Drugs Effect on Platelet Survival Time: Comparison of Two Pyrimido-Pyrimidine Derivatives in Patients with Aortic or Mitral Replacement

A prospective randomized trial of the effects of 2 antiplatelet aggregating drugs, dipyridamole (375 mg/d), a related substance RA 233 (1500 mg/d) and placebo, concomitantly with oral anticoagulants, was carried out in patients with prior valvular replacement. The study was aimed to determine effect on platelet survival time (PST) of these 2 agents. The trial sample consisted of 40 males and 15 females aged 40–70 years (average 53 years). 32 received Björk-Shiley valve in aortic position; 23 underwent mitral valve replacement: 3 with Cooley-Cutter, 11 with Lillehei- Kaster 500 and 9 with Starr-Edwards 6120 prostheses; 28 patients had aortic stenosis, 21 aortic insufficiency. All the PST measured after 3 months of treatment were within normal ranges and not different between placebo, dipyridamole or RA 233 treated subjects: averages in days were, respectively, 7.49, 7.11 and 6.88. The present study did not support the claim that modem valve prosthesis could lead to a shortened PST.

Is It Possible to Reduce the Risk of Cardiovascular Events in Subjects Suffering from Intermittent Claudication of the Lower Limbs?

This study meta-analysed randomized, double-blind, placebo controlled trials in patients with intermittent claudication of the lower limbs comparing ticlopidine to placebo in order to test the hypothesis that the drug, a pure antiplatelet agent, is able to reduce the incidence of thrombotic cardio-vascular events on atherosclerotic arteries in these patients. A highly significant reduction, from 9% to 3% (p ranging from 0.006 to 0.002), was observed for fatal or non-fatal cardio-vascular events in a total of 611 patients (301 with ticlopidine, 310 with placebo). The duration of follow-up ranged from 6 to 12 months. Side-effects, defined as withdrawal from study medication for any reason but death, cardio-vascular events or cancer, were 2.4 times more frequent in the ticlopidine treated patients as compared to placebo. We concluded that in this high risk population, prevention of cardio-vascular events is likely to be effective.

Level of Evidence as a Future Gold Standard for the Content Quality of Health Resources on the Internet

Objective: An assessment of the quality of health information on the Internet is an absolute necessity. In this study ‘sensitive’ information was defined as information found in documents published on the Internet, which could be used in a medical decision. For sensitive information, the main criterion chosen for the quality of the information was an indication of the level of evidence. A survey was conducted using the CISMeF health catalogue to assess how often a score of the level of evidence is mentioned in the information accessible on the Internet in French-language health resources.

Methods: Since 1999, members of the CISMeF team have systematically been searching for all documents containing ‘sensitive’ information and verifying whether the level of evidence was explicitly indicated as a score at least once in the document.

Results: As of June 2001, 10,190 resources were included in CISMeF; including 2964 textual ‘sensitive’ resources (29.1%). Out of all these resources, only 4.7% (95% confidence interval: 4.0 - 5.5%) indicated the level of evidence. A statistically significant difference in the prevalence of indicating the level of evidence according to resource types (e.g., 18.1% for guidelines compared to 0.0% for teaching material), year of publication (almost three times greater in 1997-2001 compared with 1990-1996) and publishers was observed.

Conclusion: As the number of people accessing the growing amount of information on the Internet is increasing daily, publishers have an ethical obligation to inform their readers about the validity of ‘sensitive’ information their sites contain. However, the vast majority of the French language Internet resources that were surveyed do not mention a score of the level of evidence for their sensitive information.

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 multiscale mathematical model of avascular tumor growth to investigate the therapeutic benefit of anti-invasive agents

With the aim of inhibiting cancer growth and reducing the risk of metastasis, pharmaceutical companies in the early 1990s developed anti-metastatic agents called inhibitors of metalloproteinases (MMPi). Despite the promising results obtained in pre-clinical studies, results of Phase III trials have been somewhat disappointing for late stage cancer patients. With the aim of mathematically investigating this therapeutic failure, we developed a mechanistically based model which integrates cell cycle regulation and macroscopic tumor dynamics. By simulating the model, we evaluated the efficacy of MMPi therapy. Simulation results predict the lack of efficacy of MMPi in advanced cancer patients. The theoretical model may aid in evaluating the efficacy of anti-metastatic therapies, thus benefiting the design of prospective clinical trials.

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.

Level of evidence as a future gold standard for the content quality of health resources on the internet

OBJECTIVE

An assessment of the quality of health information on the Internet is an absolute necessity. In this study 'sensitive' information was defined as information found in documents published on the Internet, which could be used in a medical decision. For sensitive information, the main criterion chosen for the quality of the information was an indication of the level of evidence. A survey was conducted using the CISMeF health catalogue to assess how often a score of the level of evidence is mentioned in the information accessible on the Internet in French-language health resources.

METHODS

Since 1999, members of the CISMeF team have systematically been searching for all documents containing 'sensitive' information and verifying whether the level of evidence was explicitly indicated as a score at least once in the document.

RESULTS

As of June 2001, 10,190 resources were included in CISMeF; including 2964 textual 'sensitive' resources (29.1%). Out of all these resources, only 4.7% (95% confidence interval: 4.0 - 5.5%) indicated the level of evidence. A statistically significant difference in the prevalence of indicating the level of evidence according to resource types (e.g., 18.1% for guidelines compared to 0.0% for teaching material), year of publication (almost three times greater in 1997-2001 compared with 1990-1996) and publishers was observed.

CONCLUSION

As the number of people accessing the growing amount of information on the Internet is increasing daily, publishers have an ethical obligation to inform their readers about the validity of 'sensitive' information their sites contain. However, the vast majority of the French language Internet resources that were surveyed do not mention a score of the level of evidence for their sensitive information.

Persistent asthma: disease control, resource utilisation and direct costs

Despite evidence that adverse outcomes are less frequent when asthma management is optimised, the link between the level of control, disease severity and medical resource utilisation (MRU) is poorly documented. This relationship was investigated in a group of patients suffering from persistent asthma (Global Initiative for Asthma (GINA) > or = 2) in France. In 1998 a computerised family practice database was used to identify asthma patients aged 17-50 yrs. Information from the database was complemented by a patient survey to retrospectively assess the level of asthma control and hospital contacts. Costs of MRU over a 12-month study period were related to demographics, medical history, asthma control, and doses of inhaled corticosteroids prescribed during the prestudy period. A review of the computerised medical database identified 1,038 adult patients with persistent asthma, who completed the survey questionnaire. Over a 12-month period, the mean cost of MRU was 549.8 euros for well-controlled patients, 746.3 euros per patient with moderate control, and 1,451.3 euros per patient with poor control. Costs also increased significantly with age, access to free asthma care, comorbid conditions, asthma symptoms in the past year and whether inhaled corticosteroids had been prescribed before the study period. In patients with persistent asthma, large differences were observed in the use of medical resources according to control and severity. Therefore, if patients appropriately use prescribed control therapy, their use of medical resources may be reduced.

Terbinafine in fungal infections of the nails: a meta-analysis of randomized clinical trials

BACKGROUND

Historically, there has been a general resistance to treating onychomycosis on the basis that such treatments were protracted and of uncertain outcome. However, modern treatments act more promptly and reliably.

OBJECTIVES

To carry out a meta-analysis to evaluate the efficacy and safety of terbinafine in comparison with placebo, itraconazole and griseofulvin.

METHODS

The analysis used data from published trials, supplemented where necessary by reference to the original trial reports.

RESULTS

Three trials were included in which terbinafine was compared with placebo. From four trials comparing terbinafine with itraconazole, a statistically significant advantage in favour of terbinafine was observed for negative culture and microscopy at the end of the trials. Furthermore, both patients and physicians reported terbinafine to be better tolerated than itraconazole. From two trials comparing terbinafine with griseofulvin, a significantly higher rate of negative microscopy and culture was observed with terbinafine.

CONCLUSIONS

A significant advantage in favour of treatment with terbinafine was observed.

[Identification, during development, of a methodology targeted at determining the positioning of new drugs for therapeutic strategies: examples of rheumatoid arthritis and cardiac insufficiency]

The Marketing Authorization (MA) granted to a new molecular entity does not allow for proper anticipation of its future positioning within the therapeutic strategy. A specific methodology should be devised as early as during the pre-MA development phase that could result in an initial positioning that should be subjected to further reappraisal with regard to scientific advances, the arrival of new treatments and further developments with this molecule. A methodology is thus proposed, based on early optimisation of the development plan, the granting of subsequent MAs, and reappraisal of the positioning within the strategy, based on analysis of all available data. It should be possible to take into account the economic context, within an agreed system with pre-defined medico-economic criteria. This may in turn raise the issue of the role of the various parties involved in this assessment, as well as how to understand the respective opinions of stakeholders: authorities, sponsors, prescribers and patients, each of whom has a specific view of the definition of the strategic objective that should apply to the disease concerned.

Involvement of PKC and NF-kappaB in nitric oxide induced apoptosis in human coronary artery smooth muscle cells

Apoptosis of vascular smooth muscle cells is critically involved in progression of atherosclerosis and may prevent intimal hyperplasia in restenosis and vascular remodeling. Nitric oxide (NO) is known to induce apoptosis, but the signaling pathways still remain unclear. We investigated p53 accumulation, protein kinase C (PKC) activation and nuclear transcription factor (NF-kappaB) binding activity as possible signaling mechanisms of NO-induced apoptosis. Apoptosis was induced dose-dependently with the NO-donors sodiumnitroprusside (SNP: 232+/-48%) and SIN-1 (241+/-90% of actinomycin D induced apoptosis; means +/- SEM, *p< or =0.05 vs. control) in HSMC. Inhibition of PKC significantly attenuated NO-induced apoptosis. Staurosporine reduced SIN-1/SNP-mediated DNA fragmentation by 55.3+/-13.8% and 38.3+/-13.9% respectively. Comparable results were obtained for calphostin C. However, NO-mediated induction of apoptosis was not preceded by p53 accumulation. SNP decreased NF-kappaB binding activity in HSMC. These results suggest that induction of apoptosis by exogenous NO in HSMC is not dependent on p53 accumulation but involves protein kinase C signaling and regulation of NF-kappaB binding activity. This opens a new therapeutical approach in preventing restenosis after angioplasty.

Level of control and hospital contacts in persistent asthma

The purpose of this study was to estimate relationships between asthma control and hospital contacts (visits to emergency rooms and hospitalizations) in a group of patients suffering from persistent asthma, after adjustment for prior use of inhaled corticosteroids. A computerized family practice database was used to identify patients (aged 6-50 years) with persistent asthma who received asthma therapy from January 1995. The database provided information on patient demographics and drug therapy. Asthma control was estimated by a survey of patients at the end of a 12-month study period. Frequency of hospital contacts during the study period was related to demographics, asthma control, and prescribed doses of inhaled corticosteroids during a prestudy period. Review of computerized medical files of 497 family practice physicians identified 1,966 patients with persistent asthma who met the study criteria. Of these patients, 1,251 completed the survey (63.6%). Asthma control was assessed in 1,130 patients; it was moderate or poor in 42% of the cases. During the 12-month study period, 14.8% of patients reported at least one hospital contact. The level of asthma control was significantly (p < 0.001) associated with hospital contacts. The odds ratio (OR) for hospital contact for good and poor asthma control was 0.5 (95% confidence interval [CI] 0.2-0.7) and 2.2 (95% CI 1.2-4.4), respectively. Asthma control was related to hospital contacts independently of use of inhaled corticosteroids before the study period. Overall, control of asthma was not optimal in this population. The occurrence of hospital contacts was closely related with the level of control. This association was independent of the dose of inhaled corticosteroids prescribed before the study, suggesting that in asthma, hospital contacts are primarily related to the level of control experienced by the patients.

Human cationic amino acid transporter hCAT-3 is preferentially expressed in peripheral tissues

At least five distinct carrier proteins form the family of mammalian cationic amino acid transporters (CATs). We have cloned a cDNA containing the complete coding region of human CAT-3. hCAT-3 is glycosylated and localized to the plasma membrane. Transport studies in Xenopus laevis oocytes revealed that hCAT-3 is selective for cationic L-amino acids and exhibits a maximal transport activity similar to other CAT proteins. The apparent substrate affinity and sensitivity to trans-stimulation of hCAT-3 resembles most closely hCAT-2B. This is in contrast to rat and murine CAT-3 proteins that have been reported to display a very low activity and to be inhibited by neutral and anionic L-amino acids as well as D-arginine (Hosokawa, H., et al. (1997) J. Biol. Chem. 272, 8717-8722; Ito, K., and Groudine, M. (1997) J. Biol. Chem. 272, 26780-26786). Also, in adult rat and mouse, CAT-3 has been found exclusively in central neurons. Human CAT-3 expression is not restricted to the brain, in fact, by far the highest expression was found in thymus. Also in other peripheral tissues, hCAT-3 expression was equal to or higher than in most brain regions, suggesting that hCAT-3 is not a neuron-specific transporter.

Efficacy of pneumococcal polysaccharide vaccine in immunocompetent adults: a meta-analysis of randomized trials

The use of pneumococcal polysaccharide vaccine (PPV) is low in some countries, maybe because of doubts regarding its efficacy. This meta-analysis aims at combining evidence from randomized trials of PPV assessing its efficacy in preventing Streptococcus pneumoniae related diseases in immunocompetent adults. In the fourteen trials totalling 48,837 patients retrieved, PPV prevents definite pneumococcal pneumonia by 71%, presumptive pneumococcal pneumonia by 40%, and mortality due to pneumonia by 32%, but not all-cause pneumonia or death. No preventive effect was seen in the subgroup of patients aged 55 years or more, possibly due to a lack of statistical power.

A score for predicting risk of death from cardiovascular disease in adults with raised blood pressure, based on individual patient data from randomised controlled trials

OBJECTIVE

To create a risk score for death from cardiovascular disease that can be easily used.

DESIGN

Data from eight randomised controlled trials of antihypertensive treatment.

SETTING

Europe and North America.

PARTICIPANTS

47 088 men and women from trials that had differing age ranges and differing eligibility criteria for blood pressure. MAIN OTUCOME MEASURE: 1639 deaths from cardiovascular causes during a mean 5.2 years of follow up.

RESULTS

Baseline factors were related to risk of death from cardiovascular disease using a multivariate Cox model, adjusting for trial and treatment group (active versus control). A risk score was developed from 11 factors: age, sex, systolic blood pressure, serum total cholesterol concentration, height, serum creatinine concentration, cigarette smoking, diabetes, left ventricular hypertrophy, history of stroke, and history of myocardial infarction. The risk score is an integer, with points added for each factor according to its association with risk. Smoking contributed more in women and in younger age groups. In women total cholesterol concentration mattered less than in men, whereas diabetes had more of an effect. Antihypertensive treatment reduced the score. The five year risk of death from cardiovascular disease for scores of 10, 20, 30, 40, 50, and 60 was 0.1%, 0.3%, 0.8%, 2.3%, 6.1%, and 15.6%, respectively. Age and sex distributions of the score from the two UK trials enabled individual risk assessment to be age and sex specific. Risk prediction models are also presented for fatal coronary heart disease, fatal stroke, and all cause mortality.

CONCLUSION

The risk score is an objective aid to assessing an individual's risk of cardiovascular disease, including stroke and coronary heart disease. It is useful for physicians when determining an individual's need for antihypertensive treatment and other management strategies for cardiovascular risk.

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.

[Biological markers: utilization in drug development and approval]

The objectives of the reflection on biomarkers are far ahead of the issues of surrogacy, and constitute a major stake for pharmacology: enhancement of the liability of positive or negative screening for candidate drugs, speed-up of development processing, accurate identification of responders to a specific drug, and optimization of drug monitoring. Examples illustrate the situations where biomarkers are useful: diagnosis, prognosis, prediction of therapeutic response, either favourable or unwanted. The advance of pharmacogenetics leaves hope for optimization of drug use through the adaptation of drug choice to an individual profile. Some deficiencies have been identified concerning policies of transfer, evaluation or interdisciplinary validation. The optimization of the use of highest level evidence data, which is possible when appropriate biomarkers and clinical data are systematically collected during all the steps in drug development, the formal modelling of physiological, pathological and pharmacological processes and their assessment through computer simulation, and the simultaneous conduct of pragmatic and cognitive approaches, appear to be the necessary conditions for fulfillment of the objectives defined above.

[Homeopathic specialties as substitutes for benzodiazepines: double-blind vs. placebo study]

The objective of this study was to compare the efficacy of homeopathic drugs Homéogène 46 and Sédatif PC with a placebo as substitute for benzodiazepines in patients treated for at least 3 months with low doses (less than 10 mg/d of diazepam equivalents). A double-blind randomized trial was carried out in general practice. The treatment lasted one month. Several rating scales were used. The main outcome was success/failure defined according to the doctor's clinical judgement and interruption of treatment. A total of 61 patients were randomized, and 19 interrupted their treatment. Comparability between the groups was good. No statistically significant difference between homeopathic drugs and placebo was observed for the main outcome or for the secondary outcomes. The lack of statistical power due to accrual difficulties limits the conclusions of this trial which did not confirm the efficacy of homeopathic drugs in this indication.