In flight performance and first results of FREGATE

The gamma-ray detector of HETE-2, called FREGATE, has been designed to detect gamma-ray bursts in the energy range [6-400] keV. Its main task is to alert the other instruments of the occurrence of a gamma-ray burst (GRB) and to provide the spectral coverage of the GRB prompt emission in hard X-rays and soft gamma-rays. FREGATE was switched on on October 16, 2000, one week after the successful launch of HETE-2, and has been continuously working since then. We describe here the main characteristics of the instrument, its in-flight performance and we briefly discuss the first GRB observations.Comment: Invited lecture at the Woods Hole 2001 GRB Conference, 8 pages, 15 figure

Continuous cerebroventricular administration of dopamine: A new treatment for severe dyskinesia in Parkinson’s disease?

In Parkinson’s disease (PD) depletion of dopamine in the nigro-striatal pathway is a main pathological hallmark that requires continuous and focal restoration. Current predominant treatment with intermittent oral administration of its precursor, Levodopa (l-dopa), remains the gold standard but pharmacological drawbacks trigger motor fluctuations and dyskinesia. Continuous intracerebroventricular (i.c.v.) administration of dopamine previously failed as a therapy because of an inability to resolve the accelerated dopamine oxidation and tachyphylaxia. We aim to overcome prior challenges by demonstrating treatment feasibility and efficacy of continuous i.c.v. of dopamine close to the striatum. Dopamine prepared either anaerobically (A-dopamine) or aerobically (O-dopamine) in the presence or absence of a conservator (sodium metabisulfite, SMBS) was assessed upon acute MPTP and chronic 6-OHDA lesioning and compared to peripheral l-dopa treatment. A-dopamine restored motor function and induced a dose dependent increase of nigro-striatal tyrosine hydroxylase positive neurons in mice after 7 days of MPTP insult that was not evident with either O-dopamine or l-dopa. In the 6-OHDA rat model, continuous circadian i.c.v. injection of A-dopamine over 30 days also improved motor activity without occurrence of tachyphylaxia. This safety profile was highly favorable as A-dopamine did not induce dyskinesia or behavioral sensitization as observed with peripheral l-dopa treatment. Indicative of a new therapeutic strategy for patients suffering from l-dopa related complications with dyskinesia, continuous i.c.v. of A-dopamine has greater efficacy in mediating motor impairment over a large therapeutic index without inducing dyskinesia and tachyphylaxia

Normal values of plasma methoxyamines in the setting of renal insufficiency and peri-operative stress. Consequences for the etiological diagnosis of hypertension

INTRODUCTION: HPLC plasma methoxyamines measurements are the updated technique for the diagnosis of adrenergic hypersecretion. Their reliability meets that of urinary measurements. Significance of increased values is not yet fully established for the etiological diagnosis of hypertension in some situations, especially in case of renal insufficiency and in the peri-operative period. The aim of this study is to define the "normal" range of the values of plasma methoxyamines in both of those conditions. PATIENTS AND METHODS: in a General and Endocrine Surgical Unit, 3 homogeneous group of 20 patients each have been studied: group 1, control (patients awaiting thyroidectomy); group 2, patients on maintenance hemodialysis submitted for hyperparathyroidism; group 3, patients submitted to digestive surgery. Measurements were done pre-operatively in group 1, pre and post-operatively in group 2, and post-operatively in group 3. RESULTS: in comparison to the control (11.8 nmol/l), we observed in group 2 a 18 fold increase preoperatively, and a 29 fold increase at post-operative day 1. In group 3, we observed a 2.3, 2.7 and 2 fold increase at post-operative days 1,2 and 3 respectively. All those results were statistically significant. CONCLUSION: Results of measurements of plama methoxyamines should always be matched to the serum creatinine levels. They are meaningful for the diagnosis of endocrine origin of hypertension only late after the early post-operative period

Hereditary Neuropathy with Liability to Pressure Palsies: A Clinical And Molecular Study in a South African Family of Indian Descent

Background Hereditary neuropathy with liability to pressure palsy (HNPP) first described in 1947, has been showed to be due to a 1.5Mb deletion, which includes the peripheral myelin protein 22 (PMP22) gene, on chromosome 17p11.2. HNPP is more common than previously thought. Objective We describe the clinical and molecular features in a three generation family where the index case became acutely disabled following surgery for cervical spondylosis. Method A total of 14 (including the index case) were examined. Eleven had clinical evidence of disease. The disability of this group ranged from asymptomatic (1), mild (4), moderate (4), severe (1) to death (1). The findings on examination ranged from a single nerve involvement to a confluent mononeuropathy multiplex. The patient who died had marked proximal and distal weakness. The immediate cause of death is unknown. On history two individuals (now deceased) were said to be affected. A further 2 subjects who were not available for examination but who provided blood for molecular analysis were said to be normal. A PCR based strategy for the determination of the PMP22 gene dose was undertaken in 15 subjects. Results Four of these individuals (2 on history and 2 on examination) who were clinically normal had no deletions. All the clinically affected individuals all exhibited the appropriate deletion. One was clinically normal but carried the deletion. Sample from a 16th individual, who was not examined, was insufficient. Conclusion This study is the first report of the existence of HNPP in South Africa. Cases are probably being missed. The correct diagnosis is important, as with appropriate measures and patient education, disability can be significantly reduced. Résumé Introduction Décrite en 1947, la neuropathie héréditaire avec hypersensibilité à la pression (NHHP) est une neuropathie héréditaire sensitivomotrice à transmission autosomique dominante. Cette affection est liée à un défaut de synthèse d\'une protéine de la myéline : la protéine PMP22 (peripheral myelin protein 22) en rapport dans près de 90% des cas à une délétion de 1,5 mégabases dans la région 17p11.2 incluant le gène PMP22. L\'HNPP paraît plus fréquent qu\'on ne le pensait. Objectif Nous décrivons les aspects cliniques et moléculaires d\'une famille sud africaine d\'origine indienne, sur trois générations, découverte lors d\'une décompensation aiguë suite à une intervention pour une myélopathie cervicarthrosique. Matériel et méthodes 14 cas ont été étudiés. 11 patients avaient des signes cliniques évidents. Le groupe a été classé selon les aspects suivants : asymptomatique, discret, modéré, sévère et décès. Les constatations étaient en rapport avec une atteinte tronculaire nerveuse, unique ou multiple. . Une enquête familiale a permis de réaliser des examens cliniques et biologiques . Résultats Le PCR a été pratiqué chez 15 patients. Quatre des patients asymptomatiques n\'avaient pas de délétion. Tous les patients symptomatiques avaient une délétion. Un patient asymptomatique était porteur d\'une délétion.. Le patient décédé de cause inconnue présentait une faiblesse proximale et distale très marquée Conclusion Il s\'agit du premier cas rapporté en République Sud-Africaine sans que cela ne préjuge du nombre de cas qui est vraisemblablement sous-estimé. Le diagnostic de HPPN ne doit pas être omis compte tenu des éventuelles conséquences fonctionnelles. (Af. J. of Neurological Sciences: 2003 22(1)

Proficiency test of plasma free and total metanephrines: report from a study group.

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