Dioxin-like Compounds in Lake Fish Species: Evaluation by DR-CALUX Bioassay

Fish consumption is the principal source of intake of organochlorinated compounds in humans. Compared with other types of foods of animal origin, fish contain the highest levels of polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p-dioxins, and polychlorinated dibenzofurans, all of which are classified as highly toxic organochlorine compounds. Currently, lakes and fish farms in northern Italy are not regularly monitored for PCBs and dioxins in areas contaminated by industrial sources, partially because of the high costs of traditional analytical methods that limit the number of samples to be analyzed. The DR-CALUX cell bioassay is based on the uptake of the cellular aryl hydrocarbon receptor (AhR) for dioxins and dioxin-like compounds. The aim of this study was to assess the levels of dioxins and dioxin-like PCB contamination in Lake Maggiore and Lake Como, two lakes in northwestern Italy, and in nearby areas. The levels were quantified using the cell bioassay DR-CALUX and reference controls in two wild fish species, perch ( Perca fluviatilis) and roach ( Rutilus rutilus), and in a farmed species, rainbow trout ( Oncorhynchus mykiss). Tissue samples collected from the farmed rainbow trout were also submitted to immunohistochemical analysis of CYP1A expression as a marker for environmental pollutant-induced liver damage. The levels of dioxins, furans, and dioxin-like PCBs were all below the maximum levels and action limits set by European Union Regulation, suggesting no risk for human health associated with the consumption of the fish species caught or farmed in these areas.

Diffusion kurtosis imaging probes cortical alterations and white matter pathology following cuprizone induced demyelination and spontaneous remyelination

Although MRI is the gold standard for the diagnosis and monitoring of multiple sclerosis (MS), current conventional MRI techniques often fail to detect cortical alterations and provide little information about gliosis, axonal damage and myelin status of lesioned areas. Diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) provide sensitive and complementary measures of the neural tissue microstructure. Additionally, specific white matter tract integrity (WMTI) metrics modelling the diffusion in white matter were recently derived. In the current study we used the well-characterized cuprizone mouse model of central nervous system demyelination to assess the temporal evolution of diffusion tensor (DT), diffusion kurtosis tensor (DK) and WMTI-derived metrics following acute inflammatory demyelination and spontaneous remyelination. While DT-derived metrics were unable to detect cuprizone induced cortical alterations, the mean kurtosis (MK) and radial kurtosis (RK) were found decreased under cuprizone administration, as compared to age-matched controls, in both the motor and somatosensory cortices. The MK remained decreased in the motor cortices at the end of the recovery period, reflecting long lasting impairment of myelination. In white matter, DT, DK and WMTI-derived metrics enabled the detection of cuprizone induced changes differentially according to the stage and the severity of the lesion. More specifically, the MK, the RK and the axonal water fraction (AWF) were the most sensitive for the detection of cuprizone induced changes in the genu of the corpus callosum, a region less affected by cuprizone administration. Additionally, microgliosis was associated with an increase of MK and RK during the acute inflammatory demyelination phase. In regions undergoing severe demyelination, namely the body and splenium of the corpus callosum, DT-derived metrics, notably the mean diffusion (MD) and radial diffusion (RD), were among the best discriminators between cuprizone and control groups, hence highlighting their ability to detect both acute and long lasting changes. Interestingly, WMTI-derived metrics showed the aptitude to distinguish between the different stages of the disease. Both the intra-axonal diffusivity (Da) and the AWF were found to be decreased in the cuprizone treated group, Da specifically decreased during the acute inflammatory demyelinating phase whereas the AWF decrease was associated to the spontaneous remyelination and the recovery period. Altogether our results demonstrate that DKI is sensitive to alterations of cortical areas and provides, along with WMTI metrics, information that is complementary to DT-derived metrics for the characterization of demyelination in both white and grey matter and subsequent inflammatory processes associated with a demyelinating event.

Acute complicated sphenoiditis in childhood. Case report and literature review

In ENT practice, acute uncomplicated sphenoiditis is rarely diagnosed: very often diagnosis is involved for multiform and unspecific symptomatology, such as to sham nervous, visual and upper respiratory tract diseases. Only a careful differential diagnostics and an instrumental investigation consents to realise quickly a specific treatment, avoiding some complications, still frequent. This case-report, underlines that the polyspecialists' co-operation is necessary to make a correct diagnosis, and to avert important and dangerous complications into shapes of sphenoiditis.

[Air pollution in the daily environment: study of a school-children population]

BACKGROUND

To evaluate the annual distribution of personal exposure to NO2 in a sample of school children and to study the determinants of such exposure.

METHODS

Exposure to NO2 has been evaluated using Palmes Tubes in 310 school-children (aged 5-14) in Novara. The possible differences in personal measurements by means of ANOVA and Tuckey test were evaluated. Information on the sources of potential exposure and on respiratory symptoms have been collected through a questionnaire and a clinical diary. The relative risk for these variables has been assessed using a multiple regression model (Logit).

RESULTS

The annual mean of the 6,200 measurements was 42.3 microgram/m3, with a significant difference among seasons and with higher values in winter. The only factor associated with a high exposure was identified for maternal school children living in houses close to high traffic density roads. Respiratory symptoms were non-related to NO2.

CONCLUSIONS

The use of gas cookers and heaters is not enough to explain the variability of personal exposure. Between other specific determinants, the importance of living along busy streets, of ETS and of seasons explains the level of personal exposure. The opportunity of personal, rather than environmental, monitoring is confirmed, even if we stress the necessity of studying the short-term exposure to rapidly find clinical damages in the general population.

[Bacteremia in tonsillectomy: Sluder's technique versus dissection. Preliminary results]

Fifty-one patients undergoing elective tonsillectomy for recurrent acute tonsillitis, 21 by dissection tonsillectomy (41%), and 30 guillotine tonsillectomy (59%). Positive post-operative blood cultures were obtained in 22 patients (43%), but only 4 in the dissection group (19%) and in 18 of the guillotine group (60%). Streptococci (21.5%) and Staphylococci (9.8%) are the commonest organisms cultured. This data are suggestive for the necessity of an antibiotic prophylaxis before tonsillectomy.