICAM-1) (316+/-28.8 versus 225+/-16.6 ng/mL), sVCAM-1 (743+/-52.2 versus 522+/-43.6 ng/mL), and soluble E-selectin (83+/-5.9 versus 49+/-3.6 ng/mL). ANCOVA showed that the higher sCAM levels in patients occurred independently of diabetes mellitus and other risk factors. In 27 patients who received purified n-3 fatty acid (Omacor) 4 g/d for > or =7 months, triglyceride level was reduced by 47+/-4.6%, sICAM-1 level was reduced by 9+/-3.4% (P=.02), and soluble E-selectin level was reduced by 16+/-3.2% (P<.0001), with the greatest reduction in diabetic patients. These results support previous in vitro data showing that disorders in triglyceride and HDL metabolism influence CAM expression and treatment with fish oils may alter vascular cell activation. In a parallel-plate flow chamber, recombinant sVCAM-1 at the concentration seen in patients significantly inhibited adhesion of monocytes to interleukin-1-stimulated cultured endothelial cells under conditions of flow by 27.5+/-7.2%. Thus, elevated sCAMs may negatively regulate monocyte adhesion.

Alterations in serum phosphatidylcholine fatty acyl species by eicosapentaenoic and docosahexaenoic ethyl esters in patients with severe hypertriglyceridemia.

A new and sensitive method has been developed to analyze the molecular species of glycerophospholipids. This method was used to examine the effects of hypolipidemic intervention with n-3 fatty acids on the serum phosphatidylcholine species in severely hypertriglyceridemic patients. The drug treated group (n = 19) received 4 g/day of an 85% concentrate of the ethyl esters of eicosapentenoic and docosahexaenoic acids for 6 weeks. Control patients (n = 21) received 4 g/day of ethyl esters of corn oil fatty acids. To evaluate the effects of n-3 fatty acids upon serum phosphatidylcholines (PCs), sera from treated and control patients were analyzed before and after 6 weeks of intervention. PCs isolated from sera were digested with phospholipase C to diglycerides, derivatized with 7-methoxycoumarin-3-carbonyl azide, and analyzed by reverse phase high performance liquid chromatography (HPLC) with fluorescence detection. Pre-intervention serum PC species were, in order of decreasing concentration C16:0,18:2, C16:0,18:1, C18:0,18:2, C16:0,20:1, C16:0,22:0, C18:0,20:4, C16:0,16:0, C18:0,18:1, C18:1,18:2, C16:0,20:5, and C18:1,20:5. In the treated patients, mean increases of 300% in C16:0,20:5 and of 160% in C16:0,22:6 species were observed. There were no significant changes in the molecular species of the serum phosphatidylcholines in the group receiving the corn oil ethyl esters. The cumulative relative percentages for each of the individual fatty acids measured by HPLC were comparable to those determined by gas-liquid chromatography (GLC). In the treated group plasma triglycerides were reduced 26%, while they were increased by 7% in the placebo group. Our data showed that incorporation of eicosapentaenoic and docosahexaenoic acid into the serum PCs occurred within 6 weeks primarily in the C16:0,20:5 and C16:0,22:6 species and were usually accompanied by a reduction in plasma triglyceride.

Zilascorb(2H), a new reversible protein synthesis inhibitor: clinical study of an oral preparation.

The new anti-cancer drug zilascorb(2H) has shown promising activity in preclinical models. Its putative mechanism of action is reversible protein synthesis inhibition and long-term treatment is required. As a clinical treatment modality, long-term daily zilascorb(2H) infusions, as used in previous studies, are not regarded feasible. Therefore, an oral formulation of the drug was developed, and pharmacokinetic profile, toxicity and antitumor activity of zilascorb(2H) tablets were studied. Thirteen patients with advanced solid cancer not amenable to established therapy, but with adequate performance status and organ functions, were included. The treatment was given as a daily i.v. zilascorb(2H) infusion for 5 days, followed by zilascorb(2H) tablets twice daily for 3 months. Blood and urine sampling was performed when estimated plasma steady-state level was reached for each formulation, respectively. Analyses of drug concentrations in plasma and urine were performed by high performance liquid chromatography. Zilascorb(2H) in tablet formulation had a bioavailability of 32%, was quickly absorbed and slowly eliminated. Concomitant use of the H2-blocker ranitidine possibly enhanced bioavailability. Zilascorb(2H) was well tolerated. Two patients experienced drug-related fever, disturbing the treatment schedule for one of them. Moderate nausea was reported. One objective response was obtained. The bioavailability of zilascorb(2H) tablets was satisfactory. The principle of oral administration of zilascorb(2H) is feasible for long-term treatment and the side effects are acceptable. The mechanisms of action and the very low toxicity of the drug makes it a candidate for combination with other anticancer agents.

Safety and efficacy of Omacor in severe hypertriglyceridemia.

BACKGROUND: Severe hypertriglyceridemia is a risk factor for acute pancreatitis, therefore decreasing serum triglyceride concentrations is an important component of risk management. Omega-3 fatty acids are well known hypotriglyceridemic agents, but their efficacy in severe forms of the disorder is not well documented. Our objective was to examine the effects of Omacor, a drug composed of 85% omega-3 fatty acid ethyl esters. METHODS: Forty-two patients with triglyceride concentrations between 5.65 and 22.60 mmol/l (500 and 2000 mg/dl) were studied in a prospective, double-blind, placebo-controlled trial of Omacor (4 g/day for 4 months). RESULTS: Compared with baseline values, Omacor significantly reduced mean triglyceride concentrations by 45% (P<0.00001), cholesterol by 15% (P< 0.001), very-low-density lipoprotein cholesterol by 32% (P< 0.0001) and cholesterol:high density lipoprotein (HDL) cholesterol ratio by 20% (P=0.0013), and increased HDL cholesterol by 13% (P=0.014) and low-density lipoprotein cholesterol by 31% (P=0.0014). The placebo had no effect on these parameters. Omacor was well tolerated and no patient discontinued medication because of side effects. CONCLUSIONS: Four capsules of Omacor per day markedly decreased triglyceride concentrations in patients with severe hypertriglyceridemia. The availability of a potent and safe omega-3 fatty acid preparation for this patient population should diminish the risk for acute pancreatitis, and may also reduce the long-term risk for cardiovascular disease.

Double-blind comparative trial of Nuelin Depot and TheoDur with adjusted dosage in asthmatic adults.

Equivalent doses of two sustained release preparations of theophylline, Nuelin Depot and TheoDur, were compared in a double blind, cross-over study. Twenty adult outpatients with COLD were given adjusted doses of the two preparations to reach a peak value of theophylline in steady state within the therapeutic range. The study consisted of two 14-day periods and airway function parametres, plasma concentrations, asthma symptoms, and side effects were recorded the last day in each period. In addition morning PEFR, use of beta 2 stimulant aerosol and number of nightly attacks were recorded daily. As judged from the peak-trough variation of 24.8 mumol for Nuelin Depot and 26.3 mumol/l for TheoDur as well as the tmax of 4.3 hours for Nuelin and 3.6 hours for TheoDur, both products produced a similar plasma profile. No statistically significant differences were found between the two preparations with respect to airway function parameters, relief of asthma symptoms, need for beta 2-stimulant aerosol or side effects. In conclusion these two sustained release preparations should be considered equivalent for practical use.