3-Hydroxybenzo(a)pyrene as a biomarker of dermal exposure to benzo(a)pyrene

The aim of this study was to determine the percutaneous absorption flux of BaP (20 μg/cm² in ethanol) and the usefulness of urinary 3-OHBaP as a bio-indicator of dermal exposure to BaP. The percutaneous absorbed dose and absorption flux were estimated by comparison with intravenous administration of BaP (0.01 and 0.05 mg/kg in Cremophor^®) as reference way. A percutaneous absorption flux of 0.37 μg/cm²/h was determined by killing groups of rats, following exposure time of 4.5 and 24 h. [¹⁴C] skin content was 3.1 μg/cm², after 24 h exposure to BaP. Total urinary 3-OHBaP accounted for 0.4% of the real absorbed dose, which was fourfold higher than the percentage of an intravenous dose excreted as 3-OHBaP. This finding reveals that percutaneous absorption of BaP, based on the ratio of urinary excretion of 3-OHBaP following percutaneous exposure compared to percutaneous absorption following intravenous administration of BaP, is overestimated in the rat. In vitro, BaP was intensively metabolised by rat skin. Unchanged BaP and 3-OHBaP in receptor fluid accounted for 50 and 30% of the total radioactivity. This percutaneous first past effect of BaP in rats could, in part, explain the higher urinary excretion ratio of 3-OHBaP compared to the value based on intravenous administration of BaP. Conversely, BaP was largely lower metabolised as 3-OHBaP during percutaneous absorption by humans, so BaP absorption flux should be overestimated to a lesser extent in humans than in rats.     

Ventriloquism aftereffects occur in the rear hemisphere

After exposure to a consistent spatial disparity of auditory and visual stimuli, subjective localization of sound sources is usually shifted in the direction of the visual stimuli. This study investigates whether such aftereffects can be observed in humans after exposure to a conflicting bimodal stimulation in virtual reality and whether these aftereffects are confined to the trained locations. Fourteen subjects participated in an adaptation experiment, in which auditory stimuli were convolved with non-individual head-related transfer functions, delivered via headphones. First, we assessed the auditory localization of subjects in darkness. They indicated the perceived direction of a sound using an angular pointer. We then immersed the subjects in a virtual environment by means of a head-mounted display. They were asked to reproduce sequences of movements of virtual objects with a mouse click on the objects. However, we introduced a spatial disparity of 15 degrees between the visual event and the concurrent auditory stimulation. After 20 min of exposure, we tested the subjects again in total darkness to determine whether their auditory localization system had been modified by the conflicting visual signals. We observed a shift of subjective localization towards the left in both dorsal and frontal hemifields of the subject, mainly for auditory stimuli located in the right hemispace. This result suggests that interaural difference cues and monaural spectral cues were not equally adapted, and that visual stimuli mainly influence the processing of binaural directional cues of sound localization.     

Complete Response of an Initially Non-surgical Adenocarcinoma of the Duodenum to Chemotherapy with the Folfox 4 Regimen

Introduction  

The incidence of adenocarcinoma of the small bowel is very low in comparison with that of colorectal cancer. Radical surgery is the only curative treatment, and results with chemotherapy and radiotherapy are disappointing. No standard chemotherapy is defined for non-surgical adenocarcinoma of the small bowel. In France, it is usually treated with the same chemotherapy regimens as used for colorectal cancer.     

Analytic quantification of phototype-related regional skin complexion

Background/aims: Narrow-band spectrophotometry that yields melanin (M) and erythema (E) indexes is a convenient method for assessing skin colour. The objective of the study was to assess the phenotype-associated body site differences in skin complexion.
Method: The Mexameter MX16 was used to record the skin colour in 137 subjects. Evaluations were made on the inner arm, volar forearm, dorsal forearm and forehead.
Results: The inner arm and volar forearm had similar values for each of the colorimetric values. The dorsal forearm exhibited the highest M values, and the forehead had the highest E values. Significant positive linear correlations were found between M values from the distinct body sites. The E values showed a correlation only between the inner arm and the volar forearm.
Conclusion: Regional skin colour differences are obvious. Sun-exposed skin does not react in the same way on the forearm and forehead. Regional variations in M can be predicted from the innate M value. In contrast, the regional variability in E is highly variable among subjects.     

Development of an Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Ringworm Infection in Cattle

The aim of this study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of ringworm infection in cattle. We used available recombinant forms of Trichophyton rubrum dipeptidyl peptidase V (TruDppV) and T. rubrum leucin aminopeptidase 2 (TruLap2), which are 98% identical to Trichophyton verrucosum orthologues. Field serum samples from 135 cattle with ringworm infection, as confirmed by direct microscopy, fluorescence microscopy, and PCR, and from 55 cattle without any apparent skin lesions or history of ringworm infection that served as negative controls were used. Sensitivities, specificities, and positive and negative predictive values were determined to evaluate the diagnostic value of our ELISA. Overall, the ELISAs based on recombinant TruDppV and TruLap2 discriminated well between infected animals and healthy controls. Highly significant differences (P < 0.0001, Mann-Whitney U test) were noted between optical density values obtained when sera from infected versus control cattle were tested. The ELISA developed for the detection of specific antibodies against DppV gave 89.6% sensitivity, 92.7% specificity, a 96.8% positive predictive value, and a 78.4% negative predictive value. The recombinant TruLap2-based ELISA displayed 88.1% sensitivity, 90.9% specificity, a 95.9% positive predictive value, and a 75.7% negative predictive value. To the best of our knowledge, this is the first ELISA based on recombinant antigens for assessing immune responses to ringworm infection in cattle; it is particularly suitable for epidemiological studies and also for the evaluation of vaccines and/or vaccination procedures.