Does the repetition over a short time of a microsurgical suture improve its reliability?

Our hypothesis was that immediate repetition of a microsurgery-suturing task will improve its execution and outcome. This was an experimental animal study. Ten surgeons were divided into two groups of five surgeons. Each performed two end-to-end carotid anastomoses on the same rat, one after the other. The anastomosis was evaluated by the surgeon and an instructor. The primary endpoint was permeability. The outcome was evaluated using an objective and subjective assessment grid yielding 1 to 3 points per item. The total scores for each of the 10 surgeons were used to compare the anastomosis of carotid 1 versus 2, using the ratings given by the surgeon and the instructor. Twenty anastomoses were performed, but 1 rat died intraoperatively, leaving 18 anastomoses for evaluation. No significant differences were found on the main endpoint of permeability, with all anastomoses being permeable. The surgeon's self-assessment was significantly better for the second carotid artery (P=0.05), but this was not confirmed by the proxy assessment (instructor). The analysis by subgroups-morning versus afternoon-found the second carotid anastomosis was significant better in the self-assessment and proxy assessment for the morning group (P<0.001, P=0.024). There was no significant difference in clamping times. The immediate repetition of a microsurgical procedure seems to favor its execution, which leads us to propose that the more difficult or important anastomosis should be done after an easier or less important one during complex surgeries. LEVEL OF EVIDENCE: 2B.

ZFP57 and the Targeted Maintenance of Postfertilization Genomic Imprints

Epigenetic modifications play an important role in modulating genome function. In mammals, inappropriate epigenetic states can cause embryonic lethality and various acquired and inherited diseases; hence, it is important to understand how such states are formed and maintained in particular genomic contexts. Genomic imprinting is a process in which epigenetic states provide a sustained memory of parental origin and cause gene expression/repression from only one of the two parental chromosomes. Genomic imprinting is therefore a valuable model to decipher the principles and processes associated with the targeting and maintenance of epigenetic states in general. Krüppel-associated box zinc finger proteins (KRAB-ZFPs) are proteins that have the potential to mediate this. ZFP57, one of the best characterized proteins in this family, has been shown to target and maintain epigenetic states at imprinting control regions after fertilization. Its role in imprinting through the use of ZFP57 mutants in mouse and the wider implications of KRAB-ZFPs for the targeted maintenance of epigenetic states are discussed here.

Prevalence of insomnia in a survey of 12,778 adults in France

This study was an epidemiological questionnaire survey of a representative sample of the French population that included 12 778 individuals and in which adapted DSM-IV criteria for the definition of insomnia were used. Our goals were not only to assess the prevalence of 'insomnia' using these criteria, but also to compare the results obtained with those of prior studies using different definitions of 'insomnia'. The aim of this study was also to identify where areas of agreement and disagreement existed, as we believe that it is important to emphasize these points because DSM-IV recommendations are supposedly reflected in clinical practice. Seventy-three per cent of the individuals surveyed complained of a nocturnal sleep problem, but only 29% reported at least one sleep problem three times per week for a month, and 19% (2428 subjects) had at least one sleep problem three times per week for a month and complained of daytime consequences (DSM-IV criteria). Only 9% had two or more nocturnal sleep problems with daytime consequences and were classified as 'severe insomniacs'. Our study indicates that if DSM-IV criteria are used, the diagnosis of 'insomnia' is lower than in other epidemiological studies. The DSM criteria have an advantage in that they emphasize the daytime consequences of nocturnal sleep disturbances, which seem to be responsible for the most important socio-economic costs of the problem.

Activated factor X and thrombin formation triggered by tissue factor on endothelial cell matrix in a flow model: effect of the tissue factor pathway inhibitor

The procoagulant subcellular matrix of stimulated endothelial cells that contains tissue factor (TF) was used to investigate the mechanism by which TF pathway inhibitor (TFPI) inhibits thrombin formation initiated by TF/factor VIIa (FVIIa) under flow conditions. Purified coagulation factors VII, X, and V and prothrombin were perfused at a wall shear rate of 100 s-1 through a flow chamber containing a coverslip covered with matrix of cultured human umbilical vein endothelial cells. This resulted in a TF- and FVII-dependent FXa and thrombin generation as measured in the effluent at the outlet of the system. Inhibition of this TF/FVIIa-triggered thrombin formation by TFPI purified from plasma was dependent on the amount of TF present on the endothelial cell matrix. The rate of prothrombinase assembly and steady-state levels of thrombin formation were decreased by TFPI. Because persistent albeit decreased steady-state levels of thrombin formation occurred in the presence of TFPI, we conclude that plasma-TFPI does not inhibit FXa present in the prothrombinase complex. The addition of FIX and FVIII to perfusates containing FVII and FX increased the FXa generation on endothelial matrices, and counteracted the inhibition of thrombin formation on endothelial cell matrices by TFPI. Our data provide further evidence for the hypothesis that the rapid inactivation of TF/FVIIa by TFPI in combination with the absence of either FVIII or FIX causes the bleeding tendency of patients with hemophilia A or B.

[Zopiclone. Data of experimental pharmacology and clinical use]

Zopiclone is the first of the cyclopyrrolones, a new class of psychotropic agents which is chemically different from the benzodiazepines (BZD). From an experimental point of view it has qualitatively the pharmacological profile of the tranquilizer-hyponotics, and activity quantitatively differs from hypnotic BZD by its lower myorelaxant. The electroencephalographic studies also demonstrated that its power spectrum is characteristic of a product having a tranquilizing hypnotic potential. The cyclopyrrolones interact with GABA ergic neurotransmission, and have a high affinity for GABA receptor complex. They act on sites close to BZD sites, but physically different. The sleep polygraphic studies have shown that zopiclone has a specific profile. It respects the sleep architecture, specially the delta sleep which is even increased, in some studies. Its residual effects are absent or minimal, and its acceptability is good in the usual conditions of hypnotic prescription.

Postmarketing surveillance of zopiclone in insomnia: analysis of 20,513 cases

The subjective response to the prescription drug zopiclone, an hypnotic agent belonging to the cyclopyrrolone family, was assessed under the usual conditions of prescription of an hypnotic in general practice. The study included 20,513 insomniac outpatients with at least two of the following symptoms: sleep onset latency longer than 1 hour, more than two nocturnal awakenings, early morning awakening 1 hour or more before scheduled time, total sleep time of less than 6 hours, complaint of tiredness on awakening. Insomniac patients were treated with zopiclone and followed for 21 consecutive days within the context of a follow-up surveillance study. The population was predominantly female (62.6%), and the mean age was 52.3 years. The dosage of zopiclone prescribed at the inclusion visit was 7.5 mg per day in 87.5% of the cases and 3.75 mg per day in 10.5%. A total of 93.8% of the patients completed the survey. Spiegel questionnaire improved during the 21-day survey, and 9.2% of the patients reported at least one adverse event that led to treatment discontinuation in only 2.8% of the population. No serious or unexpected adverse events were reported.

Post marketing surveillance of zopiclone: interim analysis on the first 10,000 cases in a clinical study in general practice

The tolerance of zopiclone, a hypnotic belonging to a new chemical group, the cyclopyrrolones, was studied in a follow-up trial in 23,000 insomniac outpatients treated for 3 weeks. The results from the interim analysis of the first 10,000 cases confirm the efficacy and safety of zopiclone under usual prescribing conditions. The average daily dose of zopiclone was 0.97 +/- 0.21 tablet (7.275 +/- 1.575 mg). The study population included 63.1% of female and 36.9% of male patients; the mean age was 52.3 +/- 16.6 years. 93.1% of the patients completed the trial. 8.2% of the patients experienced adverse reactions which resulted in drug discontinuation in only 2.8% of cases. In the global evaluation, the efficacy was rated excellent or good in more than 80% of the patients.

[Comparison of the effects of zopiclone and triazolam on the sleep of normal subjects]

Zopiclone 7.5 mg and triazolam 0.50 mg have been compared in a double-blind randomized cross-over sleep laboratory study. After a 6-day placebo, 12 healthy male volunteers aged 20-35 years received 2 active treatment sequences of 6 days separated by a 8-day placebo period and followed by a withdrawal period with placebo for 8 days. 22 polygraphic sleep recordings have been performed. The duration of nocturnal awakenings decreases at the beginning of treatment. Sleep onset latency is significantly decreased as well as the number of awakenings during sleep at the end of treatment. Both drugs improve the sleep efficiency index. Zopiclone increases total sleep time at the beginning and at the end of treatment. Triazolam increases this parameter at the end of the study only. Zopiclone, unlike triazolam increases the duration of deep NREM sleep-stages 3 and 4--at the beginning of treatment. No significant changes in sleep parameters were seen with zopiclone nor triazolam at the end of treatment. In sleep questionnaires, sleep onset latency is shorter under zopiclone than under triazolam and daytime drowsiness is less frequent with zopiclone.