bluuebunny/crossref_metadata_2025 huggingface dataset:
Humoral Immune Response to Keyhole Limpet Haemocyanin, the Protein Carrier in Cancer Vaccines
Authors: Kantele A. , Häkkinen M. P. , Zivny J. , Elson C. O. , Mestecky J. , Kantele J. M.
Published: June 2011

Keyhole limpet haemocyanin (KLH) appears to be a promising protein carrier for tumor antigens in numerous cancer vaccine candidates. The humoral immune response to KLH was characterized at the single-cell level with ELISPOT combined with separations of cell populations according to their expression of homing receptors (HRs). The analysis of HR expressions is expected to reveal the targeting of the immune response in the body. Eight orally primed and four nonprimed volunteers received KLH-vaccine subcutaneously. Circulating KLH-specific plasmablasts were found in all volunteers, 60 KLH-specific plasmablasts/106PBMC in the nonprimed and 136/106in the primed group. The proportion of L-selectin+plasmablasts proved high and integrinα4β7+low. KLH serving as protein carrier in several vaccines, the homing profile of KLH-specific response may be applicable to the cancer antigen parts in the same vaccines. The present data reflect a systemic homing profile, which appears advantageous for the targeting of immune response to cancer vaccines.
Determinants of Intravascular Resistance in Indian Diabetic Nephropathy Patients: A Hospital-Based Study
Authors: Thukral Anubhav , Mishra Manish , Srivastava Vaibhava , Kumar Hemant , Dwivedi Amit Nandan Dhar , Shukla Ram Chandra , Tripathi Kamlakar
Published: June 2011

Aims and Objectives. Metabolic dysregulation has failed to explain clinical variability of patients with diabetic nephropathy and hence a renewed interest emerged in haemodynamic factors as determinant of progression and development of diabetic nephropathy. We therefore studied for various factors which can correlate with raised renal vascular resistance in diabetic nephropathy.Material and Methods. Renal vascular resistance was measured in patients with established and incipient diabetic nephropathy and compared with controls using noninvasive color Doppler examinations of intrarenal vasculature.Results. Renal vascular resistance correlated with age, duration of disease, GFR, serum creatinine, and stage of retinopathy. Renal vascular resistance was significantly reduced in patients on treatment with RAAS inhibitors and insulin, than those on OHA and antihypertensives other than RAAS inhibitors.Conclusion. The study implies that renal vascular resistance may help identify diabetics at high risk of developing nephropathy, and these set of patients could be candidates for RAAS inhibition and early insulin therapy even in patients without albuminuria.
A Clinical Update on Delirium: From Early Recognition to Effective Management
Authors: Cerejeira Joaquim , Mukaetova-Ladinska Elizabeta B.
Published: June 2011

Delirium is a neuropsychiatric syndrome characterized by altered consciousness and attention with cognitive, emotional and behavioural symptoms. It is particularly frequent in elderly people with medical or surgical conditions and is associated with adverse outcomes. Predisposing factors render the subject more vulnerable to a congregation of precipitating factors which potentially affect brain function and induce an imbalance in all the major neurotransmitter systems. Early diagnosis of delirium is crucial to improve the prognosis of patients requiring the identification of subtle and fluctuating signs. Increased awareness of clinical staff, particularly nurses, and routine screening of cognitive function with standardized instruments, can be decisive to increase detection rates of delirium. General measures to prevent delirium include the implementation of protocols to systematically identify and minimize all risk factors present in a particular clinical setting. As soon as delirium is recognized, prompt removal of precipitating factors is warranted together with environmental changes and early mobilization of patients. Low doses of haloperidol or olanzapine can be used for brief periods, for the behavioural control of delirium. All of these measures are a part of the multicomponent strategy for prevention and treatment of delirium, in which the nursing care plays a vital role.
Spinal Cord Ischemia after Endovascular Repair of Infrarenal Abdominal Aortic Aneurysm: A Rare Complication
Authors: Kouvelos George N. , Papa Nektario , Nassis Christos , Xiropotamos Nikolaos , Papadopoulos George , Matsagkas Miltiadis I.
Published: June 2011

Neurologic deficit secondary to spinal cord ischemia after elective infrarenal, endovascular aneurysm repair (EVAR), consists a rare and rather disastrous complication. The etiology of such neurologic complication seems to be multifactorial, making this event unpredictable and foremost unpreventable. We report a case of paraparesis and bladder dysfunction that occurred immediately after the EVAR procedure. Prompt management by conservative or invasive methods seems to be important for the reversal of the neurologic deficit and the optimization of patient's outcome.
Effects of Encapsulated Propolis on Blood Glycemic Control, Lipid Metabolism, and Insulin Resistance in Type 2 Diabetes Mellitus Rats
Authors: Li Yajing , Chen Minli , Xuan Hongzhuan , Hu Fuliang
Published: June 2011

The present study investigates the encapsulated propolis on blood glycemic control, lipid metabolism, and insulin resistance in type 2 diabetes mellitus (T2DM) rats. The animal characteristics and biological assays of body weight, fasting blood glucose (FBG), fasting serum insulin (FINS), insulin act index (IAI), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured and euglycemic hyperinsulinemic glucose clamp technique were used to determine these effects. Our findings show that oral administration of encapsulated propolis can significantly inhibit the increasing of FBG and TG in T2DM rats and can improve IAI and M value in euglycemic hyperinsulinemic clamp experiment. There was no significant effects on body weight, TC, HDL-C, and LDL-C in T2DM rats treated with encapsulated propolis. In conclusion, the results indicate that encapsulated propolis can control blood glucose, modulate lipid metabolism, and improve the insulin sensitivity in T2DM rats.
Fibrinogen catabolism in patients with type II and type IV hyperlipidemia. Effect of dietary and clofibrate treatment on laboratory findings.
Authors: Fletcher A , Alkjaersig N , Schonfeld G , Witztum J
Published: June 2011

Fibrinogen catabolism was studied by plasma fibrinogen chromatography and other methods in 99 subjects with hyperlipoproteinemia Types IIa, IIb, and IV, and in 24 control subjects with normal blood lipid values. Subjects with either a history of thromboembolic vascular disease or clinical evidence of atherosclerosis were excluded. Type II subjects (i.e., the combined group of Type IIa and IIb subjects) showed an elevation of plasma high molecular weight fibrinogen complexes, which is indicative of enhanced fibrin formation. They also showed an elevation of fibrinogen-first-derivative, which is indicative of fibrinogenolysis and increased plasma euglobulin activity. Subjects with Type IV hyperlipoproteinemia showed similar findings to those of Type II except that high molecular weight fibrinogen complex concentration was normal. Subsequently, 36 patients received a fat-controlled, low cholesterol diet and were studied in a blind, random, crossover study of dietary vs clofibrate treatment. Although total cholesterol and triglyceride levels fell significantly during the treatment periods, chromatographic findings of abnormal plasma fibrinogen remained unchanged.
Effect of dietary fat saturation and cholesterol on LDL composition and metabolism. In vivo studies of receptor and nonreceptor-mediated catabolism of LDL in cebus monkeys.
Authors: Nicolosi R J , Stucchi A F , Kowala M C , Hennessy L K , Hegsted D M , Schaefer E J
Published: June 2011

The mechanism(s) by which polyunsaturated fats reduce low density lipoprotein (LDL) cholesterol and apolipoprotein (apo) B were investigated in 20 cebus monkeys (Cebus albifrons) fed diets containing corn oil or coconut oil as fat (31% of calories) with or without dietary cholesterol (0.1% by weight) for 3 to 10 years. Coconut-oil feeding compared to corn-oil feeding resulted in significant increases in levels of plasma total cholesterol (176%), very low density lipoprotein (VLDL)-LDL cholesterol (236%), high density lipoprotein (HDL) cholesterol (148%), apo B (78%), and apo A-I (112%). The addition of dietary cholesterol to corn oil compared to corn oil alone resulted in smaller, but significant, increases in levels of total cholesterol (44%), HDL cholesterol (40%), and apo A-I (33%). Although the increases in VLDL-LDL cholesterol were of similar magnitude (52%), they barely failed to reach statistical significance (p less than 0.08), while the changes in apo B levels were negligible. The addition of dietary cholesterol to coconut oil, compared to coconut oil alone, resulted in no significant changes in lipoprotein cholesterol or apoproteins, although levels of VLDL-LDL cholesterol and apo B values increased 22% and 16%, respectively. Although hepatic free cholesterol content was not altered by diet, coconut-oil compared to corn-oil feeding resulted in significant increases in hepatic cholesteryl esters (236%) and triglycerides (325%), the latter increasing still further when dietary cholesterol was added to coconut oil (563%). To further assess the effects of these dietary changes on LDL metabolism, radioiodinated normal and glucosylated LDL kinetics were performed. The production rate of LDL apo B was not altered by diet. With corn-oil feeding, 63% of LDL catabolism was via the receptor-mediated pathway. Coconut-oil compared to corn-oil feeding resulted in a 50% decrease in receptor-mediated LDL apo B fractional catabolic rate (FCR) and a 27% reduction in nonreceptor-mediated LDL apo B FCR. The addition of dietary cholesterol to corn oil, compared to corn oil alone, resulted in no significant effect on LDL apo B catabolism. The addition of dietary cholesterol to coconut oil, compared to coconut oil alone, was associated with no significant change in nonreceptor catabolism of LDL apo B but with a 58% decrease in receptor-mediated catabolism of LDL (p less than 0.059). The diet-induced alterations of LDL catabolism were significantly correlated with hepatic lipids, which were enriched in saturated fatty acids.(ABSTRACT TRUNCATED AT 400 WORDS)
Interleukin-1 stimulates prostacyclin production by cultured human endothelial cells by increasing arachidonic acid mobilization and conversion.
Authors: Breviario F , Proserpio P , Bertocchi F , Lampugnani M G , Mantovani A , Dejana E
Published: June 2011

Interleukin-1 (IL-1) induced slow, lasting activation of human endothelial cells (EC) to release prostacyclin (PGI2). This was accompanied by endogenous 3H-arachidonic acid (3H-AA) release and by a time-dependent increase in the cells' ability to convert exogenous AA. The continuous presence of IL-1 was not required, but about a 1-hour stimulation with the cytokine was sufficient to trigger the cells to synthesize PGI2 for several hours. The spectrum of 3H-AA conversion shows that, in addition to 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha also was raised after IL-1. The recovery of PGI2 synthesis after aspirin was faster in IL-1-treated EC than in control cells. These data define some of the characteristics of IL-1 stimulation of PGI2 and suggest that this process is mediated both by endogenous AA mobilization and by an increase in cyclooxygenase activity.
Suppression of aortic atherosclerosis in cholesterol-fed rabbits by purified rabbit interferon.
Authors: Wilson A C , Schaub R G , Goldstein R C , Kuo P T
Published: June 2011

The effectiveness of rabbit interferon in suppressing atherosclerosis was evaluated in rabbits fed a diet containing 1% cholesterol. Ten male New Zealand White rabbits received intramuscular injections of 1 million units of interferon twice a week, while a control group of 10 rabbits received injections of buffer. Both groups had average serum cholesterol levels of over 2000 mg/dl during the 8-week experimental period. Interferon treatment resulted in no significant hypolipidemic effect or changes in lipoprotein composition. Atherosclerotic lesions in aortas were quantified both macroscopically and microscopically. Interferon treatment decreased the grossly visible lesion area significantly from 25 +/- 4% to 8 +/- 1% (mean +/- SEM, p less than 0.005) compared to the untreated group. Microscopic analysis of serial cross-sections of aortic segments revealed significant (p less than 0.01) reductions in both lesion size and frequency in the interferon-treated group. Electron microscopy also showed that interferon treatment reduced the pathological effects of cholesterol feeding. Tissue analysis showed that total aortic cholesterol was reduced by 28% by interferon treatment, while the aortic phospholipid concentration was increased by 25%. The possibility exists that the interferon preparation used contained other biological response modifiers and that the observed effects may be totally unrelated with interferon. These results suggest that the mechanism of atherosclerosis suppression in these cholesterol-fed rabbits is not related to the lowering of serum cholesterol but may be associated with inhibition of lesion initiation.
Apolipoprotein E4 homozygosity predisposes to serum cholesterol elevation during high fat diet.
Authors: Tikkanen M J , Huttunen J K , Ehnholm C , Pietinen P
Published: June 2011

The hypothesis that apolipoprotein E (apo E)-isoform-related differences in plasma and LDL cholesterol concentrations are due to differential responses to dietary lipids was explored in 110 North Karelian subjects who had previously participated in dietary intervention studies. This was accomplished by collecting fresh blood samples for apo E phenotyping and by re-analysis of the original plasma lipid data according to apo E phenotypes. During high fat, high cholesterol baseline (p = 0.003) and switchback diets (p = 0.002), plasma cholesterol correlated inversely with the sum of subscript numbers (e.g., apo E3/4 = 7). Thus, subjects with the apo E4/4 phenotype had the highest (7.63 +/- 1.32 mmol/l), and subjects with the apo E3/2 phenotype had the lowest baseline levels of plasma cholesterol (5.85 +/- 1.48 mmol/l). This association became weaker during a low fat, low cholesterol diet intervention (p = 0.069). Greater reductions in plasma cholesterol occurred in subjects homozygous for the apo epsilon 4 allele (-1.84 mmol/l) as compared to subjects with other genotypes (-1.13 mmol/l) (p = 0.0097). Moreover, these subjects responded to the switchback diet by greater increases in plasma cholesterol (1.52 mmol/l) than others (0.92 mmol/l, p = 0.0141). The results suggest that the effect of apo epsilon genotype on plasma cholesterol is modulated by dietary fat and cholesterol intake.
Phenotypic effects of apolipoprotein structural variation on lipid profiles. III. Contribution of apolipoprotein E phenotype to prediction of total cholesterol, apolipoprotein B, and low density lipoprotein cholesterol in the healthy women study.
Authors: Eichner J E , Kuller L H , Ferrell R E , Meilahn E N , Kamboh M I
Published: June 2011

The apolipoprotein (apo) E structural locus has been shown to influence concentrations of total cholesterol, apo B, and low density lipoprotein (LDL) cholesterol in population studies. Apo E has six phenotypes resulting from three common alleles at this locus. In the present study, we have typed 473 healthy white women for apo E. At baseline in 1984, all women were premenopausal. To date, 109 of these women have become postmenopausal and are not on hormone therapy. Statistical analyses were done on both pre- and postmenopausal groups to assess the influence of menopausal status in combination with the apo E locus on lipid profile. Nine lipoprotein lipids and apolipoproteins were categorized by three apo E phenotypes: apo E3-2, apo E3-3, and apo E4-3. These were compared in analysis of variance. At baseline, the apo E3-2 phenotype showed the lowest average concentrations of total cholesterol (170 mg/dl), apo B (80 mg/dl), and LDL cholesterol (91 mg/dl), while the apo E4-3 phenotype demonstrated the highest average concentrations of total cholesterol (192 mg/dl), apo B (104 mg/dl), and LDL cholesterol (116 mg/dl) (p less than or equal to 0.0004). Apo E3-3 homozygotes were intermediate on all three quantitative variables. The postmenopausal subset showed the same trends by phenotype, with overall increases in total cholesterol, apo B, LDL cholesterol, and triglycerides, regardless of phenotype. Women who remained premenopausal generally showed smaller increases in these same measures. Our results suggest that, on average, the lower lipoprotein values for the apo E3-2 phenotype are maintained through early menopause despite a worsening of lipid profiles for all women as they age.(ABSTRACT TRUNCATED AT 250 WORDS)
Association of fasting insulin with blood pressure and lipids in young adults. The CARDIA study.
Authors: Manolio T A , Savage P J , Burke G L , Liu K A , Wagenknecht L E , Sidney S , Jacobs D R , Roseman J M , Donahue R P , Oberman A
Published: June 2011

The association of insulin with cardiovascular disease (CVD) may be mediated in part by the associations of insulin with CVD risk factors, particularly blood pressure and serum lipids. These associations were examined in 4576 black and white young adults in the CARDIA Study. Fasting insulin level was correlated in univariate analysis with systolic blood pressure (r = 0.16), diastolic blood pressure (r = 0.13), triglycerides (r = 0.27), total cholesterol (r = 0.10), high density lipoprotein (HDL) cholesterol (r = -0.25), and low density lipoprotein (LDL) cholesterol (r = 0.14), and with age, sex, race, glucose, body mass index, alcohol intake, cigarette use, physical activity, and treadmill duration (all p less than 0.0001). After adjustment for these covariates, insulin remained positively associated with blood pressure, triglycerides, total and LDL cholesterol, and apolipoprotein B and was negatively associated with HDL, HDL2 and HDL3 cholesterol, and apolipoprotein A-I in all four race-sex groups. Higher levels of fasting insulin are associated with unfavorable levels of CVD risk factors in young adults; these associations, though relatively small, can be expected to increase the risk of atherosclerosis. Demonstration of these relationships in a large, racially diverse, healthy population suggests that insulin may be an important intermediate risk factor for CVD in a broad segment of the U.S. population.
Regional distribution of body fat, plasma lipoproteins, and cardiovascular disease.
Authors: Després J P , Moorjani S , Lupien P J , Tremblay A , Nadeau A , Bouchard C
Published: June 2011

Several epidemiological studies have reported that the regional distribution of body fat is a significant and independent risk factor for cardiovascular disease (CVD) and related mortality. Although these associations are well established, the causal mechanisms are not fully understood. Numerous studies have, however, shown that specific topographic features of adipose tissue are associated with metabolic complications that are considered as risk factors for CVD such as insulin resistance, hyperinsulinemia, glucose intolerance and type II diabetes mellitus, hypertension, and changes in the concentration of plasma lipids and lipoproteins. The present article summarizes the evidence on the metabolic correlates of body fat distribution. Potential mechanisms for the association between body fat distribution, metabolic complications, and CVD are reviewed, with an emphasis on plasma lipoprotein levels and plasma lipid transport. From the evidence available, it seems likely that subjects with visceral obesity represent the subgroup of obese individuals with the highest risk for CVD. Although body fat distribution is now considered as a more significant risk factor for CVD and related death rate than obesity per se, further research is clearly needed to identify the determinants of body fat distribution and the causal mechanisms involved in the metabolic alterations. It appears certain, however, that an altered plasma lipid transport is a significant component of the relation between body fat distribution and CVD.
Familial defective apolipoprotein B-100. Comparison with familial hypercholesterolemia in 18 cases detected in Munich.
Authors: Schuster H , Rauh G , Kormann B , Hepp T , Humphries S , Keller C , Wolfram G , Zöllner N
Published: June 2011

It has recently been suggested that a substitution of glutamine for arginine at residue 3500 of apolipoprotein (apo) B-100 causes familial defective apo B-100 (FDB), an autosomal, dominantly inherited disorder, which leads to increased serum cholesterol levels. From a sample of 243 patients from Munich with type IIa hyperlipoproteinemia (HL), we have identified eight individuals with the apo B-100 arginine(3500)----glutamine mutation. In a group of 57 subjects with defective low density lipoprotein receptor (LDLR), no mutant apo B alleles were detected. The frequency of FDB in patients with type IIa HL was estimated to be 3%. In the kindreds of three of the probands, 10 additional carriers of the apo B mutation were identified. Clinical and biochemical data reveal a striking similarity between patients with FDB and those with a defect in the LDLR gene. Our data support previous findings that FDB is a serious disorder causing premature atherosclerosis.
Isolation and characterization of plasma lipoproteins of common marmoset monkey. Comparison of effects of control and atherogenic diets.
Authors: Crook D , Weisgraber K H , Boyles J K , Mahley R W
Published: June 2011

This study examines the potential of the common marmoset monkey (Callithrix jacchus) to serve as a model for human lipoprotein metabolism and atherosclerosis. The lipoproteins of animals fed a low-fat, low-cholesterol diet and a high-fat (12% wt/wt lard), high-cholesterol (0.34% wt/wt) diet were characterized by the combination of sequential ultracentrifugation and Pevikon block electrophoresis. Based on chemical and physical properties, equivalents of human very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL), including and HDL-with apolipoprotein E subclass, were demonstrated. In control animals, whose plasma cholesterol concentration was 140.1 +/- 20.2 mg/dl (means +/- SD), approximately 40% of the plasma cholesterol was transported by LDL as compared with approximately 70% in humans. The cholesterol-fed marmosets segregated into two groups: hypo- and hyper-responders. The hyper-responders had plasma cholesterol levels of 450 to 970 mg/ml. The hypercholesterolemia was associated with elevated concentrations of VLDL, intermediate density lipoproteins, and LDL; in addition, these lipoproteins were enriched in cholesteryl esters relative to lipoproteins isolated from control animals. The HDL (d greater than 1.09 g/ml) levels did not change in response to cholesterol feeding, although the HDL-with apolipoprotein E found in the d = 1.02 to 1.09 g/ml fraction increased approximately fivefold. Based on immunological characteristics and sialic acid content, the common marmoset appeared to lack a lipoprotein(a) equivalent. The results of a short-term feeding study (11 months) suggest that this monkey was susceptible to the development of diet-induced atherosclerosis. The hyper-responsive animals developed foam cell lesions and moderately proliferative intimal lesions, predominantly within the thoracic aorta. In summary, the results of our studies indicate that the common marmoset monkey potentially is a useful model for the study of both lipoprotein metabolism and diet-induced atherosclerosis.
Prevention of myocardial lesions in JCR:LA-corpulent rats by nifedipine.
Authors: Russell J C , Koeslag D G , Dolphin P J , Amy R M
Published: June 2011

Male rats of the JCR:LA-corpulent strain spontaneously develop atherosclerosis and myocardial lesions if corpulent. The corpulent rats exhibit a marked very low density hyperlipidemia and insulin resistance. The incidence of both vascular and myocardial lesions correlates strongly with the hyperinsulinemia, but not with the hyperlipidemia. Corpulent male rats were chronically treated with nifedipine or acetylsalicylic acid to explore the roles of smooth muscle spasm and platelet activity in induction of the myocardial lesions. Acetylsalicylic acid treatment was associated with no significant changes in fasting glucose, insulin, or lipid concentrations. Nifedipine caused no significant changes in glucose concentration but was associated with mildly increased insulin levels. Treatment with nifedipine resulted in significant decreases in serum triglyceride concentrations. The decreases were confined to longer-chain triacylglycerol molecular species with no change in the concentration of molecular species with 48 or 50 acyl carbon atoms. There was no effect on myocardial lesion frequency with acetylsalicylic acid treatment. In contrast, nifedipine prevented the development of old organized scarred lesions. This effect is similar to that seen with treatments that markedly reduce the insulin resistance. These findings suggest that platelet-initiated thrombus formation is not an important factor in lesion formation in the JCR:LA-cp rat, but that smooth muscle spasm is probably important.
Cationic polypeptides modulate in vitro association of low density lipoprotein with arterial proteoglycans, fibroblasts, and arterial tissue.
Authors: Wiklund O , Camejo G , Mattsson L , Lopez F , Bondjers G
Published: June 2011

Polymers of lys (plys) and arg (parg) were found to be efficient inhibitors of the formation of complexes between low density lipoprotein (LDL) and human chondroitin-6-sulfate-rich proteoglycans. Displacement curves indicate that efficiency was dependent on molecular weight. Inclusion of alanine in the polymer up to a 1:1 molar ratio (plys,ala) has a moderate effect on displacing capacity. Poly-L-lys (plys) and poly-L-arg (parg) exhibited similar displacing ability. Inclusion of tryptophan in plys and parg diminished their effect, whereas inclusion of serine in plys,ser (3:1) improved it. Plys (18.3 kD) stimulates LDL binding to human fibroblasts. This may be due to the association of polylysine to LDL, leading to an increase in its positive charge. These more positively charged LDL may have an increased association with the negatively charged region of the apolipoprotein B/E receptor. Perfusion experiments on rabbit aortic segments were used to measure the influx of 125I-LDL into the intima and to study the effect of basic polypeptides. Plys in a 10:1 molar ratio decreased the LDL uptake by approximately 25% when added to the system together with the LDL or in experiments in which the tissue segments were pre-perfused with plys, and LDL was added after elimination of the plys. The results suggest that polycationic polypeptides, due to their strong affinity for sulfated proteoglycans, interfere with the interactions of LDL with components of the arterial extracellular matrix.
Dysregulation of lipid metabolism in Tangier monocyte-derived macrophages.
Authors: Schmitz G , Fischer H , Beuck M , Hoecker K P , Robenek H
Published: June 2011

The cellular defect in Tangier mononuclear phagocytes (MNP) was shown to be associated with significant abnormalities in cellular phospholipid, triglyceride, and cholesteryl ester metabolism by using various radiolabeled precursors (32Pi, 3H-serine, 3H-choline, 14C-acetate, and 14C-oleic acid). Tangier MNP expressed increased rates of synthesis for phospholipids (twofold), triglycerides (fivefold), and cholesteryl esters (threefold) as compared to normal MNP when incubated in McCoy's medium containing 0.2% human serum albumin. The turnover rate of cellular phospholipids was also enhanced, while the turnover rates for triglycerides and cholesteryl esters were normal, thus leading to the accumulation of a larger pool of labeled triglycerides and cholesteryl esters in Tangier MNP. The individual phospholipid classes, phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, and phosphatidylserine were similarly affected. Cholesterol loading led to approximately 30% down-regulation of phospholipid synthesis in normal cells, but Tangier MNP showed a smaller response. When nonloaded normal MNP were exposed to high density lipoprotein3 (HDL3), they diminished cellular cholesterol esterification mediated by acyl-CoA:cholesterol acyltransferase (ACAT); in Tangier MNP, ACAT activity increased in the presence of HDL3. When cholesterol-loaded normal and Tangier MNP were treated with HDL3, an up-regulation of phospholipid synthesis was observed in both cell types, but Tangier MNP showed a smaller response. We conclude that the defect in Tangier disease, which we recently described as a "disorder of intracellular traffic" (Schmitz et al. Proc Natl Acad Sci USA 1985;82:6305-6309), is associated with a dysregulation of cellular lipid metabolism, leading to an overproduction of triglycerides and esterified cholesterol and to enhanced synthesis and catabolism of phospholipids.
Hemostatic variables in homozygous familial hypercholesterolemia. Effect of regular plasma cholesterol removal by low density lipoprotein apheresis.
Authors: Di Minno G , Cerbone A M , Cirillo F , Postiglione A , Colucci M , Semeraro N , Scarpato N , Gnasso A , Margaglione M , Gallotta G
Published: June 2011

Plasma levels of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) and the in vitro ability of platelets to aggregate and of monocytes to express procoagulant (tissue factor) activity (PCA) were evaluated in five patients who are homozygous for familial hypercholesterolemia (FH) before and after a single and a regular 5-month cholesterol removal by low density lipoprotein (LDL) apheresis. The biweekly procedure resulted in a 25% to 30% reduction (approximately 150 mg/dl) in total and LDL cholesterol (both were greater than 550 mg/dl at the beginning of the study). The basal levels of t-PA antigen and fibrinolytic activity before and after 10 minutes of venous stasis, basal PAI activity, and PAI-1 antigen were comparable to controls and were not affected by LDL apheresis. Likewise, regardless of the cholesterol removal, the PCA of freshly isolated monocytes and that of monocytes incubated with lipopolysaccharide did not differ from control values. Finally, the pre-apheresis sensitivity of platelets to adenosine diphosphate, arachidonic acid, and collagen was 1.5 to 2 times the normal value. This ratio was unchanged throughout the 5-month procedure. We conclude that fibrinolysis and monocyte PCA are normal in FH patients, whereas platelet aggregation is abnormally high, and none of these parameters is significantly affected by a 25% to 30% reduction in total and LDL cholesterol by LDL apheresis. Furthermore, our data suggest that removal of cholesterol from plasma by LDL apheresis is important for gaining insight into the mechanisms involved in the ischemic complications of arteriosclerosis in FH patients.
Characterization of a Gla-containing protein from calcified human atherosclerotic plaques.
Authors: Gijsbers B L , van Haarlem L J , Soute B A , Ebberink R H , Vermeer C
Published: June 2011

In this article we describe the isolation of a 4-carboxyglutamic acid (Gla)-containing protein from calcified human atherosclerotic plaques. The protein was extracted from pulverized calcified plaques by demineralization with ethylenediaminetetraacetate and was subsequently purified by anion-exchange fast protein and high-performance liquid chromatography by using ion-exchange and gel-filtration columns. The protein was designated as plaque Gla protein (PGP) and has an apparent mass of 23 kD as estimated from sodium dodecyl sulfate-polyacrylamide gel analysis. By determining the sequence of its first six amino acid residues, the protein was unequivocally demonstrated to be not related to any other known protein. Moreover, no immunological relationship (as tested by Western blot analysis) was found between PGP and other known Gla-containing proteins.
Net mass transfer of cholesteryl esters from low density lipoproteins to high density lipoproteins in plasma from normolipidemic subjects.
Authors: Van Tol A , Scheek L M , Groener J E
Published: June 2011

Net mass transfer of lipids was measured in plasma from fasted, normolipidemic subjects. The plasma was incubated, and lipoproteins were subsequently separated by polyanion precipitation or density gradient ultracentrifugation. Total cholesterol, unesterified cholesterol, and triglycerides were measured in the isolated lipoprotein fractions. The rate of cholesterol esterification was measured simultaneously. All plasma samples showed an increase in high density lipoprotein (HDL) cholesteryl esters during 1-hour incubations. In most cases, this increase was higher than the cholesteryl ester formation in total plasma due to cholesterol esterification. Therefore, we concluded that a net mass transfer of cholesteryl esters occurred from the very low plus low density lipoprotein (VLDL + LDL) fractions to HDL in plasma from most of the subjects studied. Transfer of triglycerides occurred from VLDL + LDL to HDL in plasma from all subjects. The cholesteryl ester transfer (measured after 1 hour) is not related to the activity of cholesteryl ester transfer protein. Inhibition of cholesterol esterification did not change the direction of cholesteryl ester or triglyceride transfer. Ultracentrifugal separation of plasma lipoproteins revealed that both HDL and VLDL are acceptors of cholesteryl esters and that VLDL donates triglycerides to both LDL and HDL. Removal of VLDL from plasma by ultracentrifugation did not affect the cholesteryl ester transfer from LDL to HDL. We conclude that LDL may act as a donor of cholesteryl esters during incubation of normolipidemic plasma.
Cholesterol esterification rates in very low density lipoprotein- and low density lipoprotein-depleted plasma. Relation to high density lipoprotein subspecies, sex, hyperlipidemia, and coronary artery disease.
Authors: Dobiasova M , Stribrna J , Sparks D L , Pritchard P H , Frohlich J J
Published: June 2011

The fractional rate of cholesterol esterification in very low density lipoprotein- and low density lipoprotein-depleted plasma (FERHDL) was studied in normolipidemic subjects and in individuals with hyperlipidemia and proven coronary artery disease (CAD). The FERHDL was significantly higher than the FER in whole plasma and was significantly higher in normal men than in normal women. In addition, men and women with primary hyperlipidemia had significantly higher FERHDL values relative to their sex-matched controls. The most significant increases in FERHDL values, however, were observed in individuals with CAD. In all patient groups, FERHDL was positively correlated with plasma triglyceride concentration. In addition, FERHDL was negatively related to plasma high density lipoprotein (HDL) cholesterol concentration in all groups except in men with CAD and in normolipidemic women. The gradient gel electrophoretic pattern of HDL from individuals with either low or high FERHDL values indicated an inverse relation between this activity and the relative amount of HDL2b particles. FERHDL likely reflects the metabolic properties of the heterogeneous population of HDL particles in the plasma and may be a function of the relative content of larger and smaller HDL particles. It appears to be a sensitive and reliable functional measure of the particle size distribution in the HDL pool and one of potential clinical value in the assessment of risk for CAD.
Quantification of fibrin deposition in flowing blood with peroxidase-labeled fibrinogen. High shear rates induce decreased fibrin deposition and appearance of fibrin monomers.
Authors: Tijburg P N , Ijsseldijk M J , Sixma J J , de Groot P G
Published: June 2011

To study fibrin incorporation into thrombi at different wall shear rates, a new method to study fibrin deposition on extracellular matrixes underlying stimulated endothelial cells under flow conditions was developed. For this method, we used fibrinogen labeled with peroxidase (Fg-PO). Fg-PO was fully exchangeable for Fg in the clotting assays tested, and PO activity was bound to fibrin-specific fragments. Fg-PO containing fibrin could be stained for microscopic studies with 3,3'-diaminobenzidine and could be quantified by oxidation of phenylenediamine. The absorbance values at 492 nm were converted to fibrin quantities via a standard curve. To study fibrin deposition, Fg-PO was added in trace amounts to whole blood anticoagulated with low-molecular-weight heparin, and perfusion studies were performed over endothelial cell matrixes containing tissue factor. In parallel perfusion studies, 125I-labeled Fg was added in trace amounts to whole blood instead of Fg-PO. Both quantitative methods demonstrated decreased fibrin deposition after perfusions at 1,300 sec-1 compared with fibrin deposition after perfusions at 300 sec-1, while fibrinopeptide A generation was independent of the wall shear rate. The decrease in fibrin deposition at 1,300 sec-1 was accompanied by the appearance of fibrin monomers in the perfusate. This suggested that the decrease in fibrin incorporation at 1,300 sec-1 was due to the impaired polymerization of fibrin monomers. This impairment was probably due to a decrease in local fibrin monomer concentration as a result of the increased removal of monomers from the surface at 1,300 sec-1.
Characterization of three mutations of the low density lipoprotein receptor gene in Italian patients with familial hypercholesterolemia.
Authors: Lelli N , Ghisellini M , Gualdi R , Tiozzo R , Calandra S , Gaddi A , Ciarrocchi A , Arca M , Fazio S , Coviello D A
Published: June 2011

Three gross rearrangements of the low density lipoprotein receptor (LDL-R) gene were recognized during a survey of 23 unrelated Italian subjects with familial hypercholesterolemia (FH). Restriction endonuclease data were obtained by Southern blotting and hybridization with exon-specific probes. Proband FH-29 is heterozygous for a 4-kb deletion, which eliminates exons 13 and 14. This mutation is similar to that previously reported by other investigators in one Italian homozygous and two British and Canadian heterozygous patients. Proband FH-30 is homozygous for a 5.5-kb insertion caused by a duplication of exons 16 and 17 of the LDL-R gene. LDL-R mRNA isolated from skin fibroblasts of FH-30 was found to be larger than normal mRNA (5.6 versus 5.3 kb), in concordance with the insertion of the 236 nucleotides corresponding to exons 16 and 17. Proband FH-44 was found to have greater than 25-kb deletion, which eliminates the first six exons and the promoter region of the gene. This is the first example of a deletion that eliminates the promoter as well as the ligand-binding domain of the LDL-R gene. In the skin fibroblasts of this patient, the level of LDL-R mRNA was approximately half that found in control fibroblasts. We designate the new mutations found in FH-30 and FH-44 as FHviterbo and FHBologna-1, respectively, after the names of the Italian cities where the two patients were born.
Modulation of actin isoform expression in cultured arterial smooth muscle cells by heparin and culture conditions.
Authors: Desmoulière A , Rubbia-Brandt L , Gabbiani G
Published: June 2011

Heparin inhibits arterial smooth muscle cell (SMC) proliferation in vivo and in vitro; moreover, it reinduces the expression of alpha-smooth muscle (SM) actin (an accepted marker of SMC differentiation) in SMCs of the intimal thickening that develops after experimentally induced endothelial lesions. We have investigated the effect of heparin on the proliferation and actin isoform expression in cultured rat SMCs. In the presence of 10% fetal calf serum (FCS), heparin-treated primary and passage 5 SMCs showed a decrease of proliferation and an increase of alpha-SM actin (measured by Western blots or two-dimensional gel electrophoresis) compared with untreated SMCs. When SMCs were cultured in the presence of 10% plasma-derived serum, no proliferation occurred and heparin did not modify alpha-SM actin expression. This suggests that the action of heparin is related to its antiproliferative activity. SMCs cultured in the presence of 10% FCS plus heparin had the same level of proliferation as SMCs cultured in 5% FCS but had a higher content of alpha-SM actin. SMCs cultured in 20% rat whole-blood serum had a proliferation similar to that observed in SMCs cultured in 10% FCS but had a higher content of alpha-SM actin. Moreover, in SMCs cultured in 20% whole-blood serum, heparin inhibited SMC proliferation but did not modify alpha-SM actin expression. Thus, the action of heparin on alpha-SM actin expression appears to be partially independent of proliferation and is related to culture conditions. The proportion of alpha-SM actin mRNA, as measured by Northern blots with an alpha-SM actin mRNA-specific probe, was increased by heparin compared with cells cultured in 10% FCS; this suggests that heparin acts at the transcriptional or posttranscriptional level. Our results show that heparin acts not only on SMC proliferation but also on SMC differentiation; further investigation along these lines may help in the understanding of the mechanisms of SMC adaptation during normal and pathological conditions.
Overproduction of a buoyant low density lipoprotein subspecies in spontaneously hypercholesterolemic mutant pigs.
Authors: Checovich W J , Aiello R J , Attie A D
Published: June 2011

We previously described the hypercholesterolemia of pigs with defined apolipoprotein B (apo B) alleles associated with reduced binding of low density lipoprotein (LDL) to its receptor in vitro and slow clearance from the circulation in vivo. The increased plasma LDL in the hypercholesterolemic pigs was confined to a buoyant LDL subspecies. Because of this qualitative change in the LDL subspecies profile, we studied the turnover of buoyant and dense LDL subspecies independently. Normal and mutant radioiodinated buoyant and dense LDLs were simultaneously injected into normal and mutant pigs, and the clearance rates, interconversion rates, and production rates were determined. The sevenfold increase in buoyant LDL levels in the mutant pigs was due to a fivefold increase in buoyant LDL production. Total mutant LDL production was increased approximately 25%, suggesting that part of the increase in buoyant LDL production is at the expense of dense LDL production. Conversion of dense LDL to buoyant LDL made a small contribution to the buoyant LDL increase. The turnover analysis showed that dense LDL, in both mutant and control pigs, is primarily derived from a source other than buoyant LDL. To test this more directly, [3H]leucine was intravenously injected, and the specific activity of the LDL subspecies was measured over 96 hours. There was a large discrepancy in the areas under the specific activity-versus-time curves, indicating that buoyant LDL cannot be the sole precursor of dense LDL and further supporting the conclusion that buoyant and dense LDL are, in part, metabolically independent particles. These results show that genetic variation in the apo B locus can affect the synthetic rate of LDL and the LDL subspecies distribution.
Toxicity of oxygenated cholesterol derivatives toward cultured human umbilical vein endothelial cells.
Authors: Pettersen K S , Boberg K M , Stabursvik A , Prydz H
Published: June 2011

Human umbilical vein endothelial cells were cultured in the presence of several oxygenated cholesterol derivatives that are known to affect the viability of other cell lines. 5-Cholestene-3 beta,7 beta-diol (7 beta-hydroxycholesterol) caused a time- and concentration-dependent perturbation of the endothelial cells. Exposure to 50 mumol/l of this compound for 18 hours resulted in marked contraction of the cells, followed by increasing cell detachment from the substrate and Trypan Blue uptake in detached cells. Concomitantly release of lactate dehydrogenase from the cells reached about 80% at 24 hours. The release of tissue plasminogen activator and tissue plasminogen activator inhibitor-1 antigens decreased at a concentration of 7 beta-hydroxycholesterol lower than that required for reducing general protein synthesis. 7 beta-Hydroxycholesterol at 50 mumol/l first increased the release and then (at 100 mumol/l) inhibited the synthesis of von Willebrand factor. Incubation with 100 mumol/l of 5-cholestene-3 beta, 7 alpha,22(R)-triol (7 alpha,22-dihydroxycholesterol)e and the isomeric 5-cholestene-3 beta, 7 beta, 22(R)-triol (7 beta, 22-dihydroxycholesterol) caused formation of intercellular gaps and some detachment of the cells after 24 hours. Cell injury was slightly more pronounced for the 7 alpha, 22-dihydroxycholesterol than for the 7 beta-isomer. Incubations with cholesterol under the same conditions gave no sign of cell injury.
Platelet adhesion to exposed endothelial cell extracellular matrixes is influenced by the method of preparation.
Authors: Aznar-Salatti J , Bastida E , Haas T A , Escolar G , Ordinas A , de Groot P H , Buchanan M R
Published: June 2011

The relative thrombogenicity of extracellular matrixes (ECMs) produced by cultured human umbilical endothelial cells (ECs) was studied under flow conditions. ECMs were prepared using a number of physical and chemical methods, and their reactivity toward platelets was morphometrically evaluated. von Willebrand factor (vWF), fibronectin (FN), and 13-hydroxy-9-cis,11-trans-octadecadienoic acid (13-HODE) were also determined. We found that platelet adhesion to ECMs differed significantly, both quantitatively and qualitatively, with the method of ECM preparation. Mechanically prepared ECM exposed a less thrombogenic surface compared with ECM prepared by chemical methods (platelet-covered surface of 20% and 50%, respectively). Evaluation of the ECM components vWF, FN, and 13-HODE showed significant changes, both in their concentrations and distribution patterns, depending on the method of ECM preparation. The decrease measured in the levels of ECM-associated vWF (from 108 to 9.2 ng/10(4) cells) and the minor changes observed in the distribution pattern of subendothelial FN did not appear to be sufficient to explain the altered platelet adhesion observed in our model. This suggests that the amount of 13-HODE probably associated to the remaining ECs present in the mechanically exposed ECM could be one factor that specifically contributed to the nonthrombogenic state of these preparations. We conclude that the degree of ECM reactivity toward platelets is dependent on the method of ECM preparation and that this is related to the removal of specific EC/ECM components that modulate their thromboresistant/thrombogenic properties. This fact should be taken into account when ECMs produced by cultured ECs are used in platelet adhesion studies.