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P Pfister

Publications and source records attributed to P Pfister.

At least 37 records · Page 2Linked to original sources
PubMed1998

Molecular analysis of Methanobacterium phage psiM2.

The methanogenic archaeon Methanobacterium thermoautotrophicum Marburg is infected by the double-stranded DNA phage psiM2. The complete phage genome sequence of 26 111 bp was established. Thirty-one open reading frames (orfs), all of them organized in the same direction of transcription, were identified. On the basis of comparison of the deduced amino acid sequences to known proteins and by searching for conserved motifs, putative functions were assigned to the products of six orfs. These included three proteins involved in packaging DNA into the capsid, two putative phage structural proteins and a protein related to the Int family of site-specific recombinases. Analysis of the N-terminal amino acid sequences of three phage-encoded proteins led to the identification of two genes encoding structural proteins and of peiP, the structural gene of pseudomurein endoisopeptidase. This enzyme is involved in the lysis of host cells, and it appears to belong to a novel enzyme family. peiP was overexpressed in Escherichia coli, and its product was shown to catalyse the in vitro lysis of M. thermoautotrophicum cells. Comparison of the phage psiM2 DNA sequence with parts of the sequence of the wild-type phage psiM1 suggests that psiM2 is a deletion derivative, which formed by homologous recombination between two copies of a direct repeat.

Amino Acid Sequence↗
PubMed1998

Direct effects of statins on the vascular wall.

The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on coronary events have generally been attributed to their hypocholesterolemic properties. Mevalonate and other intermediates of cholesterol synthesis (isoprenoids) are necessary for cell proliferation and other important cell functions; thus effects other than cholesterol reduction may help to explain the antiatherosclerotic properties of statins. Recently we provided in vitro and in vivo evidence of decreased smooth-muscle cell (SMC) proliferation and migration by fluvastatin and simvastatin, but not by pravastatin, independent of plasma cholesterol reduction. The ability of fluvastatin to interfere with arterial SMC proliferation at therapeutic concentrations (0.1-1 microM) prompted us to investigate the pharmacologic activity of sera from 10 patients treated with fluvastatin, 40 mg once daily, on the proliferation of cultured human arterial myocytes. Pravastatin, 40 mg once daily, displays a lipid-lowering activity similar to that of fluvastatin without affecting SMC proliferation and was investigated as a control for assessing this non-lipid-related effect of fluvastatin. Fluvastatin and pravastatin, given for 6 days to patients with type IIa hypercholesterolemia, resulted in a similar decrease in low-density-lipoprotein (LDL) cholesterol. However, the addition of 15% whole-blood sera from patients treated with fluvastatin to the culture medium resulted in a 43% inhibition of cholesterol synthesis in SMCs (p < 0.01) that mirrored the pharmacokinetic profile of fluvastatin. When SMC proliferation was investigated, a significant inhibition of cell growth (-30%; p < 0.01) was detected with sera obtained 6 h after the last dose. No effect on SMC proliferation or cholesterol biosynthesis was observed when sera from patients treated with pravastatin were evaluated. These results suggest that statins exert a direct antiproliferative effect on the arterial wall, beyond their effects on plasma lipids, which could prevent significant cardiovascular disease.

Adult↗
PubMed1998

HMG-CoA reductase inhibitors reduce MMP-9 secretion by macrophages.

-Macrophages secrete matrix metalloproteinases (MMPs) that may weaken the fibrous cap of atherosclerotic plaque, predisposing its fissuration. The 92-kDa gelatinase B (MMP-9) has been identified in abdominal aortic aneurysms and in atherosclerotic tissues. Fluvastatin, through the inhibition of the isoprenoid pathway, inhibits major processes of atherogenesis in experimental models (smooth muscle cell migration and proliferation and cholesterol accumulation in macrophages). We studied the effect of fluvastatin on the activity of MMP-9 in mouse and human macrophages in culture. Conditioned media of cells treated for 24 hours with fluvastatin were analyzed by gelatin zymography. In mouse macrophages, fluvastatin (5 to 100 micromol/L) significantly inhibited in a dose-dependent manner MMP-9 activity from 20% to 40% versus control. The drug, at a concentration as low as 5 micromol/L, inhibited MMP-9 activity ( approximately 30%) in human monocyte-derived macrophages as well. Phorbol esters (TPA, 50 ng/mL) stimulated MMP-9 activity by 50%, and fluvastatin inhibited this enhanced activity up to 50% in both mouse and human macrophages. The above results on the secretion of MMP-9 were confirmed by Western blotting and ELISA. The inhibitory effect of fluvastatin was overcome by the simultaneous addition of exogenous mevalonate (100 micromol/L), a precursor of isoprenoids. Fluvastatin's effect was fully reversible, and the drug did not cause any cellular toxicity. The statin did not block directly the in vitro activation of the secreted protease. Similar data were obtained with simvastatin. Altogether, our data indicate an inhibition of MMP-9 secretion by the drug. This effect is mediated by the inhibition of synthesis of mevalonate, a precursor of numerous derivatives essential for several cellular functions.

Animals↗
PubMed1997

Characterization of Methanobacterium thermoautotrophicum Marburg mutants defective in regulation of L-tryptophan biosynthesis.

Three nitrosoguanidine-induced mutants of the archaeon Methanobacterium thermoautotrophicum Marburg resistant to 5-methyltryptophan were isolated and characterized. They were found to take up L-tryptophan, as wild-type cells, via an energy-dependent, low-affinity transport system specific for L-tryptophan, with a Km of 300 microM and a Vmax of 7 nmol/mg (dry weight)/min. Resistance to 5-methyltryptophan was not due to feedback-resistant anthranilate synthase but to constitutive expression of the trp genes, as measured by the specific activities of anthranilate synthase and tryptophan synthase, the enzymes encoded by trpEG and trpB, respectively, of the trpEGCFBAD gene cluster. Estimation of trpE mRNA obtained from mutant cells grown in minimal medium with or without L-tryptophan suggested that constitutive expression resulted from deficient transcriptional regulation. The enhanced expression of the trp genes in the mutants was found to result in intracellular L-tryptophan pools that were two- to fourfold higher than in the wild type. Sequencing of the region upstream of trpE revealed in two mutants point mutations mapping on the 5'-side of the archaeal box A, whereas in the third mutant this region did not differ from that of the wild type. These results suggest that (i) in M. thermoautotrophicum the 5-methyltryptophan-resistant phenotype arises from lesions in components of a regulatory system controlling transcription of the trp genes and (ii) cis-acting sequence elements in front of the trpE promoter may form part of this system.

Base Sequence↗
PubMed1996

[Simultaneous detection of HBs antigens and antibodies: report of a case].

We reported the case of a young woman who presented simultaneously HBs antigen and HBs antibodies in blood. From historical datas, we suspected that the patient was infected by hepatitis B virus and developed a chronic infection. Lately, she received hepatitis B vaccine. Subtypes of the infectious hepatitis B virus and the immunogenic hepatitis B antigen were different and induced independent immunological responses.

Acute Disease↗
PubMed1995

Comparison of fluvastatin versus pravastatin treatment of primary hypercholesterolemia. French Fluvastatin Study Group.

Following a 6-week placebo period, 134 patients with low density lipoprotein cholesterol (LDL-C) > or = 160 mg/dL and plasma triglyceride < or = 400 mg/dL, despite following a standard lipid-lowering diet, were randomized to double-blind, double-placebo treatment with fluvastatin (22 women, 46 men; age 21-71 years) or pravastatin (25 women, 41 men; age 19-76 years). Fluvastatin at 40 mg and pravastatin at 20 mg were given for the first 4 weeks, both once daily with the evening meal. For the following 12 weeks, fluvastatin at 40 mg twice daily and pravastatin at 40 mg once daily were given with the evening meal. Both drugs were equally effective in lowering LDL-C after 4 weeks of treatment (-24.0% with fluvastatin, -24.1% with pravastatin) but, after 16 weeks, LDL-C reduction was -30.4% with fluvastatin and -26.6% with pravastatin. This further lowering of LDL-C between week 4 and week 16 was significant (p < 0.001) for fluvastatin but not pravastatin. Adverse events were reported by 23 fluvastatin patients and 22 pravastatin patients: 3 patients in each group withdrew from the study because of these. No notable abnormalities in levels of alanine or aspartate aminotransferase values (defined as > 3 times the upper limit of normal on 2 consecutive occasions) or of creatine phosphokinase (defined as > 10 times the upper limit of normal on any occasion) were observed in either treatment group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Changes in plasma apolipoprotein B-containing lipoparticle levels following therapy with fluvastatin and cholestyramine. European Fluvastatin Study Group.

Epidemiologic studies have demonstrated that apolipoprotein (apo) B-containing lipoparticles (LpE:B, LpC-III:B) are associated with the risk of coronary artery disease whereas apo A-1-containing lipoparticles (LpA-I) are protective against coronary artery disease. The effect on lipoparticle levels of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor fluvastatin, in combination with cholestyramine, was assessed in a double-blind randomized study. A total of 144 patients with primary hypercholesterolemia were recruited, who had successfully completed an original study comparing the effects of fluvastatin and cholestyramine on plasma lipoparticle levels. All subjects fulfilled the following inclusion criteria: plasma low density lipoprotein cholesterol (LDL-C) levels > 160 mg/dL, with premature coronary artery disease and 2 associated risk factors; or LDL-C > 190 mg/dL, no coronary artery disease, and triglycerides < 300 mg/dL, after a lipid-lowering diet. Patients were randomized to 1 of 3 combination therapy groups: fluvastatin 20 mg/day plus cholestyramine 4 g/day; fluvastatin 20 mg/day plus cholestyramine 8 g/day; and fluvastatin 20 mg/day plus cholestyramine 16 g/day. The study length was 6 weeks and patients were examined at 3-week intervals. Fluvastatin plus cholestyramine produced a significant (p < 0.001), dose-dependent reduction in levels of cholesterol (range, -29 to -34%), LDL-C (range, -30 to -44%), apo B (range, -23 to -34%), and apo E (range, -33 to -43%). LpE:B levels were also reduced (range, -19 to -26%), but not significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticholesteremic Agents↗
PubMed1995

High-dose fluvastatin and bezafibrate combination treatment for heterozygous familial hypercholesterolemia.

This study assessed the long-term use of fluvastatin, alone or in combination with bezafibrate, in patients with severe familial hypercholesterolemia who, in a previous study, did not achieve target levels (European Atherosclerosis Society) of low density lipoprotein cholesterol (LDL-C) with fluvastatin at 60 mg/day plus bezafibrate 200 mg/day, with or without cholestyramine (CME) at 8 g/day. This open-label study comprised 3 periods: period I, 6 weeks of fluvastatin at 40 mg twice daily (at breakfast and at bedtime); period II, fluvastatin at 80 mg/day (40 mg at breakfast, 40 mg at bedtime), and bezafibrate at 200 mg/day (at lunchtime) for 6 weeks in patients not achieving LDL-C target levels; and period III, force-titration of fluvastatin to 800 mg/day (as in period II) and bezafibrate at 400 mg/day (slow release) in patients receiving combination treatment. Patients were excluded if, during the previous study, they had experienced a serious drug-related adverse event or deterioration in liver or kidney function (liver enzymes > 3 times upper limit of normal). The standard physical and laboratory evaluations were performed at regular intervals. Lipid profiles were determined from 12-hour fasting blood samples. All adverse events occurring or worsening during the study, whether spontaneously reported or elicited by questioning, and regardless of relationship to study medication, were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Anticholesteremic Agents↗
PubMed1995

Effect of fluvastatin for safely lowering atherogenic lipids in renal transplant patients receiving cyclosporine.

The lipophilic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been associated with rhabdomyolysis in cyclosporine-treated treated patients, indicating an interaction of drugs. We therefore studied the safety and efficacy of the hydrophilic HMG-CoA reductase inhibitor fluvastatin in 14 cyclosporine-treated renal transplant patients. To qualify for inclusion, total cholesterol after dietary stabilization had to be > 240 mg/dL. Prior to starting active medication, patients underwent a 4-week placebo period. Fluvastatin was given in a dose of 20 mg once daily for 12 weeks, which was increased to 20 mg twice daily for a further 8 weeks. Fluvastatin reduced total and low density lipoprotein cholesterol in all patients at both dosages whereas no effect on high density lipoprotein cholesterol was observed. Triglyceride levels were lowered at week 20. Incremental dosages of fluvastatin did not affect cyclosporine concentration and no adjustment of cyclosporine dosage was necessary. The higher doses of fluvastatin also had no effect on renal function as judged by serum creatinine levels. Creatine phosphokinase remained unchanged throughout the study. No serious side-effects were observed. In conclusion, the hydrophilic HMG-CoA reductase inhibitor fluvastatin at either 20 or 40 mg/day appears to be both safe and effective in lowering atherogenic lipids in renal transplant patients.

Adolescent↗
PubMed1995

Comparison of the effect of fluvastatin, an hydroxymethyl glutaryl coenzyme A reductase inhibitor, and cholestyramine, a bile acid sequestrant, on lipoprotein particles defined by apolipoprotein composition.

In a double-blind, parallel-group, randomized study, the effects of fluvastatin (FLUV) 20 and 40 mg/d on lipoprotein particle levels were compared with those of cholestyramine (CME) 16 g/d. Lipoparticles were defined by apolipoprotein composition as either those containing both apolipoprotein (apo) B and apo E or CIII (lipoprotein [Lp] E-B or Lp CIII-B) or those containing apo AI alone (Lp AI) or in association with apo AII (Lp AI-AII). After an 8-week dietary stabilization period, 100 hypercholesterolemic patients were treated with FLUV 20 mg/d for 6 weeks and 40 mg/d for an additional 6 weeks and were compared with 48 hypercholesterolemic subjects treated with CME 16 g/d. Treatment with FLUV (40 mg/d) or CME (16 g/d) for 12 weeks was associated with a significant reduction in plasma cholesterol and low-density lipoprotein (LDL) cholesterol and a significant increase in high-density lipoprotein (HDL) cholesterol. However, plasma triglyceride levels decreased following FLUV treatment, whereas they increased with CME. These changes were associated with a significant reduction in the levels of apo B (FLUV, -24%, P < .001; CME, -26%, P < .001), apo E (FLUV, -36%, P < .001; CME, -32%, P < .001), and apo CIII (FLUV, -21%, P < .001; CME, -6%, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Fluvastatin reduces levels of plasma apo B-containing particles and increases those of LpA-I. European Fluvastatin Study Group.

Epidemiologic studies have demonstrated an association between apolipoprotein (apo) B-containing particles (lipoprotein [Lp] E:B; LpC-III:B) and an inverse association between LpA-I and the risk of coronary artery disease (CAD). The effect of 6 weeks of treatment with fluvastatin (20 and 40 mg/day in the evening), a novel competitive inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, on lipoparticle levels was studied in 423 patients with hypercholesterolemia after 14 weeks of standard dietary therapy. The combined data of the European double-blind controlled studies were used for the analysis. Two independent groups of hypercholesterolemic patients receiving fluvastatin (20 and 40 mg every evening) for 6 weeks were compared with a placebo group. For inclusion, patients had to fulfill the following criteria: plasma low-density lipoprotein (LDL) cholesterol levels > 160 mg/dL and premature CAD and/or two associated risk factors; LDL cholesterol > 190 mg/dL and no CAD; triglycerides < 300 mg/dL. All measurements were performed at the Pasteur Institute Central Laboratory, LpE:B and LpC-III:B were measured by double-site ELISA. Lipoprotein A-I and LpA-I:A-II were determined by differential electroimmunodiffusion. Treatment with 20 and 40 mg of fluvastatin was associated with reductions in plasma apo B (median change: -19.3% and -22.8%, respectively; p < 0.001), LpE:B (-12.5% and -22.6%, respectively; p < 0.001), and LpC-III:B (-3.6% and -36.8%, respectively; p < 0.001) particles compared with placebo. Significant increases in plasma apo A-I (1.7% and 4.8%, respectively; p < 0.001) and antiatherogenic LpA-I (2.3% and 6.9%, respectively; p < 0.001) were also observed. Levels of LpA-I:A-II were not affected by fluvastatin treatment. In conclusion, 6-week treatment with fluvastatin is associated with beneficial antiatherogenic changes in lipoparticle profiles in hypercholesterolemic patients.

Analysis of Variance↗
PubMed1994

Long-term treatment of hypercholesterolemia with fluvastatin: a 52-week multicenter safety and efficacy study. French-Dutch Fluvastatin Study Group.

In this long-term (52-week) open-label extension to an earlier randomized, multicenter, double-blind, placebo-controlled, dose-finding trial, 381 patients with primary hypercholesterolemia received fluvastatin at increasing doses of 10 to 40 mg/day to achieve plasma low-density lipoprotein (LDL) cholesterol normalization, according to the European Atherosclerosis Society guidelines. The aim of the extension study was to assess the long-term efficacy, safety, and tolerability of fluvastatin. After 52 weeks of therapy, 75% of patients were receiving fluvastatin at 40 mg/day (mean dose: 36 +/- 8 mg/day). The mean percent change in LDL-cholesterol levels from baseline was -24.8% (p < 0.001), and 82.6% of patients achieved an LDL-cholesterol reduction of > or = 15%. In patients in the lowest baseline quintile, high-density lipoprotein-cholesterol levels were significantly (p < 0.001) increased by 8.8% whereas, in the highest baseline quintile, triglycerides were significantly (p < 0.001) reduced by 15.3%. Plasma lipoparticle (a) [Lp(a)]:B levels were also significantly reduced (-38.6%; p < 0.001). Fluvastatin was considered to be well tolerated by the majority of patients by both patients and investigators. The most frequently reported adverse event was abdominal pain. Notable biochemical abnormalities were rare. In conclusion, the results of this extension study indicate that fluvastatin at dosages of 20-40 mg/day is effective and well tolerated in patients with primary hypercholesterolemia and is accompanied by no particular problems of safety.

Adult↗
PubMed1994

Efficacy of a low dose-range of fluvastatin (XU 62-320) in the treatment of primary hypercholesterolaemia. A dose-response study in 431 patients. The French-Dutch Fluvastatin Study Group.

1. In this randomised, double-blind, placebo-controlled study, the efficacy of four dosages of fluvastatin (2.5, 5, 10 and 20 mg day-1) were assessed in 431 patients with primary hypercholesterolaemia recruited in 17 centres. 2. Following an 8-week dietary stabilisation phase and a 6-week placebo phase, the patients were randomised to receive placebo or fluvastatin 2.5, 5, 10 or 20 mg once daily at night for a period of 6 weeks. 3. Total cholesterol, beta-quant LDL-C, and the beta-quant LDL-C/HDL-C ratio were significantly reduced by all doses of fluvastatin, and HDL-C was significantly increased by the 10 mg and 20 mg doses. Fluvastatin 20 mg day-1 also significantly decreased TG and Lp(a):B levels. 4. Fluvastatin was well tolerated during the study, and relatively few biochemical or haematological abnormalities occurred. 5. Of the dosages tested, 20 mg fluvastatin day-1 is the optimal hypolipidaemic dose.

Adult↗
PubMed1994

Effect of fluvastatin on plasma apolipoprotein-B-containing particles, including lipoprotein(a). European Fluvastatin Study Group.

Epidemiological studies have demonstrated an association between apolipoprotein-(apo)-B containing particles [lipoprotein (Lp) (a), LpE:B; LpC-III:B] and coronary heart disease (CHD). The effect of fluvastatin, a novel competitive inhibitor of HMG-CoA reductase, on these plasma lipoprotein levels was studied in patients with hypercholesterolaemia after 14 weeks of standard dietary therapy. The results of a placebo-controlled, dose-response study and of the combined data of the European double-blind, controlled studies on the effect of fluvastatin are presented. The patients were selected according to the following criteria of inclusion: plasma low-density-lipoprotein (LDL) cholesterol levels > 160 mg dL-1 and premature CHD and/or two associated risk factors, or LDL cholesterol > 190 mg dL-1 and no CHD, plus triglycerides < 300 mg dL-1. All measurements were performed at the Pasteur Institute Central Laboratory. Lp(a), LpE:B and LpC-III:B particles were measured by double-site ELISA. In the placebo-controlled, dose-response study, 429 subjects were randomly assigned to one of the following treatment groups: placebo, fluvastatin 2.5 mg q.p.m., 5 mg q.p.m., 10 mg q.p.m. and 20 mg q.p.m. Treatment with fluvastatin for 6 weeks was associated with a dose-dependent reduction of LDL cholesterol, apoB, LpE:B and LpCIII:B levels. In addition, treatment with fluvastatin 5 mg and 20 mg q.p.m. was associated with a significant reduction in median Lp(a) concentrations (3.2%, P < 0.05 and 6.4%, P < 0.05 respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Age-dependence and free fatty acid modulation of binding kinetics at the benzodiazepine binding site of serum albumin in neonates and adults determined using fast reaction methods.

Binding kinetics at the benzodiazepine binding site of albumin have been determined as a function of age and fatty acid concentration in serum from 32 neonates (umbilical cord blood), 28 adults aged 23-65 years and 24 adults aged 66-101 years using fluorescence-time curves obtained in a Durrum-Gibson stopped-flow apparatus and the specific marker ligand dansylsarcosine. The binding reaction can be described by a 2-step mechanism characterised by four constants: the association rate constant k2 and dissociation rate constant k-2 for the rate limiting step-2; the affinity constant KA' for the formation of an unstable intermediate complex in step-1; the affinity constant KA for the overall reaction. There were marked differences in k2 between the three groups of subjects with highest values occurring in neonates (mean: 296 s-1), intermediate values in adults aged 23-65 years (mean: 200 s-1, P less than 0.001) and lowest values in adults aged 66-101 years (mean: 144 s-1, P less than 0.001). The dissociation rate constants (k-2) averaged 18.5 s-1 overall, showed only minor changes with increasing age and corresponded to dissociation half-lives of 42 ms, 38 ms and 33 ms for neonates, adults 23-65 years and adults 66-101 years respectively. KA' in neonates and in the group of elderly subjects were lower than in adults aged 23-65 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗