Association of lipoprotein(a), prostaglandin I2––synthesis stimulating plasma factor, biological half-life of prostaglandin I2and high-density lipoproteins in HIV-1 infection of different stages

2000 ◽  
Vol 63 (5) ◽  
pp. 309-314 ◽  
Author(s):  
H. Kritz ◽  
Y. Efthimiou ◽  
J. Stamatopoulos ◽  
C. Najemnik ◽  
H. Sinzinger
Keyword(s):  
Half Life ◽  
High Density ◽  
High Density Lipoproteins ◽  
Prostaglandin I2 ◽  
Lipoprotein A ◽  
Biological Half Life ◽  
Plasma Factor ◽  
Hiv 1

Apolipoprotein A and biological half-life of prostaglandin I2 in HIV-1 infection

1996 ◽  
Vol 81 (2) ◽  
pp. 213-218 ◽  
Author(s):  
Christian Pirich ◽  
Yamis Efthimiou ◽  
John O'Grady ◽  
Christoph Zielinski ◽  
Helmut Sinzinger
Keyword(s):  
Half Life ◽  
Prostaglandin I2 ◽  
Apolipoprotein A ◽  
Biological Half Life ◽  
Hiv 1

Fetal and Maternal Lipoprotein Metabolism in Human Pregnancy

1995 ◽  
Vol 88 (3) ◽  
pp. 311-318 ◽  
Author(s):  
Richard H. Neary ◽  
Mark D. Kilby ◽  
Padma Kumpatula ◽  
Francis L. Game ◽  
Deepak Bhatnagar ◽  
...  
Keyword(s):  
Caesarean Section ◽  
High Density Lipoprotein ◽  
Cholesteryl Ester ◽  
Free Cholesterol ◽  
Cholesterol Metabolism ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Lipoprotein A ◽  
Lipid Enrichment

1. Lipid, apolipoprotein concentration and composition were determined in maternal venous and umbilical arterial and venous blood at delivery by elective Caesarean section in 13 full-term pregnancies and in 25 healthy non-pregnant females. The indications of Caesarean section were a previous Caesarean section or breech presentation. None of the women was in labour and there were no other complications of pregnancy or fetal distress. 2. The objectives of the study were to establish whether the placenta has a role in feto-maternal cholesterol metabolism through either synthesis or transplacental cholesterol flux. The potential for free cholesterol diffusion between mother and fetus and rates of cholesterol esterification and transfer between lipoproteins were determined and related to the differences in composition between fetal and maternal lipoproteins. 3. Pregnant women had raised levels of all lipid and lipoprotein fractions compared with control subjects. The greatest increases were in free cholesterol and triacylglycerol (P < 0.0001). Lipoprotein (a) levels were significantly greater in the pregnant women [112(12.2) mg/l] than in the control women [50 (10.0) mg/l]. 4. The only significant correlation between maternal and fetal lipoprotein concentrations was in lipoprotein (a) levels (r = 0.791, P = 0.002). In both umbilical venous and arterial blood, concentrations of very-low- and low-density lipoproteins, particularly apolipoprotein B, cholesteryl ester and triacylglycerol, were lower than in maternal blood (P < 0.0001), but high-density lipoprotein levels were similar. 5. There was no umbilical arteriovenous differences in lipoprotein concentration or composition. This suggests that cholesterol synthesis or free cholesterol diffusion does not occur in the placenta. The relative concentrations of free cholesterol to phospholipid in maternal and fetal lipoproteins do not indicate the existence of a concentration gradient favouring free cholesterol diffusion across the placenta. 6. The esterification of free cholesterol was significantly reduced in maternal [17.7 (2.4) μmol h−1 l−1, P < 0.001] and fetal [6.7 (3.5) μmol h−1 l−1, P < 0.0001] compared with control [40.9 (13.2) μmol h−1 l−1] blood. 7. In fetal compared with maternal high-density lipoproteins the ratios cholesteryl ester/apoliproprotein A-I [0.84 (0.35) versus 0.40 (0.05), P < 0.01] and phospholipid/apolipoprotein A-I [1.66 (0.14) versus 0.58 (0.10), P < 0.0001] indicated lipid enrichment of these particles in the fetus. 8. Lipid enrichment of high-density lipoprotein is due in part to a marked reduction in transfer of cholesteryl ester in the fetus [1.0 (0.6) μmol h−1 l−1] compared with maternal [6.15 (1.3) μmol h−1 l−1, P = 0.004] and control [17.3 (7.2) μmol h−1 l−1, P < 0.0001] blood. 9. In conclusion, there was no evidence for involvement of the placenta in cholesterol metabolism during pregnancy. In fetal life high-density lipoproteins are lipid rich, partly because of a reduction in transfer of esterified cholesterol to other particles. Maternal and fetal lipoprotein levels are not correlated, although the results suggested that lipoprotein (a) levels may be related.

Concentrations of high-density lipoprotein subfraction HDL2 and lipoprotein A-I in a random population of healthy subjects

1991 ◽  
Vol 37 (12) ◽  
pp. 2111-2113 ◽  
Author(s):  
D Roche ◽  
M L Migueres ◽  
N T Lequang ◽  
M Burstein ◽  
O G Ekindjian ◽  
...  
Keyword(s):  
Low Cost ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Strongly Correlated ◽  
Lipoprotein A ◽  
The Difference ◽  
Apoprotein Composition ◽  
Hdl2 Cholesterol

Abstract High-density lipoproteins (HDL) are now currently subdivided according either to density and size—HDL2 and HDL3—or to surface apoprotein composition—lipoprotein A-I (LpA-I) without A-II, and LpA-I:A-II. In samples from blood bank donors (60 women, 47 men), we evaluated HDL subclasses, LpA-I particles, and other classic risk factors for atherosclerosis and compared them with each other. We found a good correlation between HDL2 and LpA-I (r = 0.74, P &lt; 0.001), the correlation being more marked in women (r = 0.74) than in men (r = 0.67). LpA-I was also strongly correlated with total apolipoprotein A-I (apoA-I) (r = 0.61), which suggests that LpA-I represents a significant portion of the variable pool of apoA-I. By contrast, LpA-I:A-II but not LpA-I was correlated with HDL3, confirming the preferential association of LpA-I with HDL2. The difference between the sexes was more marked for HDL2 (+66% in women) than for LpA-I (+25%). We conclude that in normolipemic subjects the size of the HDL2 pool depends on that of LpA-I. Considering the speed and low cost of the assay, determination of HDL2 cholesterol might be a useful tool for assessing cardiovascular risk.

scholarly journals Safety, Pharmacokinetics, Pharmacodynamics, and Plasma Lipoprotein Distribution of Eritoran (E5564) during Continuous Intravenous Infusion into Healthy Volunteers

2004 ◽  
Vol 48 (9) ◽  
pp. 3233-3240 ◽  
Author(s):  
Daniel P. Rossignol ◽  
Kishor M. Wasan ◽  
Eugene Choo ◽  
Edwin Yau ◽  
Nancy Wong ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Intravenous Infusion ◽  
Half Life ◽  
Ex Vivo ◽  
Low Density Lipoproteins ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Distribution Profile ◽  
Very Low Density Lipoproteins

ABSTRACT Eritoran, a structural analogue of the lipid A portion of lipopolysaccharide (LPS), is an antagonist of LPS in animal and human endotoxemia models. Previous studies have shown that low doses (350 to 3,500 μg) of eritoran have demonstrated a long pharmacokinetic half-life but a short pharmacodynamic half-life. The present study describes the safety, pharmacokinetics and pharmacodynamics, and lipid distribution profile of eritoran during and after a 72-h intravenous infusion of 500, 2,000, or 3,500 μg/h into healthy volunteers. Except for the occurrence of phlebitis, eritoran administration over 72 h was safe and well tolerated. Eritoran demonstrated a slow plasma clearance (0.679 to 0.930 ml/h/kg of body weight), a small volume of distribution (45.6 to 49.8 ml/kg), and a relatively long half-life (50.4 to 62.7 h). In plasma, the majority (∼55%) of eritoran was bound to high-density lipoproteins. During infusion and for up to 72 h thereafter, ex vivo response of blood to 1- or 10-ng/ml LPS was inhibited by ≥85%, even when the lowest dose of eritoran (500 μg/h) was infused. Inhibition of response was dependent on eritoran dose and the concentration of LPS used as an agonist. Finally, in vitro analysis with purified lipoprotein and protein fractions from plasma obtained from healthy volunteers indicated that eritoran is inactivated by high-density but not low-density lipoproteins, very-low-density lipoproteins, or albumin. From these results, we conclude that up to 252 mg of eritoran can be safely infused into normal volunteers over 72 h and even though it associates extensively with high-density lipoproteins, antagonistic activity is maintained, even after infusion ceases.

Gastroretentive System of Fluvastatin Sodium by Using Natural Mucilage and Synthetic Polymer

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Umamaheswara G. ◽  
Anudeep D.
Keyword(s):  
Half Life ◽  
Release Kinetics ◽  
Kinetic Studies ◽  
Diffusion Path ◽  
Synthetic Polymer ◽  
In Vitro Dissolution ◽  
Direct Compression ◽  
Drug Content ◽  
Biological Half Life

Fluvastatin sodium is a novel compound used as cholesterol lowering agent which acts through the inhibition of 3- hydroxyl-3- methyl glutaryl- coenzyme A (HMG-Co A) reductase. It has short biological half life (1-3h) in humans required a dosing frequency of 20 to 40mg twice a day. Due to its short variable biological half life it has been developed to a sustained gastroretentive system with a natural and synthetic polymer and to study how far the natural mucilage improves the sustained activity. Floating tablets were prepared by direct compression method using in combination of natural mucilage and synthetic polymer. Prior to the preparation of tablets the physical mixtures were subjected to FT IR studies and pre compression parameters. After preparation of tablets they were subjected to various tests like swollen index, drug content, In vitro dissolution and release kinetics with pcp disso software etc. The tablets prepared by direct compression shown good in thickness, hardness and uniformity in drug content, the prepared tablets floated more than 12h except FS1 and FS2 shows 9 and 11h. Swollen index studies shows with increase in concentration of polymer the swelling increases the diffusion path length by which the drug molecule may have to travel and cause lag time. In vitro results shows that on increasing the amount of hibiscus polymer the sustain activity is increased because of its integrity and forms a thick swollen mass and reduces the erosion property of the HypromelloseK100M, kinetic studies shows that FS 1, FS2, FS3 followed the Korsmeyer peppas model and the rest FS 4, FS 5, FS6 follows the zero order respectively. Based on n value indicating that the drug release followed super case II transport mechanism due to the erosion of the polymer.

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