System L amino acid transporter LAT1 accumulates O-(2-fluoroethyl)-L-tyrosine (FET).

O-(2-fluoroethyl)-L-tyrosine (FET) labeled with fluorine-18 is an important and specific tracer for diagnostics of glioblastoma via positron emission tomography (PET). However, the mechanism of its quite specific accumulation in tumor tissue has not been understood so far. In this work we demonstrate that [(3)H]L-tyrosine is primarily transported by the system L transporter LAT1 in human LN229 glioblastoma cells. FET reduced tyrosine transport, suggesting that it shares the same uptake pathway. More importantly, accumulation of FET was significantly reduced after siRNA-mediated downregulation of LAT1. Xenopus laevis oocytes expressing human LAT1 together with the glycoprotein 4F2hc (necessary to pull LAT-1 to the plasma membrane) exhibited a similar accumulation of FET as observed in glioblastoma cells. In contrast, no accumulation was observed in control oocytes, not overexpressing an exogenous transporter. Because LAT1 works exclusively as an exchanger of amino acids, substrates at one side of the membrane stimulate exchange against substrates at the other side. Extracellular FET stimulated the efflux of intracellular [(3)H]L-leucine, demonstrating that FET is indeed an influx substrate for LAT1. However, FET injected into oocytes was not able to stimulate uptake of extracellular [(3)H]L-leucine, indicating that FET is not a good efflux substrate. Our data, therefore, suggest that FET is trapped within cells due to the asymmetry of its intra- and extracellular recognition by LAT1. If also found for other transporters in tumor cells, asymmetric substrate recognition may be further exploited for tumor-specific accumulation of PET-tracers and/or other tumor-related drugs.

A global phenomenological model of ischemic stroke with stress on spreading depressions.

In this paper, we establish a new global phenomenological model of ischemic stroke. It takes into account local ischemia, energy reduction, propagation of spreading depressions (SD), damages to the cells and cellular death by apoptosis or necrosis. The spatial diffusion of the ions in the extracellular space which triggers the propagation of SD is a central point here. First we expose the various biological hypotheses that we have made in this model, and then we explain how to determine the parameters and solve the system of equations that we obtain. Next we present some results of this model: we simulate a KCl injection and then a local ischemia. Finally we discuss results and propose some improvements for this model.

A numerical study of the blocking of migraine by Rolando sulcus.

Migraine with aura is a complex phenomena, which remains still not completely understood. A striking fact is that its clinical manifestations may change from one patient to another. Migraine with aura may only consist in visual hallucinations, but may as well go on to temporary aphasy. However, for all the patients it always stops before it goes from area 3 to area 4, thus just before crossing Rolando sulcus. In this paper, we give arguments showing that the detailed geometry of Rolando sulcus in human cortex may by itself explain that migraine attack never crosses Rolando sulcus.

[Non-inferiority trial used in venous thromboembolic disease. A warily interpretation is necessary!]. / Essais de non-infériorité dans la maladie thromboembolique veineuse. Une lecture critique est nécessaire!

INTRODUCTION: Equivalence trials are actually frequently used to prove non-inferiority in anticoagulant therapy. Equivalence trials consist to demonstrate that two treatments are not too much different. This difference has to be under a margin previously determined. The margin corresponds to an efficacy loss that is defined to be acceptable, in accordance to the advantages due to the new treatment. The aim of this work is to explore the equivalence trial published in the thromboembolic disease by focus on the non-inferiority margin used. METHODS: We identified published equivalence trials in the venous thromboembolic disease, by a systematic search in Medline. We calculated the efficacy loss by reference with the value of the smallest effect size of the standard treatment compared to placebo. RESULTS: We found 9 equivalence trials used in venous thromboembolic disease. The mean value of the efficacy loss was 434%, and the median value was 357%. Eighty-five percent of the values of the efficacy loss were above 100%. DISCUSSION: Eighty-five percent of the equivalence trials conclude to equivalence despite a complete efficacy loss of the effect of the standard treatment compared to placebo. The results of equivalence trials should be interpreted warily. The corresponding non-inferiority margin should be chosen more rigorously and by reference with the value of the smallest effect size of the standard treatment compared to placebo.

Low protein diets for chronic kidney disease in non diabetic adults.

BACKGROUND: For more than fifty years, low protein diets have been proposed to patients with kidney failure. However, the effects of these diets in preventing severe renal failure and the need for maintenance dialysis have not been resolved. OBJECTIVES: To determine the efficacy of low protein diets in delaying the need to start maintenance dialysis. SEARCH STRATEGY: Cochrane Renal Group trials register, the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE. Congress abstracts (American Society of Nephrology since 1990, European Dialysis Transplant Association since 1985, International Society of Nephrology since 1987). Direct contacts with investigators. Date of most recent search: December 2004. SELECTION CRITERIA: Randomised trials comparing two different levels of protein intake in adult patients suffering from moderate to severe renal failure, followed for at least one year. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected studies and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI). Collection of the number of "renal deaths" defined as the need for starting dialysis, the death of a patient or a kidney transplant during the trial. MAIN RESULTS: Eight trials were identified from over 40 studies. A total of 1524 patients were analysed, 763 had received reduced protein intake and 761 a higher protein intake. Two hundred and fifty one renal deaths were recorded, 103 in the low protein diet and 148 in the higher protein diet group (RR 0.69, 95% CI 0.56 to 0.86, P = 0.0007). To avoid one renal death, 2 to 56 patients need to be treated with a low protein diet during one year. AUTHORS' CONCLUSIONS: Reducing protein intake in patients with chronic kidney disease reduces the occurrence of renal death by 31% as compared with higher or unrestricted protein intake. The optimal level of protein intake cannot be confirmed from these studies.

Non-enzymatic glycation of antithrombin III in vitro.

Non-enzymatic glycation of antithrombin III (AT-III) has been proposed as a significant contributor to the increased incidence of thrombo-occlusive events in diabetics. AT-III, isolated from normal human plasma by means of heparin affinity and ion-exchange chromatography, was incubated with 0-0.5 M glucose in neutral phosphate buffer at 37 degrees C. The extent of non-enzymatic glycation could be monitored by uptake of radioactivity as well as by binding to a phenylboronate affinity resin, which effectively retards AT-III containing ketoamine-linked glucose. Non-enzymatically glycated AT-III (approx. 1 mol glucose/mol protein) bound heparin nearly as efficiently as non-glycated AT-III. The two AT-III preparations were equally active in inhibiting thrombin cleavage of chromogenic substrate. Following incubation with [14C]glucose, structural analyses of cyanogen-bromide-cleaved peptides of enzymatically glycated AT-III showed that the [14C]glucose adducts were distributed over many sites on the molecule. This lack of specificity contrasts with the restricted sites of modification on hemoglobin, albumin and ribonuclease A, and explains why non-enzymatic glycation of AT-III has little if any effect on its function.

Structure and function of Hb Saint-Jacques (alpha 2 beta 2 140 (H18) Ala----Thr): a new high-oxygen-affinity variant with altered bisphosphoglycerate binding.

A low P50 value in a fresh red blood cell suspension was discovered in a polycythemic patient (Hb 19 g X dl-1). Routine acid and alkaline electrophoreses of the hemolysate were identical to normal hemolysate. Isoelectrofocusing (pH gradient 6-8) did not reveal any abnormal band whether performed with the fully liganded or deoxygenated samples. Precise analyses of the oxygen dissociation curves of the propositus' red cells demonstrated a biphasic Hill plot, a normal Bohr effect and low interaction with 2,3-bisphosphoglycerate (2,3-DPG). Studies on the unfractionated hemolysate confirmed these observations and the inhibition of the effect of organic phosphates. Structural studies were carried out on the mixture of beta A + beta X chains and revealed the presence of two beta Tp14 peptides. Sequencing the abnormal beta Tp14 peptide showed the substitution Ala----Thr of the beta 140 (H18) residue. This new variant was named Hb Saint-Jacques. Examination of the three dimensional model of HbAo indicates that the substitution beta 140 (H18) Ala----Thr induces van der Waals interactions with the nearby lysine-82 (EF6) and leucine-81 (EF5) and a displacement of the EF corner of the beta chains. This is likely to change the normal position of the lysine-82 (EF6), a major anionic binding site in the central cavity between the two beta chains. Functional studies confirm the interpretation of a steric hindrance inhibiting the binding of large organic phosphates to Hb Saint-Jacques.

Oral Beraprost sodium, a prostaglandin I(2) analogue, for intermittent claudication: a double-blind, randomized, multicenter controlled trial. Beraprost et Claudication Intermittente (BERCI) Research Group.

BACKGROUND: Beraprost sodium (BPS) is a new stable, orally active prostaglandin I(2) analogue with antiplatelet and vasodilating properties. We report the results of a phase III clinical trial of BPS in patients with intermittent claudication. METHODS AND RESULTS: Patients (n=549) with a pain-free walking distance of between 50 and 300 m were entered into a 4-week single-blind placebo run-in phase. Patients whose pain-free walking distance had changed by <25% were then randomized to receive either BPS (40 microg TID, n=209) or placebo (n=213) in a double-blind manner for 6 months. Pain-free and maximum walking distances were measured on the occasion of treadmill exercise tests performed at baseline and 1.5, 3, 4.5, and 6 months after randomization. Success was defined as an improvement of >50% in pain-free walking distance at month 6 and in > or =1 earlier treadmill exercise test in the absence of critical cardiovascular events. Success was observed more frequently in the BPS group (43.5%) than in the placebo group (33.3%, P=0.036). Pain-free walking distances increased by 81.5% and 52.5%, respectively, in the BPS and placebo groups (P=0.001) and maximum walking distances by 60.1% and 35.0%, respectively (P=0.004). The incidence of critical cardiovascular events was 4.8% in the BPS group and 8.9% in the placebo group. CONCLUSIONS: These results show that BPS is an effective symptomatic treatment of patients with intermittent claudication. The beneficial effects of BPS on critical cardiovascular events should be confirmed in appropriate clinical trials.

Amiodarone interaction with beta-blockers: analysis of the merged EMIAT (European Myocardial Infarct Amiodarone Trial) and CAMIAT (Canadian Amiodarone Myocardial Infarction Trial) databases. The EMIAT and CAMIAT Investigators.

BACKGROUND: Investigations with in vitro and animal models suggest an interaction between amiodarone and beta-blockers. The objective of this work was to explore if an interaction with beta-blocker treatment plays a role in the decrease of cardiac arrhythmic deaths with amiodarone in patients recovered from an acute myocardial infarction. METHODS AND RESULTS: A pooled database from 2 similar randomized clinical trials, the European Amiodarone Myocardial Infarction Trial (EMIAT) and the Canadian Amiodarone Myocardial Infarction Trial (CAMIAT), was used. Four groups of post-myocardial infarction patients were defined: beta-blockers and amiodarone used, beta-blockers used alone, amiodarone used alone, and neither used. All analyses were done on an intention-to-treat basis. Unadjusted and adjusted relative risks for all-cause mortality, cardiac death, arrhythmic cardiac death, nonarrhythmic cardiac death, arrhythmic death, or resuscitated cardiac arrest were lower for patients receiving beta-blockers and amiodarone than for those without beta-blockers, with or without amiodarone. The interaction was statistically significant for cardiac death and arrhythmic death or resuscitated cardiac arrest (P=0.05 and 0.03, respectively). Findings were consistent across subgroups. CONCLUSIONS: These findings are based on a post hoc analysis. However, they confirm prior results from in vitro and animal experiments suggesting an interaction between beta-blockers and amiodarone. In practice, not only is the adjunct of amiodarone to beta-blockers not hazardous, but beta-blocker therapy should be continued if possible in patients in whom amiodarone is indicated.

Identification of risk factors in hypertensive patients: contribution of randomized controlled trials through an individual patient database.

BACKGROUND: Predicting individual risk is needed to target preventive interventions toward people with the highest probability of benefit over a given time period. We assessed which prognostic factors should be used in predicting risk for hypertensive patients and in searching for treatment modifiers. METHODS AND RESULTS: Data from 24 390 hypertensive participants who constituted the control groups from 8 controlled trials (1726 deaths over 5 years) were analyzed in multivariate survival models. Outcomes were coronary heart disease death, stroke death, and cardiovascular death. We explored systematically the heterogeneity of results between trials. Left ventricular hypertrophy was electrocardiographically confirmed to be a powerful risk factor and should be included in risk scoring. Height, glomerular filtration rate, and serum uric acid deserve further exploration. Body mass index and heart rate were not confirmed as independent cardiovascular risk factors in this population. The association between male sex and coronary heart disease death was significantly stronger in British cohorts. The lack of prognostic value of diastolic blood pressure was explained by an interaction with age, with a positive association before 65 years and a negative association thereafter. Previous antihypertensive treatment was a significant risk factor. CONCLUSIONS: Clinical trials provide valuable information for risk prediction. Carefully exploring the heterogeneity among trials is a way to assess the generalizability of findings. This approach, if systematically performed, should increase the ability to identify risk modifiers and to predict individual therapeutic benefit.

Comparison of 3 and 6 months of oral anticoagulant therapy after a first episode of proximal deep vein thrombosis or pulmonary embolism and comparison of 6 and 12 weeks of therapy after isolated calf deep vein thrombosis.

BACKGROUND: The optimal duration of oral anticoagulant therapy after a first episode of venous thromboembolism remains controversial. METHODS AND RESULTS: We performed an open-label, randomized trial comparing a short oral anticoagulant course (3 months for proximal deep vein thrombosis [P-DVT] and/or pulmonary embolism [PE]; 6 weeks for isolated calf DVT [C-DVT]) with a long course of therapy (6 months for P-DVT/PE; 12 weeks for C-DVT). The outcome events were recurrences and major, minor, or fatal bleeding complications. A total of 736 patients were enrolled. There were 23 recurrences of venous thromboembolism in the short treatment group (6.4%) and 26 in the long treatment group (7.4%); the 2 treatment regimens had an equivalent effect. For the hemorrhage end point, the difference between the short and the long treatment groups was not significant: 15.5% versus 18.4% for all events (P=0.302), 1.7% versus 2.8% (P=0.291) for major events, and 13.9% versus 15.3% for minor bleeding. Subgroup analysis demonstrated that the rate of recurrence was lower for C-DVT than for P-DVT or PE. CONCLUSIONS: After isolated C-DVT, 6 weeks of oral anticoagulation is sufficient. For P-DVT or PE, we demonstrated an equivalence between 3 and 6 months of anticoagulant therapy. For patients with temporary risk factors who have a low risk of recurrence, 3 months of treatment seems to be sufficient. For patients with idiopathic venous thromboembolism or permanent risk factors who have a high risk of recurrence, other trials are necessary to assess prolonged therapy beyond 6 months.

Revisiting the effect compartment through timing errors in drug administration.

The variations in the pharmacological effects induced by timing errors in drug intake are compared for two drugs, one acting by way of an effect compartment and the other directly from the central compartment. A simulation was performed for two drugs having the same concentration-effect relationship at the receptor site, the same mean effect at equilibrium and identical concentrations in the central compartment. In this article. Patrice Nony, Michel Cucherat and Jean-Pierre Boissel discuss how, for the same variability of concentrations in the central compartment, the variations in mean effects are different. When there is a large variability in the interval separating two consecutive doses, the model that includes an effect compartment dampens the pharmacokinetic variability present in the central compartment. Such an approach may be useful for the prescription recommendations of drugs, especially those with narrow therapeutic indices.

Hemoglobin South Florida. New variant with normal electrophoretic pattern mistaken for glycosylated hemoglobin.

An 8.75-yr-old Caucasian boy was discovered to have a markedly elevated (14.8%) hemoglobin A1c (HbA1c) as estimated by ion-exchange chromatography (Bio Rex 70). Glycohemoglobin (GHb) measured by a colorimetric method with thiobarbituric acid (TBA) was normal (equivalent to a 6.4% HbA1c). Nondiabetic quantities of GHb were found with affinity chromatography, and the glucose tolerance test was normal. Intensive efforts to identify an abnormal variant hemoglobin by several electrophoretic methods were unsuccessful. A family survey identified a similar abnormality in 11 other individuals, revealing an autosomal-dominant pattern. None of the affected individuals had any other hematologic abnormality. Structural analysis in one family member revealed a new hemoglobin variant (approximately 45% of the total hemoglobin) with the substitution of methionine for valine at the beta-NH2-terminal. In addition, the initiator methionine residue was preserved. Approximately 20% of the variant hemoglobin was modified by acetylation of the NH2-terminal methionine. The modified variant coeluted with HbA1c. We suggest that patients who do not have an explanation for their elevated HbA1c should have GHb measured by the TBA method or affinity chromatography because hemoglobin electrophoresis does not identify this confounding artifact.

Effect of oxprenolol on ventricular arrhythmias: the European Infarction Study experience.

In 736 patients, 24 hour electrocardiographic recordings were performed 14 to 36 days after acute myocardial infarction before the start of randomized treatment with 320 mg of slow release oxprenolol (n = 358) or placebo (n = 378). Follow-up 24 hour electrocardiographic recordings were obtained 5 to 12 days (median 10) and 3, 6 and 12 months after the first administration of the study medication. Oxprenolol-treated patients had a significantly lower daytime heart rate as compared with the placebo group, whereas no difference was found at night. At baseline, 22.1% of the patients allocated to oxprenolol treatment and 29.6% of the placebo group had more than 30 ventricular extrasystoles in 1 hour at least once during 24 hour monitoring; multiform ventricular extrasystoles were present in 58.4 and 62.7%, ventricular couplets in 29.6 and 33.9% and ventricular tachycardia (3 or more consecutive ventricular extrasystoles) in 21.5 and 20.9% of the oxprenolol-treated and placebo-treated patients, respectively. During the 1 year follow-up period, the prevalence of these arrhythmias did not change significantly in either treatment group. There was a trend toward a reduction in the daytime frequency of ventricular couplets in the oxprenolol group. After 3 and 6 months, only multiform ventricular extrasystoles were significantly less frequent in the oxprenolol group than in the placebo group (47.4 and 42.7% versus 59.7 and 57.9%, respectively). Twelve months after the acute event, however, multiform ventricular extrasystole frequency was the same in both groups of patients (52.1 versus 51.0%, respectively). Thus, oxprenolol had a weak suppressant effect on ventricular tachyarrhythmias in survivors of myocardial infarction.

Phosphodiesterase III inhibitors for heart failure.

BACKGROUND: In the treatment of chronic heart failure, vasodilating agents, ACE inhibitors and beta-blockers have shown an increase of life expectancy. Another strategy is to increase the inotropic state of the myocardium : phosphodiesterase inhibitors (PDIs) act by increasing intra-cellular cyclic AMP, thereby increasing the concentration of intracellular calcium, and lead to a positive inotropic effect. OBJECTIVES: This overview on summarised data aims to review the data from all randomised controlled trials of PDIs III versus placebo in symptomatic patients with chronic heart failure. The primary endpoint is total mortality. Secondary endpoints are considered such as cause-specific mortality, worsening of heart failure (requiring intervention), myocardial infarction, arrhythmias and vertigos. We also examine whether the therapeutic effect is consistent in the subgroups based on the use of concomitant vasodilators, the severity of heart failure, and the type of PDI derivative and/or molecule. This overview updates our previous meta-analysis published in 1994. SEARCH STRATEGY: Randomised trials of PDIs versus placebo in heart failure were searched using MEDLINE (1966 to 2004 January), EMBASE (1980 to 2003 December), Cochrane CENTRAL trials (The Cochrane Library Issue 1, 2004) and McMaster CVD trials registries, and through an exhaustive handsearching of international abstracting publications (abstracts published in the last 22 years in the "European Heart Journal", the "Journal of the American College of Cardiology" and "Circulation"). SELECTION CRITERIA: All randomised controlled trials of PDIs versus placebo with a follow-up duration of more than three months. DATA COLLECTION AND ANALYSIS: 21 trials (8408 patients) were eligible for inclusion in the review. 4 specific PDI derivatives and 8 molecules of PDIs have been considered. MAIN RESULTS: As compared with placebo, treatment with PDIs was found to be associated with a significant 17% increased mortality rate (The relative risk was 1.17 (95% confidence interval 1.06 to 1.30; p<0.001). In addition, PDIs significantly increase cardiac death, sudden death, arrhythmias and vertigos. Considering mortality from all causes, the deleterious effect of PDIs appears homogeneous whatever the concomitant use (or non-use) of vasodilating agents, the severity of heart failure, the derivative or the molecule of PDI used. AUTHORS' CONCLUSIONS: Our results confirm that PDIs are responsible for an increase in mortality rate compared with placebo in patients suffering from chronic heart failure. Currently available results do not support the hypothesis that the increased mortality rate is due to additional vasodilator treatment. Consequently, the chronic use of PDIs should be avoided in heart failure patients.

Efficacy of diuretics and beta-blockers in diabetic hypertensive patients. Results from a meta-analysis. The INDANA Steering Committee.

OBJECTIVE: To review the effectiveness of diuretic or beta-blocker-based treatment of hypertension in diabetic patients. RESEARCH DESIGN AND METHODS: A meta-analysis on individual patient data was performed on four trials of the treatment of hypertension in which diabetic patients were included and treated with first-line diuretics or beta-blockers. The main outcomes were the relative risk of death, fatal or nonfatal stroke, fatal or nonfatal coronary events, and major cardiovascular events. RESULTS: There were 92 diabetic patients who received first-line beta-blockers and 1,008 who received diuretics. In the control groups, diabetic patients had nearly twice the risk of any outcome when compared with nondiabetic patients. The same blood pressure reduction was achieved under treatment in the diabetic and nondiabetic patients, except for systolic pressure, which decreased more in the nondiabetic patients at 1 year. In the 15,843 nondiabetic patients, the risk of all four outcomes was reduced significantly in the treated group. In the 2,254 diabetic patients, the risk reduction was significant only for fatal and nonfatal stroke (36%, P = 0.011) and major cardiovascular events (20%, P = 0.032), but not for death (5%, P = 0.65) and fatal or nonfatal coronary events (15%, P = 0.23). However, no heterogeneity was detected between diabetic patients and nondiabetic patients for any outcome. The numbers of outcomes avoided for 1,000 patients treated for 5 years were higher in diabetic patients (e.g., 38 major cardiovascular events) than with nondiabetic patients (e.g., 28 major cardiovascular events). CONCLUSIONS: These results show that hypertensive diabetic patients benefit from first-line treatment with diuretics. No conclusion can be drawn for beta-blockers, owing to the small sample size.

Highly efficient liposome-mediated gene transfer of inducible nitric oxide synthase in vivo and in vitro in vascular smooth muscle cells.

OBJECTIVE: The efficient introduction of regulatory genes into vascular smooth muscle cells (SMCs) is one of the most promising options for gene therapy of cardiovascular diseases. Cationic liposome-mediated gene transfer may become a favorable transfection technique with regard to patient's safety for in vivo administration. However, this method until now has its limitation in a low transfection efficiency. Therefore, the present study was designed to improve cationic liposome-mediated transfection of rabbit vascular SMCs in vitro and in vivo, in order to enhance transfection efficiency and present an optimized system which may offer a potential therapeutic benefit for in vivo application. METHODS AND RESULTS: Optimized lipofection of rabbit SMCs with the mammalian expression vector pE-N1 and the reporter gene green fluorescent protein resulted in a mean transfection efficiency of about 50%. The unique transfection of rabbit SMCs in vitro and in vivo with the inducible isoform of human nitric oxide synthase (NOSII), using the same vector, resulted in a successful transient transcription and translation of a functionally active human NOSII in rabbit SMC, persisting 5-6 days. We could further demonstrate that the transfection procedure and the transgene product did neither induce necrosis nor apoptosis under the conditions chosen and did not result in the induction of endogenous NOSII of transfected SMCs. CONCLUSION(S): These findings indicate potential therapeutic relevance for this nonviral gene transfer system for in vivo gene therapy for cardiovascular diseases.

Bridging Systems Medicine and Patient Needs.

While there is widespread consensus on the need both to change the prevailing research and development (R&D) paradigm and provide the community with an efficient way to personalize medicine, ecosystem stakeholders grapple with divergent conceptions about which quantitative approach should be preferred. The primary purpose of this position paper is to contrast these approaches. The second objective is to introduce a framework to bridge simulation outputs and patient outcomes, thus empowering the implementation of systems medicine.

Ramipril-induced regression of left ventricular hypertrophy in treated hypertensive individuals. HYCAR Study Group.

The objective of this trial was to assess the effects of 6-month daily treatment with two doses of ramipril on left ventricular mass and the dependence of this on blood pressure changes in hypertensive patients with left ventricular hypertrophy. After a selection phase of 4 to 6 weeks with patients under antihypertensive therapy with 20 mg furosemide daily, 115 patients with either controlled or uncontrolled hypertension and left ventricular hypertrophy were randomized in a double-blind manner to receive either placebo (n = 40), 1.25 mg (low dose, n = 38), or 5 mg (regular dose, n = 37) ramipril daily for 6 months. Treatment with furosemide was continued unchanged during this phase. The main outcome measured was left ventricular hypertrophy regression as assessed from central blind reading of echocardiograms recorded at randomization and after 6 months. No significant differences were observed for changes in casual or ambulatory blood pressure between the three groups. Left ventricular mass index was found to be significantly reduced in patients receiving 5 mg ramipril compared with those receiving placebo (-10.8 +/- 3.7 versus +4.1 +/- 4.0 g/m2, P = .008); in patients receiving 1.25 mg ramipril, the difference was close to borderline significance compared with placebo (-7.0 +/- 4.3 g/m2, P = .06). Similar results were observed for changes in left ventricular mass (-20.3 +/- 6.6 and -13.0 +/- 7.8 g in the 5- and 1.25-mg ramipril groups, respectively, versus +9.1 +/- 7.2 g in the placebo group; P = .004 and .04, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects on bone mass of long term treatment with thyroid hormones: a meta-analysis.

Osteoporosis is the main cause of spine and hip fractures. Morbidity, mortality, and costs arising from hip fractures have been well documented. Thyroid hormones (TH) are widely prescribed, mainly in the elderly. Some studies (but not all) found a deleterious effect of suppressive TH therapy on bone mass. These conflicting data raised a controversy as to the safety of current prescribing and follow-up habits, which, in turn, raised major health-care issues. To look for a detrimental effect on bone of TH therapy, we performed a meta-analysis (by pooling standardized differences, using a fixed effect model) of all published controlled cross-sectional studies (41, including about 1250 patients) concerning the impact of TH therapy on bone mineral density (BMD). Studies with women receiving estrogen therapy were excluded a priori, as were studies with a high percentage of patients with postoperative hypoparathyroidism, when no separate data were available. We decided to stratify the data according to anatomical site, menopausal status, and suppressive or replacement TH therapy, resulting in 25 meta-analysis on 138 homogeneous subsets of data. The main sources of heterogensity between studies that we could identify were replacement or suppressive TH therapy, menopausal status, site (lumbar spine, femoral neck, Ward's triangle, greater trochanter, midshaft and distal radius, with various percentages of cortical bone), and history of hyperthyroidism, which has recently been found to impair bone mass in a large epidemiological survey. To improve homogeneity, we excluded a posteriori 102 patients from 3 studies, who had a past history of hyperthyroidism and separate BMD data, thus allowing assessment of the TH effect in almost all 25 subset meta-analyses. However, controls were usually not matched with cases for many factors influencing bone mass, such as body weight, age at menarche and at menopause, calcium dietary intake, smoking habits, alcohol intake, exercise, etc. For lumbar spine and hip (as for all other sites), suppressive TH therapy was associated with significant bone loss in postmenopausal women (but not in premenopausal women), whereas, conversely, replacement therapy was associated with bone loss in premenopausal women (spine and hip), but not in postmenopausal women. The detrimental effect of TH appeared more marked on cortical bone than on trabecular bone. Only a large long term prospective placebo-controlled trial of TH therapy (e.g. in benign nodules) evaluating BMD (and ideally fracture rate) would provide further insight into these issues.