Rapid desorption electrospray ionization-high resolution mass spectrometry method for the analysis of melamine migration from melamine tableware.

Migration of melamine into foods from melamine tableware has been object of recent Rapid Alert System for Food and Feed (RASFF) notifications. In this context, a rapid and sensitive desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) method was developed and validated for the determination of melamine migration from plastic materials. The migration test was performed using acetic acid 3% (w/v) as food simulant. Evaluation of DESI parameters in terms of choice of support, motion profile, geometrical configuration and operating conditions coupled to the use of an orbitrap mass analyzer allowed to achieve significant improvements in terms of selectivity and accuracy obtaining detection and quantitation limits at low microgram per kilogram level. A LC-ESI-MS method was also developed for confirmatory purposes. Both methods were applied to 44 melamine tableware samples available on Italian market in order to assess their compliance with the law. Different concentration levels ranging from 0.00773±0.0006 to 3.0±0.1 mg/kg were found after the third exposure to the simulant in new and used tableware with two samples out of 44 being characterized by a melamine release higher than the legal limit, i.e. 2.5 mg/kg. A two tailed t-test allowed to assess the good agreement between the quantitative results obtained applying the DESI-MS method with those provided by LC-ESI-MS, thus proving reliability of DESI-HRMS as rapid technique for the study of melamine release from plastic materials.

Restoration of the GM2 ganglioside metabolism in bone marrow-derived stromal cells from Tay-Sachs disease animal model.

The therapeutic potential of bone marrow-derived stromal cells for the therapy of Tay-Sachs disease is primarily related to the restoration of their own GM2 ganglioside storage. With this aim, we produced bone marrow-derived stromal cells from the adult Tay-Sachs animal model and transduced them with a retroviral vector encoding for the alpha-subunit of the lysosomal enzyme beta-hexosaminidase A (E.C. 3.2.1.52). Our results demonstrate that transduced Tay-Sachs bone marrow-derived stromal cells have beta-hexosaminidase A comparable to that of bone marrow-derived stromal cells from wild-type mice. Moreover, beta-hexosaminidase A in transduced Tay-Sachs bone marrow-derived stromal cells was able to hydrolyze the GM2 ganglioside in a feeding experiment, thus demonstrating the correction of the altered phenotype.

Evidence for the regulation of beta-N-acetylhexosaminidase expression during pregnancy in the rat.

It is believed that the lysosomal glycohydrolase beta-N-acetylhexosaminidase plays a part in several important processes of reproduction and it has been postulated that this enzyme is subject to hormonal regulation. During pregnancy, activity levels of the enzyme are strongly increased in both human and rat serum. However, little is known about the expression of this enzyme in the female reproductive apparatus and there is no evidence linking the production of hexosaminidase alpha- and beta-subunits to pregnancy. To clarify these aspects better, we examined the enzyme activity, isoenzyme subunit composition and distribution, as well as steady state levels of alpha- and beta-subunit mRNAs in the female reproductive organs and in other selected tissues of pregnant and non-pregnant rats. Among the female rat tissues tested, the ovary and kidney had the highest specific activity. Pregnancy modulated the hexosaminidase activity differently in the tissues examined. In pregnant rats, the activity decreased in the ovary but increased significantly in the uterus, liver and to a lesser extent in other tissues. The decreased hexosaminidase activity in the ovary from pregnant rats appeared to be accompanied by a disproportionately large decrease in beta-subunit mRNA abundance, whereas in the uterus and liver, an increased abundance of this transcript was detectable. The abundance of alpha-subunit mRNA was comparable in pregnant and control rat tissues. Hexosaminidase histochemical staining of tissue sections clearly demonstrates that the greatly increased activity of hexosaminidase in the uterus during pregnancy is largely due to the enzyme in the endometrium, and not to the uterus as a whole. The overall results provide evidence that, during pregnancy, a mechanism(s) of regulation of beta-N-acetylhexosaminidase expression is in operation, and that the enzyme is differentially regulated in rat tissues.

[Effects of shift work on the quality of sleep and psychological health based on a sample of professional nurses]. / Effetti dei turni lavorativi sulla qualità del sonno e sulla salute psicologica in un campione di infermieri professionali.

UNLABELLED: Impact of shiftwork on sleep and psychological health. OBJECTIVE: The purpose of the present study was to evaluate the impact of a rapid shiftwork system on sleep parameters and on psychopathological status among a sample of nurses. We hypothesize that in this type of shiftwork system, the rapid and continuous rotation of shifts doesn't lead to a lasting alteration of circadian rhythm but to a transitory increase of psychological disturbances after the night shift. METHODS: The population studied was the permanently employed staff of a public hospital in Modena. We recruited fifty-five workers. Participation was entirely voluntary. Every subject was given a self-administered questionnaire divided into three sections. Section I consisting in a base-line evaluation (sociodemographic data, use of psychotropic substances, General Health Questionnaire and Maslash Burnout Inventory). Sections II and III providing an evaluation of sleep and psychopathological parameters (Sleep Diary and Symptom Questionnaire) in two different moments during the shiftwork: respectively after the night following the night shift (corresponding to the end of the shift cycle), and after the night following the last day off (corresponding to the beginning of a new shift cycle). RESULTS: There were no significative differences in sleep parameters between the two moments of assessment. Regarding psychopathological features we found a reduction of SQ-Somatization (P = 0.002), SQ-Anxiety (p = 0.006) and SQ-Hostility (p = 0.075) subscale score at the end of the shift cycle. CONCLUSIONS: We confirm this type of shiftwork as not causing alterations of sleep parameters. We explain the improvement in psychopathological symptoms noted at the end of the shift cycle with the favourable psychological attitude of workers in the perspective of time off. The present data suggest that the psychological attitude of workers may play an important role in the clinical expression of psychopathological features.

Genetic alterations distinguish different types of ovarian tumors.

Seventy-four sporadic ovarian tumors were studied for loss of heterozygosity (LOH) and microsatellite instability (MI) with 20 polymorphic markers on chromosome 17 and at least I marker on every other chromosome. Additionally, activation of the K-ras oncogene was examined through mutation analysis of codon 12. A majority of the tumors analyzed were low grade and/or of the mucinous histologic type. A negative correlation between LOH on chromosome 17 and K-ras activation was observed, with the former alteration present in the majority of high grade serous and endometrioid tumors and the latter most commonly found in the mucinous and low malignant potential (LMP) tumors. In 60% of cases where LOH on chromosome 17 was present, it was observed at all informative markers, indicating chromosome loss. In these cases, frequent events of LOH were observed on the other chromosomes. When confined events of LOH were observed on chromosome 17, fewer events of LOH were observed on the other chromosomes. In the absence of LOH on chromosome 17, LOH on other chromosomes was rare. K-ras activation was most commonly observed in tumors with no LOH events. Two endometrioid tumors and 2 mucinous tumors demonstrated MI. Our data support the involvement of different molecular pathways in the development of different types of ovarian tumors.

Clinical study on bronchodilation induced by a metered aerosol of fenoterol in combination with ipratropium bromide.

The response to an aerosol preparation containing 100 micrograms fenoterol and 40 micrograms ipratropium bromide per puff (Duovent) was compared with a placebo in 18 asthmatic patients in a double-blind cross-over fashion. We measured changes in lung function tests and pulse rate. Duovent induced a significant improvement in lung tests with statistical relevance for VEMS and Raw in comparison with placebo. The combination of fenoterol and ipratropium bromide also provided a long-lasting bronchodilatation without side effects.