The enzymatic antioxidant system in blood and glutathione status in human immunodeficiency virus (HIV)-infected patients: effects of supplementation with selenium or beta-carotene

To investigate the effects of selenium or beta-carotene supplementation in human immunodeficiency virus (HIV)-infected patients, who are known to have deficiencies of selenium and vitamin A, we evaluated the blood enzymatic antioxidant system, including superoxide dismutase (SOD), selenodependent glutathione peroxidase (GPX), and catalase (Cat); glutathione (GSH) status; and plasma selenium concentration. The placebo group consisted of 18 HIV-infected patients with no supplementation, the selenium group was composed of 14 patients receiving oral selenium treatment, and the beta-carotene group comprised 13 patients receiving oral beta-carotene supplementation. All groups were studied for 1 y. At the beginning of the study, a significantly higher SOD activity (P < 0.001) was observed in all HIV-infected patients compared with uninfected control subjects, and GPX activity at baseline was higher in the placebo (P < 0.004) and selenium (P < 0.014) groups than in the control subjects. These higher enzyme activities could be related to an increased synthesis of these enzymes in erythrocyte precursors under oxidative stress. Moreover, we observed significantly lower GSH values in all HIV-infected patients than in control subjects at the beginning of the study (P < 0.001). After selenium or beta-carotene supplementation, no significant difference was observed for SOD activity compared with baseline. On the contrary, GPX activity increased significantly after selenium treatment (P < 0.04 between 3 and 6 mo), whereas a slight increase was found after beta-carotene treatment. Similarly, a significant increase in GSH values was observed at 12 mo compared with baseline both after selenium supplementation (P < 0.001) and beta-carotene supplementation (P < 0.01). Because GPX and GSH play an important role in the natural enzymatic defense system in detoxifying hydrogen peroxide in water, selenium supplementation could be of great interest in protecting cells against oxidative stress. The lower efficiency of beta-carotene could be attributed to the seriousness of the pathology at the time of recruitment into the beta-carotene group.

In vivo effect of diosmin on carrageenan and CCl4-induced lipid peroxidation in rat liver microsomes

The aim of this study was to compare the protective effect of a flavonoid, the 3',5,7-trihydroxy-4'-methoxyflavone 7-rutinoside or diosmin, on liver microsomal lipid peroxidation induced in rats by either carbon tetrachloride or carrageenan. Thirty rats were divided into five groups. Group 1 received no chemical product and was considered as control. Groups 2 and 3 received either an intraperitoneal injection of carrageenan or carbon tetrachloride 48 or 24 hours before killing, respectively. Groups 4 and 5 were treated first with an intraperitoneal injection of diosmin and then by carrageenan (group 4) or carbon tetrachloride (group 5) 48 or 24 hours before killing, respectively. The lipoperoxidant effect of carrageenan and carbon tetrachloride was demonstrated by both significant decreases in polyunsaturated fatty acids, principally 20:4 (n - 6) (p < 0.05) and of vitamin A (p < 0.05) in groups 2 and 3. With diosmin treatment, only thiobarbituric acid reactive substances significantly decreased in group 4, whereas vitamin A level increased. These results could suggest that the effect of diosmin differs with the choice of chemical product used; it seems a better antioxidant against products inducing inflammation.

Arbitrarily-primed PCR confirms the differentiation of strains of Ureaplasma urealyticum into two biovars

Fourteen serotypes are currently recognized in the Ureaplasma urealyticum species. These serotypes have been divided into two genomic clusters or biovars by a large number of typing methods. The parvo-biovar includes strains of serotypes 1, 3, 6 and 14 and the T960-biovar, strains belonging to the ten other serotypes. In this study, arbitrarily primed polymerase chain reaction (AP-PCR) has been applied to the analysis of reference strains of the 14 U. urealyticum serotypes. By using two different sets of 10-mer oligonucleotide primers, the method allowed the clear differentiation between the two known biovars of the species. However, further differentiation within a same biovar was only achieved for a few standard strains of the T960-biovar analysed by using a pairwise combination of primers. The reproducibility of AP-PCR profiles was shown on strains tested after repeated subcultures and with different thermal cyclers. Additional experiments were performed on forty isolates of U. urealyticum recovered from subjects of various origins. They confirmed that AP-PCR was able to identify the strains at the biovar level. With reference to the other typing methods, AP-PCR is easy to perform and can be applied to large numbers of strains for epidemiological purposes.

Relationship between red blood cell antioxidant enzymatic system status and lipoperoxidation during the acute phase of malaria

OBJECTIVE

To investigate the relationship between oxidative stress and aggrevation of the disease in patients with malaria.

METHODS AND RESULTS

In the present study lipoperoxidation was demonstrated during the acute phase of malaria by a significant decrease in polyunsaturated fatty acids (PUFA). The lowest values of PUFA were obtained for C20:4 and C22:6, which were the main targets of reactive oxygen species (ROS) when parasitemia was higher than 1%. Similarly, plasma vitamins E and A were significantly reduced during the acute phase of malaria owing to their consumption in part as antioxidants. However, evaluation of the antioxidant enzymatic system in red blood cells of malaria patients indicated no significant difference from controls. Only superoxide dismutase activity tended to decrease when parasitemia increased.

CONCLUSION

The results suggest that superoxide radicals are the main ROS produced during the acute phase of malaria, and that rejuvenation of RBC during hemolysis involving increased enzyme activities interacts to protect RBC from excessive superoxide radical production.

Evaluation of red blood cell lipoperoxidation in hemodialysed patients during erythropoietin therapy supplemented or not with iron

To investigate the effects of erythropoietin (rHuEPO) therapy supplemented or not with iron on hemolysis in hemodialysed patients (HD) we evaluated lipoperoxidation (LPO) by assaying (i) the red blood cell (RBC) antioxidant enzymatic system including superoxide dismutase (SOD), glutathione peroxidase, and catalase (Cat), (ii) RBC polyunsaturated fatty acids (PUFA) and (iii) malondialdehyde (MDA). Group 1 included 12 HD patients, group 2 had 7 HD patients with iron supplementation, group 3 comprised 12 HD patients with rHuEPO therapy and group 4 included 9 HD patients with both iron and rHuEPO therapies. No LPO was found in group 1 as regards MDA and PUFA levels. However, SOD and Cat activities were significantly elevated as compared to controls (p < 0.001). In the second group, a significant decrease in PUFA percentage was observed, particularly in 20:4(n-6) and 22:4(n-6) (the main ones involved in LPO) as compared to the other groups, whereas total MDA level was higher than that of the other groups. Similarly a decreased SOD activity was observed as compared to group 1 (p < 0.001), indicating its inactivation subsequent to an hyperproduction of reactive oxygen species through iron injection. In groups 3 and 4 no change was observed in MDA levels or PUFA percentages indicating no LPO. However, marked differences were observed in the enzymatic defense system. Particularly in group 3, SOD and Cat activities decreased when compared to group 1 (p < 0.001) whereas the association of erythropoietin and iron (group 4) increased the three enzymatic activities (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoperoxidation in plasma and red blood cells of patients undergoing haemodialysis: vitamins A, E, and iron status

In 14 patients undergoing haemodialysis, lipoperoxidation (LPO) processes were determined in plasma and red blood cells (RBC) before and after a dialysis session by determining (a) the direct substrate, polyunsaturated fatty acids (PUFA); (b) the end product of LPO, malondialdehyde (MDA); and (c) the hydrophobic antioxidant systems, vitamins A and E. In plasma before dialysis, linoleic and arachidonic acid, and the antioxidant vitamin E, were significantly lowered as compared to the healthy controls (p < 0.05). On the contrary, the free MDA level was enhanced (p < 0.05). These results were emphasized by a dialysis session. In RBC of these patients, no difference in linoleic acid, free MDA, or vitamin E level were observed before or after dialysis when compared to controls. However, only vitamin A was significantly higher in haemodialysis patients (before and after dialysis) and in renal failure patients (p < 0.05) than in the healthy control group. The present results suggest that increased RBC vitamin A may offer some degree of protection against oxidative stress in erythrocytes, but not in plasma where LPO is demonstrated.

Markedly accelerated catabolism of apolipoprotein A-II (ApoA-II) and high density lipoproteins containing ApoA-II in classic lecithin: cholesterol acyltransferase deficiency and fish-eye disease

Classic (complete) lecithin:cholesterol acyltransferase (LCAT) deficiency and Fish-eye disease (partial LCAT deficiency) are genetic syndromes associated with markedly decreased plasma levels of high density lipoprotein (HDL) cholesterol but not with an increased risk of atherosclerotic cardiovascular disease. We investigated the metabolism of the HDL apolipoproteins (apo) apoA-I and apoA-II in a total of five patients with LCAT deficiency, one with classic LCAT deficiency and four with Fish-eye disease. Plasma levels of apoA-II were decreased to a proportionately greater extent (23% of normal) than apoA-I (30% of normal). In addition, plasma concentrations of HDL particles containing both apoA-I and apoA-II (LpA-I:A-II) were much lower (18% of normal) than those of particles containing only apoA-I (LpA-I) (51% of normal). The metabolic basis for the low levels of apoA-II and LpA-I:A-II was investigated in all five patients using both exogenous radiotracer and endogenous stable isotope labeling techniques. The mean plasma residence time of apoA-I was decreased at 2.08 +/- 0.27 d (controls 4.74 +/- 0.65 days); however, the residence time of apoA-II was even shorter at 1.66 +/- 0.24 d (controls 5.25 +/- 0.61 d). In addition, the catabolism of apoA-I in LpA-I:A-II was substantially faster than that of apoA-I in LpA-I. In summary, genetic syndromes of either complete or partial LCAT deficiency result in low levels of HDL through preferential hypercatabolism of apoA-II and HDL particles containing apoA-II. Because LpA-I has been proposed to be more protective than LpA-I:A-II against atherosclerosis, this selective effect on the metabolism of LpA-I:A-II may provide a potential explanation why patients with classic LCAT deficiency and Fish-eye disease are not at increased risk for premature atherosclerosis despite markedly decreased levels of HDL cholesterol and apoA-I.

31P NMR studies of rat liver cold preservation with histidine-buffered lactobionate solution

The efficiency of a preservation medium, histidine-buffered lactobionate solution (HBLS), was determined by measuring post-ischemic recoveries of ATP and intracellular pH under Krebs-Henseleit buffer (KHB) perfusion. We used NMR spectroscopy to study the effect of 24-h cold ischemia, followed by 4 degrees C then 37 degrees C reperfusion on the isolated rat liver. Three media were compared: University of Wisconsin solution (UW-lactobionate); Bretschneider's solution (HTK); HBLS and HBLS supplemented with 2 mM Gly and 2 mM Cys (HBLSg2) or with 10 mM Gly and 2 mM Cys (HBLSg10). All values were compared to control values measured during pre-ischemic cold perfusion with KHB (ATP = 8.60 +/- 0.6 mumol/g of dry weigh and pH(in) = 7.41 +/- 0.05). The main result from 31P NMR data concerned ATP recovery during cold reperfusion, which was significantly higher in the HBLS group (112 +/- 10%) as compared to the UW and HTK groups (around 66%). The presence of glycine decreased ATP recovery (88 +/- 8% in HBLSg2, 79 +/- 15% in HBLSg10). Higher values of recovered pHin were observed in livers stored in histidine buffered solutions (around 7.30) as compared to UW (around 7.20); histidine was by 13C NMR proved to accumulate in the liver cells, thus ensuring a good buffering capacity. The thermal transition induced a decrease in both ATP level and pHin in all groups. This might be the result of a stimulation of the carbohydrate metabolism (as demonstrated by 13C NMR) especially when glycine was present in the storage solution.

Fish eye syndrome: a molecular defect in the lecithin-cholesterol acyltransferase (LCAT) gene associated with normal alpha-LCAT-specific activity. Implications for classification and prognosis

We have identified the molecular defect in two siblings presenting with classical clinical and biochemical features of Fish Eye disease (FED), including corneal opacities, HDL cholesterol < 10 mg/dl, normal plasma cholesteryl esters, and elevated triglycerides. In contrast to previously reported patients with FED who are unable to esterify HDL-associated cholesterol, our patients' plasma lecithin-cholesterol acetyltransferase (alpha-LCAT)-specific activities assayed using an HDL-like proteoliposome substrate were 12.7-25.7 nmol/micrograms (19.5 +/- 1.8 in controls). In addition, significant residual cholesterol esterification was present in VLDL/LDL-depleted plasma, confirming the presence of HDL-associated alpha-LCAT activity. DNA sequence analysis of the proband's LCAT gene identified deletion of the triplet coding for leu300, which resulted in the loss of a restriction site for MlnI. Digestion of PCR-amplified DNA using MlnI established that both siblings are homozygous for this defect. Expression of LCAT300-del. in human embryonic kidney-293 cells revealed normal mRNA and intracellular LCAT concentrations. However, reduced amounts of LCAT300-del., which had a normal specific alpha-LCAT activity, were present in the media. In summary, we report the first case of FED associated with a mutant enzyme that has a normal alpha-LCAT-specific activity. The functional significance of this LCAT gene defect has been established in an in vitro expression system, which demonstrates that very small amounts of this functional LCAT mutant enzyme accumulate in the media. Characterization of LCAT300-del. established that selective alpha-LCAT deficiency is not a prerequisite for the development of FED. On the basis of our combined results, we propose that the residual amounts of total plasma LCAT activity and not its distribution on lipoproteins primarily determines the heterogeneity in phenotypic expression observed in familial LCAT deficiency syndromes.

[Arcus juvenilis and lecithin:cholesterol acyltransferase functions. Report of a case of familial fish-eye-disease]

A Fish-Eye Disease family has been recently discovered in Bordeaux, being made up 3 homozygous and 3 heterozygous patients for a recessive hereditary anomaly of LCAT. The influence of the enzyme on the plasma lipoprotein composition and its role in cholesterol efflux explain, at least for a part, the pathophysiology of the lipidic corneal clouding which is the single symptom in the homozygous patients. The comparison of the molecular biology data resulting from the analysis of the patient's LCAT gene with those which have been obtained in other FED patients as in patients with classic LCAT deficiency allows to differenciate biochemically both pathologies. It allows too the differentiation between primary and secondary (Tangier disease, apo A-I deficiency, A-I and C-III deficiency) LCAT deficiencies, which may be all associated with a Corneal arcus. The profile of the lipidic parameters most often measured in plasma (Total cholesterol, HDL-cholesterol, cholesterol esterification rate, lipidogramme, apo A-I, apo A-II, LCAT mass and activity) is practically pathognomonic of this affection and consequently authorizes its differential diagnosis. In spite of the striking deficiency of HDL as of their atherogenesis preventing markers these patients do not show any sign of early cardio vascular disease.

Relationships between age-dependent changes in the effect of almitrine on H(+)-ATPase/ATPsynthase and the pattern of membrane fatty acid composition

The effects of almitrine on ATPase/ATPsynthase previously described in beef heart mitochondria (Rigoulet et al. (1990) Biochim. Biophys. Acta 1018, 91-97) are also observed in liver mitochondria isolated from rats older than 7 weeks. In contrast, in rats younger than 5 weeks, almitrine at the same concentration has no effect on the ATPase/ATPsynthase complex. This age-dependent action of almitrine is well correlated with age-dependent modifications of two fatty acids: linoleic and docosahexaenoic acids. The possibility of a change in H+/ATP stoichiometry of the ATPase/ATPsynthase induced by almitrine seems related to more general modifications of membrane properties during growth of the rat.

[Interferon and blood tumor necrosis factor in 95 patients with HIV infection]

We have measured TNF-alpha and interferon alpha in 95 HIV positive patients and 20 healthy subjects. TNF-alpha was higher in the HIV+ patients (P = 0.0001) and was correlated to the CD4 cell count (P = 0.02) and cholesterol (negatively) (P = 0.04). Interferon-alpha was correlated to the wasting syndrome (P = 0.002), hypertriglyceridemia (P = 0.004) and haematocrit (P = 0.04).

[Antioxidant and/or free radical scavenger vitamins in tropical medicine]

Antioxidant and/or free radical scavenger vitamins (A, E) as beta carotene are unequally distributed among intertropical peoples from Africa. In Ivory coast for example the values observed are clearly enhanced in the regions where Palm oil is usually eaten than in savanna regions. Primary liver cancer (PLC) is more frequently observed in savanna regions. Furthermore it has been recently suggested that retinoic acid which is derived from vitamin A and beta carotene could interact with the genes which are involved in the primary liver carcinogenesis. In PLC patients as in subjects suffering from sickle cell anaemia, malaria, kwashiorkor or marasmus, and AIDS, the plasma levels of vitamin A, Vitamin E and beta carotene are decreased. Though disturbances in the digestion of fats that may be observed in some pathologies (mainly in Kwashiorkor) affect the discussion of the results, haemolysis and/or acute phase reaction with increased respiratory burst are always observed. That explain, at least in part, the lowering of lipophilic-antioxidant-vitamin plasma levels. As a consequence crude palm oil addition or vitamin A and E therapy would enhance the natural defences against the deleterious effects of the oxidative stress induced by these affections. It is worth checking about.

A fish-eye disease-like familial condition with massive corneal clouding and dyslipoproteinemia. Report of clinical, histologic, electron microscopic, and biochemical features

Fish-eye disease (FED) is a rare familial condition characterized by progressive bilateral corneal clouding and dyslipoproteinemia previously described in one family and an unrelated woman of Swedish descent. Biochemical studies have clearly demonstrated the existence of this entity as a unique dyslipoproteinemia. We present a non-Swedish family of Mediterranean ancestry afflicted with bilateral corneal clouding and lipoprotein analysis consistent with FED-like state. This family's biochemical profile, corneal button histology, and electron microscopy of one member are reviewed. Other dyslipoproteinemias causing corneal changes are considered. Corneal tissue and familial biochemical analyses differed significantly from previous descriptions. On the basis of these findings, explanation of pathologic deposition and disease mechanism is proposed.

Phosphorus-31 nuclear magnetic resonance of isolated rat liver during hypothermic ischemia and subsequent normothermic perfusion

The effects of prolonged hypothermic ischemia and subsequent normothermic perfusion on the energetic metabolism and intracellular pH (pHin) of isolated rat livers were studied by phosphorus-31 nuclear magnetic resonance spectroscopy. Nucleoside triphosphate (NTP) depletion and intracellular pH were studied within an 18-h-storage phase, by using the following preservation media: Eurocollins (EC), UW Lactobionate (UW) and Bretschneider's solution (HTK). Values obtained after 8-h ischemia were chosen to estimate the performance of the various media: NTP levels were 37 +/- 7%, 10 +/- 5% and 0% of control levels, respectively, in livers stored in UW, HTK and EC solutions. pHin reached values of 7.15 +/- 0.10 in UW and HTK, and 6.96 +/- 0.10 in EC-stored livers. Ischemic damage was assessed by reperfusing the stored organ with Krebs medium: NTP recovery was around 70 +/- 20% for the three solutions used. Recovery of pHin was near the control value (7.23 +/- 0.08), except for EC solution (7.05 +/- 0.20). The main results are that (i) the rates of NTP and pHin decrease are strongly dependent on the nature of the preservation solution, whereas (ii) NTP recovery is not significantly different during post-ischemic reperfusion. With regard to animal survival, UW solution is at present considered largely superior to EC medium for liver preservation. Thus, our data suggest that the rates of NTP depletion and pHin fall during cold preservation could be both considered as better indicators assessing liver injury than the post-ischemic NTP recovery.

Discriminant analysis of urinary calculi by near-infrared reflectance spectroscopy

Near-infrared reflectance analysis has been used to determine the qualitative and semi-quantitative composition of urinary calculi. This simple method requires calibration of the most common urinary calculi. Analysis time is short (less than 1 min) and only very small amounts of calculus in powder form (less than 100 micrograms) are required without the use of any reagent. Moreover, when compared to infrared spectroscopy, this method provides sufficient accuracy to identify mixed calculi containing two or three components, and permits semi-quantitative determinations. The speed and simplicity of this technique makes it a powerful method for the routine analysis of urinary calculi in clinical laboratories.

Relationship between dietary retinol and alpha-tocopherol and lipid peroxidation in rat liver cytosol

The effects of retinol and alpha-tocopherol-deficient and supplemented diets on the cytosolic concentration of thiobarbituric acid reactive substances (TBARS) in rat liver have been studied. Physiological lipoperoxidation (LPO) was observed in liver cytosol of control rats (TBARS = 0.315 +/- 0.034 nmol of MDA equivalents/mg of liver cytosolic proteins). In retinol-deficient diets there was a decrease in retinolaemia and the absence of retinol in liver cytosol while cytosolic TBARS increased significantly (P less than 0.001). Vitamin E was not found in cytosolic fractions, except in alpha-tocopherol-supplemented diet rats. alpha-Tocopherol-deficient diets induced an absence of vitamin E in the serum and cytosolic TBARS were increased compared to controls (P less than 0.001). Supplementation of the diet with retinol and alpha-tocopherol or both in combination induced a significant decrease in liver cytosolic TBARS (P less than 0.001). Finally the combination of low dietary supplementation with retinol and alpha-tocopherol (ten times the normal diet each) induced the maximum anti-LPO effect.

A 'Fish-eye disease' familial condition with massive corneal opacities and hypoalphalipoproteinaemia: clinical, biochemical and genetic features

A Caucasian family of mediterranean origin comprising a patient whose parents were first cousins, his wife and their three children, and his two sisters have been studied. The patient and his two daughters were afflicted with the same corneal opacities and hypoalphalipoproteinaemia. The disease was shown to be transmitted as a non-sex-linked recessive trait. The corneal opacities develop at the end of the second decade of life and consist of numerous minute greyish dots in the entire corneal stroma that give the cornea a misty appearance. Vision slowly deteriorated from 40 years of age. At about 50 years of age, except in one of the two daughters who showed Marfanoid syndrome, the three patients had good general health and no symptoms of atherosclerosis. Biochemical investigations showed hypoalphalipoproteinaemia (with a faint fast-moving HDL band on polyacrylamide gel gradient electrophoresis and small arcs of HDL2 and HDL3 of low mobility determined by agarose gel immunoelectrophoresis), low total cholesterol (3.5-4.9 mmol l-1), slightly decreased cholesteryl ester/total cholesterol ratio (0.52-0.63), extremely low HDL cholesterol (0.20-0.21 mmol l-1), mild hypertriglyceridaemia (1.94-3.80 mmol l-1), and striking deficiency in apo A-I and apo A-II (0.45-0.72, 0.08-0.16 g l-1, respectively). The esterification of HDL cholesterol was low while that of LDL and VLDL was nearly normal. Other laboratory values were normal. The HDL subspecies and major apolipoprotein isoforms have been studied to differentiate FED from Tangier disease, LCAT deficiency, as Apo A-I, A-II, C-II, C-III deficiencies and variants.(ABSTRACT TRUNCATED AT 250 WORDS)

Heterogeneity of HDL in crossed immunoelectrophoresis with continuous gradient polyacrylamide gel in the first dimension and one or two antibody layers in the second dimension

We describe a new method of immunoelectrophoresis with a continuous gradient polyacrylamide gel in the first dimension and an agarose-dextran gel in the second dimension with one or two layers of antibody. The use of a polyacrylamide gel in the first dimension allows better resolution of lipoproteins than with crossed immunoelectrophoresis using agarose gel in both dimensions. The use of two layers of antibody in the second dimension also enhances the specificity of characterization and the resolution of the separation. Thus, using a layer of anti-apo A-I combined with a layer of anti-apo A-II, three particles containing only apo A-I and three containing both apo A-I and A-II could be separated.

Free and bound malondialdehyde measured as thiobarbituric acid adduct by HPLC in serum and plasma

Assay of free and total malondialdehyde (MDA) in human serum and plasma from healthy subjects and from patients with high risk of lipoperoxidation was performed as follows: (a) acidic (HClO4, pH 1, at 20 degrees C) or basic (NaOH, pH 13, at 60 degrees C) treatments for 30 min; (b) reaction of the protein-free extract (obtained by acid precipitation) with thiobarbituric acid (TBA); (c) HPLC separation on C18 columns with an eluting solution of methanol/phosphate buffer, 10 mmol/L, pH 5.8 (40/60, by vol), at a flow rate of 1.5 mL/min. Free MDA averaged 0.042 (SEM 0.008) and 0.043 (SEM 0.007) mumol/L, respectively, in serum and plasma from healthy subjects. Free (+/- SEM) MDA increased significantly in the plasma from cancer patients (0.270 +/- 0.047 mumol/L) and from hemodialyzed patients (0.214 +/- 0.035 mumol/L). In serum of hemodialyzed patients, analyses for total MDA were unsuitable because of interfering peaks. MDA bound to NH2 groups constituted 83.2% and 83.5% of total MDA in serum and plasma of healthy subjects, respectively, and only 58% in plasma of hemodialyzed patients.

Free and bound malondialdehyde measured as thiobarbituric acid adduct by HPLC in serum and plasma

Assay of free and total malondialdehyde (MDA) in human serum and plasma from healthy subjects and from patients with high risk of lipoperoxidation was performed as follows: (a) acidic (HClO4, pH 1, at 20 degrees C) or basic (NaOH, pH 13, at 60 degrees C) treatments for 30 min; (b) reaction of the protein-free extract (obtained by acid precipitation) with thiobarbituric acid (TBA); (c) HPLC separation on C18 columns with an eluting solution of methanol/phosphate buffer, 10 mmol/L, pH 5.8 (40/60, by vol), at a flow rate of 1.5 mL/min. Free MDA averaged 0.042 (SEM 0.008) and 0.043 (SEM 0.007) mumol/L, respectively, in serum and plasma from healthy subjects. Free (+/- SEM) MDA increased significantly in the plasma from cancer patients (0.270 +/- 0.047 mumol/L) and from hemodialyzed patients (0.214 +/- 0.035 mumol/L). In serum of hemodialyzed patients, analyses for total MDA were unsuitable because of interfering peaks. MDA bound to NH2 groups constituted 83.2% and 83.5% of total MDA in serum and plasma of healthy subjects, respectively, and only 58% in plasma of hemodialyzed patients.

[Brucella endocarditis of bicuspid aortic valve. Surgical treatment with successful result]

The authors report a case of Brucella Melitensis endocarditis of a bicuspid aortic valve which caused rapid progression of the hemodynamic signs of aortic stenosis, and was associated with a para-aortic abscess and a pericardial effusion. Surgery resulted in correction of the hemodynamic abnormalities and cured the infection: the results were sustained 10 months after operation. This case illustrates the precision of the Doppler, echocardiographic diagnosis of the lesions, which was confirmed at surgery so that potentially dangerous cardiac catheterisation could be avoided.

Discontinuous polyacrylamide gel-agarose gel immunoelectrophoresis for analysis of plasma lipoproteins

A modification of crossed immunoelectrophoresis for the analysis of plasma lipoproteins is described and is called polyacrylamide gel-crossed immunoelectrophoresis. The incorporation of albumin in the first-dimensional gel facilitates the transfer of the larger lipoproteins containing apolipoprotein B from the first-dimensional gel to the second dimension. Furthermore, under this condition the quantitation of total apolipoprotein B by polyacrylamide gel-crossed immunoelectrophoresis is in good agreement with the results obtained by rocket immunoelectrophoresis or nephelometry. The correlation between polyacrylamide gel-crossed immunoelectrophoresis and rocket immunoelectrophoresis is good for total apolipoprotein B (p greater than 0.001) and apolipoprotein A-I (p greater than 0.001). Polyacrylamide gel-crossed immunoelectrophoresis also offers interesting aspects to study the plasma lipoprotein classes and subclasses in different cases: normal plasma, current and complex dyslipoproteinemias in the presence or absence of lipoprotein small a. In a case of dyslipoproteinemia of Fredrickson's Type V polyacrylamide gel-crossed immunoelectrophoresis demonstrates the presence of a small-sized Lp (a) major peak in the low density lipoprotein (LDL) zone and of a large-sized Lp (a) minor peak in the very low density lipoprotein (VLDL) zone.

A compensatory mechanism improving red cell membrane fluidity in hemodialysed patients

A fluorescence polarization technique with 1,6-diphenyl 1,3,5-hexatriene as a fluorescent probe was used to determine the fluidity of red cell membranes from hemodialysed patients before and after dialysis. After dialysis, there was a decrease in fluidity and activation energy values revealed a significantly changed distribution. The membrane lipid composition showed a significant increase in cholesterol after dialysis (p less than 0.001) and a significant reduction in saturated fatty acids (p less than 0.01) with an increase in unsaturated fatty acids (p less than 0.05). A compensatory mechanism could be suggested involving a reduction of saturated fatty acids in response to the increase in the cholesterol/phospholipid ratio. This could lead to an optimization of membrane fluidity.

[Transfusion of concentrates enriched in neocytes in the thalassemic child. Preliminary results]

In this study, we compared the results of young red cells transfusion for 12 months with the administration of conventional red cells units during the year before, in three thalassemic children. We used the Neocel system (Cutter laboratories) to prepare neocytes. A quality control of neocyte units was developed: especially the phthalate oil technique which shows a 70% enrichment of young red cells. These patients received 170.4 +/- 9 ml/kg of body weight of neocytes compared with 197 +/- 20 ml/kg of body weight of conventional red cells concentrates. The mean decrease of hemoglobin transfused per kg of body weight per year was 22%. The mean pretransfusion hemoglobin level did not change during the 2 years of study. The children grow without any problem and no pathologic event occurred during the study. The control of the serological ferritin levels does not allow for definitive conclusions in the evolution of the iron overload of our three patients. However, this overload seems to decrease. It's why it's necessary to carry on with our study.

Free radical inhibitor effect of retinol after carbon tetrachloride intoxication in the rat

A study was conducted to explore the free radical inhibitor effect of retinol in Male Wistar rats. When retinol-deprived animals were considered retinol-depleted (after a period of 8 weeks), rats of each group, control and depleted, received an intraperitoneal injection of mineral oil (5 ml/kg body weight) or an equivalent volume of 20% carbon tetrachloride (CCl4) dissolved in mineral oil. The animals were killed by decapitation 4 h after administration of CCl4 and liver, heart, spleen, brain and testes were quickly removed. Minced tissues were homogenized and microsomes were prepared; vitamins A and E were monitored and malondialdehyde (MDA) content was estimated. Retinol-depleted rats showed an hepatic vitamin A level less than 10 pmol/mg protein, compared to control rats (15-45 pmol). In all hepatic preparations, we found low vitamin E levels (100-1300 pmol/mg protein). MDA production increased significantly in livers and hearts of retinol-depleted rats but not in brains, spleens and testes. Hearts contain less lipids and vitamin E than these latter organs, which could correlate with the highest production of MDA.

[Human malaria: dysglobulinemia-hypocholesterolemia syndrome]

Comparative study of protein and lipid parameters within a homogenous sample of 144 non-immune subjects having stayed for four months in Central Africa, suggests a dysglobulinemia more significant in the infected group. This dysglobulinemia affects in particular the IgM which are negatively correlated with cholesterol, positively with apoproteins A2 and H.D.L. Such a peculiar profiling involving immunoglobulins, apoproteins and cholesterol is rapidly regressive after stopping exposure to parasitic risk. It appears as an adaptation syndrome--or resistance--to tropical environment.

Free malondialdehyde determination by HPLC applied to microsomal studies

Malondialdehyde (MDA) is a product of lipid peroxidation in vivo. The most widely employed method for determination of free MDA is based on its reaction with thiobarbituric acid (TBA) which produces a pink pigment with an absorption maximum at 532-535 nm. However, quantitation of MDA is limited by its lack of specificity and a high performance liquid chromatographic (HPLC) method was recently developed in several laboratories. In the present study, free MDA levels were measured, after TBA reaction, spectrophotometrically and by HPLC in microsomes of different tissues from rats fed a vitamin A-deficient diet or not for 8 weeks, and treated or not with carbon tetrachloride. Incubation in vitro with NADPH (0.25 mM) or ascorbate (0.50 mM) in the presence of Fe2+ (5 microM)-ADP (0.5 mM), allowed us to estimate the total amount of enzymatic or non enzymatic lipoperoxidation. The MDA amount determined by HPLC is significantly lower than the TBA-reactive substances (TBA-RS) calculated spectrophotometrically as MDA equivalents. Moreover, HPLC separations performed on a mu Bondapack C18 column with a mobile phase of methanol/water 45/55 (v/v), containing 1% cetrimide revealed that three chromogens are present in microsomes incubated with ascorbate or NADPH. The TBA-RS visible spectra of microsomes incubated with activator are complex with an absorption maximum at 533 nm, which is specific for the MDA-TBA chromogen, and one at 450 nm. Identification of these TBA-RS, different from the MDA-TBA complex, is under investigation in our laboratory.

Absence of "A"-esterase activity in the serum of a patient with Tangier disease

The levels of apolipoprotein A-I, A-II and B in subjects who are homozygous or heterozygous for Tangier disease are reported and compared with the amount of "A"-esterase in the serum. The "A"-esterases hydrolyse toxic organophosphate pesticides and are currently classified by the nomenclature committee of the International Union of Biochemistry as arylesterases (EC 3.1.1.2) although recent evidence has cast doubt on this classification. The apolipoprotein data are consistent with previous data reported for a number of Tangier patients. The homozygote has a marked reduction in apo A-I and A-II levels and a 30% reduction in apo B. The heterozygotes have about a 50% reduction of apo A-I, a slight reduction in apo A-II and no change in apo B. These apolipoprotein values correspond to a marked reduction in HDL cholesterol for the homozygote and substantial reductions in the heterozygotes. The "A"-esterase activity is zero in one homozygote while heterozygotes have about 5% of the levels in control subjects. Arylesterase activity appears to be essentially normal. The data thus support previous observations that the HDL "A"-esterase activity is greatly reduced in those conditions where HDL apo A-I is markedly reduced, e.g., in "Fish-eye" Disease.

The action of free radicals on Deinococcus radiodurans carotenoids

The possible role of carotenoids as free radical scavengers has not been completely elucidated. To gain further insight into the quenching of OH radicals by carotenoids, we used a feasible bacterial model, Deinococcus radiodurans, a red pigmented bacterium. We compared the action of H2O2 which produces in vivo OH radicals by a Fenton-type reaction on the parental and two mutant strains, i.e., a red pigmented and a colorless one. While the red pigmented bacteria were resistant to H2O2 action, the colorless strain was significantly more sensitive and its sensitivity was dose-dependent. In the red pigmented strains, H2O2 induced a significant decrease in one carotenoid (X5), which could be responsible for the antioxidant activity.

Polyacrylamide gradient gel electrophoresis of cytosolic retinol- and retinoic acid-binding proteins: application to rat testis and liver

Distribution and cellular levels of retinol-binding protein and retinoic acid-binding protein, involved in the molecular action of retinoids, were analyzed in rat testis and liver. Both binding proteins of cytosolic extracts were separated by linear-polyacrylamide gradient gel electrophoresis and following electrophoretic separation, could be visualized by complementary identification tests such as autoradiography and marker proteins. The concentration of the binding proteins were evaluated by scanning the polyacrylamide gradient gels and the resulting data were found to be in accordance with those obtained by counting radioactivities. Polyacrylamide gradient gel electrophoresis appears suitable to detect and quantitatively evaluate cytosolic retinol- and retinoic acid-binding proteins.

[Glucose and its protein environment in vivo]

The non-enzyme reaction by which glucose can combine with free amines has been known since the beginning of the century: in 1912, Mallard reported the combination of glucose with amino acids. This reaction results in the formation of cetoamine or fructosamine as well as often complex sub-products responsible for a change in the color of the medium that turns brown. This process, which food chemists are well-familiar with, was not observed in vivo until three-quarters of a century later. In 1975, hemoglobin A was shown to combine with glucose by means of a non-enzyme reaction, producing hemoglobin A1c. HbA1c is now believed to be a "black box", i.e. a cumulative reflection of all the hyperglycemic episodes that occurred over the last hundred days. This discovery was followed by an impressive number of similar observations: nearly all the available amines seem able to participate in this kind of reaction. Plasma proteins, membrane proteins, structural proteins such as collagen, the apolipoproteins of circulating lipoproteins, intracellular tubulines, and even nucleic acids seem capable of undergoing glycation. A great number of bioclinica uses of this phenomenon have already been developed. Diabetes mellitus has benefited most from these investigations and, from a broader viewpoint, studies in this field are unquestionably central to our understanding of atherosclerosis, inflammation, and cancer. Furthermore, the entire spectrum of these observations are related to ageing.

Modified lipid-protein interactions in Tangier beta lipoprotein (LDL2) demonstrated by fluorescence quenching

Fluorescence quenching by iodide ions has been found to be higher in isolated Tangier low density lipoprotein (LDL2) than in isolated normal LDL2. Apolipoprotein (apo) B-100 is the main protein component of these lipoproteins and its tryptophanyl residues (Trp) are known to be the most hydrophobic and to be responsible for protein fluorescence. Trp exposure can thus be calculated; it was 0.50 in Tangier and 0.42 and 0.41 in insulin-dependent diabetics (IDD) and normal controls, respectively. The greater fluorescence quenching of Tangier LDL2 reveals a shallower embedding of Trp which is principally due to a lowered free cholesterol (FC) level in the shell and a smaller lipid core, itself dependent on a drop in cholesterol esters (CE). This is in accordance with the electrophoretic properties of Tangier LDL2 and suggests that Tangier LDL2 may be considered to be modified.

Ureaplasma-urealyticum-induced bladder stones in rats and their prevention by flurofamide and doxycycline

Struvite calculi can be produced in the bladder of Sprague-Dawley male rats after injection of ureaplasmas into the renal medulla. Calculi appear 3 to 6 days after ureaplasma injection. We have studied the inhibitory effect of flurofamide, a potent inhibitor of Ureaplasma urealyticum urease, and doxycycline, on the formation of bladder stones. Flurofamide given orally in five doses (total 125 mg) over 3 days and doxycycline in seven doses (total 20 mg) over 4 days partially prevented stone formation only when given at the time of inoculation. Ureaplasmas disappeared rapidly from the urine. The inhibitory effect of flurofamide was higher than that of doxycycline. However, doxycycline seemed to be efficient when given for a long period (5 weeks).

Evaluation of lipoproteins and apolipoproteins in serum of a Tangier patient by micro-scale two-dimensional electrophoresis

We examined lipoproteins and apolipoproteins in serum of a Tangier-disease patient. We used three different techniques of micro-scale two-dimensional electrophoresis: (a) no denaturants; (b) with sodium dodecyl sulfate (SDS) used only in the slab gel electrophoresis; (c) and with urea and a detergent used in isoelectric focusing and with SDS in slab gel electrophoresis. By technique a, an extremely low concentration of high-density lipoproteins (HDL) in the Tangier serum was seen, and lipoproteins that cannot form HDL complexes were detected as multiple spots in the acidic (pl 4 approximately 5) and relatively low apparent molecular mass (20,000 approximately 80,000) region. By technique b, Tangier low-molecular-mass lipoproteins were dissociated into their constituent apolipoproteins, and we observed a higher proportion of apoC-III, together with lower proportions of apoA-I and apoA-II, than in the normal HDL fraction. Technique c showed the total content of apolipoproteins in the whole Tangier serum, as several workers have reported. The presence of low-molecular-mass lipoproteins and a high concentration of apoC-III in this lipoprotein fraction characterized the Tangier serum.

Evaluation of lipoproteins and apolipoproteins in serum of a Tangier patient by micro-scale two-dimensional electrophoresis

We examined lipoproteins and apolipoproteins in serum of a Tangier-disease patient. We used three different techniques of micro-scale two-dimensional electrophoresis: (a) no denaturants; (b) with sodium dodecyl sulfate (SDS) used only in the slab gel electrophoresis; (c) and with urea and a detergent used in isoelectric focusing and with SDS in slab gel electrophoresis. By technique a, an extremely low concentration of high-density lipoproteins (HDL) in the Tangier serum was seen, and lipoproteins that cannot form HDL complexes were detected as multiple spots in the acidic (pl 4 approximately 5) and relatively low apparent molecular mass (20,000 approximately 80,000) region. By technique b, Tangier low-molecular-mass lipoproteins were dissociated into their constituent apolipoproteins, and we observed a higher proportion of apoC-III, together with lower proportions of apoA-I and apoA-II, than in the normal HDL fraction. Technique c showed the total content of apolipoproteins in the whole Tangier serum, as several workers have reported. The presence of low-molecular-mass lipoproteins and a high concentration of apoC-III in this lipoprotein fraction characterized the Tangier serum.

Plasma apolipoproteins in Tangier disease, as studied with two-dimensional electrophoresis

Tangier disease is characterized by a deficiency of high-density lipoproteins and of their major protein constituent, apolipoprotein (apo) A-I. We used high-resolution two-dimensional electrophoresis to examine the principal plasma apolipoproteins (A-I, A-II, A-IV, E, C-II, and C-III) of three persons with Tangier disease, one homozygous patient and his two heterozygous children, comparing the patterns with those for healthy subjects. Characteristic abnormalities were found in the distribution of the isoproteins of apo A-I, there being a normal concentration of pro apo A-I but dramatically decreased concentrations of the other apo A-I isoproteins. We also found hitherto-undescribed polypeptide abnormalities in apo C-III: sialylated and nonsialylated forms of apo C-III appear as double spots having the same isoelectric points but different molecular masses. No other substantial difference was detected in the polypeptide distribution of the other plasma apolipoproteins.