Alpha-giardins constitute the annexin proteome (group E annexins) in the intestinal protozoan parasite Giardia and, as such, represent the evolutionary oldest eukaryotic annexins. The dominance of alpha-giardins in the cytoskeleton of Giardia with its greatly reduced actin content emphasises the importance of the alpha-giardins for the structural integrity of the parasite, which is particularly critical in the transformation stage between cyst and trophozoite. In this study, we report the crystal structures of the apo- and calcium-bound forms of α1-giardin, a protein localised to the plasma membrane of Giardia trophozoites that has recently been identified as a vaccine target. The calcium-bound crystal structure of α1-giardin revealed the presence of a type III site in the first repeat as known from other annexin structures, as well as a novel calcium binding site situated between repeats I and IV. By means of comparison, the crystal structures of three different alpha-giardins known to date indicate that these proteins engage different calcium coordination schemes, among each other, as well as compared to annexins of groups A-D. Evaluation of the calcium-dependent binding to acidic phosphoplipid membranes revealed that this process is not only mediated but also regulated by the environmental calcium concentration. Uniquely within the large family of annexins, α1-giardin disengages from the phospholipid membrane at high calcium concentrations possibly due to formation of a dimeric species. The observed behaviour is in line with changing calcium levels experienced by the parasite during excystation and may thus provide first insights into the molecular mechanisms underpinning the transformation and survival of the parasite in the host.

Prepulse inhibition (PPI) of the acoustic startle response is a behavioural tool used to assess sensorimotor gating processes and its disturbances in rats and in humans. PPI in rats is reduced by an overactivity of the dopamine (DA) system. Because there are functional interactions between DA and adenosine receptors, we tested whether PPI can be influenced by the mixed DA receptor agonist apomorphine (APO) and by the unselective adenosine antagonist theophylline (THEO). Combined administration of APO (0.5 mg/kg, i.p.) and THEO (20 mg/kg, i.p.) in doses devoid of significant effects on their own significantly reduced PPI. The PPI-disrupting effect of the combined THEO plus APO treatment was dose-dependently antagonized by co-administration of the selective adenosine A1 agonist CPA (0.15-1.5 mg/kg, i.p.), but not by the A2A agonist CGS21680 (0.1-2 mg/kg, i.p.). These data demonstrate that antagonistic interactions between DA and adenosine, involving adenosine A1 receptors, play an important role in the regulation of PPI. The possible implications of these findings for the use of adenosine agonists in the treatment of schizophrenia are discussed.

Forty-nine patients, with ages ranging from eighteen to seventy years and with mild to moderate primary hypertension (sitting diastolic blood pressure of greater than or equal to 95 mmgH and less than or equal to 115 mmHg) were randomized into a twenty-one-week, double-blind, prospective study to determine the effects of monotherapy of nifedipine GITS (gastrointestinal therapeutic system) versus atenolol on serum lipids, lipid subfractions, apolipoproteins, (apo), and blood pressure (BP). Nifedipine GITS and atenolol significantly reduced blood pressure, but nifedipine GITS reduced sitting and standing systolic BP significantly more than atenolol (p = .001). Sitting and standing heart rate decreased significantly (p = 0.001) during atenolol therapy but did not change significantly during nifedipine GITS therapy. Atenolol increased weight (mean change + 2.2 lb; p = 0.011), but nifedipine GITS decreased weight (mean change - 2.4 lb; p = 0.07). Nifedipine GITS had a more favorable effect on the lipid profile. High density lipoprotein cholesterol (HDL-C) and HDL2 subfractions were increased significantly (p = .001) as were apo A1 (p = 0.037) and apo A2 (p = 0.025). Nifedipine GITS increased HDL3 (NS), reduced triglycerides (TG) (NS), and had no significant effect on total cholesterol (TC) low density lipoprotein cholesterol (LDL-C) and apo B. Atenolol significantly increased serum total cholesterol (p = 0.039) and HDL-C and HDL2 (p = 0.049 and 0.048 respectively). Atenolol increased TG (NS) and apo B (NS) with little change in apo A1 and apo A2. It is concluded that nifedipine GITS had equal or better antihypertensive efficacy than atenolol and had a more favorable effect on the lipid profile. These effects may offer advantages in reducing CHD risk.

BACKGROUND

Early diagnosis of initial metabolic derangements in young obese children could influence their management; however, this impairment is frequently not overt, but subtle and undetectable by routinely used clinical assays. Our aim was to evaluate the ability of serum proteomic analysis to detect these incipient metabolic alterations in comparison to standard clinical methods and to identify new candidate biomarkers.

METHODS

A cross-sectional study of fasting serum samples from twenty-two prepubertal, Caucasian obese (OB; 9.22 ± 1.93 years; 3.43 ± 1.08 BMI-SDS) and twenty-one lean controls (C; 8.50 ± 1.98 years; -0.48 ± 0.81 BMI-SDS) and a prospective study of fasting serum samples from twenty prepubertal, Caucasian obese children (11 insulin resistant [IR]) before (4.77 ± 1.30 BMI-SDS) and after weight reduction (2.57 ± 1.29 BMI-SDS) by conservative treatment in a reference hospital (Pros-OB) was performed. Proteomic analysis (two-dimension-eletrophoresis + mass spectrometry analysis) of serum and comparative evaluation of the sensitivity of routinely used assays in the clinics to detect the observed differences in protein expression level, as well as their relationship with anthropometric features, insulin resistance indexes, lipid profile and adipokine levels were carried out.

RESULTS

Study of the intensity data from proteomic analysis showed a decrease of several isoforms of apolipoprotein-A1, apo-J/clusterin, vitamin D binding protein, transthyretin in OB vs. C, with some changes in these proteins being enhanced by IR and partially reversed after weight loss. Expression of low molecular weight isoforms of haptoglobin was increased in OB, enhanced in IR and again decreased after weight loss, being positively correlated with serum interleukin-6 and NAMPT/visfatin levels. After statistical correction for multiple comparisons, significance remained for a single isoform of low MW haptoglobin (OB vs. C and IR vs. non-IR) and Apo A1 (IR vs. non-IR). Assays routinely used in the clinical setting (ELISA/kinetic nephelometry), only partially confirmed the changes observed by proteomic analysis (ApoA1 and haptoglobin).

CONCLUSIONS

Proteomic analysis can allow for the identification of potential new candidate biomarkers as a complement to routinely used assays to detect initial changes in serum markers of inflammation and lipid metabolism impairment in young obese children.

We investigated whether APOA1 and APOA4 genotypes interact with diet to determine changes in LDL size and their susceptibility to oxidative modifications. A total of 97 healthy volunteers each consumed 3 diets for 4 wk: a SFA diet (38% fat, 20% SFA) followed by a low-fat and high-carbohydrate (CHO) diet (30% fat, 55% carbohydrate) or a monounsaturated fatty acid (MUFA) diet (38% fat, 22% MUFA) following a randomized crossover design. For each diet, we determined susceptibility to oxidative modifications and LDL size. To investigate the combined effects of the APOA1 G-76A and APOA4 Thr347Ser single nucleotide polymorphisms (SNP), we defined 4 combined genotype groups: GG/ThrThr, GG/ThrSer, GA/ThrThr, and GA/ThrSer. After participants consumed the CHO diet, there was a significant decrease in LDL size with respect to high-fat diets in GG homozygotes for the APOA1 G-76A SNP. However, LDL size did not differ in GA carriers among participants consuming the 3 diets. Carriers of the A allele for this polymorphism had smaller LDL size as well as increased susceptibility to oxidation after the SFA diet than the GG homozygous. Moreover, the interaction between the APO A1 and APOA4 genotypes revealed that individuals with the GA/ThrSer genotype had larger LDL particle size during consumption of the MUFA diet than when they consumed the CHO diet. No differences in LDL oxidation were found in this analysis. Our study supports the concept that SNP in APOA1and APOA4 genes influences atherogenic characteristics of LDL particles in response to diet.

Ubiquinone is a carrier of the mitochondrial respiratory chain which regulates oxidative phosphorylation: it also acts as a membrane stabilizer preventing lipid peroxidation. In man the quinone ring originates from tyrosine, while the formation of the polyisoprenoid lateral chain starts from acetyl CoA and proceeds through mevalonate and isopentenylpyrophosphate; this biosynthetic pathway is the same as the cholesterol one. We therefore performed this study to evaluate whether statins (hypocholesterolemic drugs that inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase) modify blood levels of ubiquinone. Thirty unrelated outpatients with primary hypercholesterolemia (IIa phenotype) were treated with 20 mg of simvastatin for a 3-month period (group S) or with 20 mg of simvastatin plus 100 mg CoQ10 (group US). The following parameters were evaluated at time 0, and at 45 and 90 days: total plasma cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, triglycerides, Apo A1, Apo B and CoQ10 in plasma and in platelets. In the S group, there was a marked decrease in total cholesterol low-density lipoprotein-cholesterol and in plasma CoQ10 levels from 1.08 mg/dl to 0.80 mg/dl. In contrast, in the US group we observed a significant increase of plasma CoQ10 (from 1.20 to 1.48 mg/dl) while the hypocholesterolemic effect was similar to that observed in the S group. Platelet CoQ10 also decreased in the S group (from 104 to 90 ng/mg) and increased in the US group (from 95 to 145 ng/mg).(ABSTRACT TRUNCATED AT 250 WORDS)

High-density lipoprotein (HDL) cholesterol is a heterogeneous group of lipoproteins exhibiting a variety of properties like prostacyclin production stimulation, decrease in platelet aggregation, endothelial cell apoptosis inhibition, and low-density lipoprotein oxidation blockade. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and cardiovascular risk. Low HDL cholesterol is associated with increased risk for myocardial infarction, stroke, sudden death, peripheral artery disease, and postangioplasty restenosis. In contrast, high HDL levels are associated with longevity and protection against atherosclerotic disease development. Given the evolving epidemic of obesity, diabetes mellitus, and metabolic syndrome, the prevalence of low HDL will continue to rise. In the United States, low HDL is present in 35% of men, 15% of women, and approximately 63% of patients with coronary artery disease. Data extracted from the Framingham study highlight that 1-mg increase in HDL levels decreases by 2% to 3% the risk of cardiovascular disease. There is no doubt regarding clinical importance about isolated low HDL, but relatively few clinicians consider a direct therapeutic intervention of this dyslipidemia. In this sense, lifestyle measures should be the first-line strategy to manage low HDL levels. On the other hand, pharmacologic options include niacin, fibrates, and statins. Fibrates appear to reduce risk preferentially in patients with low HDL with metabolic syndrome, whereas statins reduce risk across all levels of HDL. Torcetrapib, a cholesteryl esters transfer protein inhibitor, represented a hope to raise this lipoprotein; however, all clinical trials on this drug had ceased after ILLUMINATE, RADIANCE and ERASE trials had recorded an increase in mortality, rates of myocardial infarction, angina, and heart failure. In the near future, drugs as beta-glucans, Apo-A1 mimetic peptides, and ACAT inhibitors, are the new promises to treat this condition.

BACKGROUND

Genetic susceptibility contributes to the risk of diabetic nephropathy. Lipid disorders may favour diabetic nephropathy. Thus polymorphisms in lipid metabolism are candidates for the genetic component of risk for diabetic nephropathy.

METHODS

We searched for a contribution of the genetic polymorphisms of lipoprotein lipase (LPL), cholesteryl ester transfer protein (CETP) and apolipoprotein epsilon (Apo E) to the development of diabetic nephropathy by studying 494 type 1 diabetic patients with proliferative retinopathy and various stages of diabetic nephropathy (GENEDIAB Study). The selection process ensured that all patients had expressed their risk of chronic complications due to uncontrolled diabetes. Thus the nephropathy stages were largely influenced by genetic background. The lipid profile included fasting plasma total cholesterol (TC), triglycerides (TG), apolipoprotein A1 (Apo A1) and B (Apo B), and lipoprotein (a) (Lp(a)). Genetic polymorphisms were determined by PCR-based detection of Apo epsilon (e2/e3/e4), LPL (mutation Asn 291 Ser) and CETP (TAQ:IB B1/B2).

RESULTS

One hundred and fifty-seven patients (32%) had no nephropathy, 104 (21%) incipient nephropathy, 126 (25%) established nephropathy and 107 (22%) advanced nephropathy. There was a significant relationship between the stages of diabetic nephropathy and TC (P=0.002), TG (P<0.0001), Apo B (P=0.0007) or Lp(a) (P=0. 038), but not Apo A1. However the genetic polymorphism distributions of LPL, CETP and Apo epsilon did not differ in terms of renal complications. The study power to reject the null hypothesis was 58% for the Apo epsilon genotypes.

CONCLUSIONS

These results support no or only marginal effects of a genetic basis for lipid disturbances encountered in diabetic nephropathy.

Sulfated glycoprotein 2 (SGP 2) is a 73-kDa highly glycosylated disulfide-linked heterodimer. It is a major secreted protein of Sertoli cells, is found in high abundance within the seminiferous tubule fluid (STF) and epididymal fluid (EPF), and can be found on the surface of spermatozoa. Due to its high abundance and location it is believed to play a major role in the development of spermatozoa; however, its specific function(s) within the reproductive tract is not known. Purified and renatured SGP 2 were found to have the ability to inhibit complement activity with a mean concentration of 66 mg/ml for 50% inhibition. Extraction of epididymal sperm with various reagents showed that a major fraction of the SGP 2 in EPF was free or was loosely associated with the spermatozoa whereas a smaller fraction was more tightly associated and disruption of the lipid bilayer was required for its complete removal. Ultracentrifugation techniques and gel permeation chromatography revealed that SGP 2 in plasma, STF, and EPF formed complexes with other proteins and/or lipids but was not specifically associated with the apolipoprotein-like particles containing apolipoprotein A1 (apo A1).

Recent studies suggest that release of cytokines during inflammatory states such as septic shock leads to hypocholesterolemia. To examine whether tumor necrosis factor alpha (TNF), which is the major cytokine in inflammatory disease, causes hypocholesterolemia, we measured serum levels of total (bioactive and receptor-bound) TNF, cholesterol, Apo B, and Apo A1 in seven patients with septic shock over a period of 8 days. Since elevated serum TNF levels are accompanied by the release of soluble TNF receptors, levels of TNF receptors p55 and p75 were also measured. Patients with septic shock had significantly higher serum TNF and TNF receptor levels compared with healthy controls. Increased cytokine levels were accompanied by a significant decline in total serum cholesterol apolipoprotein A1 and B. In vitro studies with cultured human skin fibroblasts, human umbilical vein endothelial cells, and HepG2 hepatoma cells showed that TNF increased the degradation of 125I-labeled low-density lipoprotein in all the cell lines tested. Recombinant soluble TNF receptors inhibited the TNF-induced stimulation of low-density lipoprotein receptor in a concentration-dependent manner. However, the calculated ratio of TNF receptors to total TNF measured in serum of these patients was not able to counteract the stimulatory effect of TNF, possibly due to the higher molar excess of TNF receptors required to achieve this effect in vitro. Our data strengthen the hypothesis that serum values of total TNF determine the extent of hypocholesterolemia during sepsis and septic shock despite the presence of a high concentration of TNF receptors. Studies with recombinant TNF also confirm the role of TNF in hypocholesterolemia in inflammation.

Both Jing and Mulao nationalities are the isolated minorities in China. Little is known about the prevalence of dyslipidemia between the two ethnic groups. Therefore, the aim of this study was to compare the differences in serum lipid profiles, the prevalence of dyslipidemia and their risk factors between the Jing and Mulao populations. A cross-sectional study of dyslipidemia was conducted in Dongxing city, Guangxi, China, during Dec 2011 and Jan 2012. A total of 1254 subjects of Jing and 1251 participants of Mulao were surveyed by a stratified randomized sampling. Information on demography, diet and lifestyle was collected with standardized questionnaire. Serum lipid levels were detected using the commercially available kits. The levels of low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) A1, and the ratio of ApoA1 to ApoB were lower but the levels of ApoB were higher in Jing than in Mulao (P < 0.001 for all). The prevalence of hypertriglyceridemia (32.38% vs. 24.38%), high ApoB (35.25% vs. 15.35%) and low ApoA1/ApoB ratio (22.65% vs. 16.87%) was higher and low high-density lipoprotein cholesterol (0.48% vs. 2.16%), high LDL-C (17.54% vs. 40.53%) and low ApoA1 (5.98% vs. 11.43%) was lower in Jing than in Mulao (P < 0.001 for all). The risk factors for serum lipid parameters and hyperlipidemia were different between the two ethnic groups. Serum lipid profiles, the prevalence of dyslipidemia and their risk factors are different between the Jing and Mulao populations. These differences may result from the combined effects of different diet, lifestyle, and genetic factors.

OBJECTIVE

Atherosclerosis is associated with insulin resistance (IR) and dyslipidaemia. Impaired glucose tolerance (IGT) is characterised by IR and is associated with a higher risk of atherosclerosis. The objective of the present study was to test whether early atherosclerosis indicated by intimal medial thickness (IMT) of common carotid artery (CCA) and internal carotid artery (ICA) is higher in IGT than in normoglycaemic subjects (NGT) and to look for an association of IMT with IR and dyslipidaemia.

METHODS

Ninety-nine randomly selected non-diabetic subjects aged>>or=35 years (48 NGT and 51 IGT) were studied. Measurements of body mass index (BMI), waist/hip ratio (WHR), blood pressure, cholesterol-total, HDL, LDL, VLDL, triglycerides (TG), lipoprotein (a), apolipoprotein-A1 (Apo A1) and apolipoprotein-B (Apo B) and ratio of Apo A1/Apo B were estimated. Insulin resistance (HOMA-IR) was calculated using the fasting plasma insulin and glucose values. IMT of CCA and ICA were measured using high-resolution beta-mode ultrasonography.

RESULTS

Subjects with IGT and NGT were matched for BMI and WHR; HOMA-IR was higher in IGT vs NGT (7.92+/-4.2 vs 6.07+/-3.76, p = 0.028). Age-adjusted IMT values were similar in NGT and IGT (CCA 0.59+/-0.17 and 0.63+/-0.22 mm and ICA 0.44+/-0.10 and 0.45+/-0.10 mm, respectively). Further analyses were done in the total group. Multiple linear regression analyses showed that CCA-IMT was significantly associated with age and negatively associated with Apo A1/Apo B ratio. ICA-IMT was associated with age only. IMT was significantly correlated with cholesterol-total and LDL-cholesterol and apolipoproteins. It was not associated with IR.

CONCLUSIONS

In southern Indians, IGT did not influence the IMT. Although insulin resistance was higher in IGT, it was not associated with higher IMT. Conventional risk factors such as cholesterol, LDL-cholesterol and apolipoproteins showed association with IMT in the insulin-resistant population.

Several independent population studies have reported that the apolipoprotein C3 (APOC3) Sst I polymorphism in apolipoprotein (apo) A1 /C3/A4/A5 gene cluster is associated with Hypertriglyceridaemia (HTG). HTG is a known risk factor for coronary atherosclerotic heart disease(CHD)and type II diabetes mellitus (non-insulin-dependent diabetes, NIDDM). The aim of this study is to investigate the association between the APOC3 gene Sst I polymorphism and the hypertriglyceridaemia in CHD and NIDDM in Chinese population. The genotype and allele frequencies of APOC3 Sst I polymorphism (S1/S2) were analyzed by PCR-restriction fragment length polymorphism in 267 CHD patients, 246 NIDDM patients and 491 unrelated healthy control individuals. The frequencies of minor allele 52 in CHD group, NIDDM group and control group were 0.301, 0.307 and 0.286, respectively. Compared with controls, there was no significant difference in distribution of genotype and allele frequencies of Sst I polymorphic site in CHD patients and NIDDM patients, respectively. However, the frequency of S1 S2 genotype in the HTG subgroup was significantly higher than that of the normal triglyceridaemia subgroup (NTG) in CHD patients (0.542>> 0.357, chi2 = 8.77, P = 0.0124). In NIDDM patients, the frequency of S2 S2 genotype in the HTG subgroup was significantly high, compared with that in the NTG subgroup (0.200>> 0.055, chi2 = 20.21, P = 0.0000), and there was significantly difference in the distribution of allele frequencies in subgroups of NTG and HTG (chi2 = 19.86, P = 0.0000). The level of triglyceride (TG) in S1 S2 genotype patients of CHD group were higher than that of S1 S1 genotype patients (P = 0.036). In NIDDM and controls groups, S2 S2 genotype individuals exhibited a significant increase in plasma TG concentrations, respectively compared with S1 S1 and S1 S2 genotype individuals of each group (P < 0.01). The minor allele S2, which was associated with both CHD with HTG and NIDDM with HTG and may contribute to the susceptibility of hypertriglyceridemia in CHD and NIDDM patients, may be one of the genetic predispositions to both CHD with HTG and NIDDM with HTG in Chinese population.

Five centers participated in a double-blind, randomized, active-drug controlled study. The selected patients had a diagnosis of primary hypercholesterolemia (phenotype IIa or IIb, total cholesterol [TC] greater than 300 mg/dl, low-density lipoprotein [LDL] cholesterol greater than 195 mg/dl, triglycerides [TG] less than 350 mg/dl). Throughout the study the patients observed a lipid-lowering diet (American Heart Association). After a baseline placebo period (4 weeks), the patients were randomly assigned to simvastatin 20 mg q.p.m. or fenofibrate 200 mg b.i.d. If after 6 weeks of treatment the LDL cholesterol level remained over 140 mg/dl the dose of simvastatin was doubled. The total duration of treatment was 10 weeks. One hundred eighty-four patients completed the study; age ranged from 17 to 72 years (mean 46; 129 men, 55 women). Seventy-nine patients had ischemic heart diseases. Simvastatin significantly reduces TC, LDL, and apolipoprotein (apo) B (30%, 35%, and 27%, respectively). These effects are larger than those of fenofibrate (19%, 22%, and 14%, respectively). Fenofibrate decreased very-low-density lipoprotein and TG, and increased high-density lipoprotein and apo A1, to a larger extent than simvastatin. However, the difference reached statistical significance only for TG (29% versus 17%). Both drugs were well tolerated. Clinical adverse experiences occurred with a low frequency, and few of these were considered drug related (6 and 8% in the simvastatin and fenofibrate groups, respectively). Only two patients had serious laboratory adverse experiences considered drug related or possibly drug related (one in each treatment group with increased SGPT, gamma-GT, and/or creatine phosphokinase).

OBJECTIVE

Hypocholesterolemia is a common finding in hospitalized elderly people and is associated with increased mortality. Changes in plasma lipid levels are well known in the acute phase response. It has also been suggested that malnutrition is a cause of hypocholesterolemia. However, malnutrition is the reflect of general condition, and the respective roles of malnutrition and inflammation have not yet been clearly established. This research project was undertaken to examine the impact of nutritional and inflammatory status on the hypocholesterolemia.

METHODS

In a prospective study, 597 elderly patients (83 +/- 7 years) consecutively admitted in a geriatric acute care unit were included. Clinical and anthropometric data: Body Mass Index (BMI), Tricipital Skinfold Thickness (TSF), Sub-Scapular Skinfold Thickness (SSF), Mid Arm Circumference (MAC) have been collected. The blood samples were obtained within the 72 hours following the admission. Nutritional proteins (albumin, prealbumin, transferrin, retinol binding protein); inflammatory proteins (CRP, alpha-1 acid glycoprotein), and blood lipids (cholesterol, LDL, HDL cholesterol, triglycerides, apoproteins A1 and B) were dosed.

RESULTS

The anthropometric and biologic parameters have been compared on the two sexes, significant differences were observed only for blood lipids. The analyses are thus realized and presented by sex separately. Four groups of patients are generated according to the quartile of total cholesterol. Means and standard deviation for all factors are calculated within each group. Both, the trend of means and analyses of correlation show associations with cholesterol in the two sexes. The analysis of variance showed that the cholesterolemia is associated with 1/ decrease in the values of the anthropometrics, and nutritional proteins and 2/ upward trends of the inflammatory parameters. Significant correlations were observed for all transport proteins and CRP with total cholesterol in men and women. The multiple linear regression of the total cholesterol retained albumin, APO A1, APO B and RBP as predictor factors of cholesterolemia for women and APO A1, APO B and tryglicerid for men. When patients with infectious diseases were compared to the others, significant differences have been observed for total cholesterol and all blood lipids, as well as for nutritional and inflammatory proteins.

CONCLUSIONS

The results confirm an association between nutritional status and hypocholesterolemia, and suggest also the responsability of inflammation as a cause of hypocholesterolemia.

Cathepsin S (CTSS) is a cysteine protease that has a central role in remodeling the extracellular matrix and, as such, has been implicated in the etiology of cardiovascular disease. This study used five tag single nucleotide polymorphisms (tSNPs) to screen the CTSS gene in healthy lean (n = 1891) and obese French populations (n = 477) for their association with various phenotypes: body mass index, waist-to-hip ratio, glycemia, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (Apo-A1) and apolipoprotein B. Significant associations were identified between rs11576175 tSNP (A/G) and Apo-A1 and HDL-C plasma levels in a sex-specific manner. Lean female subjects homozygous for the minor A-allele had higher levels of circulating Apo-A1 (p = 0.0003), while lean male A/A carriers had higher levels of HDL-C (p = 0.007) compared with the other genotypes. In the obese cohort, associations were found between three tSNPs and Apo-A1 levels in adult female subjects: rs10888390 (G/A), p = 0.01; rs10888394 (T/C), p = 0.03; and rs1136774 (C/T), p = 0.02; however, only rs10888390 remained significant in a combined model (p = 0.03). These results provide the first evidence that CTSS sequence variations are associated with two human metabolic risk factors for cardiovascular diseases: plasma Apo-A1 and HDL-C concentrations.

Over the last few years, lipoprotein(a) [Lp(a)] levels have been investigated because clinical studies have related it to increased cardiovascular and cerebrovascular risk. Although it is known that serum Lp(a) concentrations are controlled genetically, little is known about its metabolism. We studied changes in the lipid profile and Lp(a) values in 57 patients (34 males and 23 females) affected by cirrhosis of the liver subdivided into Child's classes in order to assess whether this lipoprotein is sensitive to reduced liver protein synthesis. The patients presented with low total cholesterol, normal HDL-cholesterol (HDL-c), LDL-cholesterol (LDL-c), triglycerides, apoprotein A1 (Apo-A1) and apoprotein B100 (Apo-B100) concentrations, while Lp(a) concentrations seemed elevated. Grouping the patients into Child's classes revealed that all the lipid parameters investigated reduced as the disease progressed. Lp(a) reduced significantly between Child's Classes I and II and seems to be correlated with the severity of cirrhosis and the clinical worsening of the patients' conditions. These findings suggest that Lp(a) is not only an index of atherosclerosis risk, but also plays a role in monitoring liver functions.

Relative effects of feeding ethanol and/or omega 3 fatty acid-rich fish oil for 6 wk on body lipids and lipoproteins were investigated. Ethanol increased plasma cholesterol (P less than 0.06) and triglycerides (P less than 0.0005), whereas fish oil decreased plasma cholesterol (P less than 0.005) and triglycerides (P less than 0.02). Liver cholesterol and triglycerides were increased by ethanol (P less than 0.0001) while fish oil decreased liver cholesterol (P less than 0.01) but not triglycerides. Based on Scheffé contrasts (P less than 0.05), fish oil blocked the increases in liver cholesterol and triglycerides caused by ethanol. Substitution of normal dietary fat with omega 3 fatty acid-rich fat in ethanol-fed animals lowered plasma cholesterol by 29% (P less than 0.001) and triglycerides by 30% (P less than 0.05) within 2 wk. Plasma apo A1 was increased by ethanol (P less than 0.001) and decreased by fish oil (P less than 0.002). Plasma total apo E was unaffected by either ethanol or fish oil. However, HDL apo E was decreased by ethanol (P less than 0.04) and increased by fish oil (P less than 0.02). Scheffé contrasts (P less than 0.05) also showed that plasma apo A was increased by ethanol regardless of whether the animals were consuming regular fat (1.72-fold) or fish oil fat (1.49-fold). Thus, omega 3 fatty acids can not only prevent but also reverse many of the lipid and lipoprotein abnormalities caused by alcohol abuse in the rat.

OBJECTIVE

After menopause, some women manifest coronary artery disease (CAD) with highly variable angiographic severity. For these women, postmenopausal appearing of some CAD risk factors may have differently influenced the CAD risk and severity. In this study, we attempt to unravel differences in the frequency or intensity of CAD risk factors among postmenopausal women with different angiographic severity.

METHODS

We studied 182 postmenopausal women (64+/-6 years) who underwent coronary angiography to investigate thoracic pain. Subjects with no detectable coronary lesions at angiography were recruited to the non-obstructive group and patients with CAD were grouped in one-vessel or multi-vessel groups. We compared clinical variables as the body mass index (BMI), age at menopause, age, hypertension, diabetes and cigarette smoking, and lipid measurements as plasma levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein (apo) A1, apo B and lipoprotein(a) (Lp(a)).

RESULTS

Comparing to the non-obstructive group, Lp(a) was twofold higher in the one-vessel group and threefold higher in the multi-vessel group and triglycerides were 34% higher in the one-vessel group and 50% higher in the multi-vessel group. No further difference was found among the three groups. After multivariate logistic regression analysis, triglyceride (odds ratio: 1.01; P=0.0013) and Lp(a) (odds ratio: 1.006; P<0.0001) were independently indicative of the presence of obstructive CAD.

CONCLUSIONS

We found that both Lp(a) and triglycerides constitute useful markers of CAD severity among postmenopausal women.

OBJECTIVE

Previous reports on biological variation in lipids differ widely in the time interval between sampling, the number of samples analyzed per patient and the total study period. The present investigation was carried out to determine monthly intra-individual variation in lipids over 1 year and to establish whether there was a consistent change in lipid values over the summer months. The importance of taking this variation into consideration during the assessment of risk of coronary heart disease (CHD) was also examined.

METHODS

Cholesterol, triglycerides, HDL, apo A1, and apo B were measured at monthly intervals for 12 months in 22 healthy, free-living volunteers (11 females, 11 males) by standardized methods.

RESULTS

When compared to analytical variation, biological variation was the dominant component of the intra-individual changes observed during the 1-year study period. As expected, triglycerides showed the greatest biological variation; the ratio of biological/analytical variation was 33.1. Much smaller ratios were observed for the other lipids measured in this study with values ranging from 4.2 to 6.8. Different subjects attained their maximum and minimum values in virtually every month of the year. There were significant reductions in cholesterol, HDL, LDL, and apo A1 in the summer months while triglycerides showed a non-significant increase and apo B a non-significant decrease during this period.

CONCLUSIONS

All the analytes showed considerable intra-individual variation. It is, therefore, important to measure lipids sequentially over several weeks to arrive at an average value for risk stratification for CHD.

OBJECTIVE

To determine the relative influence of diet, metabolic control, and familial factors on lipids in children with type 1 diabetes and control subjects.

METHODS

We assessed fasting serum cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, lipoprotein(a), apolipoprotein (apo)-A1, and apoB in 79 children and adolescents with type 1 diabetes and 61 age- and sex-matched control subjects, together with dietary intakes using a quantitative food frequency questionnaire.

RESULTS

Total cholesterol, LDL cholesterol, apoB, HDL cholesterol, and apoA1 were significantly higher in children with diabetes. Children with diabetes had higher percentage energy intake from complex carbohydrates (P = 0.001) and fiber intake (P = 0.02), and they had lower intake of refined sugar (P < 0.001) and percentage energy from saturated fat (P = 0.045) than control subjects. Total cholesterol (beta = 0.43, P < 0.001), LDL cholesterol (beta = 0.4, P < 0.001), and apoB (beta = 0.32, P = 0.006) correlated independently with HbA(1c) but not dietary intake. HDL cholesterol (beta = 0.24, P = 0.05) and apoA1 (beta = 0.32, P = 0.004) correlated independently with HbA(1c), and HDL cholesterol (beta = -0.34, P = 0.009) correlated with percentage energy intake from complex carbohydrates. Triglycerides correlated independently with percentage energy intake from complex carbohydrates (beta = 0.33, P = 0.01) and insulin dose (beta = 0.26, P = 0.04). Subjects with diabetes and elevated LDL (>3.35 mmol/l, >130 mg/dl), for whom dietary therapy would be recommended, had significantly higher HbA(1c) (P = 0.007), but they had higher intake of complex carbohydrates than subjects with LDL cholesterol <3.35 mmol/l.

CONCLUSIONS

Lipid abnormalities remain common in children and adolescents with type 1 diabetes who adhere to current dietary recommendations, and they relate to metabolic control but not dietary intake.

Abnormalities in lipoprotein metabolism are among the risk factors for atherosclerotic cardiovascular disease frequently present in patients with morbid obesity. We have examined the effects of dietary restriction induced by gastric bypass surgery on plasma lipoprotein levels in 22 morbidity obese patients. Operation induced weight loss in all patients. Postoperatively (12 +/- 7 mo), triglycerides decreased from 146.4 +/- 67 (mean +/- S.D. before operation) to 104 +/- 44 mg/dl (p less than 0.01), total cholesterol decreased from 187 +/- 52 to 166 +/- 39 mg/dl (p less than 0.025), LDL cholesterol levels decreased from 119 +/- 42 to 104 +/- 36 mg/dl (p less than 0.038), and HDL cholesterol levels increased from 40.1 +/- 10.1 to 45.2 +/- 9.5 mg/dl (p less than 0.012). HDL cholesterol to LDL cholesterol ratio increased from 0.37 +/- 0.13 to 0.48 +/- 0.21 (p less than 0.01). The results of apo A-1, A-2 and B determinations (n = 12) paralleled the changes in lipoprotein levels. Apo A1/Apo A2 ratio increased suggesting an increase in the concentration of HDL2. We conclude that weight loss following gastric bypass surgery is associated with favorable changes in lipoprotein metabolism which may help prevent or delay the development of atherosclerotic cardiovascular disease. The mechanism responsible for the lipoprotein changes remains to be determined.

The inclusion of protease inhibitors in serum or plasma samples has been found to significantly impact the isoform profile of selected plasma proteins as seen on 2-dimensional electrophoresis (2-DE) gels. With the addition of a protease inhibitor cocktail, several human plasma protein trains [depleted of albumin and immunoglobulin G (IgG)] exhibited higher isoelectric point (pI) isoforms. This shift was especially apparent for apolipoprotein A1 (apo A1), a relatively high abundance protein. The six protease inhibitor components of the cocktail were individually investigated with albumin and IgG depleted human plasma, and it was shown that the observed effects were caused by 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF), a serine protease inhibitor that covalently modifies proteins and/or peptides. Several serine-and/or tyrosine-containing peptides of apo A1 were modified with a concomitant mass increase of 183 Da, which is consistent with the mass increase expected following reaction with AEBSF. These modifications were observed with increasing propensity in the higher pI spots. An increase in both the number and proportion of modified peptides with increasing pI was also observed. A model is proposed for the random or stochastic coupling of AEBSF-derived moieties to serine and/or tyrosine residues throughout apo A1 and potentially other plasma proteins.

Using isoelectric focusing and immunoblotting techniques, we screened 96 serum samples from Yanomami Indians of northwestern Brazil to determine structural variation at three apolipoprotein loci: A4, E, and H. The APO-H locus, which is commonly polymorphic in white and black samples, was found to be monomorphic. At the APO-E locus only two alleles, APOE*3 and APOE*4, rather than the three-allele polymorphism commonly seen in Caucasians, was observed. At the APO-A4 locus no example of the APOA4*2 allele, found in Caucasians, was detected. However, the frequency of the less common APOA4*4 allele was above what has been observed in any other population. We investigated the impact of genetic variation at both polymorphic loci on quantitative differences in lipids, apolipoproteins, serum glucose, glycated hemoglobin, and uric acid. Contrary to the cholesterol-elevating effect of APOE*4 reported elsewhere, in both univariate analyses and after adjustments for age, sex, weight, and height, APOE*4 was associated with about a 4% lower mean serum cholesterol. Only after adjustment was this association statistically significant. The APOE*4 allele was significantly associated with unadjusted APO-A1 and APO-E levels but not with any other dependent variable; associations with adjusted APO-A1, APO-C2, and uric acid also approached standard levels of statistical significance (p < or = 0.05). In univariate analyses the APOA4*4 allele was significantly associated with APO-B, serum glucose, percent glycated hemoglobin, and uric acid, but no significant associations were observed after dependent variables were adjusted for age, sex, weight, and height. These results support the notion that apolipoprotein distributions and their associations with lipid and carbohydrate metabolism show ethnic variability.