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Biomedical subjects

A Georgopoulos

Publications and source records attributed to A Georgopoulos.

At least 73 records · Page 4Linked to original sources
PubMed1996

High-dose catecholamine treatment decreases polymorphonuclear leukocyte phagocytic capacity and reactive oxygen production.

Flow cytometry was used to study phagocytic function (uptake of fluorescein isothiocyanate-labeled bacteria) and release of reactive oxygen products (dihydrorhodamine 123 converted to rhodamine 123) following phagocytosis by neutrophil granulocytes of heparinized whole blood treated with adrenaline, noradrenaline, dopamine, dobutamine, or orciprenaline. Reduced neutrophil phagocytosis and reactive oxygen production were seen at 12 micrograms of adrenaline per liter (72% each compared with control values); at 120 micrograms of noradrenaline (72% each), dobutamine (83 and 80%, respectively), and orciprenaline (81 and 80%, respectively) per liter; and at 100 micrograms of dopamine per liter (66 and 70%) (P < 0.05 for all). At these dosages, neutrophil chemotaxis was reduced to < 50% of control values for all catecholamines. Treatment with catecholamines at lower dosages had no significant effect on phagocytosis or generation of reactive oxygen products or chemotaxis. The phagocytic capacity of granulocytes was related to the generation of reactive oxygen products (r = 0.789; P < 0.05). The results demonstrate that catecholamines have a suppressive effect on the response of phagocytic cells to bacterial pathogens at high therapeutic levels in blood.

Adult↗
PubMed1996

Influence of stress ulcer prophylaxis on translocation of bacteria from the intestinal tract in rats.

Clinical studies in critically ill patients suggest an increased rate of septicemia during stress ulcer prophylaxis with H2-blockers when compared with sucralfate, a topically active compound. In the present study we examined the effect of stress ulcer prophylaxis with sucralfate as compared with ranitidine versus untreated animals in a rat model on intestinal flora and on the translocation of bacteria from the intestinal tract. The translocation of bacteria was also determined after induction of hemorrhagic shock and, in addition, we examined bacterial translocation in animals infected with a multiple resistant Escherichia coli and following antibiotic therapy with vancomycin and gentamicin during stress ulcer prophylaxis with and without hemorrhagic shock. Male Wistar rats, which received standard meals either without stress ulcer prophylaxis or with ranitidine/sucralfate were investigated. After induction of hemorrhagic shock we analysed qualitatively and quantitatively the bacterial flora in the gastrointestinal tract, blood, mesenteric lymph nodes and visceral organs (liver, spleen). In the absence of shock no changes of the intestinal flora and no translocation of bacteria from the gut were observed in control animals nor during stress ulcer prophylaxis. However, after induction of hemorrhagic shock there was a pronounced bacterial translocation in control animals and during ranitidine, whereas the translocation rate was reduced in animals treated with sucralfate (p < 0.05). During massive E. coli challenge both without and with shock a significantly higher rate of translocation was found in all three experimental groups there were no significant differences between the three groups. We conclude that a) bacterial translocation is low or absent in healthy animals, b) hemorrhagic shock induces a massive increase in bacterial translocation, c) stress ulcer prophylaxis with sucralfate reduces translocation of bacteria during the shock state and c) during massive bacterial overgrowth and/or concomitant shock none of the treatments can reduce the massively elevated rate of bacterial translocation.

Animals↗
PubMed1995

Amoxicillin concentrations in nasal secretions of patients with acute uncomplicated sinusitis and in paranasal sinus mucosa of patients with chronic sinusitis.

In this prospective randomized clinical study a total of 59 patients of both sexes (above 18 years of age) were enrolled. Thirty patients with acute sinusitis were randomly allocated to two treatment groups, one group receiving 1000 mg amoxicillin every 12 h for 10 days and the other group receiving 500 mg amoxicillin every 8 h for 10 days. The median concentration of amoxicillin in nasal secretions was 2.34 micrograms/ml in the 12-h administration group and 1.95 micrograms/ml in the 8-h administration group. Median bioavailability of antibiotic at 8-24 h did not show any statistical differences between the two treatment schemes [probability (Z) = 0.2]. Twenty-nine patients with chronic sinusitis were then randomly allocated to three groups, with patients receiving 1000 mg amoxicillin at 12, 8 or 6 h before nasal and/or sinus surgery was carried out. The mean amoxicillin concentrations in mucosal tissues removed intraoperatively ranged from 0.69 to 0.99 microgram/g samples. Statistical evaluation by analysis of variance did not show any statistically significant differences among the three treatment groups [probability (F) = 0.1705]. In all cases of acute and chronic sinusitis, amoxicillin concentrations exceeded minimum inhibitory concentration values for pathogens common in sinusitis. Our results indicate that 1000 mg amoxicillin administered twice daily produces tissue concentrations high enough to be clinically effective in patients with either acute or chronic sinusitis.

Acute Disease↗
PubMed1995

Regulatory sites and effectors of D-[3H]aspartate release from rat cerebral cortex.

To study the effect of agents interfering with the biosynthesis and/or the K(+)-evoked Ca(2+)-dependent release of neurotransmitter glutamate, rat cerebral slices were preincubated with Krebs-Ringer-HEPES-glucose-glutamine buffer (KRH buffer), loaded with D-[3H]aspartate and superfused with the preincubation medium in the presence or in the absence of Ca2+. The difference in radioactivity release divided by the basal release per min under the two conditions represented the K(+)-evoked Ca(2+)-dependent release. The agents used were: 1) Aminooxyacetic acid (AOAA), the inhibitor of transaminases, 2) Leucine (Leu), the inhibitor of phosphate activated glutaminase (PAG), 3) NH4+, the inhibitor of PAG, 4) Phenylsuccinic acid (Phs), the inhibitor of the mitochondrial ketodicarboxylate carrier, 5) ketone bodies, the inhibitors of glycolysis, 6) the absence of glutamine, the substrate of PAG. The results show that Leu, NH4+, Phs and the absence of Gln significantly increase the K(+)-evoked Ca(2+)-dependent release of radioactivity by 64%, 200%, 95% and 147% respectively, indicating that these agents are inhibitors of the K(+)-evoked Ca(2+)-dependent release of glutamate. Ketone bodies and AOAA had no effect. These results indicate that the major if not the exclusive biosynthetic pathway of neurotransmitter glutamate in rat cerebral cortex is through the PAG reaction and support a model for the pathway followed by neurotransmitter glutamate i.e. glutamate formed outside the inner mitochondrial membrane has to enter the mitochondrial matrix or is formed within it from where it can be extruded to supply the transmitter pool in exchange of GABA.

Animals↗
PubMed1995

Application of microdialysis to clinical pharmacokinetics in humans.

OBJECTIVE: Measurement of drug concentrations in tissues would be useful for clinical pharmacokinetic studies, but appropriate experimental methods are not available at present. The aim of this study was to assess the scope and limitations of the microdialysis technique for human tissue pharmacokinetic studies. METHODS: Microdialysis probes were inserted into the medial vastus muscle or the periumbilical subcutaneous adipose layer of 13 healthy volunteers. Thereafter, volunteers received either acetaminophen (paracetamol, 1000 mg orally) or gentamicin (160 mg, intravenous bolus). Drug concentrations were monitored in plasma, muscle, and subcutaneous tissue. Calibration of the microdialysis probes was carried out in vitro and in vivo with use of the retrodialysis method. RESULTS: For both model compounds, complete concentration versus time profiles in muscle and subcutaneous tissue could be obtained. Major pharmacokinetic parameters (absorption half-life, elimination half-life, maximum concentration, time to reach maximum concentration, area under the curve, and area under the inhibitory curve) were calculated for tissues; tissue/plasma concentration ratios could be derived. Reproducibility of tissue drug concentration measurements was high. CONCLUSIONS: We have shown that microdialysis sampling is a suitable tool for measuring drug concentrations in human muscle and subcutaneous tissues. Microdialysis is readily applicable, relatively noninvasive, and reproducible. This technique may become a valuable addition for pharmacokinetic characterization of selected drugs.

Acetaminophen↗
PubMed1995

Effects of macro- and microcirculatory functions on ceftriaxone concentrations in tissues of patients with stage IV peripheral arterial occlusive disease.

The objective of the study was to determine the ceftriaxone levels achievable within lesions (toe or forefoot area) in patients with septic gangrene and to investigate the relationship between macro- and microcirculatory parameters and antibiotic concentration. Fifteen patients with severe chronic peripheral occlusive disease received an intravenous injection of 2 g of ceftriaxone. Antibiotic levels in venous and capillary blood and in an exudative part of the lesion were measured. Macrocirculatory functions were assessed by Doppler sonography, plethysmography, and angiography; microcirculatory functions were assessed by quantitative capillaroscopy and fluorescence video microscopy. The mean antibiotic concentrations measured between 4 and 8 h after injection were 92 +/- 26 micrograms/ml in venous blood and 84 +/- 46 micrograms/ml in capillary blood. The concentration in tissue reached its maximum 4 h after injection; the average concentration at between 2 and 8 h was 95 +/- 55 micrograms/ml. Only dynamic capillary parameters showed significant (P < 0.01) correlations to antibiotic levels in tissue. Significantly (P < 0.01) higher levels in tissue were observed in patients with adequate microcirculatory functions (138 +/- 48 micrograms/ml) than in patients with poor microcirculatory function (51 +/- 26 micrograms/ml). Microcirculatory dysfunction appears to be the limiting factor for tissue antibiotic levels. However, even those patients with poor microcirculatory function showed tissue antibiotic levels that were above the MICs for the pathogens most frequently isolated from gangrenous lesions. Therefore, intravenous application was found to be adequate and additional measures such as intra-arterial therapy or Bier's occlusion are basically unnecessary. Our finding that microcirculatory function is the limiting factor for the tissue antibiotic concentration is corroborated by computations based on a three-compartment model.

Aged↗
PubMed1994

Diabetic postprandial triglyceride-rich lipoproteins increase esterified cholesterol accumulation in THP-1 macrophages.

The risk of cardiovascular disease is increased in subjects with insulin-dependent diabetes mellitus (IDDM), although the mechanism remains unclear. To assess whether diabetic postprandial triglyceride (TG)-rich lipoprotein (TGRLP) subfractions (Sf > 400, 100-400, and 20-100) isolated from non-obese, normolipidemic IDDM subjects (n = 14) are potentially more atherogenic than lipoproteins from normal controls (n = 13), we measured cholesteryl ester (CE) synthesis and esterified cholesterol (EC) mass accumulation in THP-1 macrophages incubated with postprandial TGRLP. Diabetic Sf > 400 and Sf 100-400 but not Sf 20-100 significantly increased the mean (+/- SE) rate (pmol/mg cell protein/24 h) of CE synthesis in THP-1 macrophages compared with normal controls (Sf > 400, 673 +/- 26 v 301 +/- 64, P < .025; Sf 100-400, 560 +/- 27 v 298 +/- 39, P < .0005; Sf 20-100, 743 +/- 51 v 831 +/- 45). As well, all three diabetic TGRLP increased the mass of EC (microgram EC/mg cell protein/48 h) as compared with normal controls (Sf > 400, 4.9 +/- 0.61 v 2.9 +/- 0.50, P < .025; Sf 100-400, 5.7 +/- 0.91 v 3.4 +/- 0.34, P < .05; Sf 20-100, 5.4 +/- 0.7 v 3.2 +/- 0.52, P < .05). This effect is sustained for at least 7 hours postprandially and is greater than that of fasting Sf 100-400 (P < .03) and Sf 20-100 (P < .05) and similar to malondealdehyde low-density lipoprotein (MDA-LDL). To assess the mechanisms involved, the chemical composition and cellular degradation of diabetic and control lipoproteins were compared. Postprandial diabetic Sf 100-400 had abnormal composition (phospholipid to protein ratio, 1.86 +/- 0.14 v 1.5 +/- 0.13, P < .05) and in preliminary experiments demonstrated increased cell association (mean +/- SD at 6 hours, 126 +/- 34.3 v 57 +/- 4.2) and degradation (584 +/- 141 v 254 +/- 13) compared with that of normal controls, and may account for the observed increase in EC accumulation. In summary, postprandial diabetic Sf > 400 and Sf 100-400 TGRLP increase CE synthesis and Sf > 400, Sf 100-400, and Sf 20-100 lipoproteins increase EC accumulation in human macrophages compared with normal control lipoproteins. Diabetic Sf 100-400 lipoproteins have abnormal composition and seem to have increased cellular association and degradation compared with normal lipoproteins. Our findings suggest a role for postprandial TGRLP in the increased risk of cardiovascular disease among subjects with IDDM.

Cell Line↗
PubMed1994

Intraperitoneal insulin delivery decreases the levels of chylomicron remnants in patients with IDDM.

OBJECTIVE: To investigate whether intraperitoneal insulin (IPII) decreases the levels of circulating chylomicron remnants in patients with insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: Eight nonobese, normolipidemic IDDM patients were studied twice: before (while on subcutaneous insulin) and 6 months after initiation of IPII by a programmable implanted medication system. Fasting and mean blood glucose, HbA1, and lipid values were determined. Blood samples were also drawn before and every 2 h for 10 h after ingestion of a fat meal (corn oil + Vitamin A). Triglycerides (TGs), apolipoprotein B (apoB), and retinyl esters were determined over time in two TG-rich lipoprotein subfractions (Sf > 100 and Sf20-100) isolated from plasma by density-gradient ultracentrifugation. RESULTS: IPII slightly decreased the mean blood glucose from 7.8 +/- 1.1 to 7.4 +/- 1.1 mmol/l (mean +/- SD, P = 0.027, paired Student's t test) and the HbA1 from 9.4 +/- 1.5 to 8.7 +/- 1.2 (NS). TG and apoB levels in postprandial Sf > 100 and Sf20-100 were not changed by IPII. On IPII, however, retinyl ester levels in Sf > 100 decreased (P = 0.05, analysis of variance [ANOVA]) and tended to be lower in Sf20-100 (P = 0.075). In addition, following IPII, the retinyl ester:apoB ratio was lower in Sf > 100 (P = 0.0002) and marginally lower (P = 0.06) in Sf 20-100. CONCLUSIONS: IPII decreased chylomicron remnant levels, which might decrease the atherosclerotic risk in IDDM. Since glycemic control was only slightly improved, the effect was most likely due to the intraperitoneal route of delivery.

Adult↗
PubMed1994

Cell density can affect cholesteryl ester accumulation in the human THP-1 macrophage.

Esterified cholesterol (EC) accumulation was induced in THP-1 macrophages after exposure to acetylated LDL (acLDL), and the extent of accumulation was dependent on cell density. EC mass was 5-fold greater in cells plated at 1.0 x 10(6) cells/35 mm dish compared to cells plated at density 4.0 x 10(6) cells/dish. In addition, [14C]oleate incorporation into EC also increased with decreasing cell number, with 4-fold greater incorporation (6 h: 177 +/- 0.014 vs. 45 +/- 0.001 pmol/mg cell protein, P < 0.001; 24 h: 515 +/- 0.037 vs. 120 +/- 0.012 pmol/mg, P < 0.001) in cells plated less densely compared to cells plated at a higher density. The rate of 125I-labeled acLDL degradation was about 2-fold greater in cells plated at the lower density (105 vs. 60 ng/h per mg cell protein). Northern analysis showed a 2-fold reduction in the expression of human scavenger receptor mRNA in density plated cells, and immunoprecipitation also demonstrated a 2-fold decrease in scavenger receptor protein. Conditioned media did not differentially affect EC formation at either cell density. Fatty acid supplementation increased EC formation and the proportion of esterified sterol content only in cell plated at the higher density. The fatty acid effect was also seen when cells were exposed to beta-VLDL, which induced comparable levels of EC accumulation by non-scavenger receptor-mediated processes in densely plated cells. Foam cell formation in THP-1 macrophages may depend on cell density, which appears to affect both scavenger and non-scavenger receptor activity.

Acetylation↗
PubMed1994

Oropharyngeal decontamination with gentamicin for long-term ventilated patients on stress ulcer prophylaxis with sucralfate?

The incidence of nosocomial pneumonia in long-term ventilated patients has been reduced by stress ulcer prophylaxis with sucralfate. In a double-blind trial we studied whether gentamicin administered topically to the oropharynx (OPG) had additional clinical benefits in these patients. 67 critically ill adult patients fulfilled entry criteria for > or = 5 days on ventilation. The OPG group received 40 mg gentamicin, the control group received 5% dextrose topically administered to the oropharynx 4 times a day. During OPG, pharyngeal colonization rate (21 vs 44%) and tracheal secretion colonization rate (12 vs 41%) were significantly lower than during placebo (p < 0.05). Despite these differences nosocomial pneumonia rate (3 vs 12%), duration of mechanical ventilation [15.8 +/- 11.1 vs 19.9 +/- 37.5 days (means +/- SD)] and mortality (27 vs 41%) were not significantly affected by OPG. Moreover, 13 of 15 bacteria (87%) that occurred during OPG were resistant to gentamicin. Despite its reduction of bacterial colonization rates of pharyngeal and tracheal secretions, OPG did not seem to offer additional clinical benefits in long-term mechanically ventilated patients on stress ulcer prophylaxis with sucralfate.

Administration, Topical↗
PubMed1993

Preliminary study of the efficacy of insulin aerosol delivered by oral inhalation in diabetic patients.

OBJECTIVE: To maximize deposition of an aerosolized dose of insulin (mean +/- SD = 0.99 +/- 0.06 U/kg of body weight) in the lungs of subjects with non-insulin-dependent diabetes mellitus (NIDDM), and investigate its efficacy in normalizing plasma glucose levels during the fasting state. DESIGN: Nonrandomized, placebo-controlled trial. SETTING: A primary care facility. PATIENTS OR OTHER PARTICIPANTS: Six nonobese, nonsmoking volunteers with NIDDM. No subjects withdrew from the study. INTERVENTION: Aerosolized insulin was administered by oral inhalation after a 12-hour period of fasting. Aerosol was generated by a raindrop nebulizer from regular 500 U/mL pork insulin. During inhalation, inspiratory flow was regulated at 17 L/min. Plasma samples were collected after inhalation and analyzed for insulin and glucose levels. MAIN OUTCOME MEASURES: Plasma insulin and glucose levels. RESULTS: Deposition of the aerosol was maximized within the lungs, with 79% +/- 17% of the inhaled dose depositing below the larynx. Geometric mean fasting plasma insulin level was 71 pmol/L (11.8 microU/mL), rising to 269 pmol/L (44.8 microU/mL) after insulin inhalation. Average time to peak insulin level was 40 +/- 34 minutes. The mean fasting plasma glucose level (12.63 +/- 2.59 mmol/L [225.5 +/- 46.3 mg/dL]) was reduced to within the normal range in five subjects and was almost normal in the sixth subject (5.52 +/- 0.89 mmol/L [98.6 +/- 15.9 mg/dL]). Average maximum decrease in plasma glucose from baseline was 55% +/- 10% (n = 6) vs 13% +/- 9% after placebo aerosol inhalation (n = 3). No side effects were reported following insulin or placebo aerosol inhalation. CONCLUSIONS: These preliminary results indicate that a dose of approximately 1.0 U of aerosolized insulin per kilogram of body weight, delivered by oral inhalation and deposited predominantly within the lungs, is well tolerated and can effectively normalize plasma glucose levels in patients with NIDDM.

Administration, Inhalation↗
PubMed1993

Treatment of Candida albicans fungaemia with fluconazole.

Sixty-five patients with Candida albicans fungaemia, admitted to intensive care units, were treated intravenously with fluconazole. All patients had at least one blood culture which was positive for C. albicans. The first group of 34 consecutive patients received fluconazole at a dose of 5 mg/kg bodyweight/day and the subsequent 31 patients received 10 mg/kg/day. Thirty patients in each group were evaluated. The clinical response rate was 60% in the 5 mg/kg once daily group and 83% in the group which received 10 mg/kg/day. Eradication of C. albicans from the blood was achieved in all but two patients in the 5 mg/kg group and in all patients in the 10 mg/kg group. As regards other sites of infection, eradication was achieved in only nine of 25 cases from the 5 mg/kg group and in 11 of 23 cases from the 10 mg/kg group. Death related to fungal infection occurred in eight patients receiving 5 mg/kg/day and in one patient receiving 10 mg/kg/day. Fluconazole was reasonably well tolerated. Raised concentrations of liver enzymes were observed in 14 patients. Other adverse effects were fatigue, nausea, gastric pain, sleepiness and epileptic seizure. In conclusion, fluconazole at a dose of 10 mg/kg/day would seem to be an effective and safe drug for the management of C. albicans fungaemia.

Adolescent↗
PubMed1993

Induction of the release of prostaglandin E2 from polymorphonuclear neutrophil granulocytes by Bacteroides fragilis: its possible role in the pathogenesis of mixed infections.

The presence of anaerobic bacteria, especially of Bacteroides (B.) fragilis, in abdominal abscesses, infected decubitus ulcera, and the infected foot of diabetic patients is well documented. The importance, however, of these microorganisms in the pathogenesis of deep tissue infections has still to be evaluated. Therefore, the aim of this study was to evaluate the potency of B. fragilis as compared to aerobic bacteria widely known for causing inflammation, in inducing the release of prostaglandin E2 from polymorphonuclear granulocytes. Prostaglandin E2 is a potent vasodilator and contributes to edema and erythema, which are part of the inflammatory response. Furthermore, the cAMP-content of the neutrophils was determined after stimulation of the cells with the various bacteria. Of the bacterial species tested, B. fragilis proved to be one of the most potent triggers for prostaglandin E2 release from neutrophils indicating a possible major role of this microorganism in the pathogenesis of mixed infections.

Adult↗
PubMed1993

The efficacy of teicoplanin in the treatment of endocarditis caused by gram-positive bacteria.

Twenty-six patients with endocarditis caused by Streptococcus viridans (n = 12), Enterococcus faecalis (n = 5), Streptococcus bovis (n = 2), Staphylococcus aureus (n = 3) and Staphylococcus epidermidis (n = 4) were treated with teicoplanin at a dose of 600 mg/day in patients with normal renal function (creatinine clearance 80-120 mL/min) and at a dose of 400 mg/day in patients with moderately impaired renal function (creatinine clearance < 75 mL/min). In nine patients valve replacements were performed. Twenty-one patients were cured by medical treatment with teicoplanin, five patients had a surgical intervention during treatment which was subsequently stopped. Overall, eighteen patients with native valve endocarditis were cured. Out of eight patients with prosthetic valve endocarditis six patients were cured. In one patient teicoplanin therapy was withdrawn because of clinical failure. One patient had a clinical relapse. All cultures taken from blood, endocardium and excised artificial valves were sterile after a minimum of seven days therapy. Side effects were seen in seven patients and included a moderate increase in liver enzymes and mild leucopenia. No renal toxicity was observed, trough serum levels of teicoplanin were not correlated with renal function, a slight accumulation of teicoplanin on day 28 being seen. Our study confirms that teicoplanin is effective as single agent therapy in the treatment of endocarditis due to Gram-positive bacteria.

Adult↗
PubMed1993

Bacteria induce release of platelet-activating factor (PAF) from polymorphonuclear neutrophil granulocytes: possible role for PAF in pathogenesis of experimentally induced bacterial pneumonia.

The role of platelet-activating factor (PAF) as mediator of the endotoxin shock and endotoxin-dependent tissue injury has been examined. The ability of opsonized bacteria to stimulate the release of PAF from human polymorphonuclear neutrophil granulocytes was evaluated by measuring both the activity and the amount of the mediator released in the supernatant of the cell-bacteria reaction in vitro. There was no significant difference between gram-positive and gram-negative bacteria in the ability to release PAF from neutrophils. However, preincubation of the cells with the specific PAF receptor antagonist WEB 2170 decreased release of PAF from the cells. Furthermore, a possible protective effect of the PAF antagonist was examined during experimentally induced pneumonia with Klebsiella pneumoniae in NMRI mice. Oral treatment of mice with WEB 2170, followed by infection with the microorganisms, resulted in a considerable increase in the animals' survival (53 to 73%) compared with the control group (40%); this increase corresponded with a decrease in the CFU per gram of lung tissue. These findings indicate an important role of PAF in the pathogenesis of pneumonia in mice.

Animals↗
PubMed1993

Decreased postprandial response to a fat meal in normotriglyceridemic men with hypoalphalipoproteinemia.

The plasma level of high density lipoprotein cholesterol (HDL-C) has been reported to be inversely correlated with the level of triglycerides (TGs) and the magnitude of postprandial lipemia because subjects with low HDL-C accompanying high TG levels often have an increased postprandial response to a fat load. However, information is limited regarding the postprandial response to a fat load in subjects with low HDL-C and normal fasting TG values (hypoalphalipoproteinemia [hypoalpha]). We administered an oral fat load (70 g/m2 of body surface area) to six subjects with hypoalpha and six aged-matched control subjects. Plasma levels of lipids and lipoproteins and the mass of triglyceride-rich lipoproteins (TRLs: Sf > 100 and Sf 20-100) were measured every 2 hours for 8 hours. The mass and chemical composition of Sf > 100 or Sf 20-100 TRLs were not different between the fasting groups; postprandial Sf > 100 but not Sf 20-100 TRLs (mean +/- SD) was significantly lower in subjects with hypoalpha (200.4 +/- 64.8 mg/dL versus 110.6 +/- 50.9 mg/dL; analysis of variance, F test, p = 0.04). In the hypoalpha subjects, the compositions of postprandial Sf > 100 TRLs were TG poor and cholesterol and phospholipid enriched (p < 0.001) while the Sf 20-100 TRLs were enriched in cholesterol and phospholipid but relatively protein depleted (p = 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗