Synchronous Rendezvous for Networks of Marine Robots in Large Scale Ocean Monitoring.

We develop a synchronous rendezvous strategy for a network of minimally actuated mobile sensors or active drifters to monitor a set of Lagrangian Coherent Structure (LCS) bounded regions, each exhibiting gyre-like flows. This paper examines the conditions under which a pair of neighboring agents achieves synchronous rendezvous relying solely on the inherent flow dynamics within each LCS bounded region. The objective is to enable drifters in adjacent LCS bounded regions to rendezvous in a periodic fashion to exchange and fuse sensor data. We propose an agent-level control strategy to regulate the drifter speed in each monitoring region as well as to maximize the time the drifters are connected and able to communicate at every rendezvous. The strategy utilizes minimal actuation to ensure synchronization between neighboring pairs of drifters to ensure periodic rendezvous. The intermittent synchronization policy enables a locally connected network of minimally actuated mobile sensors to converge to a common orbit frequency. Robustness analysis against possible disturbance in practice and simulations are provided to illustrate the results.

[Is pediatrics excluded from pharmaceutical innovation?]. / La pédiatrie, toujours exclue de l'innovation pharmaceutique ?

OBJECTIVE: The development of therapeutic strategies for children depends unequivocally on the commercial launching of drugs with pediatric indications. New therapeutic drugs differ from one country to another, particularly considering children. The objective of this study was to compare access to new drugs by children in France (FR) and Canada (CA). MATERIAL AND METHODS: Retrospective study comparing newly marketed drugs in FR and CA from 1 January to 31 December 2009. Data were collected through independent sources: (HAS, Thériaque, ANSM for FR and CEPMB, BDPP for CA). RESULTS: Respectively, 37 and 30 new drugs were put on the market in 2009 in FR and CA. Among them, 38% (n=14) and 27% (n=8) had a pediatric indication. For 91% (FR) and 95% (CA) of the drugs not indicated for children, no clinical study has been planned to define pediatric indications. All the drugs (100%) with pediatric indications presented dosages based on age or weight, but it should be noted that two drugs had no form adapted to children. Fifty-seven percent of these drugs were first available on the French market and later on the Canadian market, with a median delay of 8.5months. CONCLUSION: This study highlights the obvious lack of pediatric drugs contributing to large prescriptions of off-label drugs for children, with no dosage or adapted pharmaceutical form for this population.

Antidepressants: general practitioners' opinions and clinical practice.

OBJECTIVE: To describe and compare general practitioners' (GPs) opinions on antidepressant drugs and their prescriptions to depressed patients. METHOD: Between November 2000 and July 2001 a representative sample of French GPs was asked their opinion of the 15 most prescribed antidepressants, and then to describe the treatments of the current depressive episode of four depressive patients each, their changes and the reasons thereof. RESULTS: One hundred and eighty-one GPs and 778 patients participated. The best-ranked antidepressants by the GPs were paroxetine, fluoxetine, sertraline and clomipramine for efficacy, and paroxetine, tianeptine, sertraline and fluoxetine for tolerability. In patients, the drugs most often prescribed were fluoxetine, paroxetine, and sertraline. Those least often stopped for intolerance were moclobemide (0%), dosulepine (0%), venlafaxine (4.5%) and citalopram (5.0%), and maprotiline (0%), citalopram (1.7%) and venlafaxine (2.3%) for lack of efficacy. The best predictor for prescription of antidepressants was the GPs' overall ranking, itself depending on opinions of the tolerability and efficacy of the drug. However, opinions of tolerability and efficacy were not related to the rates of treatment discontinuation for intolerability or inefficacy. CONCLUSION: Prescriber opinion does not seem related to actual product performance.

Familial intracranial aneurysms: recurrence risk and accidental aggregation study.

BACKGROUND: The Saguenay-Lac-Saint-Jean (SLSJ) region is a geographically isolated area (population 285,955) located in the Northeastern part of the Province of Quebec, Canada. Using a population-based register, the genealogical reconstruction of 502 individuals with ruptured intracranial aneurysm (RIA) showed a familial aggregation (the presence of aneurysm in two or more first- to third-degree relatives) for 144 (28.7%) of them; this proportion is much higher than reported elsewhere. OBJECTIVE: In order to assess the genetic predisposition to RIA in the SLSJ population, the objective of the present study is to compare familial and non-familial cases and to provide an estimate of the recurrence risk ratio for siblings. RESULTS: The age at the time of rupture, the number of intracranial aneurysms for each patient and the location of RIAs were not statistically different in the familial versus the non-familial group. Of the 3449 siblings, 20 (0.58%) had suffered a RIA. The recurrence risk ratio calculated for siblings (defined as the risk of disease among siblings divided by the estimated population prevalence) is 1.6 (CI 95% 1.0-2.4). In other respects, we observed very large kinships in the SLSJ population, with an average number of siblings of 7.2 (SD +/- 3.4), ranging from 0 to 17 individuals. With such large families and on the basis of chance alone, we expected 31.3% of the patients to have at least one first- to third-degree relative with RIA. CONCLUSION: These data show that siblings of patients with RIA in the SLSJ population have a greater risk of RIA than the general population. Nevertheless, the largest part of the familial occurrence observed in the SLSJ region can be explained by accidental aggregation, due to large kinships. We propose that, in this population, an underlying genetic predisposition must be suspected only when three or more cases of RIA are identified among first- to third-degree relatives.

Ankle radiograph utilization after learning a decision rule: a 12-month follow-up.

OBJECTIVE: To test whether the reduction in ankle radiograph ordering was sustained during a 12-month period after a formal trial to introduce the Ottawa ankle rules. METHODS: A before-after clinical trial of ankle radiograph ordering practice was performed in a university-based ED. All 1,884 (947 "during intervention," 937 "postintervention") adults seen with acute ankle injuries during 2 12-month trial periods were evaluated. The behavioral intervention was the teaching of the Ottawa ankle rules and feedback of compliance with the rules during the intervention period. No further education about the ankle rules or feedback regarding compliance occurred during the postintervention year. Physicians were unaware of any postintervention surveillance. The primary outcome was the proportion of eligible patients referred for an ankle radiograph during the intervention and postintervention periods. RESULTS: During the intervention period (January 1-December 31, 1993), the proportion of patients who received an ankle radiograph [609 x-rayed of 947 patients seen (64.3%; 95% CI 61.2-67.4%)] did not differ from the proportion who received an x-ray in the postintervention period (January 1-December 31, 1994) [583 x-rayed of 937 patients seen (62.2%; 95% CI 59.1-65.3%), p = 0.65, power > 0.80 to detect a 10% increase in the radiograph ordering rate]. There was also no difference in the radiograph ordering rate in the first 3 months of the postintervention period compared with the last 3 months of the postintervention period (68.8% vs 64.7%, respectively, p > 0.30). CONCLUSIONS: Compliance with the Ottawa ankle rules was sustained during a 12-month postintervention surveillance period when physicians did not know they were being observed. Physicians will continue to use a simple clinical guideline once it has been learned.

Factors determining compliance with screening mammography.

OBJECTIVE: To determine factors affecting compliance with screening mammography prescribed by family physicians. DESIGN: Secondary analysis of a nonrandomized trial. SETTING: University-affiliated family medicine clinic in Montreal. PATIENTS: Women aged 50 to 69 years who were given a written prescription for a screening mammography during their visit at the clinic between Oct. 12, 1991, and May 31, 1992, and who had not undergone mammography in the preceding 2 years and had never been treated for breast cancer. Information on the potential factors was obtained through a telephone questionnaire 2 months after the visit. OUTCOME MEASURES: Indicator of compliance presence of result of screening mammography in patient chart, potential factors influencing compliance: age, level of education, marital status, socioeconomic level, smoking status, perceived health status, perceived psychological well-being, risk factors for breast cancer, use of health services including frequency of Papanicolaou test, Health Belief Model variables. RESULTS: Of the 171 eligible women, 113 (66.1%) underwent the prescribed mammography within 2 months after the visit to the clinic, and 149 (87.1%) responded to the questionnaire. The patients' socioeconomic characteristics, perceived health status, health utilization indices and risk factors for breast cancer were not found to be predictors of compliance. The strongest predictor of compliance was the number of previous mammograms. Women who had undergone mammography previously were less likely to be noncompliant than those who had not (odds ratio [OR] 0.11, 95% confidence interval [CI] 0.02 to 0.51; p = 0.005). Women who did not comply were less likely than those who did to believe that a prescription from their physician would convince them to undergo mammography (OR 0.21, 95% CI 0.007 to 0.60; p = 0.004). Other factors associated with noncompliance were the expression of fear of mammography (OR 2.09, 95% CI 1.08 to 4.02; p = 0.03) and the lack of time to take the test (OR 3.07, 95% CI 1.21 to 7.80 p = 0.02). Being a smoker was negatively associated with compliance (OR 0.43; 95% CI 0.22 to 0.86; p = 0.02). The stepwise logistic regression model accounted for 87.5% of the outcome (chi2 for goodness of fit = 164.4; p = 0.0001). CONCLUSION: Family physicians who prescribe screening mammography, even to women who consult for other reasons, are likely to overcome some of the barriers observed in association with population screening rates. However, physician-oriented approaches are not likely to reach the 30% to 40% of reluctant women who appear to hold negative views toward physicians' recommendations. Further study is necessary to determine how better to reach these women.

[Breast cancer screening: is family medicine intervention effective?]. / Dépistage du cancer du sein: l'intervention du médecin de famille est-elle efficace?

A non-randomized controlled trial was conducted in two family medicine centers. The objectives were to evaluate whether or not a systematic prescription by family physicians of a screening mammography to women aged 50 to 69 belonging in majority to a disadvantaged socio-economic group, would permit to reach at least 60% of them and to explore which factors were associated with compliance to the prescription. The experimental intervention consisted in the prescription by the family physician of a mammogram to those patients found eligible for the screening procedure irrespective of the reason for encounter. A total of 468 of the 870 women who consulted a physician during the study period were eligible for a screening mammography. In the experimental group, the mammography prescription rate was 89% for eligible women. At the end of the study, 58.8% (95% Conf. Int.:51.9%-65.7%) of the women in the experimental group and 13.4% (95% Conf. Int.:9.4%-17.4%) of those in the control group had passed a mammography (p < 0.0001). The adjusted odds ratio for the family physician's intervention was 14.98 (95% Conf. Int.:7.86-28.58). Women over 60 years of age and those who perceived themself more vulnerable to breast cancer were more likely to respond positively to their physician's recommendation. This study confirms that family physicians can effectively reach, in the area of clinical prevention, individuals who might not be reached otherwise.

Comparison of traditional and molecular methods of typing isolates of Staphylococcus aureus.

Fifty-nine Staphylococcus aureus isolates and 1 isolate of Staphylococcus intermedius were typed by investigators at eight institutions by using either antibiograms, bacteriophage typing, biotyping, immunoblotting, insertion sequence typing with IS257/431, multilocus enzyme electrophoresis, restriction analysis of plasmid DNA, pulsed-field or field inversion gel electrophoresis, restriction analysis of PCR-amplified coagulase gene sequences, restriction fragment length polymorphism typing by using four staphylococcal genes as probes, or ribotyping. Isolates from four well-characterized outbreaks (n = 29) and a collection of organisms from two nursing homes were mixed with epidemiologically unrelated stock strains from the Centers for Disease Control and Prevention. Several isolates were included multiple times either within or between the sets of isolates to analyze the reproducibilities of the typing systems. Overall, the DNA-based techniques and immunoblotting were most effective in grouping outbreak-related strains, recognizing 27 to 29 of the 29 outbreak-related strains; however, they also tended to include 3 to 8 epidemiologically unrelated isolates in the same strain type. Restriction fragment length polymorphism methods with mec gene-associated loci were less useful than other techniques for typing oxacillin-susceptible isolates. Phage typing, plasmid DNA restriction analysis, and antibiogram analysis, the techniques most readily available to clinical laboratories, identified 23 to 26 of 29 outbreak-related isolates and assigned 0 to 6 unrelated isolates to outbreak strain types. No single technique was clearly superior to the others; however, biotyping, because it produced so many subtypes, did not effectively group outbreak-related strains of S. aureus.

The use of intermediate and high purity factor VIII products in the treatment of von Willebrand disease.

Since 1985, viral-attenuated blood products have been available for the treatment of patients with hemophilia. Unfortunately, similar viral-attenuated blood products, enriched for von Willebrand factor (vWF), have not been readily available for the treatment of patients with von Willebrand disease (vWD). In the current study, we examined the clinical efficacy and in vivo properties of two viral-attenuated factor VIII products, Koate-HS and Koate-HP, in the treatment of patients with vWD. Twenty-one (21) infusions were evaluated in 17 different vWD patients (4 with type IA; 8 with Type IIA; 1 with Type IID; 4 with type III). Seven (7) patients received Koate-HS and 12 patients received Koate-HP (2 patients received both products; 1 patient was studied three times). Von Willebrand factor antigen, ristocetin cofactor, bleeding time, and the multimeric composition of vWF were determined pre- and post-infusion. Complete or partial correction of prolonged bleeding times was observed in 2 of the 6 patients tested following treatment with Koate-HS and in 7 out of 11 patients tested following treatment with Koate-HP. Surgery was performed on five of these patients, two of whom were treated with Koate-HS and three of whom were treated with Koate-HP. In the surgical patients, clinical hemostasis was achieved regardless of whether the bleeding time was corrected. We conclude that both Koate-HS and Koate-HP can be utilized successfully in the treatment of patients with vWD in spite of the lack of high molecular weight multimers of vWF in these products.(ABSTRACT TRUNCATED AT 250 WORDS)

Imaging of the salivary glands.

The most common conditions affecting the salivary glands are calculi, inflammation and tumours. Plain radiography may be useful, especially in showing calculi. Sialography is the examination of choice for inflammatory diseases, whereas ultrasonography, computed tomography and magnetic resonance imaging are particularly useful in evaluating masses in the salivary glands. Radionuclide studies are sometimes helpful in evaluating inflammatory or tumoral diseases. Each technique has its place, and the methods are often complementary. In this review article the authors present the techniques that they use in evaluating diseases of the salivary glands.

Warfarin-induced complete bilateral breast necrosis.

Plastic surgeons are routinely consulted about the care of extended cutaneous necrosis. We present an unusual case of complete bilateral breast necrosis and review of the literature of warfarin-induced necrosis to inform plastic surgeons of new advances in the physiopathology of this entity. Warfarin-induced necrosis seems to be produced by an imbalance between circulating clotting factors and blood anticoagulation factors.

Diffuse metastatic involvement of the breast.

Metastases to the breast are not very common and, according to the recent literature, usually present as nodules, most often single but sometimes multiple, generally without retraction or thickening of the skin. The authors reviewed 21 such cases from the last 15 years. In six patients the metastatic infiltration presented as diffuse thickening of the skin and increased density of the breast, as can be seen in inflammatory diseases or after radiotherapy. In five of these six women lymphangitic spread of the carcinoma was demonstrated by microscopy.

Role of cytoskeleton in isotonic cell volume control of rabbit proximal tubules.

Stability of mammalian cell volume depends primarily on the sodium pump. When active cation transport of rabbit renal proximal tubules is blocked by ouabain, cells swell, but their size is limited by residual volume control mechanisms. This "ouabain-resistant" volume control is not an active process, as it operates in the presence of cyanide and dinitrophenol and in the absence of exogenous energy. Nevertheless, it remains incompletely explained by known transmembrane oncotic and hydrostatic forces. We tested the hypothesis that the cytoskeleton contributes to isotonic cell volume control. Isolated, collapsed rabbit proximal convoluted tubules (PCT) were crimped at both ends with micropipettes and had their volume assessed optically. PCT in ouabain (1 mM) swelled to 1.40 above control with protein, 1.62 without protein, and 1.89 with the cytoskeleton inhibitors vincristine (5 microM) and cytochalasin B (50 microM) and without protein. Tubulozole-C and cytochalasin D gave similar results. A hydrostatic pressure of 50 cmH2O increased tubule volume to 1.93 before the tubule basement membrane (TBM) prevented further volume increase. We conclude that volume of renal tubule cells in ouabain is limited partly by external protein, but primarily by the cytoskeleton. The TBM prevents massive swelling and tubule disaggregation.

Hemolysins and other characteristics that help differentiate and biotype Staphylococcus lugdunensis and Staphylococcus schleiferi.

Reference strains and clinical isolates representing the newly defined species Staphylococcus lugdunensis and Staphylococcus schleiferi were examined with the battery of tests previously recommended (G.A. Hébert, C.G. Crowder, G.A. Hancock, W.R. Jarvis, and C. Thornsberry, J. Clin. Microbiol. 26:1939-1949, 1988) for other species of coagulase-negative staphylococci (CNS). The Staph-Ident system (Analytab Products, Plainview, N.Y.) supplemented with tests for synergistic hemolysis, adherence to glass, pyroglutamyl-beta-naphthylamide hydrolysis, and susceptibility to a set of five antimicrobial disks differentiated each of these species from other species of CNS and separated strains within each species into several biotypes. Most strains (95%) of S. lugdunensis produced a delta hemolysin like that seen with nine other species of CNS. Most strains (91%) of S. schleiferi produced a beta hemolysin, which is a unique characteristic among CNS. Most (95%) of the S. schleiferi but very few (12%) of the S. lugdunensis were adherence positive. Both hemolysins and adherins are potential virulence factors among CNS. Some (29%) of the S. lugdunensis were beta-lactamase positive. The S. lugdunensis were resistant to polymyxin B and bacitracin (10 U), but the S. schleiferi were susceptible to both disks. Clinical isolates of S. lugdunensis were aligned in 18 biotypes because of eight biochemical profiles and eight physiologic subtypes; isolates of S. schleiferi were in 8 biotypes because of three biochemical profiles and subtypes. These tools for correctly identifying and then biotyping two more clinical species of CNS should enhance both epidemiologic and ecologic investigations.