Validation of a scanning technique with minimal compression for measuring muscle volume with freehand 3D ultrasound

Freehand 3D ultrasound (3D-US) is a promising technique for measuring muscle volume but it requires gel pads or water tanks to limit probe compression on the skin which makes it hard to use in clinical applications. Our objectives were to measure the effect of different compressions on muscle volume in order to assess the clinical applicability of a minimal compression method for lower limb muscles. 4 muscles of the lower limb on 15 healthy volunteers were scanned with a new commercial freehand 3D-US setup accessible to clinical experimentators. Each muscle was scanned with 3 levels of compression: standard compression, minimal compression and gel pad (method validated against MRI). Volume was calculated using software segmentation tools. Acquisitions and segmentations were done by the same examiner. There was a significant impact of standard compression on volume measurements, but no difference between minimal compression and gel pad. Standard compression underestimated volume with a mean bias of 16 mL. For minimal compression, 75 % of measured differences were below the predefined clinically acceptable limits of 10 mL. Mean bias for this method was 1.1 mL. In conclusion, standard compression in freehand 3D-US induces a systematic bias in volume calculations. But, with a trained examiner and the necessary precautions to minimize compression, this bias could be abolished and become acceptable in clinical applications. When a high accuracy is required, gel pads could still be important to consider.

Mathematical model of T-cell lymphoblastic lymphoma: disease, treatment, cure or relapse of a virtual cohort of patients

T lymphoblastic lymphoma (T-LBL) is a rare type of lymphoma with a good prognosis with a remission rate of 85%. Patients can be completely cured or can relapse during or after a 2-year treatment. Relapses usually occur early after the remission of the acute phase. The median time of relapse is equal to 1 year, after the occurrence of complete remission (range 0.2-5.9 years) (Uyttebroeck et al., 2008). It can be assumed that patients may be treated longer than necessary with undue toxicity.The aim of our model was to investigate whether the duration of the maintenance therapy could be reduced without increasing the risk of relapses and to determine the minimum treatment duration that could be tested in a future clinical trial.We developed a mathematical model of virtual patients with T-LBL in order to obtain a proportion of virtual relapses close to the one observed in the real population of patients from the EuroLB database. Our simulations reproduced a 2-year follow-up required to study the onset of the disease, the treatment of the acute phase and the maintenance treatment phase.

Use of analgesics in France, following dextropropoxyphene withdrawal

Background

In 2009, the European Medicines Agency recommended withdrawal of dextropropoxyphene (DXP); in March 2011 it was withdrawn from the market in France. Up until that time the combination dextropropoxyphene-paracetamol (DXP/PC) was widely used for analgesia. At withdrawal, French regulators recommended that DXP/PC be replaced by other step 2 analgesics, i.e. tramadol, codeine, or opium-containing drugs, or by PC for a weak level of pain. To investigate prescribing behaviours after DXP/PC withdrawal, dispensations of analgesics before and after withdrawal were analysed.

Methods

Aggregated dispensation data of analgesics prescribed between January 2009 and December 2012 in the Rhône-Alpes region were obtained from the general health insurance claims data; changes in analgesic dispensation over time were analysed with the ATC/DDD methodology. Pre (Jan-June 2009) and post-withdrawal (Jan-June 2012) changes of DDDs where computed for each analgesic step.

Results

The dispensations of DXP/PC experienced a two-step decrease until 2011. Over the withdrawal period 2009-2012, there was a 14% decrease in the overall use of analgesic (from 109 to 94 DDDs), while the use of step 2 analgesics declined by 46% (− 22 DDDs, from 47 to 25 DDDs). This latter decline included a cessation of use of DXP/PC (29 DDDs in 2009) that were only in part (+ 7 DDDs, from 18 to 25 DDDs) compensated by increased use of codeine, tramadol and opium, in monotherapy or combined with PC. For step 1 analgesics, use increased with 9%, mostly PC (+ 8 DDDs, from 31 to 39 DDDs). Step 3 analgesics dispensations remained largely unchanged over this period (around 3 DDDs).

Conclusions

In the Rhône-Alpes region, DXP/PC withdrawal was accompanied in part by an increased use of same level analgesics, and in part by an increased use of PC in monotherapy. The extent of DXP/PC use before withdrawal, and the increased use of PC after DXP withdrawal, underline the complexity of pain management.

Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS

Background:

Obstetrical analgesia remains a matter of controversy because of the fear of neurotoxicity of local anesthetics on demyelinated fibers or their potential relationship with subsequent relapses.

Objective:

To assess the impact of neuraxial analgesia on the risk of relapse during the first 3 months post-partum, with a focus on women who experienced relapses during pregnancy.

Methods:

We analyzed data of women followed-up prospectively during their pregnancies and at least 3 months post-partum, collected in the Pregnancy in Multiple Sclerosis (PRIMS) and Prevention of Post-Partum Relapses with Progestin and Estradiol in Multiple Sclerosis (POPARTMUS) studies between 1992–1995 and 2005–2012, respectively. The association of neuraxial analgesia with the occurrence of a post-partum relapse was estimated by logistic regression analysis.

Results:

A total of 389 women were included, 215 from PRIMS and 174 from POPARTMUS. In total, 156 women (40%) had neuraxial analgesia. Overall, 24% experienced a relapse during pregnancy and 25% in the 3 months post-partum. Women with a pregnancy relapse were more likely to have a post-partum relapse (odds ratio (OR) = 1.83, p = 0.02), independently of the use of neuraxial analgesia. There was no association between neuraxial analgesia and post-partum relapse (OR = 1.08, p = 0.78).

Conclusion:

Neuraxial analgesia was not associated with an increased risk of post-partum relapses, whatever multiple sclerosis (MS) activity during pregnancy.

Efficacy and safety of DPP-4 inhibitors in patients with type 2 diabetes: Meta-analysis of placebo-controlled randomized clinical trials

BACKGROUND

Guidelines for type 2 diabetes (T2D) recommend reducing HbA_1c through lifestyle interventions and glucose-lowering drugs (metformin, then combination with dipeptidyl peptidase-4 inhibitors [DPP-4Is] among other glucose-lowering drugs). However, no double-blind randomized clinical trial (RCT) compared with placebo has so far demonstrated that DDP-4Is reduce micro- and macrovascular complications in T2D. Moreover, the safety of DPP-4Is (with increased heart failure and acute pancreatitis) remains controversial.

METHODS

A systematic review of the literature (PubMed, Cochrane Library Central Register of Controlled Trials [CENTRAL] and https://clinicaltrials.gov), including all RCTs vs placebo published up to May 2015 and the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), published June 2015, was performed. Primary endpoints were all-cause mortality and death from cardiovascular causes; secondary endpoints were macrovascular and microvascular events. Safety endpoints were acute pancreatitis, pancreatic cancer, serious adverse events and severe hypoglycaemia.

RESULTS

A total of 36 double-blind RCTs were included, allowing analyses of 54,664 patients. There were no significant differences in all-cause mortality (RR=1.03, 95% confidence interval [CI]=0.95-1.12), cardiovascular mortality (RR=1.02, 95% CI=0.92-1.12), myocardial infarction (RR=0.98, 95% CI=0.89-1.08), strokes (RR=1.02, 95% CI=0.88-1.17), renal failure (RR=1.06, 95% CI=0.88-1.27), severe hypoglycaemia (RR=1.14, 95% CI=0.95-1.36) and pancreatic cancer (RR=0.54, 95% CI=0.28-1.04) with the use of DPP-4Is. However, DDP-4Is were associated with an increased risk of heart failure (RR=1.13, 95% CI=1.01-1.26) and of acute pancreatitis (RR=1.57, 95% CI=1.03-2.39).

CONCLUSION

There is no significant evidence of short-term efficacy of DPP-4Is on either morbidity/mortality or macro-/microvascular complications in T2D. However, there are warning signs concerning heart failure and acute pancreatitis. This suggests a great need for additional relevant studies in future.

Factors associated with 12 week case-fatality in Staphylococcus aureus bacteraemia: a prospective cohort study

Staphylococcus aureus bacteraemia (SAB) is a frequent and deadly disease. Given the lack of a randomized trial, optimal first-line antibiotic treatment is still debated. Our aim was to identify prognostic factors in SAB patients and to analyse the impact of first-line antibiotics. The VIRSTA prospective cohort study was conducted in eight tertiary care centres in France. Consecutive incident adults in whom a blood culture drawn in participating centres grew S. aureus between April 2009 and October 2011 were prospectively followed for 12 weeks. Factors associated with 12-week case-fatality were identified by multivariate logistic regression. We enrolled 2091 patients and analysed survival in 1972 (median age 67.8 years, interquartile range 55.5-78.9; females 692/1972, 35.1%). SAB was nosocomial or healthcare-related in 1372/1972 (69.6%) of cases and the primary focus was unknown in 414/1972 (21.0%) of cases. Week 12 case-fatality rate was 671/1972 (34.0%). The main independent prognostic factors on multivariate analysis were age (adjusted OR by 10-year increment 1.56; 95% CI 1.44-1.69), septic shock (OR 5.11; 95% CI 3.84-6.80), metastatic cancer (OR 4.28; 95% CI 2.88-6.38), and unknown primary focus (OR 2.62; 95% CI 2.02-3.41). In the 1538 patients with methicillin-sensitive S. aureus (MSSA) bacteraemia, first-line empiric antistaphylococcal penicillins (OR 0.40; 95% CI 0.17-0.95) and vancomycin (OR 0.37; 95% CI 0.17-0.83), alone or combined with an aminoglycoside, were associated with better outcome compared with other antibiotics. There are few modifiable prognostic factors for SAB. Initiating empiric antibiotics with antistaphylococcal penicillins or vancomycin may be associated with better outcome in MSSA bacteraemia.

Dynamic changes of depolarizing GABA in a computational model of epileptogenic brain: Insight for Dravet syndrome

Abnormal reemergence of depolarizing GABAA current during postnatal brain maturation may play a major role in paediatric epilepsies, Dravet syndrome (DS) being among the most severe. To study the impact of depolarizing GABA onto distinct patterns of EEG activity, we extended a neural mass model as follows: one sub-population of pyramidal cells was added as well as two sub-populations of interacting interneurons, perisomatic-projecting interneurons (basket-like) with fast synaptic kinetics GABAA (fast, I1) and dendritic-projecting interneurons with slow synaptic kinetics GABAA (slow, I2). Basket-like cells were interconnected to reproduce mutual inhibition mechanisms (I1➔I1). The firing rate of interneurons was adapted to mimic the genetic alteration of voltage gated sodium channels found in DS patients, SCN1A(+/-). We implemented the "dynamic depolarizing GABAA" mediated post-synaptic potential in the model, as some studies reported that the chloride reversal potential can switch from negative to more positive value depending on interneuron activity. The "shunting inhibition" promoted by GABAA receptor activation was also implemented. We found that increasing the proportion of depolarizing GABAA mediated IPSP (I1➔I1 and I1➔P) only (i.e., other parameters left unchanged) was sufficient to sequentially switch the EEG activity from background to (1) interictal isolated polymorphic epileptic spikes, (2) fast onset activity, (3) seizure like activity and (4) seizure termination. The interictal and ictal EEG patterns observed in 4 DS patients were reproduced by the model via tuning the amount of depolarizing GABAA postsynaptic potential. Finally, we implemented the modes of action of benzodiazepines and stiripentol, two drugs recommended in DS. Both drugs blocked seizure-like activity, partially and dose-dependently when applied separately, completely and with a synergic effect when combined, as has been observed in DS patients. This computational modeling study constitutes an innovative approach to better define the role of depolarizing GABA in infantile onset epilepsy and opens the way for new therapeutic hypotheses, especially in Dravet syndrome.

Model of mucociliary clearance in cystic fibrosis lungs

Mucus clearance is a primary innate defense mechanism in the human airways. Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by dehydration of airway surface liquid and impaired mucociliary clearance. As a result, microorganisms are not efficiently removed from the airways, and patients experience chronic pulmonary infections and inflammation. We propose a new physiologically based mathematical model of muco-ciliary transport consisting of the two major components of the mucociliary clearance system: (i) periciliary liquid layer (PCL) and (ii) mucus layer. We study mucus clearance under normal conditions and in CF patients. Restoring impaired clearance of airway secretions in one of the major goals of therapy in patients with CF. We consider the action of the aerosolized and inhaled medication dornase alfa, which reduces the viscosity of cystic fibrosis mucus, by selectively cleaving the long DNA strands it contains. The results of the model simulations stress the potential relevance of the location of the drug deposition in the central or peripheral airways. Mucus clearance was increased in case the drug was primarily deposited peripherally, i.e. in the small airways.

Efficacy of a home-based intervention programme on the physical activity level and functional ability of older people using domestic services: a randomised study

OBJECTIVE

Our main objective was to assess whether a home-based program supervised by home helpers (HH) during their normal working hours can prevent excessive sedentariness (mainly maximum walking time and distance) and preserve functional status in elderly people at risk for frailty or disability and using domestic services.

DESIGN

A four-month, open label, randomised trial with two groups called "prevention" and "control".

SETTING

In the homes of study participants.

PARTICIPANTS

The participants were all over 78 years old, lived independently at home, and received the visits of HHs at least once a week.

INTERVENTION

The intervention combined a self-administered exercise program, with 10 g amino-acid supplementation under the supervision of HHs.

MEASUREMENTS

Main outcome measures included physical activity (the PASE questionnaire), functional tests, nutritional and autonomy scores, and compliance (50% or more was considered satisfactory). Non-parametric methods were used for comparisons between the two groups. A linear regression model was fitted to assess the effect of the intervention on the relative variation of outcomes, adjusted for unbalanced baseline co-variables.

RESULTS

One hundred and two persons (prevention n=53, control n=49) with a median age of 85 years were included. Their median Activities of Daily Living and Instrumental Activities of Daily Living (IADL) scores were 6 and 7 respectively. Twenty-three (44%) were good compliers for both interventions. The maximum walking time remained stable while decreasing by 25% in the control group (p=0.0015); and fewer participants had a worsened IADL score in the prevention group (p=0.05). The baseline IADL Score was significantly associated with good compliance to the prevention program (p=0.0011). In good compliers, maximum walking distance and maximum walking time increased by 29.15% (0.0 to 66.7) and 33.3% (-20.0 to 50.0) respectively.

CONCLUSION

This study confirms the feasibility of a prevention program supervised by HHs, and some benefit from the intervention and identifies predictors for better compliance. It will help in the design of prevention trials for elderly people at risk for frailty.

[Design and evaluation of the quality of information written for scanner and magnetic resonance imaging in neuropediatrics]

INTRODUCTION

We designed written information concerning two medical imaging techniques: the computed tomography scanner and the magnetic resonance imaging (MRI), and we evaluated the quality of the information in particular its readability.

METHODS

Written information concerning scanner and MRI were elaborate starting from a reference frame based on a lexicon of the good practices. The written information sheets were initially reviewed by eight doctors, 45 nurses and by 26 couples of parents of hospitalized children, and finally by the communication and juridical services of our hospital. They were asked to improve the lexico-syntactic readability in order to increase the comprehension of the written information. Seventy-two couples of parents of hospitalized children who had not taken part of the protocol before evaluated the final version of the documents. The quality of the documents was evaluated using the scores of readability of Flesch and the Flesch-Kincaid, and a questionnaire of comprehension, managed before and after the delivery of written information.

RESULTS

A total of 144 persons participated in the study. The number of right answers after reading written information increased by 38 % and by 35 % for the scanner and MRI information's respectively. Flesch and Flesch-Kincaid scores were not improved in the revised version of the written information compared to the first version.

CONCLUSION

Although readability scores for information sheets were low, our results suggest that they brought information, which contributed to a better understanding of these two medical imaging techniques by parents.

Effects of plyometric training on passive stiffness of gastrocnemii and the musculo-articular complex of the ankle joint

This study aimed to determine simultaneously the effects of plyometric training on the passive stiffness of the ankle joint musculo-articular complex, the gastrocnemii muscle-tendon complex (MTC) and the Achilles tendon in order to assess possible local adaptations of elastic properties. Seventeen subjects were divided into a trained (TG) group and a control (CG) group. They were tested before and after 8 weeks of a plyometric training period. The ankle joint range of motion (RoM), the global musculo-articular passive stiffness of the ankle joint, the maximal passive stiffness of gastrocnemii and the stiffness of the Achilles tendon during isometric plantar flexion were determined. A significant increase in the jump performances of TG relative to CG was found (squat jumps: +17.6%, P=0.008; reactive jumps: +19.8%, P=0.001). No significant effect of plyometric training was observed in the ankle joint RoM, musculo-articular passive stiffness of the ankle joint or Achilles tendon stiffness (P>0.05). In contrast, the maximal passive stiffness of gastrocnemii of TG increased after plyometric training relative to CG (+33.3%, P=0.001). Thus, a specific adaptation of the gastrocnemii MTC occurred after plyometric training, without affecting the global passive musculo-articular stiffness of the ankle joint.

Factors affecting the adherence to an antenatal screening programme: an experience with toxoplasmosis screening in France

Monthly serological testing is mandatory in France for pregnant women not immune to toxoplasmosis. We assessed for the first time the adherence to this national programme, using data from antenatal tests for Toxoplasma antibodies collected by the Union of Health Insurance Services in the French Rhone-Alpes region.

Factors affecting the adherence to an antenatal screening programme: an experience with toxoplasmosis screening in France

Monthly serological testing is mandatory in France for pregnant women not immune to toxoplasmosis. We assessed for the first time the adherence to this national programme, using data from antenatal tests for Toxoplasma antibodies collected by the Union of Health Insurance Services in the French Rhone-Alpes region. Data from 34,290 pregnancies was analysed. The first test was done late in 25% of women (8,430). Women had on average 5.7 tests during pregnancy, only 40 percent (13,774) were tested seven or more times as recommended. Young women were more likely to have a late first test, but age did not significantly influence regularity and number of tests. Free medical coverage favoured a late first test, fewer tests and longer between-test intervals. An early first test did not affect test numbers or between-test intervals. A re-useable prescription for several tests was associated with better adherence. Prescription by general practitioners was associated with an earlier first test, but fewer tests and longer between-test intervals. When prescribing physician(s) included a gynaecologist, the first test was more likely to be behind schedule, but the overall number of tests was higher and between-test intervals shorter. Because data was collected through private laboratories, our conclusions apply to the majority of French patients who need to schedule a separate visit for blood testing after prescription.

Sevoflurane preconditioning at 1 MAC only provides limited protection in patients undergoing coronary artery bypass surgery: a randomized bi-centre trial † ‡

BACKGROUND

Volatile agents can mimic ischaemic preconditioning leading to a decrease in myocardial infarct size. The present study investigated if a 15 min sevoflurane administration before cardiopulmonary bypass (CPB) has a cardioprotective effect in patients undergoing coronary surgery.

METHODS

Seventy-two patients were randomized in two centres. The intervention group (S) received 1 MAC sevoflurane administrated via the ventilator for 15 min followed by a 15 min washout before CPB, the control group did not. The primary outcome was the postoperative troponin Ic peak. A biopsy of the atrium was taken during canulation for enzyme dosages. Results are expressed as mean (SD).

RESULTS

Neither troponin Ic nor tissular enzyme measurement exhibited any difference between the groups: peak of troponin Ic was 4.4 (5.6) in S group vs 5.2 (6.6) ng ml(-1) in control group (ns). Intratissular ecto-5'-nucleotidase activity was 7.1 (4.3) vs 8.5 (11.9), protein kinase C activity was 27.1 (15.7) vs 29.2 (28.7), tyrosine kinase activity was 101 (54.1) vs 98.5 (63.3), and P38 MAPKinase activity was 131.1 (76.1) vs 127.1 (86.8) nmol mg protein(-1) min(-1) in S group and control group, respectively (ns). However there were fewer patients with low postoperative cardiac index in S group (11% in S vs 35% in control group, P < 0.05) when considering the per protocol population. In S group, 25% of patients required an inotropic support during the postoperative period, vs 36% of patients in control group (ns).

CONCLUSIONS

This study did not show a significant preconditioning signal after 15 min of sevoflurane administration. The 15 min duration might be too short or the concentration of sevoflurane too low to induce cardioprotection detected by troponin I levels.

Coactivation et inhibition musculaire : influences sur la régulation du couple de force développé et les adaptations induites par un entraînement en force

This review aims at analysing the influence of antagonist muscle coactivation and muscle inhibition on the ability of the neuromuscular system to produce an external torque and to account for changes in these two mechanisms with resistance training. Indeed, antagonist muscle coactivation and muscle inhibition occur during muscle contraction in order to preserve joint integrity. The origin of these two mechanisms would be both spinal and supraspinal and would tend to decrease with resistance training, which allows, under certain conditions, increasing the external torque developed. However, antagonist muscle coactivation and muscle inhibition depend on the characteristics of movement. Moreover, the origin and the contribution of supraspinal mechanisms to the antagonist muscle coactivation and muscle inhibition processes have to be specified.

Power Responses of a Rowing Ergometer: Mechanical Sensors vs. Concept2® Measurement System

The aim of this study was to compare the power provided by a recent ergometer with the power developed by the rower determined using mechanical sensors set on the same apparatus. Six rowers and six non-rowers performed a power graded test and an all-out start on an instrumented ergometer (Concept2 system, model D, Morrisville, VT, USA). Power values displayed by the ergometer were recorded with a specific software. A strain gauge placed near the handle and a position sensor installed on the chain allowed the calculation of the power developed by the rower. Power values provided by the ergometer were strongly correlated to those determined with a direct measurement and calculation of power. However, power values given by the Concept2 system were lower (- 17.4 to - 72.4 W) than those calculated using mechanical sensors. This difference in power measurements was lower at a steady pace and for rowers. The Concept2 system underestimates the power produced by the rower by approximately 25 W. This difference in power seems to be independent of the level of power developed but increases with variations in intensity and pace. The deletion of the first strokes following changes in power production allows to limit this phenomenon. According to the use of the power parameter in the experimental design, it could be appropriate to correct values provided by the Concept2 ergometer.

[Readability of informed consent forms for subjects participating in biomedical research: updating is required]

OBJECTIVE

We compared informed consent forms of subjects participating in biomedical research with those of references texts in order to determine the factors that influence readability.

METHODS

We assessed the readability of 73 informed consent forms of research protocols conducted in the clinical investigation centres in the Rhone-Alpes area, and then compared them with 33 reference texts corresponding to 5 French school grades (first year infant, primary school, GCS level, high school, and classics aggregation), using the Flesch test and Cordial" analyser.

RESULTS

Median Flesch scores were 66 for the first year infant level, 62 for the primary school level, 58 for the GCS level, 42 for the high school level, and 43 for the aggregation level. It was 22 for the informed consent forms. Median Cordial scores were 86 for the first year infant level, 77 for the second, 74 for the third, 49 for the fourth, 43 for the fifth. It was 1 for the informed consent forms. No methodological factor correlated with Flesch and Cordial" results.

CONCLUSION

The quantitative readability scores for informed consent forms for subjects participating in biomedical research are low, lower than those proposed to aggregation candidates, whatever the type of protocol. Some thought must be given to the impact of the reduced readability on patients' understanding, and steps should be taken to improve the readability of the forms.

Thrombolytic therapy for acute ischemic stroke

Available evidence of thrombolysis in acute ischemic stroke comes from a series of recent trials conducted in patients with acute stroke, and from a meta-analysis published in the Cochrane Library. The objective of this paper is to review the literature on tolerability and efficacy of thrombolytic therapy in patients with acute ischemic stroke, to find out what the level of evidence is for each thrombolytic drug, and what should consequently be done in the routine practice. This review is based on a bibliographic search of published meta-analyses of randomized trials, published randomized trials, and ongoing randomized trials, with the outcomes of disability, death, and symptomatic intracerebral hemorrhages (fatal or non-fatal). Our primary end-point is a combination of death and disability, in terms of "death or dependency", with dependency defined as a modified Rankin Score (mRS) of >/=3. The level of evidence for the efficacy of a thrombolytic treatment is considered sufficient if there is both a statistically significant effect in the meta-analysis of all randomized trials, without statistically significant heterogeneity, together with one adequately powered and designed conclusive trial. Streptokinase has a clearly harmful effect, without any demonstrated benefit and must not be used in patients with acute ischemic stroke. The level of evidence of an effect of intra-arterial pro-urokinase to reduce death or dependency is low, available data are sparse (only 220 patients), the estimation of its real efficacy and tolerability remains unclear, and its use in clinical practice is not presently justified. The efficacy of alteplase has been incompletely demonstrated because the results vary across trials and type of outcomes (death, death or dependency), and the cut-off of the disability scale. There is a significant heterogeneity in the effect on death or dependency. However, we can conclude that there is a beneficial effect, but its clinical application is limited because of the absence of adequate criteria to identify patients most likely to benefit from treatment. Overall the use of alteplase in patients with acute stroke was associated with some benefit, but it significantly increased total mortality in two trials. Given the observed confidence interval (CI), the results are compatible with, in the best situtation, 203 advoided death or dependency and 61 avoided death per 1000 treated patients, and at worst 77 avoided death or dependency and 38 extra deaths per 1000 treated patients. Further trials aimed at validating more discriminant selection criteria are mandatory.