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V Lo Cascio

Publications and source records attributed to V Lo Cascio.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effects of troglitazone on in vitro oxidation of LDL and HDL induced by copper ions and endothelial cells.

Trolitazone is a new oral antidiabetic agent able to reduce lipid peroxidation. In this study we evaluated its effect on the susceptibility of LDL and HDL to in vitro oxidation induced by copper ions and endothelial cells. In Cu(++)-induced LDL modification, different amounts of troglitazone were added to aliquots of the same pool of plasma with subsequent ultracentrifuge separation of LDL and HDL. Differences in LDL and HDL susceptibility to in vitro oxidation with Cu(++) were studied by measuring the changes in fluorescence intensity (expressed as lag phase). LDL derived from plasma incubated with different amounts of troglitazone were also incubated with umbilical vein endothelial cells (HUVEC), the modification being monitored by LDL relative electrophoretic mobility and fluorescence. During Cu(++)- and HUVEC-induced LDL oxidation, the decay rate of vitamin E, and the potency of troglitazone as a radical scavenger in comparison with vitamin E were also studied. Troglitazone determined a significant, dose-dependent decrease in Cu(++)-induced LDL and HDL oxidation. Incubation with HUVEC was also followed by a progressive, significant decrease of LDL relative electrophoretic mobility and fluorescence intensity. During Cu(++)- and HUVEC-induced-LDL modification, troglitazone significantly reduced the rate of vitamin E decay. In this study we also demonstrated that under the same oxidative stress, troglitazone was much more potent as a radical scavenger than vitamin E. In conclusion, the results demonstrate that troglitazone can reduce LDL and HDL in vitro oxidation and that, during this process, it can protect vitamin E. In addition to ensuring blood glucose control, the drug may therefore be useful in inhibiting lipoprotein peroxidation.

Arteriosclerosis↗
PubMed1997

E-selectin plasma concentration is influenced by glycaemic control in NIDDM patients: possible role of oxidative stress.

Although elevated levels of soluble E-selectin and intercellular cell adhesion molecules-1 (ICAM-1) have been reported in non-insulin-dependent diabetes mellitus (NIDDM), it is not clear by what mechanism this elevation occurs and whether or not it is related to glycaemic control. In this study we analyse: 1) the relation of glycaemic control with the concentrations of E-selectin, vascular cell adhesion molecules-1 (VCAM-1) and ICAM-1 in NIDDM patients: 2) whether metabolic control can affect the oxidative stress (as measured by plasma hydroperoxide concentration and susceptibility of LDL to in vitro oxidation) and hence the adhesion molecule plasma concentrations. Thirty-four (19 males and 15 females) poorly controlled NIDDM patients were studied. All parameters were evaluated at the beginning of the study and after 90 days of dietary and pharmacological treatment. The treatment decreased HbA1c (p < 0.001), E-selectin (p < 0.001), plasma hydroperoxides (p < 0.003) and the susceptibility of LDL to in vitro oxidation (lag phase) (p < 0.0001). Before treatment HbA1c, lag phase and lipid hydroperoxides correlated with E-selectin plasma concentration (r = 0.51, -0.57 and 0.54, respectively, p < 0.01). There was also a correlation between HbA1c and lag phase (p < 0.01) and between HbA1c and lipid hydroperoxides (p < 0.01). In addition, the variations of HbA1c, lag phase and lipid hydroperoxide values correlated with those for E-selectin concentration after 90 days' treatment (r = 0.54, -0.64 and 0.61, respectively, p < 0.01). In multiple linear correlation analysis, however, the partial correlation coefficients of HbA1c (basal and variations) with E-selectin concentration (basal and variations) fell to non-significant values (r = 0.12 and 0.25, respectively) when LDL lag phase and plasma hydroperoxides were kept constant. The results indicate that the improvement of metabolic control in NIDDM patients is associated with a decrease of E-selectin plasma levels; they also suggest that glycaemic control per se is not directly implicated in determining E-selectin plasma concentration; glycaemic control could affect E-selectin concentration through its effect on oxidative stress.

Blood Glucose↗
PubMed1997

Troglitazone increases the resistance of low density lipoprotein to oxidation in healthy volunteers.

The oxidative modification of low density lipoprotein is of importance in atherogenesis. Antioxidant supplementation has been shown, in published work, to increase low density lipoprotein resistance to oxidation in both healthy subjects and diabetic subjects; in animal studies a contemporary reduction in atherogenesis has been demonstrated. Troglitazone is a novel oral antidiabetic drug which has similarities in structure with vitamin E. The present study assessed the effect of troglitazone 400 mg twice daily for 2 weeks on the resistance of low density lipoprotein to oxidation in healthy male subjects. Ten subjects received troglitazone and ten received placebo in a randomised, placebo-controlled, parallel-group design. The lag phase (a measure of the resistance of low density lipoprotein to oxidation) was determined by measurement of fluorescence development during copper-catalysed oxidative modification of low density lipoprotein. The lag phase was increased by 27 % (p < 0.001) at week 1 and by 24% (p < 0.001) at week 2 in the troglitazone treated group compared with the placebo group. A number of variables known to influence the resistance of low density lipoprotein to oxidation were measured. They included macronutrient consumption, plasma and lipoprotein lipid profile, alpha-tocopherol, beta-carotene levels in low density lipoprotein, low density lipoprotein particle size, mono and polyunsaturated fatty acid content of low density lipoprotein and pre-formed low density lipoprotein hydroperoxide levels in low density lipoprotein. Troglitazone was associated with a significant reduction in the amount of pre-formed low density lipoprotein lipid hydroperoxides. At weeks 1 and 2, the low density lipoprotein hydroperoxide content was 17% (p < 0.05) and 18% (p < 0.05) lower in the troglitazone group compared to placebo, respectively. In summary the increase in lag phase duration in the troglitazone group appeared to be due to the compound's activity as an antioxidant and to its ability to reduce the amount of preformed low density lipoprotein lipid hydroperoxides. This antioxidant activity could provide considerable benefit to diabetic patients where atherosclerosis accounts for the majority of total mortality.

Administration, Oral↗
PubMed1997

Antioxidants inhibit the expression of intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1 induced by oxidized LDL on human umbilical vein endothelial cells.

The oxidative modification of low density lipoprotein (LDL) and the endothelial expression of adhesion molecules are key events in the pathogenesis of atherosclerosis. In this study we evaluated the effect of oxidized LDL on the expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin on human umbilical vein endothelial cells (HUVECs). The hypothesis that oxidized LDL functions as a prooxidant signal was also evaluated, by studying the effect of different radical-scavenging antioxidants on expression of adhesion molecules. LDL was oxidized by using Cu2+, HUVECs or phospholipase A2 (PLA2)/ soybean lipoxygenase (SLO), the degree of oxidation being measured as thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (CD). Exposure of 200 micrograms/ml of native LDL to 1 microns Cu2+, HUVECs and to PLA2/ SLO resulted in four- to fivefold higher levels of TBARS and CD than in native LDL. Cu(2+)-(1 microM), HUVEC-, and PLA2/SLO-oxidized LDL caused a dose-dependent, significant increase of ICAM-1 and VCAM-1 (p < .01). The expression of E-selectin did not change. LDL oxidized with a 2.5 and 5 microM Cu2+ did not increase ICAM-1 and VCAM-1 significantly. Both the Cu(2+)- and HUVEC-oxidized LDL, subjected to dialysis and ultrafiltration, induced ICAM-1 and VCAM-1 expression. After incubation with the ultrafiltrate, the expression of ICAM-1 and VCAM-1 was not significantly different from that obtained with native LDL. LDL pretreated with different antioxidants (vitamin E and probucol) and subjected to oxidation by Cu2+ and HUVECs induced a significantly lower expression of ICAM-1 and VCAM-1 than nonloaded LDL (p < .01). The pretreatment of HUVECs with vitamin E and probucol significantly reduced the expression of VCAM-1 on HUVECs induced by oxidized LDL (p < .01); the effect on ICAM-1 was much less evident. In conclusion, oxidized LDL can induce the expression of different adhesion molecules on HUVECs; this induction can be prevented by pretreating either the LDL or the cells with radical-scavenging antioxidant.

Antioxidants↗
PubMed1997

Lacidipine inhibits the activation of the transcription factor NF-kappaB and the expression of adhesion molecules induced by pro-oxidant signals on endothelial cells.

OBJECTIVE: The adhesion of monocytes to endothelium, an early event in atherosclerosis is mediated by cell adhesion molecules. Signal-transduction pathways for these binding molecules include the translocation of the transcription factor NF-kappaB; moreover, intracellularly generated oxygen-derived free radicals play a major role in this process. In this study we evaluated the extent to which lacidipine, a calcium antagonist with antioxidant properties, affects the expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin on human umbilical vein endothelial cells, induced by different pro-oxidant signals such as oxidized low density lipoprotein (LDL) and tumor necrosis factor-alpha (TNF-alpha). METHODS: We incubated 5 micromol/l Cu2+-oxidized LDL and TNF-alpha (2 ng/ml) with human umbilical vein endothelial cells for 48 and 6 h, respectively. ICAM-1, VCAM-1 and E-selectin were measured by flow cytometry. NF-kappaB was evaluated by electrophoretic mobility shift assay. RESULTS: The incubation of 5 micromol/l Cu2+-oxidized LDL not only caused a dose-dependent increase in ICAM-1, VCAM-1 and E-selectin (P < 0.001), but also synergically increased their TNF-alpha-induced expression (P < 0.001). The addition of lacidipine to human umbilical vein endothelial cells significantly reduced the expression of ICAM-1, VCAM-1 and E-selectin induced by TNF-alpha alone or with oxidized LDL (P < 0.001). The reduction in adhesion molecule expression caused by lacidipine was paralleled by a significant fall in NF-kappaB translocation. CONCLUSIONS: The results suggest that lacidipine may have prevented NF-kappaB-mediated adhesion molecule expression by exerting its effects on oxygen-derived free radicals. The results support previous observations that lacidipine may have therapeutic effects in atherosclerosis.

Calcium Channel Blockers↗
PubMed1997

Effect of once daily and twice daily sustained release theophylline formulations on daytime variation of bronchial hyperresponsiveness in asthmatic patients.

BACKGROUND: Previous studies evaluating spirometric values and symptoms have shown that once daily theophylline administered in the evening produces greater stabilisation of the airway function in asthmatic patients than the prototype theophylline given twice a day. The aim of this study was to compare the effects on bronchial responsiveness to methacholine of an ultrasustained release theophylline formulation (Diffumal-24, Malesci, Florence, Italy) administered once a day, a sustained release theophylline formulation (Theo-Dur, Recordati, Milan, Italy) administered twice a day, and placebo. METHODS: The study was performed in 12 adult patients with asthma using a randomised, double blind, three phase, cross-over design. Each phase lasted seven days and was followed or preceded by at least three days of theophylline washout. Diffumal-24 was administered once a day at 20.00 hours whereas Theo-Dur was given twice a day at 08.00 hours and 20.00 hours. In each patient the total daily dose of theophylline was the same during both phases. The dose of the two active preparations was titrated to individual needs before the beginning of the study and then given in divided or once daily doses. At 08.00, 14.00, and 20.00 hours on day 7 of each phase serum theophylline concentrations were measured and spirometric tests (FEV1) and bronchial challenge with methacholine were also performed. RESULTS: When the administration of Diffumal-24 was compared with that of Theo-Dur, a higher serum theophylline concentration of the former was seen in the morning whereas at 20.00 hours the reverse was true. Compared with placebo, at 08.00 hours Diffumal-24 improved FEV1 whereas Theo-Dur did not (difference between treatments 0.29 1, 95% CI 0.12 to 0.45). At 08.00 hours Diffumal-24 decreased bronchial sensitivity to methacholine, expressed as a natural logarithm of PD20, to a greater extent than Theo-Dur (difference between treatments 0.54 log units, 95% CI 0.016 to 1.08). The morning advantage observed with Diffumal-24 administration was not associated with a deterioration in the state of the airway during the daytime, the protective activity against methacholine during the 12 hours of the monitoring period being constant. Furthermore there was no difference in the mean FEV1 between the two treatments at 14.00 and 20.00 hours. CONCLUSIONS: In adults with stable bronchial asthma treatment with a single dose of Diffumal-24 administered in the evening improved airflow obstruction and reduced bronchial hyperresponsiveness.

Adult↗
PubMed1996

Mechanisms involved in the in vitro modification of low density lipoprotein by human umbilical vein endothelial cells and copper ions.

In this study we evaluated the time course and mechanism of low density lipoprotein (LDL) oxidation induced by human umbilical vein endothelial cells (HUVECs), cell-free medium (CFM) and Cu2+. After incubating LDL (200 micrograms/ml) with HUVECs, CFM and Cu2+ (concentration adjusted to obtain the same degree of LDL modification as with HUVECs), the extent of LDL lipid peroxidation and apoprotein B modification was monitored at different times from 0 to 24 h. This involved evaluating the time course of LDL conjugated diene, peroxide, malonyldialdehyde (MDA), fluorescence, relative electrophoretic mobility (REM), vitamin E and monounsaturated and polyunsaturated fatty acids. After incubation with HUVECs, the LDL REM was significantly higher than that obtained in CFM (p < 0.01). When balanced for the same degree of LDL modification as obtained with HUVECs, Cu2+ gave a REM similar to that obtained with HUVECs. At the different times of incubation there was no statistical difference between conjugated diene and peroxide values after incubation with HUVECs and with CFM. The values obtained with Cu2+ were significantly higher than those obtained with HUVECs and CFM (p < 0.01). MDA and LDL fluorescence were significantly higher after exposure to HUVECs than to CFM (p < 0.01), values being similar to those obtained with Cu2+. There was no statistical difference between the values of LDL oleic, linoleic, arachidonic and eicosapentaenoic acids after incubation with HUVECs and CFM. Eicosatetraynoic acid (ETYA), a lipoxygenase inhibitor, determined dose-dependent reduction of MDA formation induced by the incubation of LDL with HUVECs; it did not affect LDL conjugated diene. ETYA did not have any effect on the MDA derived from LDL after incubation with Cu2+ or CFM. The results of this study demonstrate that, unlike Cu2+, the contribution of HUVECs to LDL modification does not involve only lipid peroxidation of the lipoprotein; it also includes intracellular radical and non-radical processes.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1995

Acute effects of deflazacort and prednisone on rates of mineralization and bone formation.

The aims of this study were to determine (1) whether acute suppression of bone formation could be evaluated after the administration of corticosteroids in man by quantitative bone histomorphometry; and (2) whether there were significant differences between the effects of prednisone and its analog deflazacort. Thirteen patients who needed high-dose corticosteroid therapy were randomly allocated to two groups of treatment (prednisone or deflazacort). Quantitative bone histomorphometry, using the technique of triple labeling, and biochemical measurements of bone turnover were studied. There were no differences in biochemical indices of bone turnover between prednisone and deflazacort at the beginning and end of the 15 days of treatment course. During corticosteroid treatment, there were no significant changes in biochemical indices of bone turnover but a significant decline in total alkaline phosphatase (P < 0.01). Histomorphometric indices, as revealed by measurements of tetracycline interval and extent of labeling, showed no significant differences in either mineral apposition rate or bone formation rate in the two groups. We conclude that the acute glucocorticoid suppression of bone turnover by glucocorticoids is not detectable within the first 2 weeks of treatment by histomorphometric techniques. No differences in bone effects of prednisone and deflazacort were detected in this short-term study.

Adult↗
PubMed1995

Elevated levels of soluble E-selectin in patients with IDDM and NIDDM: relation to metabolic control.

The adhesion of leucocytes to the endothelium, an early step in atherogenesis, is mediated by cell adhesion molecules. In this study we evaluated the concentration of soluble adhesion molecules in patients with insulin-dependent (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM) and studied its relation to glycaemic control. Soluble adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) were measured in 31 diabetic patients (18 with IDDM and 13 with NIDDM), 20 hyperlipoproteinaemic patients (10 with type IIa and 10 with type IIb) and 20 healthy subjects. Increased E-selectin concentrations were found in the patients with IDDM and NIDDM and in the hyperlipoproteinaemic patients when compared to the control subjects (p < 0.01 for all the groups). ICAM-1 was found to be elevated only in the patients with NIDDM (p < 0.01). No significant differences in VCAM-1 concentration were found in the different groups of subjects. The concentration of plasma E-selectin was positively correlated with the glycated haemoglobin (r = 0.54, p < 0.01) in patients with IDDM and NIDDM. In the same patients E-selectin was not related to the concentrations of plasma lipids in spite of the fact that it was found to be elevated in hyperlipoproteinaemic subjects. The results though preliminary suggest that in diabetic patients the concentration of soluble adhesion molecules and especially of E-selectin may be related to metabolic control.

Adult↗
PubMed1995

Effect of three different doses of a slow-release theophylline formulation on bronchial response to inhaled methacholine in asthmatic patients.

This study investigated whether or not a sustained release formulation of theophylline (SRT) at different dosages had any effect on bronchial hyperresponsiveness as measured by the methacholine challenge. On four separate occasions, 16 patients with mild asthma took either placebo or 300, 400, 500 mg of SRT twice a day. SRT had a slight bronchodilating effect that was not dose-related, but produced a dose-related decrease in the bronchial response to inhaled methacholine (r = 0.39, p = 0.007). This effect was present after all three treatment periods with the active drug when mean +/- SE theophylline serum concentrations of 10.3 +/- 0.7, 12.6 +/- 0.9 and 17.1 +/- 1.1 mg/l respectively were reached. A highly significant relationship between theophylline serum concentration and the degree of protection against methacholine bronchospasm was also found (r = 0.45, p = 0.001). It is concluded that oral theophylline does reduce bronchial hyperresponsiveness in a dose dependent fashion, this effect being present at all the serum concentrations within the normal range.

Adult↗
PubMed1995

Tussive effect of capsaicin in patients with gastroesophageal reflux without cough.

The aim of this study was to clarify the influence of gastroesophageal reflux (GER) on cough threshold in patients with digestive symptoms but free from respiratory involvement. Of 57 consecutive subjects referred for 24-h esophageal pH monitoring because of digestive reflux symptoms, 29 patients free from respiratory disorders were studied. They underwent esophageal pH monitoring and manometry, upper gastrointestinal endoscopy, pulmonary function tests, and methacholine and capsaicin challenges. The methacholine test was performed by inhalation of increasing doses of methacholine up to 4,000 micrograms; the results were expressed as the dose causing a 20% decrease in FEV1 from baseline (PD20). The capsaicin threshold was evaluated by inhalation of increasing doses of capsaicin from 0.3 up to 9.84 nmol, expressing the results as the dose of capsaicin eliciting five coughs (PD5). Fifteen patients were considered refluxers on the basis of a total esophageal acid exposure time above 4.7%. Esophagitis grade 0 was found in 15 patients, grade 1 in seven patients, grade 2 in seven patients. PD5 was significantly lower in refluxers (median 0.51 micrograms, range 0.22 to 19.8) than in nonrefluxers (19.8 micrograms, range 0.31 to 19.8) (p < 0.001); there was no difference in baseline ventilatory parameters and in airway responsiveness to methacholine between the two groups. All patients with a pathologic acid exposure time but one had a low cough threshold, irrespective of the presence or absence of esophagitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Capsaicin↗
PubMed1994

Effect of plasma on the degradation of hydroperoxides of unesterified linoleic acid and copper-peroxidized LDL.

The determination of lipid hydroperoxides in plasma and lipoproteins recently reached a clinical relevance in disorders such as atherosclerosis, where oxidative reactions have been suggested to play a fundamental pathogenetic role. The peroxide content of lipoproteins is usually measured after ultracentrifugation and extraction. During this procedure, some peroxides might decompose causing a too low recovery. To screen this possibility, the disappearance, in the presence of human plasma, of hydroperoxides of linoleic acid and Cu-oxidized low density lipoprotein (LDL) have been investigated, using both a iodometric titration and an enzymatic assay. While only in the presence of GSH plasma decomposes linoleic acid hydroperoxides quite rapidly, peroxides in Cu-oxidized LDL were stable both in presence as well as in absence of GSH. This indicated that lipid hydroperoxides are stable in plasma and that peroxides of Cu-oxidized LDL are not substrate for the glutathione-dependent peroxidase activity in plasma. The relevant decrease of the iodometric titre of LDL peroxides observed in the presence of elevated amounts of plasma was shown to be artifactual, since some compounds extracted from plasma do react with iodine generated by peroxides. Whole plasma itself, indeed, has been shown to reduce back to I- appreciable amount of free iodine.

Copper↗
PubMed1994

Increased susceptibility of LDL to in vitro oxidation in patients with insulin-dependent and non-insulin-dependent diabetes mellitus.

The susceptibility of LDL to copper-catalyzed oxidation was evaluated in 24 patients with insulin-dependent and 16 patients with non-insulin-dependent diabetes mellitus, 14 abdominal and 14 gluteal-femoral obese women, 22 familial hypertriglyceridemic and 28 control subjects. Differences in the LDL susceptibilities were studied by measuring the changes of fluorescence intensity and expressed as lag-phase. The lag-phase was significantly shorter in patients with insulin-dependent, non-insulin-dependent diabetes mellitus, abdominal obesity and familial hypertriglyceridemic patients than in gluteal-femoral obese subjects and controls (p < 0.01). The shortest lag-phase was found in familial hypertriglyceridemic patients while intermediate values were found in insulin-dependent, non-insulin-dependent and abdominal obese patients who had only a slight increase in triglyceride values. Similarly the lowest value of the LDL cholesterol to protein ratio, as expression of LDL particle size, was found in familial hypertriglyceridemic patients (p < 0.01), while the patients with insulin-dependent, non-insulin-dependent diabetes mellitus and abdominal obesity had intermediate values. The ratio was found to be directly correlated with the length of the lag-phase (r = 0.87, p < 0.001). In spite of similar triglyceride and cholesterol to protein ratio values, however, the length of the lag-phase was significantly shorter in patients with insulin-dependent diabetes mellitus than in those with abdominal obesity. So it is concluded that the different susceptibility to oxidation found in the different groups of patients is only partially explained by plasma triglyceride values.

Adult↗
PubMed1994

[EC Respiratory Health Surgery in the north of Italy: methodological problems of a multicenter study of prevalence of asthma].

The EC Respiratory Health Survey (ECRHS) design is presented: the survey aim is to estimate asthma prevalence and risk factors distribution in the various European countries population. In Italy three centres are involved: Pavia, Turin and Verona. EC Health Respiratory Survey is an international two stages cross-sectional survey on probability samples of general population aimed to asses asthma prevalence in different countries. In the first stage a random sample was sent a Screening Questionnaire by post; in the second stage a subsample was invited to clinical centres in order to undergo lung function tests, allergy tests and a standardised clinical interview. The analysis of the response pattern in Italy shows that both in stage 1 and in stage 2 a selection bias overestimating real prevalence is present. Some methodological issues concerning the design of cross sectional surveys are addressed.

Adult↗
PubMed1993

Determination of lipid hydroperoxides in native low-density lipoprotein by a chemiluminescent flow-injection assay.

Lipid hydroperoxides have been implicated in the pathogenesis of atherosclerosis. This work was therefore set up to obtain a fast and specific chemiluminescent assay for measuring hydroperoxides in native low-density lipoprotein (LDL). The apparatus was a complete HPLC system including two pumps, an autosampler, a computer and a chemiluminescent detector with a T-mixing coil in the place of the column. Samples were injected from the autosampler and mixed with luminescent reagent (3 microM luminol and 1 microM microperoxidase in 0.1 M carbonate buffer (pH 10)) in the T-piece. To generate a calibration curve, linoleic acid hydroperoxide was obtained by incubating soybean lipoxygenase with linoleic acid. The calculated conjugated diene concentration was in good agreement with the nominal linoleic acid hydroperoxide concentration. The chemiluminescence was linear with the amount of linoleic acid hydroperoxide injected and the detection limit was about 3 pmol linoleic acid hydroperoxide. The chemiluminescence induced by copper-oxidized LDL was linear with concentration; the detection limit, when compared with linoleic acid hydroperoxide, was similar. The reproducibility of the linoleic acid hydroperoxide and of oxidized LDL hydroperoxide was examined in single pools. The coefficient of variation on the triplicates of each pool was about 3%. The titre of the linoleic acid hydroperoxide and oxidized LDL peroxides was quite stable for at least 10 days when stored under argon at 4 degrees C in the presence of EDTA. The mean value of the LDL hydroperoxides in 16 control subjects was 145.20 +/- 98.81 pmol/mg LDL protein. In conclusion, the microperoxidase-luminol-dependent chemiluminescence flow-injection assay is a rapid, sensitive and selective method for measuring lipid hydroperoxides in native LDL.

Chromatography, High Pressure Liquid↗
PubMed1993

Long-term effects of transdermal and oral estrogens on serum lipids and lipoproteins in postmenopausal women.

The transdermal and oral administration of estrogens for one year were compared with respect to the effects on lipid metabolism. Eighty-one postmenopausal women (1.5-3 years after menopause) were randomly divided into three groups. The first two groups received sequential estrogen treatment with either transdermal estradiol (Estraderm TTS, Ciba Geigy; 50 micrograms/day; 24 women) or 0.625 mg/day conjugated estrogens (Premarin, Wyeth; 20 subjects), respectively. In both groups medroxyprogesterone (10 mg/day per os) was added for 12 days of each cycle. Thirty-five subjects served as control group without therapy. No significant changes in the lipid profile was observed in control subjects after 1 year of follow-up. Serum triglycerides decreased significantly (-10.9 +/- 26% S.D.; P < 0.05) in transdermal treated women, whereas it slightly rose in oral estrogen group. Comparable significant decreases in total and low density lipoprotein (LDL) cholesterol (mean range -6.5/-18.0%) were observed in women on estrogen replacement therapy. High density lipoprotein (HDL) cholesterol significantly diminished in transdermal estradiol group, but it rose slightly in the oral estrogen group. Thus the fraction of HDL cholesterol over LDL cholesterol did not change in the transdermal group whereas it significantly rose in subjects treated with oral estrogens. It remains to be established to what extent these differences on lipid metabolism are relevant for the prevention of cardiovascular diseases.

Administration, Cutaneous↗