Degree of Coordination between Breathing and Rhythmic Arm Movements During Hand Rim Wheelchair Propulsion

This study aimed (i) to quantify the spontaneous coordination between breathing and hand rim wheelchair propulsion, (ii) to manipulate arm movement frequency and assess its effects on spontaneous coordination, and (iii) to investigate the hypothesis that entrainment of breathing improves economy of locomotion and leads to a lower rate of perceived exertion (RPE) compared with spontaneous breathing. Nine male, able-bodied participants completed four bouts of 6 min submaximal steady state exercise at 60 % of maximal propulsion velocity on a wheelchair ergometer, with spontaneous breathing and arm frequencies (Fspont), with 20 % higher and lower arm frequencies (F +20 and F -20, respectively) compared to Fspont accompanied with spontaneous breathing frequency, and by synchronising expiration phase with pushing time and inspiration phase with upper limb recovery time (C). Oxygen uptake and propulsion frequency were continuously recorded. The degree of coordination was expressed as a percentage of inspiration starting in the same phase of the wheelchair propulsion cycle (i.e. pushing and recovery times). No difference in degree of coordination was observed between Fspont, F -20 and F +20 conditions (49.2 +/- 12.1 %, 49.1 +/- 29.0 % and 48.2 +/- 29.4 %, respectively). Oxygen uptake increased significantly during C condition while RPE was significantly lower for C and F -20 (p < 0.05) compared to F +20 conditions. Contrary to what we expected, entrainment of breathing using a monofrequency ratio (C) induced a higher energy cost probably due to the mechanical properties of the wheelchair propulsion activity itself. In conclusion, this study showed that the same locomotor-respiratory coupling occurred during hand rim wheelchair propulsion regardless of the arm movement frequency, and that entrainment of breathing did not improve economy of locomotion.

Prise en charge de la migraine en médecine générale

INTRODUCTION

A national survey has been conducted with 349 general practitioners in order to analyze the management of concerned episodic headache in general practice.

METHOD

This survey enabled collection of data from 2537 headache patients. The main data concered IHS diagnosis, severity of headache using the MIGSEV scale, management, practices and the impact on daily living (QVM and HIT-6 scales).

RESULTS

Out of the 2537 included patients, 52 percent were migraine sufferers according to IHS criteria (code 1.1/1.2), 34 percent presented with migrainous disorders (code 1.7), and 14 percent were non-migraine headache patients. The distribution of management practices showed that 71 percent of them were given non-specific treatments, 46 percent of them specific treatments and 27 percent of them prophylactic treatments. Analysis of the impact of headache using the QVM or the HIT-6 demonstrated a relationship between diagnosis, migraine severity and disability. Analysis of the correlation between the severity of the last migraine attack as evaluated by the patient and that estimated by the doctor showed that the practitioner tended to underestimate the patient's pain. These results highlight the importance of communication between practitioners and migraine sufferers.

CONCLUSION

Training of general practitioners in the use of simple tools such as the HIT-6 scale, should be helpful for a better evaluation of the impact of headache on daily living, and hence should lead to more optimal therapeutic management of headache patients.

Tomographie par émission de positons dans la migraine

Due to technical constraints and randomness of migraine attacks, studies using PET are scarce. Nevertheless, these studies have given new insights into migraine pathogenesis. One of the main facts revealed by PET studies is that posterior cerebral hypoperfusion accompanying migraine auras could also be present in migraine attacks without aura. This hypoperfusion is probably due to an increase of intrinsic vasoconstrictive tone in the cerebral circulation. Using PET within 6 hours after the onset of a spontaneous migraine attack, significant activations of brainstem (midbrain and pons) and of hypothalamus, persisting after headache relief by sumatriptan have been shown. These structures could play the role of migraine attack generators, modulating intrinsic vascular tone and central pain transmission.

Traitement des céphalées trigémino-vasculaires : nouveautés et perspectives

Remarkable therapeutic improvements have come forward recently for trigemino-autonomic cephalalgias. Attack treatment in cluster headache is based on sumatriptan and oxygen. Non-vasoconstrictive treatments are opening a new post-triptan era but are not yet applicable. Prophylactic treatment of cluster headache is based on verapamil and lithium. The efficacy of anti-epileptic drugs in cluster headache remains to be demonstrated. Surgical treatment aimed at the parasympathetic pathways and at the trigeminal nerve demonstrates a high rate of recurrence and adverse events and questions about the relevance of a "peripheral" target in cluster headache. The efficacy of continuous hypothalamic stimulation in patients with intractable headache constitutes a breakthrough, but must be demonstrated at a larger scale and the benefice/risk ratio must be carefully evaluated. Indomethacin still remains the gold standard in paroxysmal hemicrania treatment. Until recently SUNCT was considered an intractable condition. However there are some reports of complete relief with lamotrigine, topiramate and gabapentin.

Effect of bioactive compounds from Sainfoin ( Onobrychis viciifolia Scop.) on the in vitro larval migration of Haemonchus contortus : role of tannins and flavonol glycosides

Anthelmintic bioactivity against gastrointestinal nematodes has been associated with leguminous forages supporting the hypothesis of a role of condensed tannins. However, the possibility that other compounds might also been involved has received less consideration. Using bio-guided fractionation, the current study aimed at characterizing the biochemical nature of the active compounds present in sainfoin (Onobrychis viciifolia ), previously identified as an anthelmintic leguminous forage. The effects of sainfoin extracts were evaluated on 3rd-stage larvae (L3) of Haemonchus contortus by using a larval migration inhibition (LMI) assay. Comparison of extracts obtained with several solvent systems showed that the bioactivity was associated with the 70ratio30 acetone/water extract. Further fractionation of the later allowed the separation of phenolic compounds. By use of a dialysis method, compounds were separated with a molecular weight cut-off of 2000 Da. The in vitro anthelmintic effect of the fraction with condensed tannins was confirmed. In the fraction containing molecules of MW <2000 Da, 3 flavonol glycosides were identified as rutin, nicotiflorin and narcissin. At 1200 mug/ml, each inhibited significantly the migration of larvae. Addition of polyvinyl pyrrolidone (PVPP) to both fractions before incubation restored larval migration. These results confirmed the role of both tannins and flavonol glycosides in the anthelmintic properties of sainfoin.

Deep Brain Stimulation for Parkinson’s Disease: Correlation between Intraoperative Subthalamic Nucleus Neurophysiology and Most Effective Contacts

Though intraoperative neurophysiology is essential to precisely define the definitive target, little is known regarding its predictive value in defining the most effective contact for chronic deep brain stimulation. In this retrospective study, we reviewed the correlation between intraoperative neurophysiology and contacts selected for chronic stimulation. Twenty consecutive patients implanted for subthalamic nucleus (STN) stimulation were reviewed. There was no significant correlation between the electrophysiologically defined STN and the most effective contact for chronic stimulation at 3 months or at 6 months. Furthermore, there was a discrepancy between the most effective contact for rigidity versus akinesia or tremor at 3 months. Interestingly, at 3 months, the same electrode contact was maximally efficient for rigidity, akinesia and tremor in only 13 of the 39 cases. This lack of correlation did not affect the global improvement.

A new hepatoma cell line for toxicity testing at repeated doses

Many cell models that are used to assess basic cytotoxicity show a good correlation with acute toxicity. However, their correlation with the toxicity seen following chronic in vivo exposure is less evident. The new human hepatoma cell line HBG BC2 possesses the capacity of being reversibly differentiated in vitro and of maintaining a relatively higher metabolic rate when in the differentiated state (3 weeks) as compared to HepG2 cells, and thus may allow the conduct of repeated toxicity testing on cells in culture. In order to evaluate the genetic background of HBG BC2 cells, the expression of selected genes was analyzed in untreated cultures and, in addition, the behavior of HBG BC2 cultures under conditions of repeated treatment was studied with acetaminophen as a test substance and coupled with the use of standard staining techniques to demonstrate toxicity. Results showed that cultures of HBG BC2 cells retained a capacity to undergo apoptosis and proliferation, allowing probable replacement of damaged cells in the culture monolayer. MTT reduction was used to evaluate the toxicity of acetaminophen, acetylsalicylic acid, perhexiline, and propranolol, after both single and repeated (3 times/week for 2 weeks) administration. Under the conditions of repeated treatment, cytotoxicity was observed at lower doses as compared to single administration. In addition, the lowest nontoxic doses were in the same range as plasma concentrations measured in humans under therapeutic use. Our results suggest that the new human hepatoma HBG BC2 cell line is of interest for the evaluation of cell toxicity under conditions of repeated administration.

[Influence of general practitioners' personal knowledge on migraine in medical attitudes towards their patients suffering from migraine]

The subjective aspects of the doctor-patient relationship may impact disease management methods applied to migraine patients. This prospective study compared the medical attitudes of doctors towards migraine headache in relationship to their personal sensitivity to this disease. The study concerned data on the health care management of migraine headache by 711 general practitioners, 325 of whom suffer from migraine headache themselves, 227 who do not suffer from migraines, but who have a close family member that does, and 159 who neither suffer from migraine headache, nor have anyone close who does. Each doctor filled out a medical practice questionnaire concerning this pathology and included one migraine patient in the survey. Each patient answered a specific quality of life questionnaire. It was shown that doctors suffering from migraine headache themselves declared having more migraine patients in their practices than the other doctors. Nonetheless, the doctor's sensitivity to migraine headache does not seem to have an impact on the diagnosis and therapeutic care of patients; diagnosis criteria are the same within the three groups and correspond to international headache society criteria. Furthermore, the therapeutic means applied, whether acute first or second intention treatment, or long-term treatment, do not differ amongst the three groups. Quality of life and patients' feelings about medical support were significantly related to the doctor's level of sensitivity towards the disease: they were highest amongst patients treated by doctors suffering from migraines themselves, and lowest amongst patients treated by doctors with no close family members suffering from migraines. Although therapeutical attitudes do not vary, the quality of life perceived by patients is better when the doctors themselves are concerned by the disease.

Dyskinesia: L-dopa-induced and tardive dyskinesia

Neuroleptic induced tardive dyskinesia and L-dopa-induced dyskinesia are the two most common types of drug-induced abnormal involuntary movements. These two drug-induced dyskinesias are clearly different with respect to the offending drugs and the underlying disease, but they both share a number of intriguing similarities in terms of clinical phenomenology, epidemiology, risk factors, pathophysiological mechanisms and therapeutic responses. In both instances, it is believed that some dysregulation occurring at the level of the striatal dopaminergic receptors, and related non-dopaminergic neurotransmitters systems are playing a crucial role in the development and persistence of the mechanisms causing dyskinesia. These long-lasting functional changes, known as the "priming" phenomenon, are responsible for an impaired balance within the relays of the cortico-subcortical motor loops that release an inadequate output from the basal ganglia leading to an abnormal motor behavior. From a therapeutic perspective, there are also many similarities in the strategies proposed to manage these two dyskinesias. In both cases, unprimed patients not previously exposed to the offending drugs, are offered alternative medications to reduce, at least partly, the risk of occurrence of future dyskinesia: "atypical" neuroleptics in the place of "typical" neuroleptics, and dopamine agonists in the place of L-dopa. In both cases, once dyskinesias are present, in already "primed" patients, both types of dyskinesia appear to be poorly and only partly reversible. Based on limited clinical evidence, it is a common proposal to switch the dyskinetic subject from "typical" to "atypical" neuroleptics for tardive dyskinesia, or to switch from (or more pragmatically to substitute as much as possible) L-dopa to a dopamine agonist for L-dopa-induced dyskinesia. In both cases, efficacious symptomatic antidyskinetic interventions, to reduce the severity of a ready present dyskinesia, are rare. There are some uncontrolled data suggesting that dopamine depleting agents, like tetrabenazine, are possibly useful for tardive dyskinesia; however, there is more clinical evidence to support the efficacy of amantadine and functional surgery in parkinsonian patients with L-dopa-induced dyskinesia.

Constituents of Pilocarpus trachylophus

Four flavonoids, two terpenoids and a mixture of three polyprenols have been isolated from the leaves of Pilocarpus trachylophus.

Three clerodane diterpenoids from Croton eluteria Bennett

Three furanoid clerodanes have been isolated from the stem bark of Croton eluteria Bennett. Their structures have been established by spectroscopic methods. The compounds were named cascarillin B (7alpha-acetoxy-3,4,15,16-diepoxy-12-oxo-cleroda-13(16),14-dien-20-al), cascarillin C (7alpha-acetoxy-15,16,12,20-diepoxy-20-hydroxy-cleroda-3,4,13(16),14-triene) and cascarillin D (7alpha-acetoxy-3,4,15,16-diepoxy-cleroda-13(16),14-dien-20-al).

Idazoxan, an alpha-2 antagonist, and L-DOPA-induced dyskinesias in patients with Parkinson's disease

Dyskinesia is a frequent and disabling side effect in patients with Parkinson's disease treated with chronic dopa-therapy. Preclinical data in the 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP) monkey suggest that alpha-2 antagonists may reduce dihydroxyphenylalanine (L-DOPA)-induced dyskinesia. We assessed, in a pilot randomised placebo-controlled study, the effects of single oral doses (10 mg, 20 mg, and 40 mg) of idazoxan, an alpha-2 antagonist, on motor parkinsonian disability and L-DOPA-induced dyskinesia following an acute oral challenge of L-DOPA in 18 patients with Parkinson's disease. The severity of L-DOPA-induced dyskinesia improved after 20 mg idazoxan pretreatment, while there was no concommittant deterioration in the antiparkinsonian response to L-DOPA. These results suggest that blocking alpha-2 receptors in patients with Parkinson's disease might improve L-DOPA-induced dyskinesia without the cost of a return of parkinsonian symptomatology. Further studies are required to assess whether this property could have potential therapeutic applications in the long-term management of dyskinetic patients with Parkinson's disease.

Determination of flavone, flavonol, and flavanone aglycones by negative ion liquid chromatography electrospray ion trap mass spectrometry

Eleven naturally occurring flavonoid aglycones, belonging to the representative flavone, flavonol, and flavanone types were separated by high performance liquid chromatography and analyzed on-line with negative ion electrospray ionization tandem mass spectrometry (ESI-MS/MS). In order to resolve the MS/MS spectra obtained, each compound was reinvestigated by direct loop injections using an ion trap mass spectrometer. The MSn spectra obtained allowed us to propose plausible schemes for their fragmentation supported by the analysis of five complementary synthetic flavonoid aglycones. The negative ion ESI-MS/MS behavior of the different aglycones investigated in this study revealed interesting differences when compared with the previously described patterns obtained using various ionization techniques in positive ion. Thus, concerning the retro Diels-Alder (RDA) fragmentation pathways, several structurally informative anions appeared highly specific of the negative ion mode. In addition, a new lactone-type structure, instead of a ketene, was proposed for a classic RDA diagnostic ion. We also observed unusual CO, CO2, and C3O2 losses which appear to be characteristic of the negative ion mode. All these results and these unusual neutral losses show that the negative ion mode was a powerful complementary tool of the positive ion mode for the structural characterization of flavonoid aglycones by ESI-MS/MS.

[Treatment of cluster headache]

Management of cluster headache has greatly changed in recent years although most of the drugs used have not received approval for this indications. Subcutaneous injections of sumatriptan has been found to be remarkable effective for acute episodes. This drug continues to exhibit efficacy for long periods of use up to several months and has no serious adverse effects if used according to recommendations. Nasal administration of oxygen (not approved for this indication in France) continues to be an adjuvant treatment for patients with a contraindication for sumatriptan or for those with more than two acute episodes per day. Other treatments are under debate. Prophylactic first intention verapamil (not approved in France for this indication) could be useful. Lithium (not approved in France for this indication) could also be helpful, particularly for certain clinical forms. Other options are discussed.

Induction by dopamine D1 receptor agonist ABT-431 of dyskinesia similar to levodopa in patients with Parkinson disease

BACKGROUND

Dyskinesias are a frequent adverse effect of long-term levodopa therapy. The relative contribution of dopamine D(1) and D(2) receptor function to the pathophysiology of levodopa-induced dyskinesias remains a matter of controversy.

OBJECTIVE

To establish whether a selective D(1) dopamine agonist induces more or less dyskinesia than levodopa in primed dyskinetic patients with Parkinson disease.

METHODS

We studied ABT-431, the prodrug of a fully selective D(1) agonist, in 20 subjects with advanced Parkinson disease and a fluctuating response to levodopa complicated by dyskinesias. Eight patients were studied in a double-blind, randomized design (French centers); 12, in an open, randomized design (US centers). We assessed and compared the antiparkinsonian (Unified Parkinson's Disease Rating Scale) and dyskinetic (response induced by an acute challenge of a suprathreshold dose of levodopa and by 4 different ascending doses (5, 10, 20, and 40 mg) of ABT-431 during the 6 hours after the challenge.

RESULTS

The separate analysis of the double-blind and open data led to the same findings, ie, the antiparkinsonian and dyskinetic responses induced by ABT-431 were dose related. At the most effective doses (20 and 40 mg), ABT-431 exhibited similar antiparkinsonian benefit and produced similar dyskinesias as levodopa.

CONCLUSION

Dopamine D(1) agonists can induce a full antiparkinsonian response but do not support previous hypotheses suggesting that D(1) agonists are more or less likely to produce dyskinesias than levodopa.

Direct characterization of isoquinoline alkaloids in a crude plant extract by ion-pair liquid chromatography-electrospray ionization tandem mass spectrometry: example of Eschscholtzia californica

An ion-pair HPLC-ESI-MS-MS method has been developed for the direct and rapid characterization of isoquinoline alkaloids in a crudely purified extract of the aerial parts of Eschscholtzia californica (Papaveraceae). This plant was chosen because of its increasing use in pharmaceutical industries and because its well known alkaloid composition allows the optimization of the experimental procedure through an on-line analytical sequence. Thus, 14 isoquinoline alkaloids of different types were detected and characterized. The identities of these compounds were confirmed unambigously by their fragmentation and UV spectra obtained by LC-diode-array detection. Various experiments including tandem mass spectrometry and in-orifice collision induced dissociation were performed and prove that MS-MS is a very efficient technique to identify these compounds. An explanation for each isoquinoline alkaloid type MS-MS fragmentation pattern is proposed and indicates similar neutral and/or radical losses. The order of the fragmentation depended on the type of compound but the lost fragments were similar.

An antioxidant sinapic acid ester isolated from Iberis amara

The isolation of 6-O-sinapoyl sucrose (1) from Iberis amara seeds and an evaluation of its antioxidative properties in comparison with sinapic acid and ascorbic acid are reported.

Cortical motor reorganization in akinetic patients with Parkinson's disease: a functional MRI study

Using functional MRI (fMRI), we have studied the changes induced by the performance of a complex sequential motor task in the cortical areas of six akinetic patients with Parkinson's disease and six normal subjects. Compared with the normal subjects, the patients with Parkinson's disease exhibited a relatively decreased fMRI signal in the rostral part of the supplementary motor area (SMA) and in the right dorsolateral prefrontal cortex, as previously shown in PET studies. Concomitantly, the same patients exhibited a significant bilateral relative increase in fMRI signal in the primary sensorimotor cortex, lateral premotor cortex, inferior parietal cortex, caudal part of the SMA and anterior cingulate cortex. These fMRI data confirm that the frontal hypoactivation observed in patients with Parkinson's disease is restricted to the rostral part of the SMA and to the dorsolateral prefrontal cortex. These results also show that, apart from the lateral premotor and parietal cortices, increased fMRI signals can be found in other cortical motor areas of these patients, including the posterior SMA, the anterior cingulate cortex and the primary sensorimotor cortices, which are then likely to participate in the same putative attempt by the dopamine-denervated brain to recruit parallel motor circuits in order to overcome the functional deficit of the striatocortical motor loops.

[Fast visual categorization and speed of processing in migraine]

It has been suggested that the visual cortex of migraine sufferers is hypersensitive. To test this hypothesis, we compared the speed of visual processing in eight migraine patients (including three with aura) and nine controls performing two categorisation tasks of different complexity. In the complex task developed by Thorpe et al. (1996), subjects had to detect the presence of animals in briefly presented photographs (20 ms). The speed of visual processing was measured by the latency of the differential cerebral activity that appears around 150 ms between target and non-target trials. In the simple task, subjects performed a square/circle categorisation. All subjects were faster (445 ms/497 ms) with a higher rate of success (97%/91%) in the simple task. But in both tasks, the behavioural performance and the associated evoked potentials did not show any difference suggesting a cortical hypersensitivity in migraine sufferers.

ABT-431, a D1 receptor agonist prodrug, has efficacy in Parkinson's disease

Studies in animal models show a selective D1 receptor agonist with full functional efficacy compared with dopamine to have antiparkinsonian efficacy of similar magnitude to levodopa, without the same propensity for inducing dyskinesia. To date, no such agent has been tested in humans. ABT-431 is the prodrug of A-86929, a full, selective D1 receptor agonist. Subjects (n = 14) with levodopa-responsive Parkinson's disease received five doses of ABT-431 (5, 10, 20, 30, and 40 mg) and one of placebo after a 12-hour levodopa holiday. Response was assessed by using the Unified Parkinson's Disease Rating Scale motor subsection. Dyskinesia was separately graded. ABT-431 showed efficacy significantly superior to placebo at doses of 10 mg and more, and of similar magnitude to that seen with levodopa. Dyskinesia was reduced in several patients after receiving ABT-431. There were no serious adverse events, the most common minor events being nausea and emesis, dizziness, and hypotension. Assuming that ABT-431 is not transformed in humans into an unknown active D2 metabolite, and remains selective for D1 receptors, it is the first dopamine D1 receptor agonist to demonstrate a full antiparkinsonian effect in patients with Parkinson's disease. These preliminary findings also suggest that it may exhibit a reduced tendency to provoke dyskinesia. The emergence of a well-tolerated D1 agonist should allow for the development of a better understanding of the relation between motor efficacy and dyskinesia in Parkinson's disease.