Estimating evaporation rates and contaminant air concentrations due to small spills of non-ideal aqueous organic solvent mixtures in a controlled environment.

Although small spills of non-ideal organic solvent mixtures are ubiquitous undesirable events in occupational settings, the potential risk of exposure associated with such scenarios remains insufficiently investigated. This study aimed to examine the impact of non-ideality on evaporation rates and contaminant air concentrations resulting from small spills of organic solvent mixtures. Evaporation rate constants alphas (α) were experimentally measured for five pure solvents using a gravimetric approach during solvent evaporation tests designed to simulate small spills of solvents. Two equations were used for estimating contaminants' evaporation rates from aqueous mixtures assuming either ideal or non-ideal behavior based on the pure-chemical alpha values. A spill model also known as the well-mixed room model with exponentially decreasing emission rate was used to predict air concentrations during various spill scenarios based on the two sets of estimated evaporation rates. Model predictive performance was evaluated by comparing the estimates against real-time concentrations measured for the same scenarios. Evaluations for 12 binary non-ideal aqueous mixtures found that the estimated evaporation rates accounting for the correction by the activity coefficients of the solvents (median = 0.0318 min-1) were higher than the evaporation rates estimated without the correction factor (median = 0.00632 min-1). Model estimates using the corrected evaporation rates reasonably agreed with the measured values, with a median predicted peak concentrations-to-measured peak concentrations ratio of 0.92 (0.81 to 1.32) and a median difference between the predicted and the measured peak times of -5 min. By contrast, when the non-corrected evaporation rates were used, the median predicted peak concentrations-to-measured peak concentrations ratio was 0.31 (0.08 to 0.75) and the median difference between the predicted and the measured peak times was +33 min. Results from this study demonstrate the importance of considering the non-ideality effect for accurately estimating evaporation rates and contaminant air concentrations generated by solvent mixtures. Moreover, this study is a step further in improving knowledge of modeling exposures related to small spills of organic solvent mixtures.

Predicting first-order evaporation rate constant alpha (α) from small spills of organic solvents in a controlled environment.

Exposures to vapors generated by small spills of organic solvents are common in the occupational hygiene practice. In these scenarios, contaminant mass release is exponentially decreasing, driven by an evaporation rate constant alpha (α). Knowing α is fundamental for adequately modeling peak concentrations and/or short-term exposures that occur and for achieving efficient occupational risk analysis and management. The purpose of this study was to measure alpha experimentally using a gravimetric approach in a controlled environment during solvent evaporation tests designed to simulate small spills of solvents. The effects of several factors on α were evaluated. Equations based on regression models derived from the experimental data were proposed for predicting α. Predictions were externally validated against experimental data. A total of 183 tests was performed. Data analyses found that alpha (α) values increased with vapor pressure, spill surface area-to-spill volume ratio, and air speed across the spill. Larger α were associated with petri dish containers compared to watch glasses. Three regression models were created for predicting α. They had four variables in common, namely vapor pressure, molecular weight, air speed above the liquid, and surface tension of the liquid. The fifth variable was either spill volume, spill surface area, or spill surface area-to-spill volume ratio. The R2 of the regression models were equal to 0.98. External validation showed mean relative errors of -32.9, -32.0, and -25.5%, respectively, with associated standard deviations of the relative errors of 17.7, 33.3, and 26.0%, respectively, and associated R2 of 0.92, 0.65, and 0.87, respectively. The proposed equations can be used for estimating α in exposure scenarios similar to those evaluated in this study. Moreover, these models constitute a step further in the improvement of knowledge on estimating evaporation rates for small spills of organic solvents.

Modeling occupational exposure to solvent vapors using the Two-Zone (near-field/far-field) model: a literature review.

The Two-Zone model is used in occupational hygiene to predict both near-field and far-field airborne contaminant concentrations. A literature review was carried out on 21 scientific publications in which the Two-Zone model was used to assess occupational exposure to solvent vapors. Data on exposure scenarios, solvents, generation/emission rates, near- and far-field parameters, and model performance were collected and analyzed. Over the 24 exposure scenarios identified, 18 were evaluated under controlled conditions, 5 under normal workplace activities, and 1 was reported based on literature data. The scenarios involved a variety of tasks which consisted, mostly, of cleaning metal parts, spraying solvents onto surfaces, spilling liquids, and filling containers with volatile substances. Twenty-eight different solvents were modeled and the most commonly tested were benzene, toluene, and acetone. Emission rates were considered constant in 16 scenarios, exponentially decreasing in 6 scenarios, and intermittent in 2 scenarios. Four-hundred-and-forty-six (446) predicted-to-measured concentration ratios were calculated across the 21 studies; 441 were obtained in controlled conditions, 4 under normal workplace activities, and 1 was calculated based on the literature data. For controlled studies, the Two-Zone model predictive performance was within a factor of 0.3-3.7 times the measured concentrations with 93% of the values between 0.5 and 2. The model overestimated the measured concentrations in 63% of the evaluations. The median predicted concentration for the near-field was 1.38 vs. 1.02 for the far-field. Results suggest that the model might be a useful tool for predicting occupational exposure to vapors of solvents by providing a conservative approach. Harmonization in model testing strategies and data presentation is needed in future studies to improve the assessment of the predictability of the Two-Zone model. Moreover, this review has provided a database of exposure scenarios, input parameter values, and model predictive performances which can be useful to occupational hygienists in their future modeling activities.

Filtering performances of 20 protective fabrics against solid aerosols.

Workers can be exposed to solid airborne particles in some occupational environments, and they might be required to wear chemical protective clothing to prevent skin exposure. Dedicated standards exist to certify the protective value of such clothing, but they are not informative enough to identify the main pathways of entry for solid particles nor to compare performances between different chemical protective clothing. In this work, 20 non-woven fabrics used to make chemical protective clothing for solid particle protection were selected to be examined for both filtration and comfort performances. Nine were microporous fabrics (MP), 10 were multilayered nonwoven fibrous media (SMS) and one was a flash spun material (FS). To assess their filtration performances, fabrics were challenged in a benchtop wind tunnel with a 20-3,000 nm diameter sodium chloride aerosol at three low fabric face velocities (0.05, 0.15, 0.3 cm/sec). Airflow resistance and water vapor transmission rate were also measured to provide indications of comfort for the wearer. The penetration results led to the classification of the 20 fabrics into distinct groups of filtration efficiency. The data were analysed based on the porous media characteristics (thickness, fiber diameter, porosity, etc.). MPs were the most efficient fabrics, and SMSs showed a wide range of performances, mostly due to variations in the thickness of the filtering layer as well as to the fabric treatment. Measurements of airflow resistance and water vapor transmission rates revealed major differences between MPs and FSs and SMSs. This highlights the potential of some SMS fabrics to meet a compromise between protection and comfort.

Risk analysis for confined space entries: Critical analysis of four tools applied to three risk scenarios.

Investigation reports of fatal confined space accidents nearly always point to a problem of identifying or underestimating risks. This paper compares 4 different risk analysis tools developed for confined spaces by applying them to 3 hazardous scenarios. The tools were namely 1. a checklist without risk estimation (Tool A), 2. a checklist with a risk scale (Tool B), 3. a risk calculation without a formal hazard identification stage (Tool C), and 4. a questionnaire followed by a risk matrix (Tool D). Each tool's structure and practical application were studied. Tools A and B gave crude results comparable to those of more analytic tools in less time. Their main limitations were lack of contextual information for the identified hazards and greater dependency on the user's expertise and ability to tackle hazards of different nature. Tools C and D utilized more systematic approaches than tools A and B by supporting risk reduction based on the description of the risk factors. Tool D is distinctive because of 1. its comprehensive structure with respect to the steps suggested in risk management, 2. its dynamic approach to hazard identification, and 3. its use of data resulting from the risk analysis.

Particle loading time and humidity effects on the efficiency of an N95 filtering facepiece respirator model under constant and inhalation cyclic flows.

It is necessary to investigate the efficiencies of filtering facepiece respirators (FFRs) exposed to ultrafine particles (UFPs) for long periods of time, since the particle loading time may potentially affect the efficiency of FFRs. This article aims to investigate the filtration efficiency for a model of electrostatic N95 FFRs with constant and 'inhalation-only' cyclic flows, in terms of particle loading time effect, using different humidity conditions. Filters were exposed to generated polydisperse NaCl particles. Experiments were performed mimicking an 'inhalation-only' scenario with a cyclic flow of 85 l min(-1) as the minute volume [or 170 l min(-1) as mean inhalation flow (MIF)] and for two constant flows of 85 and 170 l min(-1), under three relative humidity (RH) levels of 10, 50, and 80%. Each test was performed for loading time periods of 6h and the particle penetration (10-205.4nm in electrical mobility diameter) was measured once every 2h. For a 10% RH, the penetration of smaller size particles (<80nm), including the most penetrating particle size (MPPS), decreased over time for both constant and cyclic flows. For 50 and 80% RH levels, the changes in penetration were typically observed in an opposite direction with less magnitude. The penetrations at MPPS increased with respect to loading time under constant flow conditions (85 and 170 l min(-1)): it did not substantially increase under cyclic flows. The comparison of the cyclic flow (85 l min(-1) as minute volume) and constant flow equal to the cyclic flow minute volume indicated that, for all conditions the penetration was significantly less for the constant flow than that of cyclic flow. The comparison between the cyclic (170 l min(-1) as MIF) and constant flow equal to cyclic flow MIF indicated that, for the initial stage of loading, the penetrations were almost equal, but they were different for the final stages of the loading time. For a 10% RH, the penetration of a wide range of sizes was observed to be higher with the cyclic flow (170 as MIF) than with the equivalent constant flow (170 l min(-1)). For 50 and 80% RH levels, the penetrations were usually greater with a constant flow (170 l min(-1)) than with a cyclic flow (170 l min(-1) as MIF). It is concluded that, for the tested electrostatic N95 filters, the change in penetration as a function of the loading time does not necessarily take place with the same rate under constant (MIF) and cyclic flow. Moreover, for all tested flow rates, the penetration is not only affected by the loading time but also by the RH level. Lower RH levels (10%) have decreasing penetration rates in terms of loading time, while higher RH levels (50 and 80%) have increasing penetration rates. Also, the loading of the filter is normally accompanied with a shift of MPPS towards larger sizes.

Contribution of breathing frequency and inhalation flow rate on performance of N95 filtering facepiece respirators.

The investigation of particle penetration through filtering facepiece respirators under cyclic flows is very necessary because cyclic flows represent actual breathing flow patterns. This article reports the development of a procedure to investigate the individual impact of breathing frequency and flow rate on the performance of N95 filtering facepiece respirators. Experiments were performed for two peak inhalation flows (PIFs; 135 and 360 l min(-1)) and two breathing frequencies [24 and 42 breaths per minute (BPM)] for a total of four cyclic flows (Flow A: 135 l min(-1) and 24 BPM; Flow B: 135 l min(-1) and 42 BPM; Flow C: 360 l min(-1) and 24 BPM; and Flow D: 360 l min(-1) and 42 BPM). Each experiment was performed using two different set-ups: the first set-up included both inhalations and exhalations through the filter media and test chamber, while with the second set-up, only inhalation flows were considered. The results showed that, for the most penetrating particle size range, an increase in both PIF and breathing frequency could potentially enhance the penetration with both set-ups; however, the effect of PIF was observed to be much more pronounced than that of frequency. The results indicated that with both set-ups, when the PIF was increased from 135 to 360 l min(-1) (for the given frequency: 24 or 42 BPM), an increase of up to 139-152% in penetration was observed. On the other hand, only a 10-16% increase in penetration occurred when the frequency was changed from 24 to 42 BPM (for a given PIF: 135 or 360 l min(-1)). This suggests that, from low to high respiratory efforts, a huge portion of penetration enhancement is due to PIF variations and only a small portion is contributed by frequency variations.

Evaluation of N95 filtering facepiece respirator efficiency with cyclic and constant flows.

An increasing demand for protecting workers against harmful inhalable ultrafine particles (UFPs), by means of filtering facepiece respirators (FFRs), necessitates assessing the efficiency of FFRs. This article evaluates the penetration of particles, mostly in the ultrafine range, through one model of N95 FFRs exposed to cyclic and constant flows, simulating breathing for moderate to heavy work loads. The generated particles were poly-dispersed NaCl, within the range of 10-205.4 nm. The tests were performed for several cyclic flows, with mean inhalation flows (MIFs) ranging from 42 to 360 L/min, and constant flows with the same range. The measurements were based on filter penetration and did not consider particle leakage. With the penetrations recorded for the selected constant and cyclic flows, the worst-case scenario penetrations at the most penetrating particle size (MPPS) were obtained. The MPPS penetrations measured with the cyclic and constant flows equivalent to minute volume, MIF and peak inhalation flow (PIF) of the cyclic flows were then compared. It was indicated that the constant flows equivalent to the minute volume or PIF of the cyclic flow could not accurately represent the penetration of the corresponding cyclic flow: the constant flow equal to the minute volume of the cyclic flow significantly underestimated the MPPS penetration of the corresponding cyclic flow, while the constant flow equal to the PIF of the cyclic flow overestimated it. On the other hand, for the constant flow equal to the MIF of the cyclic flow, the MPPS penetrations were almost equal for both the constant and cyclic flows, for the lower flow rates (42 to 170 L/min). For higher flow rates (230 to 360 L/min), however, the MPPS penetration was exceeded under the constant flows, compared with the corresponding cyclic flows. It was therefore concluded that the constant flow equal to the MIF of the cyclic flow could better predict the results of corresponding cyclic flow, since it could provide the MPPS penetrations (worst-case scenario) equal to or greater than the MPPS penetrations of the cyclic flow.

The need for a comprehensive approach to managing confined space entry: summary of the literature and recommendations for next steps.

Despite all the regulatory and standard-setting efforts that have been made in North America, judging from the most recent statistics many fatal incidents related to work in confined spaces still occur. In Canada, fatal incidents in the province of Quebec reveal failures in and absence of the identification and preparation of work situations in confined spaces and in risk management. In this study, we performed a literature review consisting of 77 documents on existing hazards and risk assessment for confined spaces. Moreover, we formulated proposals regarding the design of specific and improved tools for assessing such risks. We found that atmospheric hazards monopolized attention in the literature on confined spaces, while risk estimation specific to confined space interventions received little practical coverage overall, apart from atmospheric hazards. The parameters used to establish classes or groupings of confined spaces in existing tools were imprecise. The development of a risk analysis process that is (i) more systematic and based on the concepts recognized in risk management standards, (ii) multidisciplinary, and (iii) adapted to the specific characteristics of confined spaces is therefore needed. Such a process will better support managers and occupational health and safety (OH&S) personnel in their efforts to prioritize and reduce risks. Suggestions on such a risk analysis tool and categorization of interventions in confined spaces are proposed in this article. Lastly, risk analysis tools adapted to confined space interventions are needed to ensure the inherently safe design of these spaces.

Filtration performance, fit test and side effects of respiratory personal protective equipment following decontamination: Observations for user safety and comfort.

OBJECTIVE: While facing personal protective equipment (PPE) shortages during the COVID-19 pandemic, several institutions looked to PPE decontamination and reuse options. This study documents the effect of two hydrogen peroxide treatments on filtration efficiency and fit tests as well as the side effects for volunteers after the decontamination of N95 filtering facepiece respirators (FFRs). We also propose an efficient and large-scale treatment protocol that allows for the traceability of this protective equipment in hospitals during PPE shortages. METHODS: The effects of low-temperature hydrogen peroxide sterilization and hydrogen peroxide vapor (HPV) on two FFR models (filtration, decontamination level, residual emanation) were evaluated. Ten volunteers reported comfort issues and side effects after wearing 1h FFRs worn and decontaminated up to five times. RESULTS: The decontamination process does not negatively affect FFR efficiency, but repeated use and handling tend to lead to damage, limiting the number of times FFRs can be reused. Moreover, the recommended 24-h post-treatment aeration does not sufficiently eliminate residual hydrogen peroxide. Prolonged aeration time increased user comfort when using decontaminated FFRs. CONCLUSIONS: HPV and low-temperature hydrogen peroxide sterilization seem to be appropriate treatments for FFR decontamination when the PPE is reused by the same user. PPE decontamination and reuse methods should be carefully considered as they are critical for the comfort and safety of healthcare workers.

Characterization of Si and SiO2 in Dust Emitted during Granite Polishing as a Function of Cutting Conditions.

Particles emitted during manufacturing processes such as polishing can represent a serious danger for the environment and for occupational safety. The formation mechanisms responsible for these dust emissions include chip formation, friction at the tool/workpiece and chip/tool interfaces, shearing and cutting. These mechanisms thus depend on workpiece and tool properties, as well as the polishing conditions. In the case of granite polishing, particle emissions during polishing can contain chemical compounds such as silica, which represent harmful health risks for the worker. It is therefore important to characterize the particles emitted and to search for possible interactions between the particles (size and composition) and the machining conditions in order to find ways of reducing emissions at the source. In this study, an investigation was undertaken to characterize the particles emitted during granite polishing as a function of polishing conditions, type of granite, and abrasive grit sizes used. Scanning electron microscopy (SEM) was employed for particle morphology characterization and particle grain size and chemical composition were evaluated using X-ray diffraction (XRD) and energy dispersive X-ray (EDX) techniques, respectively. Results show that the influence of polishing speed and feed rate on particle emission depends mainly on the granite type used, providing useful information for controlling the polishing procedure, and thereby dust emission.

Genotyping of Tunisian azoospermic men with Sertoli cell-only and maturation arrest.

Azoospermia factor (AZF) deletions were associated with severe oligospermia and azoospermia with testicular histologies varying from maturation arrest (MA) to Sertoli cell-only (SCO) phenotypes. Abnormal androgen receptor (AR) structure or function has also been implicated in male infertility. To assess the contribution of these genetic defects to azoospermic patients, 19 Tunisian men with SCO (n = 13) or MA (n = 6) were enrolled in this study. Using immunohistochemistry method, we evaluated the expression of AR in testicular biopsy for the two phenotypes. PCR with primers flanking the AR-(CAG)n region and direct sequencing were used to determine AR-(CAG)n length. And PCR amplification of 14 sequence-tagged sites (STSs) located at Yq was used to determine the rate and extent of Y microdeletions. We found a significant difference of the AR expression between SCO and MA cases. Hence, this expression in the testis depends on the status of spermatogenesis. However, we did not find any relationship between the (CAG) repeat and the testicular histology (neither for SCO nor MA). On the other hand, we found a high frequency of AZF deletions (46.2%) in SCOS and in MA (50%). The present results also suggest the contribution of Y chromosome microdeletions in SCO and MA pathogenesis.

How Effective Is the Filtration of 'KN95' Filtering Facepiece Respirators During the COVID-19 Pandemic?

OBJECTIVES: The high demand of filtering facepiece respirators (FFRs) worldwide during the period of the COVID-19 pandemic has led to a critical situation for decision-makers regarding their supply. After authorizing the use of FFRs certified by other regions of the world, decision-makers in many countries have published alerts, particularly concerning the 'KN95' type. METHODS: This paper investigated the filtration performance of different FFRs using an experimental setup already employed during several studies on FFRs filtration performance. Its high-resolution measuring devices permit to determine filtration performance according to the normative criteria: the pressure drop and the filtration efficiency. Eight different FFRs have been used: four NIOSH-approved FFRs and four not NIOSH-approved with a 'KN95' shape available during the beginning of the COVID-19 pandemic. RESULTS: The data show a high disparity between different FFRs purchased by healthcare establishments, and between those that are NIOSH-approved and those that are not NIOSH-approved. The results confirm that the NIOSH certification offers good protection according to the normative criteria. The 'KN95' types present pressure drops which correspond to the normative value, however their efficiencies are lower than the efficiencies of FFRs certified by NIOSH and lower than 95% at the most penetrate particle size. CONCLUSIONS: FFRs marking is not sufficient to conclude on the FFRs' efficiency. Visual inspection can not determine which samples are counterfeit or have manufacturing defects.

Childhood nephrectomy indications: a changing profile.

AIM: To assess the changing profile of children's nephrectomy indications in the south of Tunisia during the last two decades. METHODS: There were 94 children who underwent nephrectomy between 1982 and 2007. They were classified into two groups. The first group included 55 out of 511 hospitalized children between 1982 and 1994, the second included 39 out of 382 hospitalized children between 1995 and 2007. K2 (Chi-squared) test was used for this statistical analysis. A P value of < 0.05 was considered statistically significant. RESULTS: The average was 7. Pathologies leading to nephrectomies were dominated in both groups by 3 main aetiologies: urolithiasis (42.5%), Wilm's tumors (21.3%) and pelvi-ureteric junction (13.8%). While in the first group, urolithiasis was found to be the major indication of nephrectomy (54.5%, p<0.05), in the second group, kidney tumors had become the major indication (33%, p<0.05) followed by urolithiasis (25.6%). So, the rate of nephrectomies performed due to urolithiasis had clearly decrease (P = 0.005), but there were no statistical differences observed between the rates of nephrectomies performed due to tumors or upper urinary tract malformations in the two groups. CONCLUSION: The profile of children's nephrectomy indications in Tunisia stretches currently to be similar to the one of the industrialized countries, with regression of evolved kidney lithiasis leaving place to the tumorous pathologies, because of early detection, improvement and appropriate treatment of urinary lithiasis.

Genetic association between AZF region polymorphism and Klinefelter syndrome.

Because of conflicting results about the association between azoospermic patients with Klinefelter syndrome (KFS) and azoospermia factor (AZF) polymorphism, and because nothing is known about the association of KFS with partial AZFc deletions, an association study was performed in Tunisian KFS patients. A total of 29 azoospermic patients and 13 fertile men were enrolled in this study. The classical microdeletions were found in six out of nine KFS patients (67%). Gr/Gr deletions and b2/b3 deletions are partial AZFc deletions. One KFS patient without classical microdeletions had a gr/gr deletion. This deletion (gr/gr) was observed in four out of 18 azoospermic patients without chromosomal abnormalities. In addition, two b2/b3 and one AZFc deletion were identified in this group. All KFS patients had elevated plasma FSH and LH concentrations, but normal plasma testosterone concentration. The testis biopsy of three samples with Y microdeletions revealed Sertoli cell-only syndrome. No Y microdeletions or partial AZFc deletions were found in the fertile group. It is concluded that in the patient population KFS patients may harbour Y microdeletions, and screening for these should be part of the diagnostic work-up, particularly in those considering assisted reproductive techniques. However, partial AZFc deletions might not play a role in predisposing genetic background for the phenotype of azoospermic KFS subjects.

Cancer on cryptorchid testis revealing a Persistent Müllerian Duct Syndrome: A rare case.

The persistence of Müllerian derivatives syndrome or PDMS is a rare form of male pseudohermaphrodism. Its association to ectopic testicular cancer is even rarer. Because of its rarity it is difficult to diagnose preoperatively. We present a case of a cancer on cryptorchid testis revealing a persistent Müllerian duct syndrome.

Ectopic adrenal cortex tissue: an incidental finding during inguinoscrotal operations in pediatric patients.

OBJECTIVE: The aim of the present study was to assess the occurrence of ectopic remnants of adrenal cortex tissue encountered in pediatric patients who underwent groin surgical explorations. MATERIALS AND METHODS: We studied 1,862 patients with groin surgical explorations during a period of 12 consecutive years (1995-2006). Nodules resembling ectopic adrenal tissue were removed and the histopathological examination was performed using hematoxylin and eosin staining. RESULTS: We found ectopic adrenal cortex tissue along the spermatic cord in 31 patients in 1,862 groin surgical explorations, an overall incidence of 1.66%. None were found in females. Of the 31 cases, 20 were diagnosed as having undescended testes, 8 communicating hydrocele, and 3 inguinal hernia. Median age at diagnosis was 6.5 years (range 2-14). The nodules were found located along the spermatic cord, in the apex of the hernial sac, and between the testis and epididymis. Macroscopically, the nodules were round to oval in shape, 2-6 mm in diameter, and bright yellow to orange in color. Microscopically, they had three well-defined layers of adrenal cortex, with predominance of the zona fasciculata, surrounded by a fibrous capsule and none contained any medulla. CONCLUSION: Ectopic adrenal cortical tissue is a benign lesion. Although a routine search for this lesion is not indicated, it should be resected for histological analysis and differential diagnosis when it is found during a surgical procedure in this area.

[Uncommon retroperitoneal and bone lesions: Erdheim-Chester disease]. / Lésion rétropéritonéale et osseuse rare : maladie d'Erdheim-Chester.

We report a case of Erdheim-Chester disease, revealed by a polyuropolydipsic syndrome. During the patient's work-up, osteocondensing lesions were found; the biopsy of these lesions showed an infiltration by spumous cells of histiocytic lineage, CD68+, CD1a-, associated with a lymphoid infiltrate within an extensive fibrosis. Lung and retroperitoneal lesions were discovered. The surgical resection of the involved ureter was required. Histological examination of the resected specimen showed the same pattern of histiocytic infiltration. Our case report underlines the variety of lesions associated with Erdheim-Chester disease and the importance of a complete exploration.

[Surgical treatment of varicocele improves fertility and facilitates medically assisted procreation]. / Le traitement chirurgical de la varicocèle améliore la fertilité et aide à la procréation médicalement assistée.

PURPOSE: To assess the effect of varicocelectomy in sperm quality and natural pregnancy and to determine if it can change couple candidacy for assisted reproductive technology (ART) procedures. MATERIALS AND METHODS: We performed a retrospective study about 164 infertile men with varicocele associated to sperm abnormalities. We divided our patients into four groups, according to the total motile sperm count (TMC). Group 1 includes 21 azoospermic men, group 2 includes 62 patients who had a TMC strictly less than 1.5x10(6), group 3 includes 22 patients who had a TMC between 1.5 and 5x10(6) and group 4 includes 59 patients who had a TMC strictly greater than 5x10(6). All patients underwent surgical or percutaneous embolisation to repair varicocele. RESULTS: After treatment, the mean spermatozoid concentration and motility were significantly increased, respectively from 24.8 to 29.2x10(6)spermatozoids per millilitre and 14.4 to 23.2%. Spontaneous pregnancy was observed in 59 couples (35.9%). Concerning the couples who had no pregnancies (105), 51 (48.5%) showed increase of the TMC, which allowed them to change the foreseen preoperative ART by an other one more simple. CONCLUSION: Varicocelectomy has a significant potential not only to improve sperm quality and natural pregnancy, but also to downstage the level of ART needed to male infertility management.

Tag STS in the AZF region associated with azoospermia in a Tunisian population.

The aim of this study was to determine the appropriate tag sequence tagged site (STS) associated with azoospermia. We evaluated the incidence of Y chromosome microdeletions in Tunisian infertile male patients by polymerase chain reaction using 14 STSs in the azoospermia factor (AZF) region of Yq11. A logistic regression analysis was performed to test the association of STSs with semen quality. Haploview version 3.11 was used to identify the possible blocks of deletion involving a minimum number of STSs and that can be used to tag the deletion block in future analysis. Using the 14 STSs, 48% infertile patients (102 of 210) had microdeletions of Y chromosome but, following the European Academy of Andrology guidelines, only 16% of patients had microdeletions. A statistically significant difference was found with some STSs for azoospermia and oligozoospermia. A candidate combinaison composed of 4 STSs (RBMY-sy157-sy84-sy130) was associated with azoospermia in a Tunisian population. According to this study, this tag can be used in the screening of Y chromosome microdeletions before assisted reproduction treatment in a Tunisian population.