A positron emission tomography (PET) study of cerebral dopamine D2 and serotonine 5-HT2A receptor occupancy in patients treated with cyamemazine (Tercian)

RATIONALE

Cyamemazine (Tercian) is an antipsychotic drug with anxiolytic properties. Recently, an in vitro study showed that cyamemazine possesses high affinity for serotonin 5-HT(2A) receptors, which was fourfold higher than its affinity for dopamine D(2) receptors (Hameg et al. 2003).

OBJECTIVES

The aim of this study is to confirm these previous data in vivo in patients treated with clinically relevant doses of Tercian.

METHODS

Eight patients received 37.5, 75, 150 or 300 mg/day of Tercian depending on their symptomatology. Dopamine D(2) and serotonin 5-HT(2A) receptor occupancies (RO) were assessed at steady-state plasma levels of cyamemazine with positron emission tomography (PET), using [(11)C]raclopride and [(11)C]N-methyl-spiperone, respectively. The effective plasma level of the drug leading to 50% of receptor occupancy was estimated by fitting RO with plasma levels of cyamemazine at the time of the PET scan.

RESULTS

Cyamemazine induced near saturation of 5-HT(2A) receptors (RO=62.1-98.2%) in the frontal cortex even at low plasma levels of the drug. On the contrary, occupancy of striatal D(2) receptors increased with plasma levels, and no saturation was obtained even at high plasma levels (RO=25.2-74.9%). The effective plasma level of cyamemazine leading to 50% of D(2) receptor occupancy was fourfold higher than that for 5-HT(2A) receptors. Accordingly, individual 5-HT(2A)/D(2) RO ratios ranged from 1.26 to 2.68. No patients presented relevant increased prolactin levels, and only mild extrapyramidal side effects were noticed on Simpson and Angus Scale.

CONCLUSION

This in vivo binding study conducted in patients confirms previous in vitro findings indicating that cyamemazine has a higher affinity for serotonin 5-HT(2A) receptors compared to dopamine D(2) receptors. In the dose range 37.5-300 mg, levels of dopamine D(2) occupancy remained below the level for motor side effects observed with typical antipsychotics and is likely to explain the low propensity of the drug to induce extrapyramidal side effects.

Molecular characterization of the idiopathic hypereosinophilic syndrome (HES) in 35 French patients with normal conventional cytogenetics

Idiopathic hypereosinophilic syndrome (HES) characterized by unexplained and persistent hypereosinophilia is heterogeneous and comprises several entities: a myeloproliferative form where myeloid lineages are involved with the interstitial chromosome 4q12 deletion leading to fusion between FIP1L1 and PDGFRA genes, the latter acquiring increased tyrosine kinase activity. And a lymphocytic variant, where hypereosinophilia is secondary to a primitive T lymphoid disorder demonstrated by the presence of a circulating T-cell clone. We performed molecular characterization of HES in 35 patients with normal karyotype by conventional cytogenetic analysis. TCRgamma gene rearrangements suggesting T clonality were seen in 11 (31%) patients, and FIP1L1-PDGFRA by RT-PCR in six (17%) of 35 patients, who showed no evidence of T-cell clonality. An elevated serum tryptase level was observed in FIP1L1-PDGFRA-positive patients responding to imatinib, whereas serum IL-5 levels were not elevated in T-cell associated hypereosinophilia. Sequencing FIP1L1-PDGFRA revealed scattered breakpoints in FIP1L1-exons (10-13), whereas breakpoints were restricted to exon 12 of PDGFRA. In the 29 patients without FIP1L1-PDGFRA, no activating mutation of PDGFRA/PDGFRB was detected; however; one patient responded to imatinib. FISH analysis of the 4q12 deletion was concordant with FIP1L1-PDGFRA RT-PCR data. Further investigation of the nature of FIP1L1-PDGFRA affected cells will improve the classification of HES.

rHuEpo before high-dose therapy allows autologous peripheral stem-cell transplantation without red blood cell transfusion: a pilot study

To decrease red blood cell (RBC) transfusion requirements during high-dose therapy (HDT) for hematological malignancies, we conducted a pilot study to assess the effect of recombinant human erythropoietin (rHuEpo) given during chemotherapy before HDT and autologous peripheral stem-cell transplantation (APSCT). The transfusion histories of 15 HDT and APSCT for hematological disease performed in 11 consecutive patients who received rHuEpo (10 000 U subcutaneously three times/week) were compared to those of 22 HDT and ASCT performed in 17 consecutive historical controls matched for hematological parameters. rHuEpo increased the hemoglobin (Hb) level from 10.3+/-2.3 g/dl at diagnosis to 12.9+/-2.2 g/dl at the time of HDT in 11 patients; no major adverse effects occurred. Compared to historical controls (95%, 21/22), RBC transfusion requirements were significantly lower for rHuEpo recipients (26%, 4/15) (P=0.00001) and rHuEpo responders (15%, 2/13) (P=0.000002). After HDT and APSCT, fewer RBC transfusions were needed: 3.3, 1.2 and 0.3 RBC units for controls, rHuEpo recipients and rHuEpo responders, respectively (P=0.006 and 0.00002). Therefore, rHuEpo should be administered before, and not after HDT and APSCT, to lower RBC transfusion requirements after HDT and APSCT.

Acute phase response in acute pancreatitis: a comparison with abdominal sepsis

BACKGROUND

Increased knowledge on the underlying pathophysiological mechanisms in acute pancreatitis (AP) and abdominal sepsis (AS) is essential, not least for the development of novel ways of treatment. The present study aims at determining dynamic changes in the systemic inflammatory response in AP and AS.

METHODS

AP was induced by the intraductal injection of sodium taurodeoxycholate in the rat, while AS was induced by caecal ligation and puncture. The animals were killed 1, 3, 6 and 9 h after challenge. Plasma exudation of radiolabelled albumin, myeloperoxidase (MPO), TNF-alpha, MCP-1, superoxide and hydrogen peroxide was measured.

RESULTS

Leakage index of human serum albumin showed a significant increase early (I h) after induction of AP and later (9h) in AS compared to controls (P < 0.05). Hydrogen peroxide generation by circulating monocytes/macrophages was high early (1 h) in AP and after 3 and 6h in AS. Superoxide generation increased by time after both challenges. MPO activity increased significantly, starting at 3 h in both AP and AS (P < 0.05). TNF-alpha increased significantly at 6 and 9 h in both models.

CONCLUSION

Our results indicate differences in the release of systemic inflammatory mediators and cellular response in AP and AS. However, potential similarities in end-effect, such as the development of remote organ injury (lungs), may exist as implied by the MPO results. Further investigations of the mechanisms are crucial.

Carotid artery stenting to prevent stroke in a patient with bilateral extracranial internal carotid dissection and vasospasm following rupture of an intracranial aneurysm

The stenting of carotid dissection has been described for the prevention of cerebral ischemia in patients who remain symptomatic despite therapeutic anticoagulation, in those who present contraindications for anticoagulation therapy, or who present a local or extensive stenosis, with an associated pseudoaneurysm. We here report a case associating a high clinical grade aneurysmal rupture with a bilateral extracranial carotid dissection. Because of the haemodynamic risk due to the acute bilateral stenosis-induced dissection and the occurrence of a vasospasm, the carotid dissections were treated with self-expendable stents.

Reduction of extracellular dopamine and metabolite concentrations in rat striatum by low doses of acute cyamemazine

The low incidence of extrapyramidal effects with atypical neuroleptics has been ascribed to their 5-HT(2A)- and 5-HT(2C)-serotonin receptor antagonistic properties. On the other hand, the acute increase in striatal dopamine release by submaximal dopamine D(2) autoreceptor blockade can be respectively reduced and increased by 5-HT(2A)- and 5-HT(2C)-antagonists. Cyamemazine is a neuroleptic D(2)- and 5-HT(2A)-receptor antagonist, with small antagonistic activity at 5-HT(2C) receptors and low incidence of extrapyramidal side effects. Therefore, submaximal cyamemazine was tested in rats for its acute action on the extracellular concentrations of dopamine and dopamine metabolites (DOPAC: 3,4,dihydroxyphenylacetic acid and HVA: 4-hydroxy-3-methoxy-phenyl-acetic acid) in the corpus striatum. The serotonin metabolite 5-HIAA (5-hydroxy-indole-acetic acid) was measured in parallel. Rats prepared for microdialysis (striatum) were intraperitoneally given cyamemazine 1 mg/kg, 5 mg/kg or vehicle ( n=4 in each group). Dopamine, DOPAC, HVA and 5-HIAA concentrations in perfusates under basal conditions and after stimulation by high K(+) were measured by HPLC coupled to electrochemical detection. Cyamemazine 1 mg/kg significantly reduced extracellular concentrations of basal dopamine (-77%), DOPAC (-54%), HVA (-54%) and 5-HIAA (-65%). No such effects were seen with the dose of cyamemazine 5 mg/kg or for K(+)-evoked dopamine release. In conclusion, submaximal cyamemazine can acutely reduce basal dopamine release and metabolism in the rat striatum. Such unusual action can be explained by the original pharmacological profile of cyamemazine (potent D(2)- and 5-HT(2A)-antagonist, with small antagonistic activity at 5-HT(2C) receptors). Further experiments are required to explain the low incidence of extrapyramidal side actions with cyamemazine.

[Folic acid and prevention of anomalies of foetal neural tube closing in women treated for epilepsy]

Anomalies of neural tube closing are serious malformations which are encountered most often in babies of epileptic women treated with anti-epileptic drugs during pregnancy. Dietary supplementation of folic acid has been suggested as a preventive measure in these cases, based on the long suspected association between folic acid deficiency and congenital malformations. Folic acid deficiency usually results from insufficient dietary intake, or increased requirements during pregnancy. Moreover, certain anti-epileptic drugs can reduce the availability of folic acid. In secondary prevention, the protective effect of folic acid has been clearly demonstrated, whilst epidemiological data suggest that such treatment is also useful in primary prevention. With respect to women with epilepsy, there is a clear consensus as to the interest of dietary supplementation with folic acid before conception and during the first three months of pregnancy (the period of organogenesis), particularly given the fact that side-effects are extremely rare. Apart from recurrence prevention, where a dose of 4mg/day is recommended, no standard dosing guidelines exist. We would suggest that this same dose be used for epileptic patients in pregnancy, particularly if they are treated with barbamazepine or valproic acid.

Endovascular treatment of ruptured intracranial aneurysms in patients aged 65 years and older: follow-up of 52 patients after 1 year

BACKGROUND AND PURPOSE

We sought to describe the clinical outcome and results obtained in the endovascular therapy of ruptured cerebral aneurysms in the elderly over an 8-year period. We compared endovascular therapy results in patients aged > or =65 and <65 years.

METHODS

During 1993-1999, 52 patients aged 65 to 85 years (mean age, 71.5+/-4.7 years) were embolized with the use of Guglielmi detachable coils (group I). During the same period, 143 patients aged <65 years (mean age, 47+/-11 years) with ruptured cerebral aneurysm were treated with the same technique (group II). A clinical assessment was made on admission with the Hunt and Hess (HH) classification and again in the 12th month with the Glasgow Outcome Scale (GOS), with arteriographic control in months 3 and 12.

RESULTS

In group I, clinical grades on admission were as follows: HH 1, 9.5%; HH 2, 33%; HH 3, 21%; HH 4, 34.5%; HH 5, 2%. Outcome was favorable in 48% of patients (GOS 1 or 2); the mortality rate was 23%. No rebleeding was observed. Patients presenting lesions > or =10 mm had an unfavorable outcome in >77% of cases. Thromboembolic complications were present in 13% of cases. In group II, clinical grades on admission were as follows: HH 1, 14.5%; HH 2, 47%; HH 3, 11%; HH 4, 24%; HH 5, 3.5%. Favorable outcome (GOS 1 or 2) was observed in 77% of cases, with 14% mortality. Complications due to the endovascular procedure were present in 4.2% of cases. Patients with HH grades 1 or 2 on admission showed a positive outcome (GOS 1 or 2) in 77% of cases in group I and in 88.5% of cases in group II. Mortality was 9% in the first subgroup compared with 2.8% in the second. Patients who had a high clinical grade on admission (HH 4 or 5) showed a favorable outcome (GOS 1 or 2) in 16% of cases in group I compared with 41% in group II.

CONCLUSIONS

Endovascular treatment of ruptured intracranial aneurysms in patients aged > or =65 years appears to be effective against rebleeding and represents an alternative to surgery. However, perioperative thromboembolic complications are more frequent in the elderly population.

[Study of the real situation of improvement by Zopiclone in treatment of insomnia among persons working during night shifts]

We investigated the effect of adapted management of sleep on the duration and quality of sleep in shift workers working the night shift. Twenty-nine shift workers suffering from insomnia were included and treated with zopiclone (7.5mg/day) or placebo according to a random double-blind protocol. Patients completed a sleep diary and a wrist actigraph was used to evaluate episodes of rest/activity. A self-administered subjective sleep questionnaire was filled out just after awakening. Zopicone was found to increase the duration of sleep significantly (p<0.05) over the baseline duration after the first and second night on duty. Subjective estimation of sleep was better in patients taking zopiclone who exhibited a smaller number of shorter awakening episodes.

IN CONCLUSION

zopiclone improves the quality and duration of sleep in shift workers suffering from insomnia.

Stroke after chiropractic manipulation as a result of extracranial postero-inferior cerebellar artery dissection

OBJECTIVE

To describe a case of dissection of the postero-inferior cerebellar artery (PICA) after cervical manipulation.

CLINICAL FEATURES

After cervical manipulation, a 42-year-old woman had a cerebellar syndrome related to an infarct in the area supplied by the PICA, confirmed by computed tomography of the brain. Cerebral angiography showed a normal appearance of the vertebral artery, a cervical extradural origin of PICA, and a dissection of the latter at the C1-C2 level.

INTERVENTION AND OUTCOME

Anticoagulant treatment with heparin was implemented. A positive outcome was achieved after 3 weeks.

CONCLUSION

Anatomical variations of the vertebral arteries and their branches are not infrequent and may constitute a predisposing factor to complications after neck manipulation.

Riluzole rescues cochlear sensory cells from acoustic trauma in the guinea-pig

Acoustic trauma is the major cause of hearing loss in industrialised nations. We show in guinea-pigs that sound exposure (6 kHz, 120 dB sound pressure level for 30 min) leads to sensory cell death and subsequent permanent hearing loss. Ultrastructural analysis reveals that degeneration of the noise-damaged hair cells involved different mechanisms, including typical apoptosis, autolysis and, to a lesser extent, necrosis. Whatever the mechanisms, a common feature of noise damage to hair cells was mitochondrial alteration. Riluzole (2-amino-6-trifluoromethoxy benzothiazole) is a neuroprotective agent that prevents apoptosis- and necrosis-induced cell death. Perfusion of riluzole into the cochlea via an osmotic minipump prevents mitochondrial damage and subsequent translocation of cytochrome c, DNA fragmentation, and hair cell degeneration. This was confirmed by functional tests showing a clear dose-dependent reduction (ED(50)=16.8 microM) of permanent hearing loss and complete protection at 100 microM. Although less efficient than intracochlear perfusion, intraperitoneal injection of riluzole rescues the cochlea within a therapeutic window of 24 h after acoustic trauma.These results show that riluzole is able to prevent and rescue the cochlea from acoustic trauma. It may thus be an interesting molecule for the treatment of inner ear injuries.

Efficacy of oral ketoprofen in acute migraine: a double-blind randomized clinical trial

BACKGROUND

Certain nonsteroidal anti-inflammatory drugs are effective in the acute treatment of migraine attacks. The authors report a double-blind, placebo-controlled, randomized cross-over trial of a dual-release formulation of oral ketoprofen in the acute treatment of migraine attacks.

METHODS

The authors compared the efficacy of two doses of ketoprofen (75 or 150 mg) with that of placebo (primary analysis) and zolmitriptan 2.5 mg (secondary analysis) on one to four consecutive attacks in 235 intent-to-treat patients (out of 257 randomized patients) with migraine with or without aura. The principal efficacy outcome was headache relief (reduction in headache severity from severe or moderate to mild or absent at 2 hours).

RESULTS

Results are based on 838 attacks with a severe or moderate headache that were evaluable at 2 hours. Relief was reported for 62.6% of headaches treated with ketoprofen 75 mg, 61.6% with ketoprofen 150 mg, and 66.8% with zolmitriptan. The difference between the three active treatments and placebo (27.8% relief) was highly significant, both tests of ketoprofen vs placebo being globally controlled at a 5% level for the type I error (primary analysis). Headaches at 2 hours disappeared more frequently for the active treatments than for placebo. The authors also demonstrated efficacy on most other secondary outcomes. The tolerance of ketoprofen was good (similar to that of placebo).

CONCLUSIONS

Oral ketoprofen (75 mg or 150 mg) in a dual-release formulation is an effective and well-tolerated drug in the acute treatment of migraine attacks.

A single split-signal FISH probe set allows detection of TAL1 translocations as well as SIL-TAL1 fusion genes in a single test

About 30% of T cell acute lymphoblastic leukemias (T-ALL) carry TAL1 gene aberrations. In the majority of cases (approximately 25%), this concerns a submicroscopic deletion of approximately 90 kb in chromosome region 1p32, which deletes the coding regions of the SIL gene and the untranslated region of the TAL1 gene, thereby placing the TAL1 gene under control of the SIL promoter region. Translocation (1;14)(p32;q11) involving the TAL1 gene occurs at a much lower frequency (3%), whereas some other rare variant translocations have been described as well. In this study we developed a set of TAL1 FISH probes based on the split-signal FISH principle that enables detection of both types of TAL1 gene aberrations in single test. For this purpose, one probe was designed downstream of the TAL1 gene (TAL1-D) and the second probe in the region upstream of the TAL1 gene, partly covering the SIL gene (SIL-U). We show that this split-signal FISH probe set allows reliable detection of the unaffected SIL-TAL1 gene region with a fusion signal, SIL-TAL1 fusion genes with loss of the SIL-U signal, and TAL1 gene translocations with a split-signal, independent of the involved partner gene.

Role of mast cells in the development of pancreatitis-induced multiple organ dysfunction

BACKGROUND

Activated mast cells can produce and release a number of inflammatory mediators involved in the pathophysiology of acute conditions. The aim of the present study was to evaluate the role of activated tissue mast cells in the pathogenesis of multiple organ dysfunction syndrome following acute pancreatitis (AP).

METHODS

AP was induced by the intraductal infusion of 5 per cent sodium taurodeoxycholate in the rat. Some 30 min before induction of AP, a mast cell stabilizer (sodium cromoglycate (SCG)) or antihistamines (pyrilamine, cyproheptadine, meclizine and amitriptyline) were administered intra peritoneally. Plasma exudation of radiolabelled albumin, histamine, myeloperoxidase (MPO), monocyte chemoattractant protein (MCP) 1 and adhesion molecules (platelet endothelial cell adhesion molecule (PECAM) 1 and L-selectin) were measured.

RESULTS

The mast cell stabilizer significantly reduced plasma exudation in the pancreas, colon and lungs (P < 0.05), decreased the release of histamine at 1 h (P < 0.05), and reduced MPO activity and MCP-1 levels in the colon and lungs (P < 0.05) but not in the pancreas. Expression of PECAM-1 and L-selectin on total circulating leucocytes in rats with AP and SCG pretreatment did not differ from that in sham controls, while levels in animals that had AP and saline pretreatment were half of those seen following sham operation.

CONCLUSION

Activation of mast cells after induction of AP is involved in the development of endothelial barrier dysfunction in both the pancreas and extrapancreatic organs/tissues, particularly in the lungs and colon. This may, at least partly, contribute to the sequential development of multiple organ dysfunction and organ/tissue-specific endothelial barrier dysfunction.

Role of mast cells in the development of pancreatitis-induced multiple organ dysfunction

BACKGROUND

Activated mast cells can produce and release a number of inflammatory mediators involved in the pathophysiology of acute conditions. The aim of the present study was to evaluate the role of activated tissue mast cells in the pathogenesis of multiple organ dysfunction syndrome following acute pancreatitis (AP).

METHODS

AP was induced by the intraductal infusion of 5 per cent sodium taurodeoxycholate in the rat. Some 30 min before induction of AP, a mast cell stabilizer (sodium cromoglycate (SCG)) or antihistamines (pyrilamine, cyproheptadine, meclizine and amitriptyline) were administered intra peritoneally. Plasma exudation of radiolabelled albumin, histamine, myeloperoxidase (MPO), monocyte chemoattractant protein (MCP) 1 and adhesion molecules (platelet endothelial cell adhesion molecule (PECAM) 1 and L-selectin) were measured.

RESULTS

The mast cell stabilizer significantly reduced plasma exudation in the pancreas, colon and lungs (P < 0.05), decreased the release of histamine at 1 h (P < 0.05), and reduced MPO activity and MCP-1 levels in the colon and lungs (P < 0.05) but not in the pancreas. Expression of PECAM-1 and L-selectin on total circulating leucocytes in rats with AP and SCG pretreatment did not differ from that in sham controls, while levels in animals that had AP and saline pretreatment were half of those seen following sham operation.

CONCLUSION

Activation of mast cells after induction of AP is involved in the development of endothelial barrier dysfunction in both the pancreas and extrapancreatic organs/tissues, particularly in the lungs and colon. This may, at least partly, contribute to the sequential development of multiple organ dysfunction and organ/tissue-specific endothelial barrier dysfunction.

[Tolerance of riluzole in a phase IIIb clinical trial]

Within the framework of an early drug access programme launched in 1995, a multicentre open study was initiated in France in order to assess, inter alia, the safety of riluzole (50 mg twice a day) in a total of 2069 patients from 28 centres. This programme, a phase IIIb study with direct individual benefit, had two main objectives: to enable patients to receive riluzole therapy pending regulatory approval and commercial availability and to provide further data on the safety of riluzole in a broader ALS population. The most frequent adverse events related to riluzole treatment were: asthenia, nausea and elevation of serum transaminase levels. These observations, similar to data derived from previous pivotal clinical trials, confirm that riluzole has a satisfactory tolerability profile.

[Diurnal consequence of insomnia: impact on quality of life]

Insomnia is not only a disease of sleep, it has also daily consequences: fatigue, irritability, impaired daytime functioning. These complaints are regent reported by the patients, however the objective tests assessing alertness in insomnia are usually not impaired when compared with good sleepers. We wanted to appreciate more accurately the daily consequences of insomnia, in terms of quality of life. 240 severe insomniacs (according to the DSM-IV criterias) and 391 good sleepers received a questionnaire on quality of life items. Depressed and anxious patients were excluded from this group. The questionnaire was built by a multidisciplinary group, based on insomniac's interviews. It was primarily tested in a small sample and then proposed in the entire group. Insomniac's quality of life appeared to be significantly impaired in comparison with good sleepers. They experienced more fatigue and more sleepiness during the daytime. They reported more attention disorders and memory complaints. They seemed to be more irritable and sensitive to the environment. At work they made more mistakes and had more sic leave. They also had poorer relationships with relatives and family than good sleepers.

Cyamemazine as an anxiolytic drug on the elevated plus maze and light/dark paradigm in mice

Several studies have demonstrated that cyamemazine, a classic antipsychotic compound, possesses anxiolytic properties in humans as well as a potent antagonistic effect on 5-HT(2C) and 5-HT(3) receptors. In this study the level of anxiety of mice was assessed in the light/dark exploration test and the elevated plus maze (EPM) following both acute and chronic administration. Spontaneous locomotor activity was measured using a photoelectric actimeter. Acute or chronic administration of cyamemazine dramatically decreases the spontaneous locomotor activity of mice at the dose of 1 mg/kg in comparison with the control group. In the light/dark exploration test, cyamemazine (0.375 mg/kg) only demonstrated anxiolytic-like activity following acute administration. In the elevated plus maze (EPM), cyamemazine did not induce any anxiolytic like effects after acute administration. However, after chronic administration, cyamemazine at doses of 0.25, 0.375, 0.5 and 1 mg/kg significantly increased the time spent in the open arms. The number of open arm entries was also increased at 0.25 and 0.5 mg/kg. Various serotonergic ligands were then used to examine the role of the various receptors in mediating the effects of cyamemazine in the EPM. Concerning the 5-HT(2) ligands DOI and mCPP antagonised the effects of cyamemazine and N-desmethyl clozapine potentiated the effects. For 2-methyl-5-HT and ondansetron, the 5-HT(3) receptor ligands did not seem to have any effect. It appears that the 5-HT(2C) receptors are more implicated in the function of mediating the anxiolytic effect of cyamemazine in the EPM. The discrepancy of results obtained in the tests, following acute or chronic administration could be the result of the combined activity of dopamine D(2) receptor antagonism with antagonism of 5-HT(2C) and 5-HT(3) receptors.

Methodological issues and therapeutic perspectives in vascular dementia: a review

Vascular dementia (VaD) is the most common form of dementia after Alzheimer's disease (AD). However, it is now increasingly recognized that not only is VaD a heterogeneous syndrome but also that VaD and AD are not mutually exclusive. Thus, the currently used criteria may no longer be sufficient for an accurate diagnosis of VaD. In addition, although it is widely assumed that risk factors for vascular disease are also risk factors for VaD, the evidence, in most cases, is circumstantial. For the effective prevention of VaD, therefore, large-scale and long-term clinical trials are required to investigate the validity of these putative risk factors. These trials should also include the VaD subtypes in their outcome measurements and to this end a simplified classification system should be adopted. Additional large-scale trials are required to facilitate the secondary prevention and symptomatic treatment of VaD, in particular to investigate the potential application of several nootropic and neuroprotective drugs. In both cases, these clinical trials should aim to move the field of VaD from opinion-based medicine to evidence-based medicine.

[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.