A novel strategy for human papillomavirus detection and genotyping with SybrGreen and molecular beacon polymerase chain reaction.

Human papillomaviruses (HPVs) play an important role in the pathogenesis of cervical cancer. For identification of the large number of different HPV types found in (pre)malignant lesions, a robust methodology is needed that combines general HPV detection with HPV genotyping. We have developed for formaldehyde-fixed samples a strategy that, in a homogeneous, real-time fluorescence polymerase chain reaction (PCR)-based assay, accomplishes general HPV detection by SybrGreen reporting of HPV-DNA amplicons, and genotyping of seven prevalent HPV types (HPV-6, -11, -16, -18, -31, -33, -45) by real-time molecular beacon PCR. The false-positive rate of the HPV SybrGreen-PCR was 4%, making it well suited as a prescreening, general HPV detection technology. The type specificity of the seven selected HPV molecular beacons was 100% and double infections were readily identified. The multiplexing capacity of the HPV molecular beacon PCR was analyzed and up to three differently labeled molecular beacons could be used in one PCR reaction without observing cross talk. The inherent quantitation capacities of real-time fluorescence PCR allowed the determination of average HPV copy number per cell. We conclude that the HPV SybrGreen-PCR in combination with the HPV molecular beacon PCR provides a robust, sensitive, and quantitative general HPV detection and genotyping methodology.

Linear 2' O-Methyl RNA probes for the visualization of RNA in living cells.

U1snRNA, U3snRNA, 28 S ribosomal RNA, poly(A) RNA and a specific messenger RNA were visualized in living cells with microinjected fluorochrome-labeled 2' O-Methyl oligoribonucleotides (2' OMe RNA). Antisense 2' OMe RNA probes showed fast hybridization kinetics, whereas conventional oligodeoxyribonucleotide (DNA) probes did not. The nuclear distributions of the signals in living cells were similar to those found in fixed cells, indicating specific hybridization. Cytoplasmic ribosomal RNA, poly(A) RNA and mRNA could hardly be visualized, mainly due to a rapid entrapment of the injected probes in the nucleus. The performance of linear probes was compared with that of molecular beacons, which due to their structure should theoretically fluoresce only upon hybridization. No improvements were achieved however with the molecular beacons used in this study, suggesting opening of the beacons by mechanisms other than hybridization. The results show that linear 2' OMe RNA probes are well suited for RNA detection in living cells, and that these probes can be applied for dynamic studies of highly abundant nuclear RNA. Furthermore, it proved feasible to combine RNA detection with that of green fluorescent protein-labeled proteins in living cells. This was applied to show co-localization of RNA with proteins and should enable RNA-protein interaction studies.

Simultaneous A8344G heteroplasmy and mitochondrial DNA copy number quantification in myoclonus epilepsy and ragged-red fibers (MERRF) syndrome by a multiplex molecular beacon based real-time fluorescence PCR.

The association of a particular mitochondrial DNA (mtDNA) mutation with different clinical phenotypes is a well-known feature of mitochondrial diseases. A simple genotype-phenotype correlation has not been found between mutation load and disease expression. Tissue and intercellular mosaicism as well as mtDNA copy number are thought to be responsible for the different clinical phenotypes. As disease expression of mitochondrial tRNA mutations is mostly in postmitotic tissues, studies to elucidate disease mechanisms need to be performed on patient material. Heteroplasmy quantitation and copy number estimation using small patient biopsy samples has not been reported before, mainly due to technical restrictions. In order to resolve this problem, we have developed a robust assay that utilizes Molecular Beacons to accurately quantify heteroplasmy levels and determine mtDNA copy number in small samples carrying the A8344G tRNA(Lys) mutation. It provides the methodological basis to investigate the role of heteroplasmy and mtDNA copy number in determining the clinical phenotypes.

Effect of pravastatin, a HMG CoA reductase inhibitor, on blood lipids and aortic lipidosis in cholesterol-fed White Carneau pigeons.

The effect of pravastatin, an inhibitor of HMG CoA reductase, on blood lipids and aortic lipidosis was studied in young cholesterol-fed White Carneau pigeons. The birds were fed with normal ('N group', n = 20) or atherogenic diet (grains + 0.4% cholesterol + 4% lard) alone ('C group', n = 20) and in association with pravastatin ('P group', n = 20). Plasma lipids and aortic intima lipidosis were studied after 3-5 and 8-12 months of the diet. Compared to the N group, pigeons from C group exhibited hypercholesterolemia (TC = 1000 mg/dl) and hyperlipoproteinemia of which level was independent of the duration of the diet. Total VLDL (VLDL+LDL)-cholesterol and apolipoprotein-B levels rose significantly 15, 8 and 4 times, respectively, whereas HDL were increased two times (P < 0.01) in females only. Macroscopically visible intima lipidosis areas covered 40% and 80% of aortic surface after 3-5 and 8-12 months of the diet. In P group, the increase in plasma lipid values was significantly lower than in WC from C group: -40% for total cholesterol (600 mg/dl) (P < 0.01), -71% for VLDL (P < 0.001), -53% for (VLDL+LDL)-cholesterol (P < 0.01) and -54% for apo-B (P < 0.05). HDL remained as high as in C group. Consequently TC/HDL-C ratio was improved and atherogenic risk of cholesterol was reduced by 41% (P < 0.05). Intima lipidosis areas were lowered by 35% (P < 0.01). We conclude that pravastatin treatment involves (1) a decrease in hypercholesterolemia and hyperlipoproteinemia and (2) a lowering in extensiveness and severity of macroscopically visible aortic lipidosis in cholesterol-fed White Carneau pigeon.

Relationship between smoking status and serum lipids in a hyperlipidemic population and analysis of possible confounding factors.

The aim of our study was to estimate the potential relationship between smoking behavior and other coronary heart disease risk factors in 250 hyperlipidemic patients. We present data obtained through self-reporting of the number of cigarettes smoked per day, measurements of three tobacco markers, and data on dietary habits and lipid variables. We measured cotinine (by HPLC) and thiocyanate and used a recent colorimetric assay for the indirect evaluation of the nicotine metabolites in a single urine specimen. Mean values of nicotine metabolites, expressed as cotinine equivalents, were 6.7, 39.9, and 79.4 mumol/L, respectively, for nonsmokers, light smokers (7.7 cigarettes per day), and heavy smokers (25.8 cigarettes per day). We found that light smokers have higher concentrations of cotinine and nicotine metabolites in proportion to the number of cigarettes smoked per day than do heavy smokers. Thus, the simple colorimetric assay can accurately evaluate smoking status. Hyperlipidemia and smoking are linked by an intricate network of multiple relations. The concentration of high-density lipoprotein (HDL) cholesterol is lower in heavy smokers, and the concentrations of triglycerides and cholesterol are higher. The 0.11 mmol/L difference in HDL cholesterol between light and heavy smokers is close to the results of previous papers; however, when gender, dietary habits (including alcohol intake), and data on body mass index are included in a multiple regression analysis, there is no longer an association between HDL cholesterol concentrations and smoking status. Therefore, these different dietary habits may be confounding factors that partly explain the pattern of lipid variables.

Carotid stenosis is a powerful predictor of a positive exercise electrocardiogram in a large hyperlipidemic population.

Hypercholesterolemia is a major risk factor in coronary heart disease (CHD) and ischemic stroke. However, there is no general agreement on the usefulness of systematic screening of patients with hyperlipidemia by stress exercise electrocardiogram (ECG). The feasibility of this approach would depend on selecting patients with a high risk of CHD, since the sensitivity and specificity of the test depends on the prevalence of the disease. In view of the association of CHD and ischemic stroke, we undertook a study to determine whether the presence of atherosclerosis in the carotid arteries was predictive of a positive exercise ECG in a group of 778 asymptomatic patients referred to their hyperlipidemia. We a much higher percentage of positive exercise ECG in patients with carotid atherosclerosis in our ultrasonographic examinations. In a multiple regression analysis which included 13 parameters (age, sex, body mass index, arterial blood pressure, lipid parameters, serum level of glucose, smoking status and the severity of carotid lesions), the strongest predictors of a positive exercise ECG test were age (P = 0.014) and the degree of carotid atherosclerosis (P = 0.010). We therefore conclude that hyperlipidemic patients with atherosclerotic lesions on carotid arteries would benefit most from screening by the exercise ECG.

Screening for new mutations in the LDL receptor gene in seven French familial hypercholesterolemia families by the single strand conformation polymorphism method.

To investigate the molecular basis of familial hypercholesterolemia (FH) in France, we applied the single strand conformation polymorphism (SSCP) method to the promoter region and the 18 exons of the low density lipoprotein receptor (LDLR) gene. Seven probands, 4 heterozygotes, 2 compound heterozygotes, and 1 homozygote, belonging to FH families were tested. In all cases, previous genetic analysis and/or LDL receptor fibroblast assay had shown that the disease was due to defects in the LDLR gene. Out of the nine mutations expected, one nonsense mutation in exon 2 and six missense mutations were identified in exons 3, 6, 8, 11, and 15. Two of the latter were found in exon 6. In each family, cosegregation of the base substitution and the disease was observed. Ninety-five control subjects were screened for the presence of the six missense mutations. None was detected, implying that the mutations identified are deleterious. Our results indicate that the SSCP analysis of amplified genomic DNA fragments can be successfully used to rapidly screen mutation containing exons in large genes. Furthermore, all these mutations are newly described and demonstrate heterogeneity of LDLR gene mutations responsible for FH in the French population, as in other reported Caucasian populations.

[Comparison about the efficacy and tolerability between simvastatin and bezafibrate in the treatment of hypercholesterolemia]. / Comparaison de l'efficacité et de la tolérance de la simvastatine et du bézafibrate dans le traitement des hypercholestérolémies.

Simvastatin and bezafibrate actions on blood lipids and their side effects were compared in a double-blind trial involving 24 adults with severe type IIa or IIb primary hypercholesterolemia (mean plasma cholesterol = 4.35 g/l). During a 12-week period, the patients received either bezafibrate, 600 mg 3 times a day, or simvastatin, 10 or 20 mg once a day, with a doubling of the dosage at week 6 if the LDL-cholesterol level remained above 1.40 g/l. Simvastatin significantly reduced LDL-cholesterol by -39.5% (p less than 0.001), total cholesterol by 33.9% (p less than 0.005) and apoprotein B by -28% (p less than 0.001). Bezafibrate significantly reduced LDL-cholesterol (-19.8%, p less than 0.001) and total cholesterol (-17.5%, p less than 0.002), but not apoprotein B. Bezafibrate also reduced triglycerides by -26.6% and raised HDL-cholesterol by +27.6%. Simvastatin was more effective than bezafibrate in lowering LDL-cholesterol (p less than 0.002), total cholesterol (p less than 0.005) and apoprotein B (p less than 0.05). Tolerance of both drugs was considered excellent.

Lp(a) levels in different types of dyslipidemia in the French population.

The serum lipoprotein Lp(a) concentration was measured in 1065 individuals in order to assess whether there was a relation between the type of dyslipidemia and the level of Lp(a). Males and females, aged between 2 and 83 years old, were included in the study. Quantification was performed by an immunonephelometric technique. The whole population was divided into normolipidemic (NL), type IIa without xanthoma (type IIa), type IIa with xanthoma (FH), type IIb and type IV phenotypes. Lp(a) level was arbitrarily divided into 5 subclasses in each group of dyslipidemia and in the normolipidemic group. In addition each group was divided according to sex and whether or not they were under treatment. We observed a significant difference between the median Lp(a) level of the normolipidemic group (NL) and of the dyslipidemic group as a whole. Median Lp(a) levels in the 4 dyslipidemic groups did not differ significantly. Sex, age and treatment did not influence the distribution of Lp(a) values distribution. Only weak correlations (Spearman's rank test) were observed between Lp(a) and other lipid parameters (total cholesterol, LDL, apo B, HDL, triglycerides): the highest correlation (r' = 0.15) was between Lp(a) and apo B. We conclude that Lp(a) level is not influenced by the type of dyslipidemia, sex or hypolipidemic drugs.

An initiation codon mutation in the apoC-II gene (apoC-II Paris) of a patient with a deficiency of apolipoprotein C-II.

We have identified the genetic defect that leads to a deficiency of apoC-II in the proband from the Paris kindred. Analysis of the apoC-IIParis DNA by Southern blot hybridization revealed no major gene rearrangements, but sequencing of polymerase chain reaction-amplified apoC-IIParis DNA revealed an A to G transition that changed the initiation AUG (methionine) codon to GUG (valine). Potential initiation of translation at the closest inframe methionine codon eliminates the entire signal peptide and the first 8 amino-terminal residues of apoC-II which would prevent apoC-II secretion into plasma. In agreement with this, no apoC-II was detected in the patient's plasma by radioimmunoassay or by two-dimensional gel electrophoresis and immunoblotting. Direct sequencing of amplified patient DNA from 12 different polymerase chain reaction samples demonstrated the presence of the A to G substitution in all, indicating that the proband is a homozygote for the defect. We propose that in the apoC-IIParis gene, a mutation in the initiation methionine codon prevents the normal initiation of apolipoprotein synthesis and leads to a deficiency of apoC-II. This initiation methionine mutation represents a new type of molecular defect that can result in Type I hyperlipoproteinemia.

[Lipoprotein Lp(a): a new risk factor of atherogenesis]. / La lipoprotéine Lp (a): nouveau facteur de risque athérogène.

Lp(a) is a lipoprotein present in all individuals in concentrations that are genetically determined. Its structure is characterized by the presence of an apoprotein with a high carbohydrate content called apoprotein a. Since 1972, numerous concordant data have endowed Lp(a) with a high risk of atherogenesis. This risk applies to the coronary and cervico-encephalic arteries. For the latter, Lp(a) even is a lipid parameter regarded as a major risk factor. The origin and metabolism of Lp(a) are little known, by they seem to differ from those of low-density lipoproteins. Its specific apoprotein of Lp(a). At the moment, there is no simple dietetic or medicinal treatment that can lower substantially the serum level of Lp(a).

Coagulation factor VII and plasma triglycerides. Decreased catabolism as a possible mechanism of factor VII hyperactivity.

High circulating levels of coagulation factor VII (FVII) are known to be associated with elevated concentrations of blood lipids. More specifically, hypertriglyceridemia is correlated with raised FVII coagulant activity (FVIIc). Recently, evidence has been described which suggests that elevation in FVIIc might reflect an increase in the total concentration of FVII, as evaluated by quantitation of FVII antigen (FVIIag). It is also known that FVIIc represents a risk factor for cardiovascular death, but the prediction of cardiovascular risk based on triglyceride estimation is the subject of conflicting results. Since dyslipidemia featuring abnormal triglyceride metabolism is pathophysiologically heterogeneous, we analyzed the possible relationships between FVII and triglyceride further and under standardized postprandial conditions. For this purpose we studied FVIIc and FVIIag in relation to triglyceridemia after a standardized test meal. Our results confirm that FVIIc and FVIIag levels are strongly correlated with each other (r = 0.714; p = 0.01). In addition, both were significantly increased (p less than 0.02) in patients who exhibited abnormal triglyceride levels 8 h after a standardized test meal, as compared to those who displayed normal triglyceridemia. Furthermore, we found that apolipoprotein B levels were also increased in such patients. The deficient postprandial catabolism of triglycerides, therefore, appears to be related to an increase in total FVII concentration, suggesting that some association between the metabolism of triglyceride-rich lipoproteins and FVII might underlie the mechanism of the elevation in FVII. Given the important contribution of FVII to hypercoagulability, then our results may be relevant to the understanding of the role of postprandial triglyceride in atherogenesis and in consideration of the circadian prevalence of cardiovascular thrombosis.

Plasma factor VII, triglyceride concentration and fibrin degradation products in primary hyperlipidemia: a clinical and laboratory study.

There is evidence that the increase in coagulation factor VII (FVII) represents a predictive risk factor of arterial thrombosis in coronary heart disease. Its relative contribution to this multifactorial process and its relationship to other risk factors, namely cholesterol and triglycerides, is yet a matter of investigation. In this study we aimed to clarify whether FVII synthesis or activation correlated with plasma lipid concentrations. For this, we assayed the plasma levels of FVII antigen (FVII:ag) and FVII coagulant activity (FVIIc) in types IIa, IIb and IV hyperlipidemic individuals, together with the levels of cholesterol, triglycerides, high-density lipoproteins and apolipoprotein B. FVII activation state (FVIIa) was then assessed by FVIIc/FVII:ag. In order to assess the possible correlation of FVII levels with the generation of thrombin and formation of fibrin, we also assayed the plasma concentration of fibrin degradation products (D-dimers) in these patients. Considering all the patients studied, there was a fair correlation between FVIIc and FVII:ag (r = 0.704; p less than 0.01). The mean levels of FVIIc and FVII:ag were significantly higher in type IV hyperlipidemia than in controls (t = 4.260; p less than 0.001 and t = 3.015; p less than 0.01, respectively) and other types of hyperlipidemia. We also found that FVIIc and FVII:ag significantly correlated to triglyceride concentration. We could not detect an evident activation of FVII in these patients since FVIIc/FVII:ag was not elevated in comparison with controls, nor did it correlate with any of the lipid determinations in any of the types of hyperlipidemia studied.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison between treatments of severe forms of familial hypercholesterolemia by total plasma exchange and selective removal of low density lipoproteins (LDLapheresis)]. / Comparaison des traitements des formes sévères d'hypercholestérolémie familiale par échange plasmatique total et épuration sélective des lipoprotéines de basse densité (LDLaphérèse).

A plasma exchange program for familial hypercholesterolaemia was started in 1982. Ten patients aged from 7 to 58 years were progressively included: 3 had an heterozygous form of the disease with ischaemic heart disease; 3 had an homozygous form with defective low density lipoprotein receptor activity, 4 had a receptor-negative homozygous familial hypercholesterolaemia and had previously undergone portacaval shunt. During total plasma exchange against human albumin (470 sessions in 9 patients) low density lipoprotein cholesterol values, but also high density lipoprotein cholesterol values, decreased by 40 per cent. More recently, 5 patients had selective low density lipoprotein absorption on dextran sulfate column (Liposorber); 90 exchanges were performed. High density lipoprotein cholesterol values decreased by 55 per cent and high density lipoprotein cholesterol values by only 27 per cent. The patients' attitude to treatment was excellent, with less fatigue and better compliance.

[Van Bogaert's cerebrotendinous xanthomatosis. A study of 3 cases]. / Xanthomatose cérébro-tendineuse de Van Bogaert. Etude de trois observations.

The authors report three observations of cerebro-tendinous xanthomatosis (CTX). The three patients presented tendinous xanthoma and cataract. The neurologic disorders were different in each case. The first one, a 43 years old woman suffered from dementia, ataxia and pseudobulbar palsy: CT scan showed cerebellar hypodense lesions. After the apparition of bulbar signs ans cachexia she died at 45. The second patient, a 39 years old man had an ataxia and mild psychiatric disorders. He was stabilized with a treatment of chenodesoxycholic acid. The third one, a 49 years old women suffered only from tendinous xanthoma, cataract, and had no neurological disorder. His plasmatic cholestanol level was high. CTX is a recessive deficit of the hepatic 26 hydroxylase with deposits of abnormal metabolites in tendons, crystalline lenses and central nervous system. Reviewing the 44 observations of CTX in the literature, the authors define the genetical, clinical, biochemical and therapeutical aspects of CTX, and underline the necessity of a early diagnosis with cholestanol dosage, before the apparition of neurological disorders and the short terminal phase. CTX is a rare but fortunately treatable neurolipidosis.