Ex-vivo assessment of chronic toxicity of low levels of cadmium on testicular meiotic cells.

Using a validated model of culture of rat seminiferous tubules, we assessed the effects of 0.1, 1 and 10 µg/L cadmium (Cd) on spermatogenic cells over a 2-week culture period. With concentrations of 1 and 10 µg/L in the culture medium, the Cd concentration in the cells, determined by ICP-MS, increased with concentration in the medium and the day of culture. Flow cytometric analysis enabled us to evaluate changes in the number of Sertoli cells and germ cells during the culture period. The number of Sertoli cells did not appear to be affected by Cd. By contrast, spermatogonia and meiotic cells were decreased by 1 and 10 µg/L Cd in a time and dose dependent manner. Stage distribution of the meiotic prophase I and qualitative study of the synaptonemal complexes (SC) at the pachytene stage were performed by immunocytochemistry with an anti SCP3 antibody. Cd caused a time-and-dose-dependent increase of total abnormalities, of fragmented SC and of asynapsis from concentration of 0.1 µg/L. Additionally, we observed a new SC abnormality, the "motheaten" SC. This abnormality is frequently associated with asynapsis and SC widening which increased with both the Cd concentration and the duration of exposure. This abnormality suggests that Cd disrupts the structure and function of proteins involved in pairing and/or meiotic recombination. These results show that Cd induces dose-and-time-dependent alterations of the meiotic process of spermatogenesis ex-vivo, and that the lowest metal concentration, which induces an adverse effect, may vary with the cell parameter studied.

[Occupational noise induced hearing loss acknowledgement: Opinions of a regional occupational disease commission]. / Reconnaissance des surdités professionnelles : il faudrait réduire le nombre de dossiers mal documentés soumis au Comité régional de reconnaissance des maladies professionnelles.

CONTEXT: In France, occupational noise-induced hearing loss is compensated by the "Régime Général" of the French Social Security according to the system of the tables of occupational diseases. If administrative and/or exposure criteria are lacking, the regional occupational disease commission (CRRMP) is seized to pronounce an opinion - favourable or not - on the direct link between occupational activity and the deafness. OBJECTIVE: This study aimed at determining the decisive factors in this opinion. METHODS: An exhaustive retrospective investigation analysed conclusions of CRRMP of the region Provence-Alpes-Côte d'Azur-Corsica related to the noise-induced hearing loss declarations emitted anonymously between January 1st, 2005 and December 31st, 2007. Favourable and unfavourable opinions were listed then cross-examined against the sociodemographics data of the employees, areas of expertise of the physicians at the origin of the initial medical certificate, grounds for submission to the commission, the occupational physician's opinion on the occupational origin, the results of the engineering consultant's investigation, the audiogram of the first observation of injury and those made in period of noise exposure. RESULTS: One hundred and twenty conclusions were analyzed. Claimants, typically male, 59-year-old on average, mainly came from the sectors of the metal industry (46.7%), transportation (20.8%) and building and civil engineering works (15.8%). All in all, 57.5% of the declarations were refused. These refusals were mainly connected to an opinion unfavourable, unexploitable or absent in the occupational physician, an overrun of the care period when it lasted 5 years and more and the absence of hearing deficit during the exposure. PERSPECTIVES: The results of our study lead to recommend the implementation of a certificate of noise exposure and the realization of an audiogram at the end of exposure to reduce the number of badly informed files and bring an answer more adapted to the demands of occupational noise-induced hearing loss acknowledgements.

Validation of a rat seminiferous tubule culture model as a suitable system for studying toxicant impact on meiosis effect of hexavalent chromium.

There is evidence that exposure to environmental factors is at least partly responsible for changes in semen quality observed over the past decades. The detection of reproductive toxicants under Registration, Evaluation and Authorisation of Chemicals (REACH) will impact animal use for regulatory safety testing. We first validated a model of culture of rat seminiferous tubules for toxicological studies on spermatogenesis. Then, using this model of culture, we assessed the deleterious effects of 1, 10, and 100 microg/l hexavalent chromium [Cr(VI)] on meiotic cells. The prophase I of meiosis was studied in vivo and ex vivo. Bromo-2'-deoxyuridine (BrdU) was used to describe the kinetics of germ cell differentiation. SCP3 labeling allowed to establish the distribution of the stages of the meiotic prophase I and to perform a qualitative study of the pachytene stage in the absence or presence of Cr(VI). The development of the meiotic step of pubertal rats was similar in vivo and ex vivo. The number of total cells appeared not affected by the presence of Cr(VI) irrespective of its concentration. However, the numbers of late spermatocytes and of round spermatids were decreased by Cr(VI) even at the lower concentration. The percentage of synaptonemal complex abnormalities increased slightly with the time of culture and dramatically with Cr(VI) concentrations. This model of culture appears suitable for toxicological studies. This study shows that Cr(VI) is toxic for meiotic cells even at low concentrations, and its toxicity increases in a dose-dependent manner.

Occupational exposures obtained by questionnaire in clinical practice and their association with semen quality.

In industrial countries, evidence suggests that semen quality has been steadily decreasing over the past 5 decades. We employed a short questionnaire to examine the association between self-reported physical or chemical occupational exposures and semen quality. The study included 402 men consulting for couple infertility (314 with oligospermia, asthenospermia, or teratospermia and 88 with normal semen; World Health Organization criteria). Exposure effects on global sperm quality and total sperm count, sperm motility, and sperm morphology were investigated. We found significant associations between semen impairment and occupational risk factors such as exposure to heavy metals (adjusted odds ratio [OR] = 5.4; 95% confidence interval [CI], 1.6-18.1), solvents (OR = 2.5; 95% CI, 1.4-4.4), fumes (OR = 1.9; 95% CI, 1.1-3.4), and polycyclic aromatic hydrocarbons (OR = 1.9; 95% CI, 1.1-3.5). Exposure to pesticides or cement was nearly significant (OR = 3.6; 95% CI, 0.8-15.8, and OR = 2.5; 95% CI, 0.95-6.5, respectively). Physical risk factors were associated with some sperm anomalies, such as mechanical vibrations with oligospermia and teratospermia as well as excess heat and extended sitting periods with impaired motility. Exposure to ionizing radiation and electromagnetic fields was not associated with semen impairment; these results, however, may be skewed, because very few subjects reported such exposure. Despite the small dataset, self-reported exposures were correlated with semen impairment. This approach may be recommended in routine clinical practice to seek relationships between occupational exposures to reprotoxic agents and impaired semen parameters. This knowledge would allow preventive measures in the workplace to be established and could be complemented by the use of biomarkers to better characterize exposure to chemical substances and their spermiotoxic effects.

Nebulisers comparison with inhaled tobramycin in young children with cystic fibrosis.

BACKGROUND: This randomised cross-over pilot study was undertaken in 10 cystic fibrosis children aged 10 to 63 months to describe lung absorption of tobramycin delivered by the PariLC+/PariTurboboyN (Pari GmbH) and the disposable NL9M/AtomisorBoxPlus (Diffusion Technique Française) nebulising systems. METHODS: Each child inhaled 300 mg tobramycin delivered with one or the other apparatus via a facemask in two separate and standardised sessions. Urine was collected for 6 h. Tobramycin concentrations determined by immunoprecipitation were expressed in mg per g of creatinine and compared by a Wilcoxon test for matched pairs. The influences of age, weight and Brasfield score on this parameter were evaluated by correlation tests, and those of sex, previous nebulisation treatment, and crying or coughing were evaluated by Student's t-test. RESULTS: The amount of tobramycin measured in urines was low and variable. Median values for urinary tobramycin concentration were 47.6 mg/g (14.9-79.6) with the PariLC+ and 42.6 mg/g (6.3-112.8) with the NL9M (p=0.6). PariLC+ delivered tobramycin in 22 min and NL9M in 12 min (p=0.005). Crying or coughing dramatically reduced the amount of tobramycin collected. CONCLUSION: This pilot study shows that evaluation of nebulisers based on tobramycin renal excretion is feasible in young children with cystic fibrosis.

Use of lidocaine-prilocaine patch for the mantoux test: Influence on pain and reading.

A formulation of a eutectic mixture of lidocaine-prilocaine (EMLA) changes basal skin perfusion. Its use for alleviating pain associated with the Mantoux test may modify the recruitment of sensitised lymphocytes and then the response to tuberculin test. Twenty-four healthy BCG-vaccinated volunteers (26.7+/-4.1 years) received on each forearm an intradermal injection of 10IU tuberculin, one of the forearms being randomly pre-treated for 1h with EMLA-patch 5%. Pain associated with the Mantoux test was evaluated using a visual analogue scale. The transversal diameter of the induration was read at 72h. Subjects with 6mm difference between diameters (i.e. twice the usual variation for a Mantoux test) were recorded. Results were compared using a paired t-test. When using lidocaine-prilocaine prior to the test, a three-fold decrease in pain was noted (p<0.0001). Reading of the test were not affected by the lidocaine-prilocaine application (p=0.26). Four subjects had 6mm or more difference between their two tests, two of them having an induration greater than 15mm with lidocaine-prilocaine. Lidocaine-prilocaine reduces significantly pain associated with the Mantoux test but does not normally affect the test reading. However, when the induration is more than 15mm, a control without lidocaine-prilocaine has to be considered.

An implantable loop recorder study of highly symptomatic vasovagal patients: the heart rhythm observed during a spontaneous syncope is identical to the recurrent syncope but not correlated with the head-up tilt test or adenosine triphosphate test.

OBJECTIVES: The aim of this study was to analyze the heart rhythm during spontaneous vasovagal syncope (VVS) in highly symptomatic patients with implantable loop recorders (ILR) and to correlate this rhythm with the heart rhythm observed during head-up tilt test (HUT). BACKGROUND: Heart rhythm obtained during provocative condition is often used to guide therapy in VVS. To date there is no conclusive evidence that the heart rhythm observed during a positive HUT can predict heart rhythm during VVS or that the heart rhythm observed during a spontaneous syncope will be identical to the recurrent syncope. METHODS: Twenty-five consecutive VVS patients (age 60.2 +/- 17.1 years; 14 women,) presenting with frequent syncopes (6.9 +/- 4.6 episodes/year) and a positive HUT (cardioinhibitory in 8 patients) were implanted with an ILR. Seven of them also had a positive adenosine triphosphate (ATP) test. RESULTS: Follow-up was 17.0 +/- 3.6 months. Thirty VVS were observed in 12 patients. Nine episodes showed bradycardia of <40 beats/min or asystole; progressive sinus bradycardia preceding sinus arrest was the most frequent electrocardiographic finding. Twenty-one syncopes occurred without severe bradycardia. The heart rhythm observed during the first syncope was identical to the recurrence. No correlation was found between slow heart rate at the ILR interrogation and a cardioinhibitory HUT response (p = 1.0) or a positive ATP test (p = 1.0). CONCLUSIONS: In highly symptomatic patients with VVS, the heart rhythm observed during spontaneous syncope does not correlate with the HUT. The heart rhythm during the first spontaneous syncope is identical to the recurrent syncope.

Phenotypes of asthma revisited upon the presence of atopy.

Immunological studies claimed that atopic and non-atopic asthma share more similarities than differences. However, these two phenotypes of asthma are considered to be distinguishable upon distinct clinical patterns, which were not systematically assessed before in a large population. We studied characteristics discriminating atopic from non-atopic asthma among 751 asthmatic patients and 80 factors were analysed in univariate and multivariate analysis. Age, age of onset of asthma, female/male ratio were higher in non-atopic (n=200) than in atopic (n=551) asthmatics. Familial asthma, seasonal symptoms, rhinitis, conjunctivitis, allergen-triggered symptoms, improvement in altitude, exercise-induced asthma were associated with atopy. Non-atopic asthmatics displayed lower FEV(1) and FVC. Smoking was more frequent and asthma was more severe in these patients. Younger age, early onset, male sex, rhinitis and smoking were independent factors discriminating atopic from non-atopic asthma. This study establishes in a large population of asthmatics that although similarities exist between atopic and non-atopic asthma, two clinical phenotypes can still distinguish both kinds of asthma.

Assessment of lifestyle effects on the overall antioxidant capacity of healthy subjects.

Oxidative damage is increasingly recognized as playing an important role in the pathogenesis of several diseases such as cancer and cardiovascular diseases. Using a biologic test based on whole blood resistance to free-radical aggression, we sought to evaluate lifestyle factors that may contribute to the normal variability of the overall antioxidant status. We assessed this global antiradical defense capacity in 88 men and 96 women in relation to information on lifestyle obtained by questionnaire. In our relatively young, healthy population, we found a weak negative relation between male sex or aging and the resistance to oxidant stress. Among the factors studied, nonsmoking, vitamin and/or mineral supplementation, and regular physical activity were closely associated with an increased overall antioxidant capacity. Conversely, the antioxidant potential was negatively related to tobacco smoking; psychologic stress; alcohol consumption; moderate vegetable, low fruit, and low fish consumption; and, to a lesser extent, high natural ultraviolet light exposure. Thus, we were able to determine "unhealthy" and "healthy" lifestyle patterns that truly contributed to the variation of individual antioxidant capacity. We conclude that lifestyle determinants of cancer and cardiovascular risks were associated with a decreased overall antioxidant status as dynamically measured by means of a biologic test. Thus, the evaluation of the total human resistance against free-radical aggression, taking into account nutritional habits, lifestyle, and environmental factors, may be useful in preventive medicine as a precocious diagnosis to identify healthy subjects who are at risk for free-radical-mediated diseases.