Toxicological impact of organic ultrafine particles (UFPs) in human bronchial epithelial BEAS-2B cells at air-liquid interface.

Air pollution has significant health effects worldwide, and airborne particles play a significant role in these effects. Ultrafine particles (UFPs) have an aerodynamic diameter of 0.1 µm or less, can penetrate deep into the respiratory tree, and are more toxic due to their large specific surface area, which should adsorb organic compounds. The aim of this study is to show the toxicological effects of UFPs with high organic content at low dose on BEAS-2B cells through at air-liquid interface (ALI) exposure using a Vitrocell® technology and a miniCAST (Combustion Aerosol Standard) generator. In conjunction with this approach, chemical analysis of particles and gas phase was performed to evaluate the presence of polycyclic aromatic hydrocarbons (PAHs). Chemical analyses confirmed the presence of PAHs in UFPs. With this experimental setup, exposure of the BEAS-2B cells induced neither cytotoxicity nor mitochondrial dysfunction. However, an increase of oxidative stress was observed, as assessed through Nrf2, NQO1, HO-1, CuZnSOD, MnSOD, and Catalase gene expression, together with significant induction of genes related to xenobiotic metabolism CYP1A1 and CYP1B1. Negative regulation of inflammatory genes expression (IL-6 and IL-8) was present three hours after the exposition to the UFPs. Taken together, this experimental approach, using repeatable conditions, should help to clarify the mechanisms by which organic UFPs induce toxicological effects.

Basal Ti level in the human placenta and meconium and evidence of a materno-foetal transfer of food-grade TiO2 nanoparticles in an ex vivo placental perfusion model.

BACKGROUND: Titanium dioxide (TiO2) is broadly used in common consumer goods, including as a food additive (E171 in Europe) for colouring and opacifying properties. The E171 additive contains TiO2 nanoparticles (NPs), part of them being absorbed in the intestine and accumulated in several systemic organs. Exposure to TiO2-NPs in rodents during pregnancy resulted in alteration of placental functions and a materno-foetal transfer of NPs, both with toxic effects on the foetus. However, no human data are available for pregnant women exposed to food-grade TiO2-NPs and their potential transfer to the foetus. In this study, human placentae collected at term from normal pregnancies and meconium (the first stool of newborns) from unpaired mothers/children were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and scanning transmission electron microscopy (STEM) coupled to energy-dispersive X-ray (EDX) spectroscopy for their titanium (Ti) contents and for analysis of TiO2 particle deposition, respectively. Using an ex vivo placenta perfusion model, we also assessed the transplacental passage of food-grade TiO2 particles. RESULTS: By ICP-MS analysis, we evidenced the presence of Ti in all placentae (basal level ranging from 0.01 to 0.48 mg/kg of tissue) and in 50% of the meconium samples (0.02-1.50 mg/kg), suggesting a materno-foetal passage of Ti. STEM-EDX observation of the placental tissues confirmed the presence of TiO2-NPs in addition to iron (Fe), tin (Sn), aluminium (Al) and silicon (Si) as mixed or isolated particle deposits. TiO2 particles, as well as Si, Al, Fe and zinc (Zn) particles were also recovered in the meconium. In placenta perfusion experiments, confocal imaging and SEM-EDX analysis of foetal exudate confirmed a low transfer of food-grade TiO2 particles to the foetal side, which was barely quantifiable by ICP-MS. Diameter measurements showed that 70 to 100% of the TiO2 particles recovered in the foetal exudate were nanosized. CONCLUSIONS: Altogether, these results show a materno-foetal transfer of TiO2 particles during pregnancy, with food-grade TiO2 as a potential source for foetal exposure to NPs. These data emphasize the need for risk assessment of chronic exposure to TiO2-NPs during pregnancy.

[Place of the exercise stress test at the sportsman]. / Place de l'épreuve d'effort chez le sportif.

Is the stress test still part of the useful examinations in the detection of risk heart disease in sports subjects? Should we continue to use it as a surveillance examination in coronary sports patients? Meta-analysis, considering a ST subshift of more than 1mm as a criterion for positivity, underline the low prevalence of abnormal examinations and a significant rate of false-positives. But for the diagnosis of coronary artery disease, it is mainly the evolution of the ST segment to effort or recovery and the occurrence of stress arrhythmias that detect true positivity. When coronary risk is more important (presence of risk factors, resumption of sport, intense and prolonged efforts), it seems lawful to recommend such a review on a regular basis among men over 40 years of age with two risk factors but Also among veterans taking up sport after a period of prolonged inactivity. For the asymptomatic coronary athlete the stress test remains at the centre of the final decision for the resumption of a sport in competition irrespective of the method of revascularization. Of course the stress test, even inevitable, remains flawed in the detection of coronary artery disease in the asymptomatic athlete. However, it provides additional information on the condition of being maximal, and attaching importance to arrhythmias, the tensional profile and the maximum power developed in addition to the ST segment's only study.

Presentation, diagnosis, and management of popliteal artery entrapment syndrome: 11 years of experience with 61 legs.

Popliteal artery entrapment syndrome (PAES) is still underdiagnosed yet it may significantly interfere with lifestyle, especially among young sportspeople, with symptoms like intermittent claudication. Although case reports and small case series are sometimes published, studies with larger populations are quite rare. This study summarizes our experience with PAES on 61 limbs (35 patients) over a period of 11 years, describing the demographics, the disease, and the diagnostic and therapeutic methods used with PAES patients. In a population of 327 consecutive explored symptomatic sportspersons, PAES was confirmed in 35 patients on 61 pathologic limbs. The median time with the symptoms before diagnosis was 34 months (range, 3-180 months). The mean age of patients was 30.5 years (range, 17-52 years) with 83% of males. The proportion of patients diagnosed with bilateral PAES was 74%. The main sports practiced were running (15 patients, 43%), soccer (nine patients, 26%), rugby (two patients), and athletics (two patients). Among 21 patients, intra-compartmental pressure measurements (ICP) found 18 (86%) to have an associated chronic exertional compartment syndrome (CECS). Among the patients followed up after PAES surgery, 80% were able to resume sport at a level comparable to that before the onset of pain. PAES could be sought earlier in young sportspeople who experience unexplained leg pain during exercise to diagnose the disease and avoid complications in a timely manner. Compartmental pressures should systematically be measured in the search for an associated CECS.

Electron microscopy approach for the visualization of the epithelial and endothelial glycocalyx.

This study presents a methodological approach for the visualization of the glycocalyx by electron microscopy. The glycocalyx is a three dimensional network mainly composed of glycolipids, glycoproteins and proteoglycans associated with the plasma membrane. Since less than a decade, the epithelial and endothelial glycocalyx proved to play an important role in physiology and pathology, increasing its research interest especially in vascular functions. Therefore, visualization of the glycocalyx requires reliable techniques and its preservation remains challenging due to its fragile and dynamic organization, which is highly sensitive to the different process steps for electron microscopy sampling. In this study, chemical fixation was performed by perfusion as a good alternative to conventional fixation. Additional lanthanum nitrate in the fixative enhances staining of the glycocalyx in transmission electron microscopy bright field and improves its visualization by detecting the elastic scattered electrons, thus providing a chemical contrast.

Ethical considerations and palliative care in patients with amyotrophic lateral sclerosis: A review.

Amyotrophic lateral sclerosis (ALS) is not a curable disease, but it is treatable. By definition, much of the care provided to ALS patients is palliative, even though active life-sustaining strategies are available to prolong survival. Healthcare professionals must develop communication skills that help patients cope with the inexorable progression of the disease and the inevitability of death. Symptomatic treatments as well as respiratory insufficiency and nutritional life-sustaining therapies must be regularly evaluated as the disease progresses, without losing sight of the burden placed on the patient's non-professional caregivers. The decision-making process regarding tracheostomy with invasive ventilation (TIV) is of greater complexity. Providing full information is crucial. Several long interviews are necessary to explain, discuss and allow assimilation of the information. Also, physicians should be careful not to focus exclusively on the biomedical aspects of disease, as ALS patients generally welcome the opportunity to discuss end-of-life issues with their physicians. Psychological factors, education level and cognitive status (especially the level of executive dysfunction) have a major influence on their decisions. However, as many patients do not complete advance directives with regard to TIV, advance care planning may instead be suggested in anticipation of emergency interventions. This should be discussed by healthcare professionals and the patient, and based on the wishes of the patient and caregiver(s), and communicated to all healthcare professionals. Many healthcare professionals are involved in the management of an ALS patient: they include not only those at ALS centers who provide diagnosis, follow-up and treatment initiation (particularly for respiratory and nutritional care), but also the medical and social care networks involved in disability support and home care. Specialist palliative care teams can work in partnership with ALS centers early in the course of the disease, with the center coordinating information-sharing and collaborative discussions.

[Secondary opacification of hydrophilic acrylic intraocular lenses: report of two cases]. / Opacification secondaire d'implants intraoculaires acryliques hydrophiles : à propos de deux cas.

PURPOSE: To describe two cases of secondary opacification of hydrophilic acrylic IOLs after vitreoretinal surgery. METHODS: Analysis of IOL deposits with anterior segment optical coherence tomography (OCT Visante(®)) and high-frequency ultrasound biomicroscopy (CineScan HF, Quantel Medical(®)) was carried out preoperatively. The explanted IOLs were analyzed with optical and electron microscopy, and energy dispersive spectrometry (EDS). RESULTS: In both patients, the deposits were located on the surface and within the implant and were composed of calcium phosphate crystals. Vitreoretinal surgery performed a few months prior to the secondary opacification was identified as a risk factor. CONCLUSION: When a patient presents with a secondary opacification of the IOL involving the visual axis, explantation is sometimes necessary, fortunately with typically good functional recovery in the postoperative period. While this complication is rare and the exact pathophysiology poorly understood, it must be considered in a pseudophakic patient with an unexplained decrease in visual acuity who has undergone more than one intraocular procedure.

Energy restriction only slightly influences protein metabolism in obese rats, whatever the level of protein and its source in the diet.

BACKGROUND: High protein (HP) diets during energy restriction have been studied extensively regarding their ability to reduce body fat and preserve lean body mass, but little is known about their effects on protein metabolism in lean tissues. OBJECTIVE: To determine the effects of energy restriction and protein intake on protein anabolism and catabolism in rats. METHODS: For 5 weeks, 56 male Wistar rats were fed an obesity induction (OI) diet . They were then subjected to a 40% energy restriction using the OI diet or a balanced HP diet for 3 weeks, whereas a control group was fed the OI diet ad libitum (n=8 per group). HP-restricted rats were divided into five groups differing only in terms of their protein source: total milk proteins, casein (C), whey (W), a mix of 50% C and W, and soy (n=8). The animals were then killed in the postprandial state and their body composition was determined. Protein synthesis rates were determined in the liver, gastrocnemius and kidney using a subcutaneous (13)C valine flooding dose. mRNA levels were measured for key enzymes involved in the three proteolysis pathways. RESULTS: Energy restriction, but not diet composition, impacted weight loss and adiposity, whereas lean tissue mass (except in the kidney) was not influenced by diet composition. Levels of neoglucogenic amino acids tended to fall under energy restriction (P<0.06) but this was reversed by a high level of protein. The postprandial protein synthesis rates in different organs were similar in all groups. By contrast, mRNA levels encoding proteolytic enzymes rose under energy restriction in the muscle and kidney, but this was counteracted by a HP level. CONCLUSIONS: In adult obese rats, energy restriction but not diet composition affected fat pads and had little impact on protein metabolism, despite marked effects on proteolysis in the kidney and muscle.

[Survey of cardiovascular risk assessment and the behaviour of a sporting population]. / Enquête sur les comportements et l'évaluation du risque cardiovasculaire dans une population de sportifs.

In order to better understand the risk factors and behaviour of a general sports population, a questionnaire was handed to 603 consecutive sportsmen of various disciplines during a specific sports medicine consultation and a half-marathon. Among the discovered risk factors, smoking was the most common (19.3% for the entire study population), predominantly in the youngest group (26%). A resting ECG had been performed very frequently within the previous year in those over 40 years (86.5%), but less often in the younger sportsmen (44.8%). An exercise test had also very often been performed in those aged over 40 years (69.2 vs 10.6%). Behaviour associated with cardiovascular risk was common. Undertaking physical activity while febrile (58%) and smoking just before or after exertion (13.1%) were widespread behaviours. This population appeared casual in its approach to possibly suspicious cardiac symptoms of exercise, particularly the females and paradoxically the subjects doing the most sport. Lastly, only a minority of sportsmen knew the telephone number for the emergency medical service (45%) or claimed to be competent at first aid (32%). This survey underlines a practice relatively in accordance with the recommendations for detecting cardiovascular pathology, but shows a failure of preventive education.

Poaceae in the natural diet of the snail Helix aspersa Müller (Gastropoda, Pulmonata).

The natural diet of Helix aspersa was studied in two populations by analysing faeces. Picris echioides, Carduus tenuifloris, Urtica dioica, Galium molugo (Dicotyledons) and Poaceae (Monocotyledons) were the principal resources of the studied populations. The species of Poaceae ingested by Helix aspersa in July were determined by analysing the phytoliths present in the faeces. Festuca rubra, Dactylis glomerata and Bromus hordeaceus seemed to be attractive for the snails whereas Elytrigia repens was rejected. These results were convergent with the ingestion rates of Poaceae in the laboratory but assimilation efficiencies did not explain these choices. Poaceae with the highest energetic values were not preferred to others. The texture, the mineral and organic contents of the Poaceae may be responsible for the snails feeding choices. The importance of Poaceae for this species is discussed.

Different expression of an S-adenosylmethionine synthetase gene in transgenic tobacco callus modifies alkaloid biosynthesis.

Transformed callus cultures of Nicotiana tabacum were generated in which the SAM-1 gene from Arabidopsis thaliana encoding S-adenosylmethionine synthetase (SAM-S), under the control of the 35S promoter, had been integrated. The presence of the SAM-1 gene was detected in all tested transformants and the SAM-S activity correlated with the accumulation of SAM in the tobacco callus cultures. Three distinct phenotypic classes were identified among the transgenic cell lines in relation to growth of the cells, structure of the calli, and level of SAM. Transgene silencing was observed in several cultivated transgenic calli and this phenomenon was correlated directly with a low level of SAM-1 mRNA accompanied by a decrease of the SAM-S activity. The transgenic calli overexpressing the SAM-1 gene accumulated a high SAM level. The modifications in SAM-S activity were reflected in the pattern of secondary products present in the different cell lines, thereby demonstrating that the flux through the biosynthetic pathway of a plant secondary product can be modified by means of genetic engineering.

Correlation model to predict residual immiscible organic contaminants in sandy soils.

Researchers in both environmental and petroleum engineering have conducted studies in one-dimensional columns to quantify the amount of residual nonaqueous phase liquids (NAPL) trapped in the porous media as a function of capillary, viscous and buoyancy forces. From these previous studies, it is proven that significant amounts of the original NAPL spill remain as a trapped residual. The objective of this research was to extend this body of work and to develop a correlation model that could predict residual NAPL saturation as a function of common soil characteristics and fluid properties. These properties include parameters derived from sieve analysis, namely, the uniformity coefficient (C(u)), the coefficient of gradation (C(c)), as well as fluid properties (interfacial tension, viscosity and density). Over 100 column experiments were conducted across a range of nine different soil gradations. The data produced by these tests, along with measured soil and fluid properties, were used to generate correlation models to predict residual NAPL saturation (S(rn)). The first correlation model predicts S(rn) for the region where residual NAPL saturation is independent of the capillary number, and dependent on C(u), C(c) and the Bond number. The second correlation model predicts S(rn) for the region where residual NAPL saturation is dependent on capillary number, as well as C(u), C(c) and the Bond number. The third correlation model predicts S(rn) over the entire region as a function of C(u), C(c) and the total trapping number. The correlation models have a R(2) value of 0.972, 0.934 and 0.825, respectively. Hence, the models may potentially be integrated into site characterization approaches.

[Significance of exercise induced ST elevation in patient without a history of previous myocardial infarct]. / Signification d'une élévation du segment ST liée à l'effort chez des patients sans antécédent d'infarctus.

UNLABELLED: Between 1980 and 1995, we observed twenty-five patients (22 males, 3 females) at the mean age of 50.6 +/- 13 years, without previous myocardial infarction who presented exercise induced ST elevation on a bicycle stress test. METHODS: Significant ST elevation was defined as a > or = 1 mm change present in > or = 1 lead measured 0.08 sec after the J point and in 3 consecutive beats. All patients have undergone coronary angiography in the days following the exercise test. RESULTS: Most of patients (56%) presented a history of typical angina that was either purely exertional (8 pts) or also occurred at rest (6 pts). Others (36%) had non typical angina or no angina (8%); 78% of pts were smokers. Sixteen patients (group I) had ST elevation during exercise (exercise duration: 7.6 +/- 4 min; peak heart rate: 135.5 +/- 29 batt/min; ST = 3.5 +/- 1.5 mm) and nine (group II) during the recovery phase (exercise duration 16.3 +/- 1.6 min; p < 0.05; peak heart rate 168 +/- 22 batt/min; p < 0.05; ST: 5.8 +/- 3 mm; p < 0.05). In group I, 1 patient had no vessel disease, 12 had one vessel disease, 3 had multivessel disease with 6 cases of hypersevere coronary stenose (> 90%). In group II, 4 patients had normal coronary arteries, there was one vessel coronary artery disease in 4 patients and multivessel in one subject, without hypersevere coronary stenosis. Correlation between anatomic location of stenosis and electrocardiographic ST elevation was excellent, particularly in case of single vessel disease (100%). All patients underwent one or more new exercise tests after therapeutic intervention (surgery n = 3; angioplasty n = 7; medical treatment n = 15), only 2 patients had persistent exercise induced ST elevation. During follow-up (5 +/- 3 years), 3 patients died (2 cardiac deaths) and 3 had recurrent angina controlled by new treatment. CONCLUSION: Exercise-induced ST elevation is a rare phenomenon in patients without prior myocardial infarction. When occurring purely during exercise, coronary lesions are frequent and often servere, in the other hand ST elevation of the recovery phase is frequently associate with normal arteries or less severe lesions. In most cases, revascularisation or medical therapy can abolish clinical and electrocardiographic abnormalities.

Efficiency of physical (light) or chemical (ABA, tetracycline, CuSO4 or 2-CBSU)-stimulus-dependent gus gene expression in tobacco cell suspensions.

In this study, the efficiency of inducible promoters to switch on gene expression in the presence of inducer or to switch it off in its absence was evaluated in tobacco cell suspensions transformed with the gus gene coding sequence. Either plant (pats1A, pSalT, pIn2-2) or microbial (pMre, pTet) inducible promoters were used to drive gus expression. The inducers were light, abscisic acid, 2-CBSU, CuSO4, tetracycline, respectively. For each construct (inducible promoter-gus coding sequence), the optimal induction conditions were determined (inducer concentration, induction time, and age of cells in culture cycle before induction). The efficiency of the inducible promoter was then evaluated under optimal induction conditions. GUS-expression levels obtained under non-inducing and inducing conditions were systematically compared. Thirty or forty percent of the clones transformed with the pSalT-gus or pTet-gus construct, respectively, showed high induction rates (>1000) and GUS activities of the same order as those obtained with a constitutive system. However, basal GUS levels were always high for the pTet-gus cell lines. Seventy or eighty-five percent of the cell lines transformed with the pMre-gus or pln2-2-gus construct, respectively, had induction rates of 1.5 to 1000. The pats1A-gus construct gave very low induction rates-55% of cell lines had induction rates less than 1.5. Only the pSalt-gus construct gave both the highest induction rates and basal GUS-levels equivalent to the endogenous GUS background.

Physical training improves exercise capacity in patients with mitral stenosis after balloon valvuloplasty.

BACKGROUND: Haemodynamic measurements taken at rest and during exercise showed that percutaneous transvenous mitral commissurotomy results in both acute and long-term improvement. However, the time lag before there is an increase in exercise and in peak oxygen uptake appears to be delayed and irregular. PATIENTS AND METHODS: To assess the potential of physical training to restore better physical capacity after percutaneous transvenous mitral commissurotomy, 26 patients with mitral stenosis were studied after the procedure. The group was split into two. Thirteen underwent a 3-month rehabilitation programme, and the other 13, who did not, acted as controls. RESULTS: The mitral valve orifice area increased similarly, from 1.12 +/- 0.17 to 1.88 +/- 0.28 cm2 in the training group and from 1.04 +/- 0.16 to 1.88 +/- 0.19 cm2 in the control group. Cardiopulmonary parameters were similar before percutaneous transvenous mitral commissurotomy (peak VO2: 19.9 +/- 2.4 vs 18.9 +/- 4.5 ml. min-1.kg-1; peak workload: 94.6 +/- 29.3 vs 96.1 +/- 25 watts; VO2 at anaerobic threshold: 17 +/- 3.4 vs 16.1 +/- 5.2 ml.min-1.kg-1; all P = ns). Three months later the results were higher in the training group 1 (peak VO2: 26.6 +/- 4.7 vs 21.6 +/- 3.8 ml.min-1.kg-1, P = 0.03; peak workload: 125.4 +/- 26.6 vs 108.5 +/- 23 watts, P = 0.03; VO2 at anaerobic threshold: 19.6 +/- 5.8 vs 15.8 +/- 2.9 ml.min-1.kg-1; P = 0.02). CONCLUSION: These results indicate that patients should take up exercise after successful percutaneous transvenous mitral commissurotomy for better functional improvement.

[Fortuitous discovery of Brugada syndrome in an asymptomatic 70-year-old sportsman]. / Découverte fortuite d'un syndrome de Brugada chez un septuagénaire sportif asymptomatique.

The authors report the case of an elderly sportsman presenting with the electrical signs of the syndrome described by Brugada. The absence of any serious clinical events in this patient questions the pejorative prognosis usually reported and the specific identity of this syndrome in relation to right ventricular arrhythmogenic dysplasia.

[Segmental rehabilitation in cardiac failure: short and long-term results]. / Réadaptation segmentaire chez les insuffisants cardiaques: résultats à court et à long terme.

Many patients with chronic cardiac failure may benefit from exercise rehabilitation. However, the usual protocols, which may lead to haemodynamic disturbances or induce arrhythmias, are rarely applicable in the most severe cases. Therefore, the authors developed a protocol of segmental rehabilitation where the same muscle groups as in global readaptation are involved, but successively and not simultaneously. This study included 25 patients in the NYHA class III. Many parameters were analysed before and after forty sessions. Although the resting isotopic ejection fraction (0.26 +/- 0.1 vs 0.27 +/- 0.11; p = NS), oxygen consumption at the ventilatory threshold (14.3 +/- 3.5 vs 18.3 +/- 5.2 ml/kg/min; p = NS) or at peak effort (17.4 +/- 4.7 versus 18.3 +/- 5.2 ml/kg/min, p = NS) were unchanged, three other parameters were significantly improved: the duration of exercise (9.2 +/- 2.4 vs 10.4 +/- 3.4 min; p < 0.02) maximum work load (3 046 +/- 1 510 vs 3 992 +/- 2 482; p < 0.01) and muscular force (151 +/- 35 versus 220 +/- 41 kg; p < 0.0001). In addition, after a follow-up period of 43 +/- 18 months, a close inverse relationship was observed between the gains obtained in terms of duration of exercise and maximum work load and the number of hospital readmissions. Similarly, the 10 patients having undergone rehabilitation with this protocol had 11.7 times fewer hospital readmissions than the other 15. Segmental rehabilitation would therefore seem to be a safe technique for patients with severe cardiac for significantly increasing exercise capacity and lowering the number of readmissions to hospital.