Secondary organic aerosol origin in an urban environment: influence of biogenic and fuel combustion precursors.

Source contributions of organic aerosol (OA) are still not fully understood, especially in terms of quantitative distinction between secondary OA formed from anthropogenic precursors vs. that formed from natural precursors. In order to investigate the OA origin, a field campaign was carried out in Barcelona in summer 2013, including two periods characterized by low and high traffic conditions. Volatile organic compound (VOC) concentrations were higher during the second period, especially aromatic hydrocarbons related to traffic emissions, which showed a marked daily cycle peaking during traffic rush hours, similarly to black carbon (BC) concentrations. Biogenic VOC (BVOC) concentrations showed only minor changes from the low to the high traffic period, and their intra-day variability was related to temperature and solar radiation cycles, although a decrease was observed for monoterpenes during the day. The organic carbon (OC) concentrations increased from the first to the second period, and the fraction of non-fossil OC as determined by (14)C analysis increased from 43% to 54% of the total OC. The combination of (14)C analysis and Aerosol Chemical Speciation Monitor (ACSM) OA source apportionment showed that the fossil OC was mainly secondary (>70%) except for the last sample, when the fossil secondary OC only represented 51% of the total fossil OC. The fraction of non-fossil secondary OC increased from 37% of total secondary OC for the first sample to 60% for the last sample. This enhanced formation of non-fossil secondary OA (SOA) could be attributed to the reaction of BVOC precursors with NOx emitted from road traffic (or from its nocturnal derivative nitrate that enhances night-time semi-volatile oxygenated OA (SV-OOA)), since NO2 concentrations increased from 19 to 42 µg m(-3) from the first to the last sample.

Adaptive preconditioning in neurological diseases - therapeutic insights from proteostatic perturbations.

In neurological disorders, both acute and chronic neural stress can disrupt cellular proteostasis, resulting in the generation of pathological protein. However in most cases, neurons adapt to these proteostatic perturbations by activating a range of cellular protective and repair responses, thus maintaining cell function. These interconnected adaptive mechanisms comprise a 'proteostasis network' and include the unfolded protein response, the ubiquitin proteasome system and autophagy. Interestingly, several recent studies have shown that these adaptive responses can be stimulated by preconditioning treatments, which confer resistance to a subsequent toxic challenge - the phenomenon known as hormesis. In this review we discuss the impact of adaptive stress responses stimulated in diverse human neuropathologies including Parkinson׳s disease, Wolfram syndrome, brain ischemia, and brain cancer. Further, we examine how these responses and the molecular pathways they recruit might be exploited for therapeutic gain. This article is part of a Special Issue entitled SI:ER stress.

Measurements of VOC/SVOC emission factors from burning incenses in an environmental test chamber: influence of temperature, relative humidity, and air exchange rate.

This study investigates the influence of three environmental indoor parameters (i.e., temperature, relative humidity, and air exchange rate) on the emission of 13 volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) during incense burning. Experiments have been carried out using an environmental test chamber. Statistical results from a classical two-level full factorial design highlight the predominant effect of ventilation on emission factors. The higher the ventilation, the higher the emission factor. Moreover, thanks to these results, an estimation of the concentration range for the compounds under study can be calculated and allows a quick look of indoor pollution induced by incense combustion. Carcinogenic substances (i.e., benzene, benzo(a)pyrene, and formaldehyde) produced from the incense combustion would be predicted in typical living indoors conditions to reach instantaneous concentration levels close to or higher than air quality exposure threshold values.

French intensive training course in laparoscopic surgery (HUGOFirst) on live porcine models: Validation of a performance assessment scale and residents' satisfaction in a prospective study.

INTRODUCTION: Simulation as a method for practical teaching of surgical residents requires objective evaluation in order to measure the student's acquisition of knowledge and skills. The objectives of this article are to publish our evaluation and validation grids and also the measure of student satisfaction. METHOD: A teaching platform based on practical exercises with a porcine model was created in 2009 at seven French University Hospitals. Three times a year, 31 Diplôme d'Études Spécialisées Complémentaires (DESC) surgical residents underwent timed assessment of the performance of five surgical tasks: trocar insertion (trocars) testing the convergence of instruments (convergence), intra-corporeal knot tying (knots), running of the small intestine to find a lesion (exploration), and performance of a running suture closure of the peritoneum (closure). Two experts evaluated performances prospectively on grid score sheets specifically designed and validated for these exercises. We measured time, scores on a rating scale, and the interest and satisfaction of the residents. RESULTS: Data for 31 residents between May 2011 and March 2012 were analyzed. Rating scales were statistically validated and correlated (Kappa correlation coefficient K>0.69) for each task. The performance times of the most experienced residents decreased significantly for all tasks except for small bowel exploration (P=0.2). After four sessions, times were significantly improved with better quality (fewer errors and higher average scores [>88%]), regardless of the residents' experience. Of the participants, 92% were satisfied, 86% thought that the sessions improved their technical skills and 74% thought it had a favorable impact on their clinical practice. CONCLUSION: This study shows that the performance of surgical techniques can be improved through simulation, that HUFEG grids are valid, and that this teaching program is popular with surgical residents.

Parastomal hernia.

Despite advances in surgery including new prosthetic materials and the advent of laparoscopy, the treatment of parastomal hernias remains a challenge for the surgeon. This is mainly due to the very high recurrence rate. Adequate management requires preoperative multidisciplinary consultation to offer the most appropriate surgical solution to each patient. We propose a review of current knowledge about this complication.

The impact of obesity on secretion of adiponectin multimeric isoforms differs in visceral and subcutaneous adipose tissue.

OBJECTIVE: Hypoadiponectinemia observed in obesity is associated with insulin resistance, diabetes and atherosclerosis. The aim of the present study was to investigate secretion of adiponectin and its multimeric isoforms by explants derived from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in obese and non-obese subjects. DESIGN: Paired samples of SAT and VAT and blood samples were obtained from 23 subjects (10 non-obese and 13 obese) undergoing elective abdominal surgery. Total adiponectin quantities and adiponectin isoforms were measured in conditioned media of explants derived from SAT and VAT using enzyme-linked immunosorbent assay and non-denaturing western blot, respectively. RESULTS: Total adiponectin plasma levels were lower in obese than in non-obese subjects (P<0.05). Secretion of total adiponectin in adipose tissue (AT) explants was lower in obese than in non-obese subjects in SAT (P<0.05) but not in VAT. In both, SAT and VAT, the most abundant isoform released into conditioned media was the high-molecular weight (HMW) form. Its relative proportion in relation to total adiponectin was higher in conditioned media of explants from both fat depots when compared with plasma (P<0.001). The proportion of secreted HMW vs total adiponectin was higher in VAT than in SAT explants in the group of non-obese individuals (49.3±3.1% in VAT vs 40.6±2.8% in SAT; P<0.01), whereas no difference between the two depots was found in obese subjects (46.2±3.0 % in VAT vs 46.0±2.4 % in SAT). CONCLUSION: Obesity is associated with the decrease of total adiponectin secretion in SAT. The profile of adiponectin isoforms secreted by SAT and VAT explants differs from that in plasma. Secretion of total adiponectin and HMW isoform of adiponectin are different in obese and non-obese subjects in relation to AT depot.

Macrophage gene expression is related to obesity and the metabolic syndrome in human subcutaneous fat as well as in visceral fat.

AIMS/HYPOTHESIS: Our goal was to identify a set of human adipose tissue macrophage (ATM)-specific markers and investigate whether their gene expression in subcutaneous adipose tissue (SAT) as well as in visceral adipose tissue (VAT) is related to obesity and to the occurrence of the metabolic syndrome. METHODS: ATM-specific markers were identified by DNA microarray analysis of adipose tissue cell types isolated from SAT of lean and obese individuals. We then analysed gene expression of these markers by reverse transcription quantitative PCR in paired samples of SAT and VAT from 53 women stratified into four groups (lean, overweight, obese and obese with the metabolic syndrome). Anthropometric measurements, euglycaemic-hyperinsulinaemic clamp, blood analysis and computed tomography scans were performed. RESULTS: A panel of 24 genes was selected as ATM-specific markers based on overexpression in ATM compared with other adipose tissue cell types. In SAT and VAT, gene expression of ATM markers was lowest in lean and highest in the metabolic syndrome group. mRNA levels in the two fat depots were negatively correlated with glucose disposal rate and positively associated with indices of adiposity and the metabolic syndrome. CONCLUSIONS/INTERPRETATION: In humans, expression of ATM-specific genes increases with the degree of adiposity and correlates with markers of insulin resistance and the metabolic syndrome to a similar degree in SAT and in VAT.

Light induced multiphase chemistry of gas-phase ozone on aqueous pyruvic and oxalic acids.

In this study for the first time it has been shown that pyruvic acid can affect the atmospheric multiphase reactions of ozone with oxalic acid due to its properties as a photosensitizer. To this end, the photochemical batch multiphase reactions of a mixture of pyruvic acid/oxalic acid (PA/OA) and gas-phase ozone under simulated sunlight were studied as a function of time using high pressure liquid chromatography equipped with a UV detector (HPLC-UV) and electrospray ionization mass spectrometry (ESI-MS) to investigate product formation. Following the simultaneous ozone and light irradiation the first peak for pyruvic and oxalic acids (retention time = 3.68 min) decreased to 67% of the initial intensity after a 12 h reaction while a broad and not well defined peak appeared at longer retention times. After prolonged exposure times this broad peak shifted to shorter retention times: from 14 min at 2 h reaction to 8 min at 12 h. The HPLC-UV analysis of the reaction mixture simultaneously exposed to ozone and irradiated by simulated sunlight for 6-12 h revealed the presence of high weight molecular mass products and formation at longer times of highly non-polar products. The results obtained from ESI-MS have clearly demonstrated that the distribution of high molecular weight products is consistent with an oligomer system. No evidence of oligomer formation was found after the sample (PA/OA) was exposed only to either ozone or irradiated with UV/Vis light using the same instrumental conditions.

[MALT (mucosa-associated lymphoid tissue) lymphoma of the lacrimal gland]. / Lymphome de la glande lacrymale de type MALT (Tissu Lymphoïde Annexé aux Muqueuses).

MALT lymphoma of the lacrimal gland is rare. Orbital involvement is usually located on the anterior orbit. We report the case of a 65-year-old man consulting for an eyelid tumor located on the right upper and lateral lid, which clinically recalled lacrimal gland involvement. The gland biopsy and the immunohistochemical analysis concluded in the diagnosis of B and MALT lymphoma. The assessment of the ganglion and extra-ganglion enlargement of these lymphomas is of capital importance in treatment. A multidisciplinary analysis, especially oncological, is important so that the best therapeutic plan can be adopted.

[Assessment of the Quantel Medical 20-Mhz Ultrasound Cinescan in intraocular measurements]. / Evaluation de l'échographie 20 MHz CineScan dans les mesures intra-oculaires.

BACKGROUND AND OBJECTIVE: Evaluation of the Quantel Medical 20-MHz Ultrasound Cinescan using a closed transducer in intraocular measurements and its reproducibility. PATIENTS AND METHODS: We measured sulcus-to-sulcus distance of 40 control eyes using the20-MHz Cinescan. Then we compared the sonography to the Oculus Pentacam based on the Scheimpflug principle in the measurements of anterior chamber depth, cornea-to-implant distance, and implant-to-crystallin lens distance in patients who underwent phakic implantation (56 eyes). RESULTS: With this technique, the sulcus-to-sulcus distance can be measured with a reproducibility of 86%-88% (p<0.05). The authors show that the corneal diameter is not correlated with the sulcus measurement (R=24%, p<0.05). DISCUSSION: Several techniques are used to quantify anterior segment biometry. Some of these methods, such as White-to-White, are too empirical and others, such as the Scheimpflug camera - for example the EAS-1000 (Nidek) - or high-frequency ultrasound - Ultrasound BioMicroscopy UBM P45 (Paradigm) - are too expensive. The 20-MHz Cinescan has good reproducibility and provides easier access to anterior segment biometry. CONCLUSION: The 20-MHz Cinescan appears to be an accessible technique that may become a useful tool in the refractive surgery of the phakic intraocular lens.

Differentiation of antitumor-specific cytotoxic T lymphocytes from autologous tumor infiltrating lymphocytes in non-Hodgkin's lymphomas.

The present study describes a new culture protocol allowing the activation and proliferation of autologous tumor infiltrating T lymphocytes (TIL), and the generation of antitumor specific CTL in non-Hodgkin's lymphoma (NHL). Cells from eight patients with indolent NHL were used. We performed 3-week co-cultures of TIL with irradiated autologous malignant B cells in the presence of low doses of IL-1beta, IL-2 and IL-12. The proliferation, phenotype and cytotoxicity, and antitumor specificity of T cells recovered were studied. T-cell clonality was analyzed using TCRgamma gene rearrangement amplification by a multiplex PCR. Under these culture conditions, TIL proliferated, and the CD8+ T lymphocytes that were in a minority at the beginning of the culture increased dramatically in 6 out of 8 cases. In two cases, CD4+ T lymphocytes expanded. We showed that an oligoclonal selection of reactive T cells occurred in culture. Specific cytotoxicity developed against autologous malignant B cells in the 6 cases where there was an expansion of CD8+ T lymphocytes. Inhibition experiments performed with mAb directed against HLA class I and II molecules, CD4, CD8 and TCRgammadelta showed that the cytotoxic effector cells were CD8+ T lymphocytes probably expressing TCRalphabeta+. Cytokine secretion was analyzed in culture medium, and we detected significant levels of IFN-gamma, TNF-alpha, and IL-10 and no IL-4 (except in one case). Our results demonstrate that memory T cells from lymphoma patients can be amplified and differentiated into antitumor cytotoxic cells using a combination of the cytokines IL-1beta, IL-2, and IL-12 in association with non modified tumor cells.

Interest of direct radionuclide cystography in repeated urinary tract infection exploration in childhood.

108 children with repeated urinary tract infection were examined both with direct contrast cystography and radionuclide cystography. There was a good correlation between the two procedures in the majority of the cases (79), but in 21 cases, direct radionuclide cystography alone was positive and for 8 other children, direct contrast cystography showed a low-grade vesico-ureteric reflux even though radionuclide cystography was negative. When comparing the two procedures and taking into consideration the age of the patients we find that radionuclide cystography is more sensitive to detect vesico-ureteric reflux in the younger population (p < 0.02). This advantage is less clear for older children who more often present a low-grade reflux. Low radiation exposure is also a great advantage of radionuclide cystography, but anatomic definition is better with contrast cystography. It seems thus that the two procedures complement rather than rival each other. Their respective interest for evaluation of repeated urinary tract infection in children therefore depends on age, attain-ability of the procedure, and the possibility of a bladder or ureteral abnormality. Quite a few authors consider radionuclide cystography as at least as valid as contrast cystography, and even more sensitive. We have attempted to compare both procedures and to determine their respective role in repeated urinary tract infection exploration.

[Vitamin-resistant rickets cured by removal of a bone tumor. Review of the literature]. / Rachitisme vitamino-résistant guéri par l'éxérèse d'une tumeur osseuse. Revue de la littérature.

PURPOSE OF THE STUDY: Rickets secondary to bone or soft tissue tumors are rare in children. Majority of the reported cases occurred in adults older than thirty. This entity can be cured after tumor removal. The authors present a case in a ten year boy and literature review. MATERIAL: A ten year boy complained of diffuse bone and muscle weakness for two years. A diagnosis of arthritis was made but the patient continued to complain. Serum calcium level was normal (2.33 mmol/l), phosphorus was very low (0.43 mmol/l), serum alkaline phosphatase was high, parathyroid hormone and vitamin D level were normal. Urinalysis showed abnormal phosphate excretion. METHODS: The absence of malabsorption, no family history of rickets or hypophosphatermy presence of a marked excess of urinary phosphate, very low serum phosphate and normal serum calcium, vitamin D and parathyroid hormone levels led us to consider a diagnosis of tumor induced osteomalacia. Radiographs showed a large round radiolucent lesion in the left superior pubic ramus and generalized demineralisation. RESULTS: We performed a complete tumor resection and the space was filled with bone graft. On histopathologic examination it was a benign mesenchymal tumor. Rapid reversal of biochemical anomalies, radiographs anomalies and clinical manifestation were observed after complete tumor resection. DISCUSSION: The authors have described the tumor, the osteomalacia and the pathogenesis of tumor rickets. Histologically the most common causative tumors were vascular tumors, mesenchymal tumors and non ossifying tumors. The tumor were of bone or soft tissue origin. Clinical symptoms were muscular weakness, bone and muscle pain. Biochemically there is a very low phosphate level, a normal serum calcium level as well as a normal vitamin D and PTH level. There is a significant high level of urinal phosphate. The mechanism proposed to explain oncogenic osteomalacia includes tumor secretion of phosphaturic substance other than PTH and calcitonin. Another hypothesis is a substance interfering with normal vitamin D metabolism. The pathogenesis is not clearly defined. CONCLUSION: Regardless to the mechanism of osteomalacia, complete removal of the tumor will cure the patient. A diligent search for tumors should be done in patients with vitamin D resistant rickets.

Smooth muscle tumors associated with X-linked Alport syndrome: carrier detection in females.

X-linked Alport syndrome (AS) associated with diffuse esophageal leiomyomatosis (DL) has been reported to be due to deletions removing the 5' ends of both the COL4A5 and COL4A6 genes, encoding the alpha 5 and alpha 6 chains of type IV collagen, respectively, whereas a variety of mutations in COL4A5 has been identified in patients with AS alone. Here we report three additional DL-AS patients who also display deletions removing the 5' ends of both COL4A5 and COL4A6 genes. Furthermore, we tracked the mutation in 15 females belonging to six DL-AS families by gene copy number determination. We found that, like AS, DL is transmitted as an X-linked dominant trait but, contrary to AS, DL is fully penetrant and completely expressed in females. These results are in agreement with our previous work suggesting that DL could be due to a dominant effect of an abnormal alpha 6 (IV) collagen chain. Finally, we have detected a similar deletion of the COL4A5 and COl4A6 genes in a DL affected female who showed no sign of nephropathy, demonstrating the AS carrier status of this DL patient. These results emphasize the importance of molecular analysis of female DL patients for genetic counseling.

Four cases of spuriously low WBC count due to in vitro leukocyte agglutination: contribution of the hematology analyzer Coulter STKS in detecting this clinically misleading artefact.

Four spuriously lowered WBC counts due to in vitro leukoagglutination were reported from an automated cell counter (Coulter STKS). Leukocyte aggregates (3 to 50 cells), detected in the peripheral blood smears, included different cell types, normal (neutrophils, eosinophils, monocytes, lymphocytes) or abnormal (lymphoma cells). The phenomenon was associated with either a spurious leukoneutropenia or an underestimation of hyperleucocytosis. Leukoagglutination was extensively investigated in 3 cases : as shown in several reports, leukoagglutination may occur with various features, especially due to temperature and anticoagulant dependence. Our four cases reflected this variability. Furthermore, one case was found both temperature-dependent and anticoagulant-independent, a pattern not yet described in the literature. A common STKS graphic pattern was found in our 4 cases, suggesting that hematology analyzers such as Coulter STKS may be useful to detect leukoagglutination. In conclusion, each leukoneutropenia and/or each suggestive graphic pattern must be controlled by means of a blood smear examination in order to rule out the possibility of in vitro leukoagglutination.

Thermal diffusion probe and instrument system for tissue blood flow measurements: validation in phantoms and in vivo organs.

A minimally invasive probe and instrument system for real-time measurements of temperature, thermal conductivity and tissue blood flow has been designed for research and clinical use. The essence of the probe is a thermistor, located at the tip of catheters or glass and steel needles, and operating in transient self-heated mode at constant temperature increment. Thermal conductivity and tissue blood flow are determined by use of a coupled tissue-probe thermal model. The effects of temporal baseline temperature shifts are minimized by a novel, automatic, analog compensation circuit. Very short heating periods (3 s) and cooling periods (12 s) provided near-continuous measurements (4/min). Calibration experiments performed in media of known thermal conductivity exhibit a linear response with respect to thermal conductivity. In vitro experiments performed in isolated perfused dog liver preparations are presented to evaluate this instrument system. In vivo experiments performed in cat brain, dog liver, and human tumor demonstrate the ability of this instrument system to perform physiologically valid measurements (comparison inter-subjects and intra-subjects). The minimally invasive probes (0.8 mm OD) are capable of long term measurements (several months), with minimal tissue reactions (0.3 mm around the probe).

Platelet activating properties of murine monoclonal antibodies to beta 2-glycoprotein I.

Previously developed murine monoclonal antibodies (MAbs) to human beta 2-glycoprotein I (beta 2 GPI), a plasma protein required for the binding of anti-phospholipid antibodies, were studied for anti-platelet reactivity and influence on platelet function. The six MAbs (IgG1 isotype) tested interacted with both intact and fixed platelets in a beta 2 GPI-dependent manner. Carbamylated beta 2 GPI was still recognized by MAbs but was unable to mediate platelet-antibody binding. MAbs induced aggregation and secretion responses of platelets in platelet-rich plasma (PRP) and whole blood, provided subthreshold concentrations of weak agonists (i.e. ADP or adrenaline) were added. When aggregation in PRP was evaluated by a counting technique instead of turbidometrically, the sole addition of MAbs led to a rapid fall in single platelets. Triggering gel-filtered platelets with MAbs together with beta 2 GPI, but not its carbamylated form, led to platelet activation after a lag time, as monitored by aggregometry, measurements of ATP and beta-thromboglobulin secretion and calcium mobilization. F(ab')2 fragments of one of the MAbs failed to activate platelets but inhibited the responses to the whole antibody. This process thus depends on MAbs binding to platelets through both Fab and Fc domains, as confirmed by the suppression of platelet responses upon pretreatment with the anti-Fc gamma RII MAb IV.3. Aggregation and secretion induced by MAbs plus beta 2 GPI did not require exogenous fibrinogen and were variably inhibited in the presence of acetyl salicylic acid, apyrase or Ca2+, depending on the concentrations used for the two proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Alport syndrome and diffuse leiomyomatosis: deletions in the 5' end of the COL4A5 collagen gene.

Alport syndrome (AS) is an hereditary glomerulonephritis that is mainly inherited as a dominant X-linked trait. Structural abnormalities in the type IV collagen alpha 5 chain gene (COL4A5), which maps to Xq22, have recently been detected in several patients with AS. The association of AS with diffuse esophageal leiomyomatosis (DL) has been reported in 24 patients, most of them also suffering from congenital cataract. The mode of transmission and the location of the gene(s) involved in this association have not been elucidated. Southern blotting using cDNA probes spanning the whole COL4A5 and a 5' end COL4A5 genomic probe showed that three out of three patients with the DL-AS association had a deletion in the 5' part of the COL4A5 gene extending beyond its 5' end. This indicates that the same gene, COL4A5, is involved in classical AS and in DL-AS and that the transmission of DL-AS is X-linked dominant. These results also suggest that leiomyomatosis might be due to the alteration of a second gene involved in smooth muscle cell proliferation, which is located upstream of the COL4A5 gene, and that there might be a contiguous gene deletion syndrome, involving at least the genes coding for congenital cataract, DL and AS.