Effects of postprandial hyperlipemia on the vitamin E content of lipoproteins. GERBAP section Lipoprotéines. Groupe d'Evaluation et de Recherche de l'Assistance Publique des Hôpitaux de Paris

Delayed postprandial clearance of triglyceride-rich lipoproteins (TGRL) could induce a decrease of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) vitamin E content through its transfer into TGRL. We thus studied lipoprotein vitamin E content during postprandial hypertriglyceridemia induced by a high fat meal without vitamin E supplement. Venous blood was drawn from five healthy male volunteers following a 12 h fast at (t0) then 2 h (t2), 4 h (t4), 6 h (t6) and 8 h (t8) after a 80 g fat meal. In plasma, only TG significantly varied during the postprandial period with a large interindividual variability. Mean composition of lipoproteins in terms of mass was not significantly modified. The amount of vitamin E significantly increased in TGRL and decreased in LDL plus HDL at t4 and t6 relative to t0. Vitamin E content of TGRL and LDL but not of HDL decreased significantly at t4. The mean decrease was 20% (range 5%-54%) for the LDL. LDL- and HDL vitamin E content correlated inversely with plasma TGRL levels. Our data suggest that LDL from subjects with delayed chylomicron clearance could be less protected against oxidation.

Characterization of lipoproteins during human cholestasis

We have characterized changes in lipoproteins from cholestatic individuals and reproduced them by incubating lipoproteins from healthy individuals with cholic acid. The cholestatic patients showed an increase in low density lipoprotein (LDL) (>85%), with a smaller proportion of esterified cholesterol, and a fall in high density lipoprotein (HDL) (<10%), with a larger proportion of phospholipids. The protein composition of cholestatic HDL1 was characterized by a smaller proportion of apo A (I, II) and a prominent apo E fraction (39% vs. 9%). These changes involved an increase in degree of molecular packing (order) of HDL1. The addition of cholic acid to serum from healthy individuals altered the lipoprotein distribution, with an increase in LDL, the disappearance of HDL2 and HDL3 and the appearance of HDL1. These HDL1 were characterized by increased phospholipid and reduced apo AI fractions. They also showed a lower density and appeared as spherical particles in contrast to cholestatic HDL. Incubation of healthy HDL with cholic acid in vitro reproduces some of the alteration observed in cholestatic HDL.

[Comparison of Orth-Evac and Solcotrans Plus devices for the autotransfusion of blood drained after total knee joint arthroplasty]

Surgical wound blood which is ched through drains after total knee replacement surgery with a tourniquet may be returned to the patient using special collecting devices. This study aimed to compare two systems, Orth-Evac and Solcotrans Plus an to assess the safety of the reinfusion of non washed blood cells. It included 30 patients scheduled for total knee replacement surgery, free from tumoral or coagulation disease and allocated randomly in three groups of 10 each: the Orth-Evac group (OGr), the Solcotrans Plus group (SGr) and the Control group (CGr). The devices, not containing an anticoagulant, were connected to the deep suction drains in the operating room, after skin closure and before the tourniquet removal. The salvaged blood was reinfused in the subsequent six hours via a 40 microns filter. The volume of collected blood was measured and homologous blood was added as required, to maintain a hematocrit of 30%. A blood sample was obtained the day before surgery (D - 1), before reinfusion (D0), two hours later (D + 2h), one day later (D + 1), and from the collecting device before reinfusion. The statistical analysis used the Kruskal-Wallis test and Steel-Dwass procedure to confirm the difference between two groups. The three groups did not differ in age, weight, height and gender. The volume of salvaged and autotransfused blood was 925 +/- 156 mL in OGr and 605 +/- 178 mL in SGr respectively, transfusion of homologous blood was required in two patients of OGr, four of SGr and six of CGr. At D + 1, the hematocrit was comparable in all groups (OGr = 28%, SGr = 28.2% and CGr = 28.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

The immunomodulating agent RU 41740 complexed with very-low-density lipoproteins enhances human polymorphonuclear neutrophil oxidative metabolism in vitro

Added to human serum in vitro, RU 41740, an immunomodulating agent extracted from Klebsiella pneumoniae, binds selectively to lipoproteins containing apolipoprotein B (low-density lipoproteins and very-low-density lipoproteins, VLDL) and, at higher concentrations, to lipoproteins containing apolipoprotein A (high-density lipoproteins). The fact that lipoproteins modulate polymorphonuclear neutrophil (PMN) functions led us to suspect that the VLDL-RU 41740 complex might affect PMN functions. In this study, the effect of this complex on PMN superoxide generation was measured in the presence and absence of the classical stimulants formyl-methionyl-leucyl-phenylalanine and phorbol myristate acetate. The VLDL-RU 41740 complex enhanced the stimulating effect of VLDL on quiescent PMN, but not following stimulation with formyl-methionyl-leucyl-phenylalanine. In contrast, it partially counteracted the inhibiting effect exerted by VLDL alone on phorbol myristate acetate stimulation. Such a complex might be formed in vivo during RU 41740 therapy and constitute an important feature in the immunostimulating properties of the drug.

[Metabolism and septic shock]

Despite continuous monitoring progress, septic shock remains the main cause of death in Intensive Care Units. Septic stress triggers a complex array of biological modifications resulting in an acquired disease of intermediary metabolism whose main characteristic is an inefficient cellular use of glucidic, lipidic and protidic substrates together with oxygen. The purpose of this review is to present metabolic disturbances observed during sepsis and septic shock.

[Oral administration of sodium citrate before general anesthesia in elective cesarean section. Effect on pH and gastric volume]

A study was carried out to assess the effects of oral sodium citrate on the pH and volume of gastric content in 52 unpremedicated women undergoing elective Caesarean section under general anaesthesia. The patients were randomly assigned to two groups: group T (n = 26) without antacids and group C (n = 26) receiving orally 30 ml of 0.3 M sodium citrate solution 5 min before induction of anaesthesia. After tracheal intubation, a size 18 double lumen naso-gastric tube was introduced. The gastric content was sampled 10 min (n = 52), 50 min (n = 52) and 80 min (n = 24) later. Before extubation, the stomach was completely emptied and the naso-gastric tube removed. On each sampling time, the pH was measured with a digital pHmeter; a search for biliary salts (pyloric reflux) was carried out with thin layer chromatography; the volume of the gastric content was measured using the phenol red dilution method. At 10 min, none patient in group C had a gastric pH less than 2.5, in the opposite to 92% of patients in the control group T. The alkalinizing effect of the citrate lasted throughout the evaluation time. The mean pH was respectively 5.3 +/- 1.07, 5.23 +/- 1.2 and 5.53 +/- 1.3 at 10, 50 and 80 min in group C (controls: 1.9 +/- 0.7; 2.49 +/- 1.3; 2.40 +/- 0.61). However, the citrate solution increased significantly the volume of the gastric content. It was respectively 51.1 +/- 29.9 ml, 79.15 +/- 70.9 ml and 32.9 +/- 22.1 ml; 29.6 +/- 28.5 ml; 26.6 +/- 10.9 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Individual free fatty acids and lactate uptake in the human heart during severe sepsis

Coronary haemodynamics and myocardial metabolism of nonesterified fatty acids (NEFA) and lactate were studied in 11 patients with severe sepsis, and compared to 10 control subjects. Coronary sinus blood flow was evaluated by thermodilution. Arterial and coronary sinus blood samples were collected for the measurement of lactate and total and individual NEFA concentrations both in septic and control patients. There was an increase in lactate and total NEFA arterial concentrations with a marked increase in palmitic and linolenic acids. The uptake of the main NEFA (C14:0 to C18:2) was significantly decreased. In the control group, individual NEFA uptake was proportional to their arterial concentrations. This relationship was not observed in patients with sepsis: there was no preferential extraction of any particular NEFA. Furthermore, in patients with sepsis, myocardial oxygen consumption did not correlate with NEFA, but only with lactate uptake. Alterations in NEFA uptake were found to be constant during severe sepsis and are consistent with major disturbances in myocardial metabolism.

Delipidation of alpha 1-acid glycoprotein. Propranolol binding to this glycoprotein and its modification by extracted material and exogenous lipids

Propranolol binding to human alpha 1-acid glycoprotein (AAG) delipidated by two methods is described. Commercial AAG (99% pure) was either precipitated by ethanol-acetone and then washed by ether, or it was precipitated by ethanol. Binding capacity was quantified by the product n x Ka where n denotes the number of binding sites and Ka the association constant (M-1). Propranolol binding to nondelipidated AAG (n x Ka = 0.113 +/- 0.013 microM-1) was clearly increased after precipitation by ethanol-acetone (n x Ka = 0.386 +/- 0.109 microM-1) or precipitation by ethanol (n x Ka = 0.312 +/- 0.096 microM-1). Binding capacity potentiation cannot be due to modification of AAG microheterogeneity forms, as two-dimensional gel electrophoresis pattern of AAG in presence of concanavalin A was not altered after both methods. Recombination of precipitated AAGs with supernatant dry residue resulted in the abrogation of observed potentiation. Moreover, addition of a polar lipid, linoleic acid, (from 30 to 300 microM) strongly inhibited propranolol binding. These results indicated that glycoprotein precipitation by ethanol provided a simple method to further study binding inhibitors associated with isolated AAG.

Alpha-1-acid glycoprotein concentrations and protein binding of propranolol in Sprague-Dawley and Dark Agouti rat strains treated by phenobarbital

Propranolol binding to rat serum samples was studied after 7 days of phenobarbital (PB) administration to induce alpha-1-acid glycoprotein (AAG). In male Sprague-Dawley rats, serum AAG concentrations and the bound/free propranolol ratio (B/F) were increased slightly after enzyme-inducing drug administration (mean +/- S.D.): from 0.30 +/- 0.04 to 0.49 +/- 0.05 g/l for AAG and from 6.79 +/- 1.24 to 8.81 to 1.31 for B/F. In male DA (Dark Agouti) rats, the same parameters increased greatly: from 0.20 +/- 0.01 to 1.38 +/- 0.13 g/l for AAF and from 8.75 +/- 1.01 to 27.15 +/- 3.28 for B/F. PB concentrations determined on the same serum samples were similar in both rat strains. Female DA rats also were responsive to PB administration. Propranolol binding to DA rat serum from the treated group was characterized by an increase in high-affinity binding site concentrations. The binding of propranolol to isolated rat AAG at various concentrations (0.2-1 g/l), alone or associated with rat serum albumin at a constant concentration (36 g/l), also was studied. Propranolol binding capacities to rat AAG were increased 2.4 times by the presence of albumin and consequently B/F values for both proteins agreed with values obtained with serum samples. These results indicate that increased propranolol binding to rat serum induced by PB administration is probably a direct consequence of increased concentrations of AAG. The high sensitivity of DA rats to PB suggests that this strain should be used preferentially for the study of the effect of cytochrome P-450 inducers on AAG metabolism and cationic drug binding.

Measurement of total, monomeric and polymeric IgA in human faeces by electroimmunodiffusion

Total (t), monomeric (m) and polymeric (p) immunoglobulin A (IgA) levels were simultaneously measured in mixed faecal material collected over three consecutive days using a modified one-dimensional immunoelectrophoretic assay, which is a precise and reproducible method. Faecal t-, m- and p-IgA levels were statistically higher in 32 diarrhoeic patients than in a group of 16 healthy subjects (respectively 2.2, 2.6 and 2.0 times the normal). The values were also significantly different (P less than 0.001) when results were expressed as output per day in order to estimate the secreting capacity of gut. Moreover, the m-IgA/t-IgA percentages were significantly higher in faeces from diarrhoeic patients (42.3%) than in normal faeces (26.5%). These results confirm the importance of faecal IgA determination in estimating the local production of the IgA in various gastrointestinal tract disorders.

Differential measurement of monomeric and polymeric IgA by one-directional immunoelectrodiffusion

A technique to specifically quantify monomeric IgA and total IgA in colostrum has been developed using a modified one-dimensional immunoelectrophoretic assay. This method employed electrophoresis in antibody-containing polyacrylamide-agarose gel in the presence of a gel barrier which blocks polymeric IgA. The addition of PEG (polyethylene-glycol 6000) to the anodic gel increased the sharpness of the peaks, the height of which was proportional to the antigen concentration. This method proved to be sufficiently simple, precise, reproducible (CV less than 3%) and linear (from 20-300 mg/l) to measure the monomeric IgA: total IgA ratio rapidly (14 +/- 4.5% for 20 samples in duplicate). Immunoelectrodiffusion studies confirmed that human colostral and serum IgA standards could be used to determine directly monomeric IgA, total IgA and polymeric IgA levels (by difference) rather than to apply correction factors to estimate these IgA levels.

Free fatty acid microdetermination by gas-liquid chromatography without transmethylating effects of methylation procedure

A fast and practicable gas-liquid chromatographic method for the quantitation of non-esterified fatty acids (C14:0-C18:2) from 100 microliter plasma is described. This technique includes extraction, purification using the solvents n-heptane and 0.5 M Na2CO3, and methylation by 0.1 M HCl-methanol. Extraction, quantification and optimal methylation conditions without transmethylation have been investigated. Reproducibility is good and results agree with values found in the literature.

Changes in human high density lipoproteins in patients with extra-hepatic biliary obstruction

Plasma high density lipoproteins (HDL) from patients with obstruction of the common bile duct were studied by crossed immunoelectrophoresis and isoelectric focusing. All cholestatic HDL fractions were rich in phospholipids (51.5 +/- 9%) with high proportions of free cholesterol (13.8 +/- 1.5%). Moreover, crossed immunoelectrophoresis of sera against anti-Apo A revealed the presence of multiple immunoprecipitates sharply contrasting with the pattern formed by normal sera. Tandem crossed immunoelectrophoresis against anti-Apo A and anti-Apo B was performed with whole serum and with the HDL fraction from various cholestatic subjects. Crossed identity was observed for two of these precipitates, which could be explained by the decrease in HDL stability due to the detergent effect of bile salts. The most noteworthy changes found in cholestatic patients appeared to be the apolipoprotein pattern of HDL. Both Apo AI (48%) and Apo AII (5.5%) were greatly diminished and Apo E was present in remarkably high amounts (39%) with two additional isoforms (Apo E'1 and Apo E'2).

Type IV hyperlipoproteinemia in patients with algodystrophy

The present work studies lipid metabolism in patients with algodystrophy (AD). A correct positive correlation (r = 0.75) between the triglyceride levels and low density lipoprotein (LDL)/very low density lipoprotein (VLDL) ratio and the VLDL increase observed by gel disk electrophoresis confirm that a type IV hyperlipoproteinemia is associated with AD. In contrast, the degree of high density lipoprotein (HDL) saturation in cholesterol (HDL-cholesterol/HDL-phospholipids) and the classical atherogenous index (cholesterol/HDL-cholesterol) were not modified. The decrease of plasma post-heparin lipolytic activities (PHLA) was not significant but further studies should be performed to correlate PHLA with a reduced activity of the adipose tissue lipoprotein lipase.

[Algodystrophy and metabolic abnormalities]

The French Society of Rheumatology national study of reflex dystrophy revealed a serum glucose greater than 1.20 g/l in 9.09 p. cent of cases, a serum uric acid greater than 70 mg/l in 25 p. cent of men and greater than 60 mg/l in 14 p. cent of women. Serum cholesterol was normal in males, but higher than the mean + 2 sigma in 23 p. cent of females. Serum triglycerides were higher than m + 2 sigma in 55 p. cent of men and 56 p. cent of women. From a group of 80 patients, 54 (67.5 p. cent) had at least one of the three metabolic abnormalities and 49 (61.25 p. cent) were hypertriglyceridaemic. This hypertriglyceridaemia is the most frequent abnormality found. When hyperglycaemia or hyperuricaemia are present it is almost always in association with hypertriglyceridaemia. Hypertriglyceridaemia is more common in algoneurodystrophy of the lower limbs (54/78, 69 p. cent) than in algoneurodystrophy of the upper limbs (5/22, 22.7 p. cent). Algoneurodystrophy is more often primary, when it occurs in the lower limbs and post-traumatic when it occurs in the upper limbs. A prospective study comparing several parameters of lipid metabolism in 24 patients with algoneurodystrophy and 15 matched controls showed a significant drop in the HDL Chol/HDL P1 ratio and in the DHL - HDL Chol/TG ratio in patients with algoneurodystrophy. Serum insulin was comparable in the 2 groups. Lecithin cholesterol acyl transferase (LCAT), SGOT, SGPT and GGT were normal. The essential role of hypertriglyceridaemia in the genesis of the characteristic bony lesions of algoneurodystrophy is discussed.

[Algodystrophy and metabolic anomalies]

The French Society of Rheumatology national study of reflex dystrophy revealed a serum glucose greater than 1.20 g/l in 9.09 p. cent of case, a serum uric acid greater than 70 mg/l in 25 p. cent of men and greater than 60 mg/l in 14 p. cent of women. Serum cholesterol was normal in male cases, but higher than the mean + 2 sigma in 23 p. cent of female cases. Serum triglycerides was higher than m + 2 sigma in 55 p. cent of men and 56 p. cent of women. From a group of 80 patients, 54 (67.5 p. cent) had at least one of the three metabolic abnormalities and 49 (61.25 p. cent) were hypertriglyceridaemic. This hypertriglyceridaemia is the most frequent abnormality found. When hyperglycaemia or hyperuricaemia are present it is almost always in association with hypertriglyceridaemia. Hypertriglyceridaemia is more common in algoneurodystrophy of the lower limbs (54/78, 69 p. cent) than in algoneurodystrophy of the upper limbs (5/22, 22.7 p. cent). Algoneurodystrophy is more often primary, when it occurs in the lower limbs and post-traumatic when it occurs in the upper limbs. A prospective study comparing several parameters of lipid metabolism between 24 patients with algoneurodystrophy and 15 matched controls showed a significant drop in the HDL Chol/HDL P1 ratio and in the DHL--HDL Chol/TG ratio in patients with algoneurodystrophy. Serum insulin was comparable in the 2 groups. Lecithin cholesterol acyl transferase (LCAT), SGOT, SGPT and GGT were normal. The essential role of hypertriglyceridaemia in the genesis of the characteristic bony lesions of algoneurodystrophy is discussed.

Total automated method for determination of cholesterol concentration in high density lipoprotein by heparin-magnesium-albumin precipitation

We describe an automated procedure for determination of high-density-lipoprotein cholesterol in serum by use of heparin-MgCl2-albumin reagent. 'AutoAnalyzer' II equipment was used in which high-density lipoprotein was separated from precipitate containing very-low and low-density lipoproteins by filtering on-line across a cellulose acetate membrane. Cholesterol concentration was measured by the enzymic method of Allain. Good correlation was obtained using the automated method compared to the heparin-MgCl2-albumin (r=0.99) or sodium phosphotungstate-MgCl2 procedure (r=0.97). Contamination was minimal with a contamination coefficient lower than 2.5%. The method presented was linear (0 to 2.50 mmol/1) and could be applied to lipemic samples with a coefficient of variation better than 3%. This study showed thus that this new procedure was suitable for routine work with a good rate (60 samples/h) in almost any laboratory.

[Serum amylase determination : automated continuous flow method (author's transl)]

A simple automated assay was described for the determination of serum amylase using a chromogenic substrate. The reaction was stopped by filtration across a cellulose nitrate membrane. The analytic parameters of this method were studied. Repeatability, reproducibility and precision were convenient. The calibration curve was linear up to 850 U/I. An excellent correlation was obtained after comparison with the manual method (Phadebas amylase test). The effects of haemolysis and very high ascorbic concentrations of bilirubin, glucose, uric acid and ascorbic acid were negligible on the value measured. The serum turbidity was alone to induce a variation by excess.

Heparin--magnesium chloride--albumin method for enzymic measurement of cholesterol in high-density lipoprotein

We describe a new method for measuring high-density-lipoprotein cholesterol in sera, with use of heparin, MgCl2, and albumin to precipitate very-low- and low-density lipoproteins, Lipoprotein electrophoresis and immunochemical methods show that high-density lipoprotein is completely and specifically isolated in the supernate, the cholesterol concentration of which is estimated by the enzymic method of Allain et al. (Clin. Chem. 20, 470, 1974). The precision of the method is excellent (CV = 1%) and the response is linear. Values so obtained correlate well with those obtained with the heparin-Mn2+ (r = 0.98) or the phosphotungstate-Mg2+ (r = 0.98) procedures. The technique is appropriate for routine clinical laboratory use.

Heparin--magnesium chloride--albumin method for enzymic measurement of cholesterol in high-density lipoprotein

We describe a new method for measuring high-density-lipoprotein cholesterol in sera, with use of heparin, MgCl2, and albumin to precipitate very-low- and low-density lipoproteins, Lipoprotein electrophoresis and immunochemical methods show that high-density lipoprotein is completely and specifically isolated in the supernate, the cholesterol concentration of which is estimated by the enzymic method of Allain et al. (Clin. Chem. 20, 470, 1974). The precision of the method is excellent (CV = 1%) and the response is linear. Values so obtained correlate well with those obtained with the heparin-Mn2+ (r = 0.98) or the phosphotungstate-Mg2+ (r = 0.98) procedures. The technique is appropriate for routine clinical laboratory use.

[Critical aspects of actual methods for high-density-lipoprotein cholesterol quantitation]

In this study we compare various methods for h;igh-density-lipoprotein cholesterol quantitation: ultracentrifugation; electrophoresis either on cellulose acetate or on agarose gel; precipitation methods with polyanions-bivalent cations; adsorption procedure using concanavalin A (Con A). quantification by electrophoresis is slow and not precise. Except heparin-Mn++ and dextran (MM 5 X 10(5) and 2 X 10(6)) - CaCl2 procedures, precipitation and Con A methods own a good repeatability (VC 2%) and give a linear response after VLDL or LDL-VLDL addition to tested sera. Regression analysis of the data obtained using these methods in pairs demonstrate a correct accuracy (r > 0.95). The Student t-test shows that the usual values must be evaluated for each method. We suggest to use either phosphotungstate - Mg++ or Con A procedure as method for HDL cholesterol quantitation.

[Enzyme-immuno assay for total estrogens and human placental lactogen. Comparison with radio-immuno-assay in normal pregnancy-monitoring (author's transl)]

The concentrations of estrogens (E) and human placental lactogen (HLP) are estimated in sera by radio immuno-assay (RIA) and enzyme-immuno-assay (EIA). Statistical data indicate mean intra-assay variation coefficients of 7% and 12% for E and HLP tests, respectively. The correlation coefficient (RIA/EIA) are found higher than 0,9% for both hormonal assays. The dilution curves obtained by RIA and EIA are similar. However, Student'test gives a significant difference for E determination. In fact, total E and E 3 only are measured by EIA and RIA, respectively. In most cases biological interferences are negligible except for HLP in presence of higher protein or haemoglobin levels. RIA and EIA are performed to study serum HLP and E levels throughout normal pregnancies. Results allow to use EIA for HLP and E evaluations in pregnancy-monitoring.