Artificial muscle to wash blood out of fibrillating atrium: an alternative to lifelong anticoagulation.

The Atripump is a motorless, volume displacement pump based on artificial muscle technology that could reproduce the pump function of normal atrium. It could help prevent blood clots due to blood stagnation and eventually avoid anticoagulation therapy in atrial fibrillation (AF). An animal study has been designed to assess mechanical effects of this pump on fibrillating atrium. The Atripump is a dome shaped silicone coated nitinol actuator. A pacemaker like control unit drives the actuator. In five adult sheep, the right atrium (RA) was exposed and dome sutured onto the epicardium. Atrial fibrillation was induced using rapid epicardial pacing (600 beats/min). Ejection fraction of the RA was obtained with intracardiac ultrasound in baseline, AF and Atripump assisted AF conditions. The dome's contraction rate was 60/min with power supply of 12V, 400 mA for 200 ms and ran for 2 hours in total. Mean temperature on the RA was 39+/-1.5 degrees C. Right atrium ejection fraction was 31% in baseline conditions, 5% and 20% in AF and assisted AF, respectively. In two animals a thrombus appeared in the right appendix and washed out once the pump was turned on. The Atripump washes blood out the RA acting as an anticoagulant device. Possible clinical implications in patients with chronic AF are prevention of embolism of cardiac origin and avoidance of hemorrhagic complication due to chronic anticoagulation.

Independent relations of left ventricular structure with the 24-hour urinary excretion of sodium and aldosterone.

Previous studies reported on the association of left ventricular mass index (LVMI) with urinary sodium or with circulating or urinary aldosterone. We investigated the independent associations of LVMI with the urinary excretion of both sodium and aldosterone. We randomly recruited 317 untreated subjects from a white population (45.1% women; mean age 48.2 years). Measurements included echocardiographic left ventricular (LV) properties, the 24-hour urinary excretion of sodium and aldosterone, plasma renin activity (PRA), and proximal (RNa(prox)) and distal (RNa(dist)) renal sodium reabsorption, assessed from the endogenous lithium clearance. In multivariable-adjusted models, we expressed changes in LVMI per 1-SD increase in the explanatory variables, while accounting for sex, age, systolic blood pressure, and the waist-to-hip ratio. LVMI increased independently with the urinary excretion of both sodium (+2.48 g/m(2); P=0.005) and aldosterone (+2.63 g/m(2); P=0.004). Higher sodium excretion was associated with increased mean wall thickness (MWT: +0.126 mm, P=0.054), but with no change in LV end-diastolic diameter (LVID: +0.12 mm, P=0.64). In contrast, higher aldosterone excretion was associated with higher LVID (+0.54 mm; P=0.017), but with no change in MWT (+0.070 mm; P=0.28). Higher RNa(dist) was associated with lower relative wall thickness (-0.81x10(-2), P=0.017), because of opposite trends in LVID (+0.33 mm; P=0.13) and MWT (-0.130 mm; P=0.040). LVMI was not associated with PRA or RNa(prox.) In conclusion, LVMI independently increased with both urinary sodium and aldosterone excretion. Increased MWT explained the association of LVMI with urinary sodium and increased LVID the association of LVMI with urinary aldosterone.

Investigations on carbon isotope ratios and concentrations of urinary formestane.

The aromatase inhibitor formestane (4-hydroxy-androst-4-ene-3,17-dione, F) is prohibited in sports by the World Anti-Doping Agency (WADA). F possesses only weak androgenic properties and is presumed to be employed in order to suppress estrogen production during the illicit intake of anabolic steroids by athletes. Former studies additionally showed that F is an endogenous steroid produced in low amounts. According to the regulations of WADA, urinary concentrations above 100 ng/ml are assumed to be due to ingestion of F. To distinguish between endogenous or exogenous sources of urinary F, isotope ratio mass spectrometry (IRMS) is the method of choice. Therefore, a method to determine the carbon isotope ratio (CIR) of F in urine samples was developed and validated. Routine samples (n = 42) showing concentrations of F above 5 ng/ml were investigated and enabled elucidation of the CIR of endogenous F and subsequent the calculation of a reference limit. A reference population encompassing n = 90 males and females was investigated regarding endogenous concentrations of F. An excretion study with one male volunteer was conducted to test and validate the developed method and to identify possible impact of F administration on other endogenous steroids. By CIR determination of F it is clearly possible to elucidate its endogenous or exogenous source. Taking into account the CIR of other target analytes like testosterone, a differentiation between F and androstenedione intake is possible. In 2011, the first exogenous F below the WADA threshold could be detected by means of the developed IRMS method.

Artificial neural network study of whole-cell bacterial bioreporter response determined using fluorescence flow cytometry.

Genetically engineered bioreporters are an excellent complement to traditional methods of chemical analysis. The application of fluorescence flow cytometry to detection of bioreporter response enables rapid and efficient characterization of bacterial bioreporter population response on a single-cell basis. In the present study, intrapopulation response variability was used to obtain higher analytical sensitivity and precision. We have analyzed flow cytometric data for an arsenic-sensitive bacterial bioreporter using an artificial neural network-based adaptive clustering approach (a single-layer perceptron model). Results for this approach are far superior to other methods that we have applied to this fluorescent bioreporter (e.g., the arsenic detection limit is 0.01 microM, substantially lower than for other detection methods/algorithms). The approach is highly efficient computationally and can be implemented on a real-time basis, thus having potential for future development of high-throughput screening applications.

Incontinence urinaire chez la femme: prise en charge en médecine de premier recours [Urinary incontinence in women: management in primary care]

Urinary incontinence in women is a largely under-evaluated problem that affects nearly one out of two adult women. Even thouh its physiopathology is complex and its etiologies are multiple (and often intricate), urodynamic investigations are not considered necessary before starting a conservative therapy, which can be initiated by the primary care physician. Conservative management is based upon lifestyle modifications, specialized physiotherapy, and in certain cases medication. In the case of insufficient response after three months, the patient should be recommended to a specialist who can evaluate the need for a surgical procedure.

Urinary analysis of 16(5alpha)-androsten-3alpha-ol by gas chromatography/combustion/isotope ratio mass spectrometry: implications in anti-doping analysis.

We present a method for the analysis of urinary 16(5alpha)-androsten-3alpha-ol together with 5beta-pregnane-3alpha,20alpha-diol and four testosterone metabolites: androsterone (Andro), etiocholanolone (Etio), 5alpha-androstane-3alpha,17beta-diol (5alphaA), 5beta-androstane-3alpha,17beta-diol (5betaA) by means of gas chromatography/combustion/isotopic ratio mass spectrometry (GC/C/IRMS). The within-assay and between-assay precision S.D.s of the investigated steroids were lower than 0.3 and 0.6 per thousand, respectively. A comparative study on a population composed of 20 subjects has shown that the differences of the intra-individual delta(13)C-values for 16(5alpha)-androsten-3alpha-ol and 5beta-pregnane-3alpha,20alpha-diol are less than 0.9 per thousand. Thereafter, the method has been applied in the frame of an excretion study following oral ingestion of 50 mg DHEA initially and oral ingestion of 50mg pregnenolone 48 h later. Our findings show that administration of DHEA does not affect the isotopic ratio values of 16(5alpha)-androsten-3alpha-ol and 5beta-pregnane-3alpha,20alpha-diol, whereas the isotopic ratio values of 5beta-pregnane-3alpha,20alpha-diol vary by more 5 per thousand upon ingestion of pregnenolone. We have observed delta(13)C-value changes lower than 1 per thousand for 16(5alpha)-androsten-3alpha-ol, though pregnenolone is a precursor of the 16-ene steroids. In contrast to 5beta-pregnane-3alpha,20alpha-diol, the 16-ene steroid may be used as an endogenous reference compound when pregnenolone is administered.

OnabotulinumtoxinA and multiple sclerosis.

Lower urinary tract dysfunction is present in two of three patients with multiple sclerosis five years after the diagnosis. Most frequent symptoms are related to neurogenic detrusor overactivity, often associated with detrusor-sphincter dyssynergia. From the end of the 1990s, there is growing evidence that neurogenic detrusor overactivity can be effectively managed by intradetrusorial injections of botulinum toxin type A. This treatment has shown, in different randomised placebo-controlled trials, to be safe and effective on clinical and urodynamic parameters with significant improvement in quality of life. The median duration of effect is in mean nine months. The vast majority of studies have been conducted with onabotulinumtoxinA. The dose of onabotulinumtoxinA commonly used to treat neurogenic detrusor overactivity in patients with multiple sclerosis is 200 UI, even if in selected patients lower doses can be preferred. To be considered eligible for treatment, all patients should accept and be instructed to perform clean intermittent self-catheterisation, since the risk of increased post-void residual volume and/or urinary retention after injection is high, especially with 200 UI of onabotulinumtoxinA. However, quality of life and patient satisfaction seem not to be affected by the need of intermittent catheterisation. The risk of urinary infection after the procedure is to be kept in mind, mainly in patients with multiple sclerosis, so that adequate antibiotic prophylaxis is highly recommended.

Influences of β-HCG administration on carbon isotope ratios of endogenous urinary steroids.

Several factors influencing the carbon isotope ratios (CIR) of endogenous urinary steroids have been identified in recent years. One of these should be the metabolism of steroids inside the body involving numerous different enzymes. A detailed look at this metabolism taking into account differences found between steroids excreted as glucuronides or as sulphates and hydrogen isotope ratios of different steroids pointed out possibility of unequal CIR at the main production sites inside the male body - the testes and the adrenal glands. By administration of β-HCG it is possible to strongly stimulate the steroid production within the testes without influencing the production at the adrenal glands. Therefore, this treatment should result in changed CIR of urinary androgens in contrast to the undisturbed pre-treatment values. Four male volunteers received three injections of β-HCG over a time course of 5 days and collected their urine samples at defined intervals after the last administration. Those samples showing the largest response in contrast to the pre-administration urines were identified by steroid profile measurements and subsequent analysed by GC/C/IRMS. CIR of androsterone, etiocholanolone, testosterone, 5α- and 5β-androstanediol and pregnanediol were compared. While pregnanediol was not influenced, most of the investigated androgens showed depleted values after treatment. The majority of differences were found to be statistically significant and nearly all showed the expected trend towards more depleted δ(13)C-values. These results support the hypothesis of different CIR at different production sites inside the human body. The impact of these findings on doping control analysis will be discussed.

Description of a new artificial diet for rearing ant colonies as Iridomyrmex humilis, Monomorium pharaonis and Wasmannia auropunctata (Hymenoptera, Formicidae)

A diet which does not desiccate was developed for rearing various ant species. this diet was found to be very attractive forIridomyrmex humilis. Monomorium pharaonis andWasmannia auropunctata in which species it permitted the rearing of colonies for long periods and the regular production of sexuals. Nous présentons la recette d'une nourriture artificielle élaborée pour élever des fourmis en laboratoire. Cette nourriture ne se dessèche pas et s'est avérée adéquate pour l'élevage de plusieur espèces telles queIridomyrmex humilis, Monomorium pharaonis etWasmannia auropunctata. Des sexués mâles et femelles ont été régulièrement produits dans ces sociétés.

Assessment of particulate exposure and surface characteristics in association with urinary levels of 8-hydroxy-2'-deoxyguanosine, considered as marker of oxidative stress

Epidemiological studies have demonstrated that exposure to fine particles is associated to adverse health effects, including cancer, respiratory and cardiovascular diseases. However, mechanisms by which particles induce health effects remain unclear. According to one of the most investigated hypotheses, particles cause adverse effects through the production of reactive oxygen species (ROS), which are very hazardous compounds able to attack directly biological structures, including the DNA strand or the lipid bilayer of the cells. If the defense mechanisms, constituted of antioxidants, are not able to counter ROS, then these compounds will cause in the body a range of oxidation reactions called "oxidative stress". The aim of the present research project was to better understand mechanisms by which exposure to fine particles induces oxidative stress. The first point of this project was to check whether exposure to high levels of fine particles is directly linked to oxidative stress, and whether this oxidative stress is accompanied by the activation of the defense mechanisms (antioxidants). The second point was to study the role played by the particle surface characteristics in the oxidative stress process. For that purpose, a study was conducted in bus depots with the participation of 40 mechanics. First, occupational exposure to particles (PM4) and to other pollutants (NOx, O3) was measured over a two-day period. Then, urine samples of mechanics were collected in order to measure levels of 8-hydroxy-2'-deoxyguanosine (8OHdG) and antioxidants. 8OHdG is a molecule formed by the oxidation of DNA and allowing to assess the oxidative stress status of the mechanics. Finally, particles were collected on filters, and functional groups located on the particle surface were analyzed in the laboratory using a Knudsen flow reactor. This technique allows not only to quantify functional groups on the particle surface, but also to measure the reaction kinetics. Results obtained during the field campaign in bus depots showed that mechanics were exposed to rather low levels of PM4 (20-85 μg/m3) and of pollutants (NOx: 100-1000 ppb; O3: <15 ppb). However, despite this low exposure, urinary levels of the oxidative stress biomarker (8OHdG) increased significantly for non-smoking workers over a two-day period of shift. This oxidative stress was accompanied by an increase of antioxidants, indicating the activation of defense mechanisms. On the other hand, the analysis of functional groups on the particle surface showed important differences, depending on the workplace, the date and the activities of workers. The particle surface contained simultaneously antagonistic functional groups which did not undergo internal reactions (such as acids and bases), and was usually characterized by a high density of carbonyl functions and a low density of acidic sites. Reaction kinetics measured using the Knudsen flow reactor pointed out fast reactions of oxidizable groups and slow reactions of acidic sites. Several exposure parameters were significantly correlated with the increase of the oxidative stress status: the presence of acidic sites, carbonyl functions and oxidizable groups on the particle surface; reaction kinetics of functional groups on the particle surface; particulate iron and copper concentrations; and NOx concentration.