Assessment of carbamazepine acute toxicity in the cockle Cerastoderma edule through chemical, physiological and biochemical tools / Avaliação da toxicidade aguda da carbamazepina no berbigão Cerastoderma edule por meio de ferramentas químicas, fisiológicas e bioquímicas

The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 μg L-¹) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 μg l-¹ of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.

O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 μg L-¹) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 μg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.

Determination of Chlorophenols in Water Samples Using Solid-Phase Extraction Enrichment Procedure and Gas Chromatography Analysis.

Solid-phase extraction (SPE) procedure followed by derivatization and gas chromatography electron capture detection was evaluated for the determination of trace amounts of chlorophenols (CPs) in waters samples. Different parameters affecting extraction efficiency such as, volume of elution solvent, volume and pH of water sample, quantity of sorbent phase were studied and optimized. SPE was carried out on polystyrene-divinylbenzene (Bond Elut ENV) and high recoveries were obtained using 1000 mg of this cartridge for the treatment of 500 mL of acidified water sample. The described method was then tested on spiked tap, mineral, ground and surface water samples. The overall procedure provided limits of detection lower than 20 ng L(-1), recoveries of 70%-106% and an enrichment factor of 500 for the examined CPs in 500 mL water samples. Among the studied compounds, pentachlorophenol was detected in tap water at a concentration level of 0.06 µg L(-1).

Particulate polycyclic aromatic hydrocarbons (PAH) in the atmosphere of Bizerte city, Tunisia.

The particle-phase concentrations of polycyclic aromatic hydrocarbons (PAH) were determined in 13 air samples collected in an urban area of Bizerte (Tunisia) during 2009-2010. Atmospheric particulate samples were extracted by ultrasonic bath and analyzed by high-performance liquid chromatography with fluorescence detection. PAH were found in all the analyzed air samples and the most abundant compounds were pyrene, fluoranthene, benzo[g,h,i]perylene, benzo[b]fluoranthene, chrysene and benzo[a]pyrene. ∑14-PAH concentrations ranging from 9.38 to 44.81 ng m(-3) with mean value of 25.39 ng m(-3). PAH diagnostic ratio source analysis revealed gasoline and diesel vehicular emissions as major sources. The mean total benzo[a]pyrene toxicity equivalent calculated for samples was 3.66 ng m(-3) and the mean contribution of the carcinogenic potency of benzo[a]pyrene was determined to be 55.8 %. Concentrations of particulate PAH in Bizerte city atmosphere were approximately eight times greater than sampled at a nearby rural site.

[Radiation therapy of sinonasal natural killer/T-cell lymphoma]. / Radiothérapie des lymphomes NK/T localisés aux fosses nasales.

Natural killer (NK)/T-cell lymphoma are part of lymphoproliferative diseases, they are rare in Europe and the United States but relatively common in Asia and South America. Natural killer (NK)/T-cell lymphoma present clinically as destructive lesions of the upper aerodigestive tract with perforation of deep structures of the face, destruction of the palate or an invasion of orbits. Treatment modalities of these lymphomas are still discussed because of the lack of available studies and the rarity of this disease. Radiotherapy provides a rapid control of the disease and is positioned as a major treatment of localized stages of NK/T-cell lymphoma of the nasal cavity. We therefore studied the different forms of radiation therapy in the early stages of nasal NK/T-cell lymphoma.

Modeling thermal influence on animal growth and sex determination in reptiles: being closer to the target gives new views.

Many species of oviparous reptiles, including crocodilians, a majority of turtles, some lizards and the 2 closely related species of Sphenodon have been shown to display temperature-dependent sex determination (TSD). Whereas it has been demonstrated very early that TSD also occurs in natural conditions, the relationship between a time series of changing temperatures and sex ratio remains a challenging problem for reptiles. We describe how a physiological model of embryo growth, gonadal development and aromatase activity can produce outputs that mimic well TSD. We provide an enhancement of a previously published model taking into account direct effect of temperature on aromatase activity. The comparison between the original model and the new one suggests that aromatase expression is controlled by a repressor factor expressed at masculinizing temperatures rather than its enhancement at feminizing temperatures.

[Videomicroscopy in alopecia areata]. / Vidéomicroscopie au cours de la pelade.

BACKGROUND: Diagnosis of alopecia areata is generally made on clinical examination alone. However, diagnosis may be difficult, particularly in the diffuse forms. Videomicroscopy is a recently developed non-invasive technique that has been little studied in the diagnosis of alopecia. In a preliminary study, we attempted to describe the semiological appearance at videomicroscopy and its diagnostic value for alopecia areata. PATIENTS AND METHODS: Forty patients with confirmed diagnosis of alopecia were successively studied by videomicroscopy: alopecia areata (18 cases), androgenogenetic alopecia (7 cases), pseudo alopecia areata (7 cases), telogenic effluvium (4 cases), folliculitis decalvans (3 cases) and lupus discoides (1 case). Patients with types of alopecia other than alopecia areata were studied as controls. The videomicroscopic examination was carried out on the centre and area surrounding the plaques of alopecia. The images were recorded and reviewed retrospectively. The semiological appearance of the scalp and hair was noted. RESULTS: Various types of semiological appearance were observed in alopecia areata: yellowish or erythematous macules centred around the ostium, short exclamation mark hairs, a white down or persistent white hair, pustules with a whitish keratin plug in the ostium and depigmentation of the shaft of the terminal hairs. However, in patients with alopecia areata there was none of the predominantly squamous, inflammatory or atrophied appearance seen in pseudo-alopecia areata or lupus discoides, folliculitis (folliculitis decalvans) or shrinkage of the hair shafts (androgenogenetic alopecia). DISCUSSION: Videomicroscopy allows a detailed semiological description of damage to the scalp. In the majority of patients with alopecia areata, the yellowish ring was centred around the ostium. A knowledge of the appearance of this finding is helpful in diagnosing diffuse forms of alopecia areata or forms likely to be confused with pseudo alopecia areata. It would perhaps be of value to investigate for a correlation between the semiological appearances noted in our study and the progression and prognosis of alopecia areata.