Local energy exchange in a storage-ring free-electron laser.

In this paper a theoretical model is presented, which is based on a pass to pass analysis of the localized interaction between a short laser pulse with a wider electron distribution. It can be applied to a large class of physical phenomena and, in particular, to the case of a storage-ring free-electron laser (FEL). Numerical results are confirmed by experimental measurements done on the ACO and Super-ACO FELs.

Influence of somatostatin on acute pancreatitis in rats.

OBJECTIVE: To assess the effect of two regimens of somatostatin on the morbidity and short term outcome of acute pancreatitis in rats. DESIGN: Randomised laboratory study. SETTING: Teaching hospital, France. ANIMALS: 24 male Wistar rats. INTERVENTIONS: Rats were randomised to 3 groups of 8, 2 of which were given somatostatin (one 25 microg/kg/hour by continuous infusion and one as a bolus injection of 5 microg before the infusion of 25 microg/kg/hour); the third (control) group was given 0.9% of saline 25 microg/kg/hour. Acute pancreatitis was induced by ligating the pancreatic duct at the junction with the duodenum. MAIN OUTCOME MEASURES: Serum amylase and lipase activities at 2 and 4 hours, and histological changes after 4 hours, at which time the animals were killed and the pancreas removed. RESULTS: Amylase and lipase activities were significantly lower in the somatostatin groups than in the control group throughout the experiment (p < 0.001). They were slightly but not significantly lower in the bolus group than the infusion group. The degree of necrosis and the extent of inflammatory infiltration were significantly less in the somatostatin groups (p < 0.008). CONCLUSION: Somatostatin has an early favourable effect on the course of experimentally induced pancreatitis in rats.

[Comparison of 6 different methods for lorazepam withdrawal. A controlled study, hydroxyzine versus placebo]. / Comparaison de 6 différentes modalités de sevrage du lorazépam. Une étude contrôlée, hydroxyzine versus placebo.

PATIENTS AND METHODS: 154 outpatients with generalized anxiety (DSM III-R criteria), followed by general practitioners, gave an informed written consent to participate in this multicenter, randomized, placebo controlled study previously approved by a legal ethic committee (CCPPRB). The patients had to be long term consumers (at least 3 months) of 2 mg daily of lorazepam and were withdrawn using transiently an antihistaminic anxiolytic (hydroxyzine or placebo TAD) according to 6 different procedures defining 6 parallel groups: hydroxyzine 50 mg, abrupt or progressive withdrawal; hydroxyzine 25 mg, abrupt or progressive withdrawal; placebo, abrupt or progressive withdrawal. Following this 4 week-period of withdrawal, the patients were without any treatment for a post-study follow up 2 month-period. Clinical evaluations for anxiety (HARS, Zung), sleep (Spiegel), BZD withdrawal syndrome (Tyrer), adverse reactions and clinical global impression (CGI) were performed at D0, D7, D14, D28, D35 and D88. Investigators opinion and patients attitude towards BZD were collected at D88. STATISTICAL ANALYSIS: Analysis of variance for quantitative variables and chi square test for qualitative or ordinal variables. RESULTS: Whatever abrupt or progressive, with or without hydroxyzine support, using half or full dosage, lorazepam withdrawal proved to be feasible even after a long term BZD treatment (mean = 64 months +/- 60). GPs opinion (72% satisfied: D35; 78% satisfied: D88) is satisfying but patients attitude (at D88: 54% patients desired to be regiven a tranquilizer, 31% patients occasionally had a BZD and 22% formally demanded a prescription of BZD) is more questionable. Despite a high initial level of anxiety under lorazepam (HARS = 21 +/- 10 at D0), after a one-month period of withdrawal (under placebo or hydroxyzine) followed by a 2 month-period without any treatment, 75% patients were totally free of any drug and their level of anxiety was significantly decreased (D88: HARS = 12 +/- 9). Progressive withdrawal appeared preferable if compared to abrupt since the number of drop outs between D28 and D88 was less important and the procedure judged more favourably by the patients. Levels of anxiety significantly decreased in both the groups (progressive and abrupt) but sleep parameters and number of withdrawal symptoms between D7 and D28 were improved only in abrupt withdrawal group (p < 0.0001). Considering hydroxyzine, 2 patients dropped out between D0 and D28 in the group hydroxyzine 25 mg, 6 patients in the group 50 mg and 5 patients in the group placebo. Levels of anxiety (HARS et Zung) were significantly improved in hydroxyzine 50 mg group (p < 0.007) and in hydroxyzine 25 mg group (p < 0.012) but not in placebo group. Withdrawal symptoms (Tyrer) between D0 and D28 were improved only in hydroxyzine 50 mg group and the number of side effects was significantly improved in both the hydroxyzine (25 et 50 mg) groups but not in placebo group. However, no significant difference was found between the 3 groups. Daytime sleepiness is more frequent in hydroxyzine 50 mg group. DISCUSSION: These results proved a significant improvement of anxiety, a decrease of side effects in both the groups treated with hydroxyzine and a reduction of withdrawal symptomatology in hydroxyzine 50 mg group. When a patient is engaged to be withdrawn from of a lorazepam long term treatment, it can therefore be proposed as a support a transient prescription of hydroxyzine 25 mg TAD to markedly anxious patients and of hydroxyzine 50 mg TAD to patients presenting a withdrawal symptomatology.

[Effects of co-administration of an antidepressant and an anxiolytic drug in the "learned helplessness" paradigm: importance of hydroxyzine]. / Effets d'une coadministration d'antidépresseur et d'anxiolytique dans le paradigme de "learned-helplessness": intérêt de l'hydroxyzine.

Whereas benzodiazepines are routinely coadministered with tricyclic antidepressants, in patients undergoing treatment for depressive disorders, little information is known about the combination of benzodiazepines with other antidepressants such as specific serotonin reuptake inhibitors (SSRI's), and combination with other anxiolytic drugs. On the other hand, it is known that benzodiazepines decrease the serotoninergic transmission. The present study was undertaken to evaluate the effect of concomittant administration of anxiolytic drugs such as benzodiazepines (diazepam, lorazepam) or diphenylmethane derivative (hydroxyzine) with specific serotonin reuptake inhibitors, (fluvoxamine, fluoxetine, indalpine) on the ability of antidepressant drugs to reverse helpless behavior in this test. Our results show that: daily injection of diazepam (0.25-2 mg/kg), lorazepam (0.06-0.25 mg/kg) or hydroxyzine (8.32 mg/kg) failed to reverse the behavioral deficit in rat. In contrast fluvoxamine: 4 mg/kg/day; fluoxetine: 4 mg/kg/day; indalpine: 1 mg/kg/day significantly reverse the helpless behavior in this test; the reversal of helpless behavior by fluvoxamine or indalpine was dose-dependently antagonized by daily coadministration of diazepam or lorazepam; in contrast, the reversal of helpless behavior by fluvoxamine or fluoxetine was not modified by daily coadministration of hydroxyzine (8 mg/kg). In conclusion, it may be suggested that combined benzodiazepine-specific serotonin reuptake inhibitors, should be avoided. We suggest that anxiolytic drugs such as hydroxyzine might be better in coadministration with antidepressants, particularly with specific serotonin reuptake inhibitors.

[Multicenter study on the efficacy of Zyrtec (Cetirizine) in the treatment of perennial allergic rhinitis in 875 adolescents]. / Etude multicentrique sur l'efficacité de Zyrtec (Cétirizine) dans le traitement des rhinites allergiques perannuelles de 875 adolescents.

875 adolescents of both sexes, aged between 12 and 15 years, who had presented with a perennial allergic rhinitis, were included in an open study that was conducted by pediatricians and allergologists on the efficacy of ZYRTEC (CETIRIZINE). There were four evaluations in the study, at Day-10, D 0, D15 and D30 and it was conducted according to the following plan: A first period (D-10 to D 0) to establish the eligibility of the subjects to be tested, and to establish the clinical allergic history, before definitive inclusion at D 0. A second period, of therapy, of 30 days, during which the subjects took a 10 mg tablet of ZYRTEC as a daily dose. Efficacy was evaluated at each visit by scores of intensity of major symptoms (sneezing, nasal discharge, nasal obstruction, nasal pruritus) and secondary symptoms (ocular score ... ) of rhinitis, as well as anterior rhinoscopy. The patients made an auto-evaluation of symptoms at different times. Analysis of the different parameters showed a real efficacy of ZYRTEC, for 30 days of treatment, in young patients. Furthermore, the tolerance of the product is excellent. This study has shown an overall improvement in the symptoms of perennial allergic rhinitis in patients who were treated with ZYRTEC in conditions similar to those of usual medical practice by pediatricians and allergologists.

[Multicenter hospital study on the efficacy of Zyrtec (R) (cetirizine) compared to a placebo, in the treatment of perennial allergic rhinitis in 254 adolescents aged 12-15]. / Etude multicentrique hospitalière sur l'efficacité de Zyrtec (cétirizine) comparé à un placebo, dans le traitement des rhinites allergiques perannuelles de 254 adolescents de 12 à 15 ans.

In this multicenter parallel group randomized trial 254 teenagers, aged 12-15, suffering from perennial allergic rhinitis were investigated. Four evaluations (D-10, D0, D15, D30) were performed according to the following design: a 10-day run-in period (D-10, D0) to determine/establish the patient eligibility and to perform an allergologic checkup. The decision to include the patient was made at D0 according to selection criteria. a 30-day treatment period (D0 to D30). The patient received either cetirizine 10 mg once a day or placebo given in a double blind way according to randomization. Efficacy was assessed at each visit with a nasal symptom score (sneezing, rhinorrhea, obstruction, pruritus) and an ocular symptom score (watery eyes, conjunctival pruritus, red eyes). In addition, an objective evaluation was performed by means of anterior rhinoscopy. Global evaluations by the investigator and the patient on visual analog scales were assessed. Side effects were recorded. At baseline there was no significant difference between the two groups. At day 15 and day 30, all symptoms, subjective as well as objective, were significantly improved in the cetirizine group. Tolerance was good with no significant difference between cetirizine and placebo.

[Modification of cognitive functions by 2 anxiolytic treatments in patients suffering from generalized anxiety]. / Retentissement sur les fonctions cognitives de deux traitements anxiolytiques chez des patients souffrant d'anxiété généralisée.

The aim of this randomized, double-blind, multicentric study was to assess and compare cognitive impairment in patients treated with either lorazepam or hydroxyzine, for generalized anxiety. Only non depressed patients were selected according to MADRS criteria. The cognitive assessment was performed with the BEC 96 rating scale, the intensity of anxiety symptoms was evaluated through the Hamilton-anxiety and Covi scales. The level of relation, mood and sedation was assessed for each item with a visual analog scale (VAS). The patient's and investigator's opinion on the global efficiency of the treatment were also evaluated on VAS. After an 8-day wash-out period under placebo, the treatment was given in a double-blind way for 28 days: either hydroxyzine 25 mg at a daily dosage of 100 mg t.i.d. (25 mg - 25 mg - 50 mg), or lorazepam 1 mg at a daily dosage of 4 mg t.i.d. (1 mg - 1 mg - 2 mg). The results were as follows: after the 28-day treatment period, patients showed at the BEC 96 a cognitive improvement in both groups, but the improvement in the hydroxyzine group was significantly higher. Furthermore, the improvement appeared more quickly in the hydroxyzine group. The Hamilton-anxiety and Covi scales showed an improvement in the anxiety level in both groups with no significant difference. The visual analog scales assessing relation, mood and sedation improved in both groups as well as the patient's and investigator's opinion. The five assessments all showed a significant by higher improvement in the hydroxyzine group.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of hydroxyzine in generalized anxiety disorder: controlled double-blind study versus placebo]. / Intérêt de l'hydroxyzine dans le trouble anxiété généralisée: étude contrôlée en double aveugle versus placebo.

A multi-centre study was designed to evaluate the efficacy of hydroxyzine in the treatment of patients presenting a generalized anxiety disorder (GAD). One hundred and thirty three patients, suffering from a GAD (according to DSM III-R criteria with 6 months duration criteria), were enrolled in a randomised, double-blind, hydroxyzine (50 mg/day) versus placebo, over a 4-week trial period. By the end of the first week, the decrease of anxiety scores was significant for the hydroxyzine group, as compared to placebo (in respect of all rating criteria of anxiety). The statistical superiority for hydroxyzine continued to the end of the 4-weeks study period, and persisted at a further evaluation a week after abrupt discontinuation of active treatment. The tolerance evaluation showed that side effects were reported in 52% of hydroxyzine group versus 35% of placebo group. The most commun side effects were sleepiness (28% vs 14% with placebo), weight gain (12% vs 10%), dry mouth (14% vs 5%), loss of concentration (9% vs 8%) and insomnia (9% vs 6%). Sleepiness in the hydroxyzine group appeared during the first week and progressively disappeared later during treatment. We concluded that hydroxyzine at 50 mg/day produces a statistically and clinically significant anxiolytic effect, commencing during the first week of treatment and maintained throughout the 4-week period and after abrupt discontinuation without rebound of anxiety or withdrawal symptoms. The most commun side effect with hydroxyzine is transient sleepiness.

Long-term and high-dose piracetam treatment of Alzheimer's disease.

Preclinical research suggests that piracetam (a nootropic drug) may improve cognitive functions, but previous studies have failed to demonstrate a clear benefit for the treatment of Alzheimer's disease (AD). We report a 1-year, double-blind, placebo-controlled, parallel-group study with a high dose of piracetam (8 g/d per os) in 33 ambulant patients with early probable AD. Thirty subjects completed the 1-year study. No improvement occurred in either group, but our results support the hypothesis that long-term administration of high doses of piracetam might slow the progression of cognitive deterioration in patients with AD. The most significant differences concerned the recall of pictures series and recent incident and remote memory. The drug was well-tolerated.

Comparative randomized double-blind study of hydroxyzine versus placebo as premedication before injection of iodinated contrast media.

The use of ionic contrast media in radiologic examinations may cause a wide variety of anaphylactoid reactions. The aim of this double-blind randomized study was to determine whether a simple and inexpensive premedication based on an antihistamine could reduce the number of idiosyncratic reactions in 400 patients (251 men and 149 women) without a clinical history of allergy who were to receive an intravenous injection of a low-osmolality iodinated contrast medium. Twelve hours before examination, a group of 200 patients was given one 100-mg tablet of hydroxyzine; another group of 200 was given a placebo tablet under the same conditions. Results in the two groups were comparable at the .05 level of significance. Twenty-five patients in the placebo group had a reaction (mainly urticaria); only two patients in the hydroxyzine group had a reaction (P less than .0001; odds ratio, 14.1). No severe reaction occurred in either group. Because hydroxyzine and placebo were allocated at random, it is concluded that hydroxyzine reduces the frequency of minor anaphylactoid reactions in patients at low risk.

Fabry-Perot effects in the exponential decay and phase shift reflectivity measurement methods.

The exponential decay and phase shift reflectivity measurement methods are examined for a real optical cavity, i.e., one that includes mechanical vibrations and light source fluctuations in wavelength and amplitude. We compare the two methods and examine the problems inherent in each and present methods for overcoming these. Both methods are shown to be excellent for measuring high reflectivity cavity losses (particularly for the free electron laser case) although suitable precautions should be taken.

[Importance of Zyrtec in the treatment of chronic urticaria and allergic rhinopathies apropos of 1168 cases seen by hospital practitioners]. / Intérêt du Zyrtec dans le traitement de l'urticaire chronique et des rhinopathies allergiques à propos de 1,168 cas réalisés par des praticiens hospitaliers.

This was a phase IV prospective trial involving out-patients from 80 hospital respiratory diseases and ENT departments, and 40 hospital dermatology departments. More than 1,000 cases were collected and used to evaluate the efficacy of Zyrtec at the dose of 10 mg per day. The aim of the trial was to assess the rapidity of action and good acceptability of treatment for 10 days and 2 weeks respectively in cases of seasonal and perennial rhinopathy. Similarly, in pruritic allergic skin disorders, the aim was to measure the degree of activity and acceptability of treatment for 2 weeks. Overall evaluation of results provided clinical evidence of satisfactory rapidity of action with an appreciable acceptability level. This prospective study confirms the good therapeutic index of Zyrtec as a new anti-allergic agent.

Diagnostic techniques and UV-induced degradation of the mirrors used in the Orsay storage ring free-electron laser.

Due to its low gain, the Orsay storage ring free-electron laser necessitates the use of high reflectivity mirrors. Three techniques for measuring the mirror losses are presented, based on cavity decay time measurements using either an external laser, the synchrotron radiation stored in the cavity, or the free-electron laser itself. The high signal-to-noise ratio allowed the detection of loss variations as low as 10(-7)/sec(1/2). From these diagnostics three distinct processes of UV-induced degradation of TiO2/SiO2 dielectric mirrors were identified. One was a surface absorption of the upper SiO2-air interface; it was not affected by annealing. The other two corresponded to a volume absorption of the layers which completely recovered after annealing.