Teratogenic and neuro-behavioural toxic effects of bisphenol A (BPA) and B (BPB) on Xenopus laevis development

Bisphenol A (BPA) is a plastic additive with endocrine disruptive activity, classified in 2017 by EU ECHA as substance of very high concern. A correlation between environmental exposure to BPA and congenital defects has been described in humans and in experimental species, including the amphibian Xenopus laevis. Among BPA analogues, bisphenol B (BPB) is used as alternative in different not-EU countries, including US, but seems to share with BPA its endocrine disruptor properties. Aim of the present work is the evaluation of the effects of BPB versus BPA exposure in a X. laevis developmental model. A windowed exposure (R-FETAX method) was applied covering the developmental phylotypic period (teratogenicity window), or the late tailbud stages (neuro-behavioural toxicity window, corresponding to the spontaneous swimming acquisition period). Samples were monitored for lethal effects during the full test period. External morphology evaluation and deglutition functional test were applied in any group. Abnormal tadpoles were also processed for cartilage staining. In groups exposed during neuro-behavioural toxicity window the swimming test was also applied. Lethality and malformations were obtained only in samples exposed during the teratogenicity window; these data were modelled using PROAST software and BPB relative potency resulted about 3 times higher than BPA. The day-by-day evaluation revealed that lethality was correlated to embryonic abnormal development of gills and apoptosis in gill primordia. Teratogenicity was never detected in groups exposed during the neuro-behavioural toxicity window, where some significant neuro-behavioural deficits were detected in tadpoles exposed to the highest tested concentrations of BPA and BPB.

Determinants of health-related quality of life in morbid obese candidates to gastric banding

OBJECTIVE

To analyse determinants of self reported health-related quality of life (HR-QoL) in morbid obese patients candidates to laparoscopic adjustable gastric banding (LAGB).

METHODS

Determinants of HR-QoL were investigated in 383 morbid obese patients (82 M and 301 F) with BMI≥40 kg/m² (BMI≥35 kg/m² if complicated obesity) and age 18-60 years. HR-QoL was determined with the SF-36 questionnaire. Determinants of the two summary measures of SF-36 (physical component and mental component) were analysed by stepwise multiple linear regression analysis with age, BMI, physical comorbidites, mental comorbidites and eating behaviour disorders as independent variables. Physical comorbities (diabetes, hypertension, hypertriglyceridemia, low HDL, sleep apnea and osteoarthritis) were coded as present or absent on the basis of simple diagnostic clinical criteria; mental comorbidities (depression) and eating behaviour disorders (binge eating, sweet eating and nibbling) on the basis of an unstructured clinical interview.

RESULTS

Mean age was 38.8±10.2 years and mean BMI was 41.5±5.4 kg/m². Scores in the eight SF-36 subscales were lower in women than in men and lower than in the general Italian population. However, 18.4-43.5% of the participants had HR-QoL levels above the normative values, depending on the scale. In both genders, low scores in the mental component of the SF-36 were associated to the presence of depression and eating behaviour disorders and not to physical comorbidities or BMI levels. Low physical self-perceived well being was associated to high BMI levels in men and to depression, hypertension and hypertriglyceridemia in women.

CONCLUSION

HR-QoL was poor in morbid obese candidates to LAGB, particularly in women, and was negatively affected more by mental comorbidites and eating behaviour disorders than by physical comorbidities or BMI levels.

Comparative pharmacokinetic analysis of 5-fluorouracil and its major metabolite 5-fluoro-5,6-dihydrouracil after conventional and reduced test dose in cancer patients

The aim of this study was to investigate the clinical pharmacokinetics of 5-fluorouracil (5-FU) and its major metabolite 5-fluoro-5,6-dihydrouracil (5-FDHU) in 20 colorectal cancer patients given two dose levels of 5-FU, 250 and 370 mg/m2, administered by i.v. bolus. A reverse-phase high-performance liquid chromatographic method was used for the simultaneous assay of 5-FU and 5-FDHU in plasma samples obtained at baseline and at multiple time points from 5 min to 4 h after 5-FU bolus as well as to assess the activity of dihydropyrimidine dehydrogenase (DPD) in peripheral blood mononuclear cells (PBMCs) before 5-FU dosing. Plasma pharmacokinetic parameters of patients given 250 mg/m2 5-FU were significantly different from those receiving 370 mg/m2; main differences were observed in the trapezoidal areas under the plasma levels-versus-time curve from to to the last measurable concentration (area under the curve, 3.77+/-0.21 versus 13.61+/-2.3 h x microg/ml), peak plasma concentration (Cmax, 18.15+/-1.35 versus 48.41+/-7.69 microg/ml), and total body clearance (CL(TB), 54.64+/-3.54 versus 25.43+/-2.3 l/h/m2). Significant differences were also observed in the main pharmacokinetic parameters of 5-FDHU after 250 and 370 mg/m2 5-FU including the area under the curve from to to 4 h (5.39+/-0.32 versus 8.75+/-1.24 h x microg/ml), Cmax (3.60+/-0.16 versus 5.26+/-0.55 microg/ml) and time to Cmax (Tmax, 0.45+/-0.03 versus 0.69+/-0.06 h). The mean DPD activity in PBMCs in this group of patients was 205.7+/-36.4 pmol of 5-FDHU/min/mg of protein and was within the normal range; however, no significant correlations were found between 5-FU or 5-FDHU pharmacokinetic parameters at two dose levels and DPD activity of PBMCs. The results of the present study provide the first detailed comparison of the distribution of 5-FU and its major metabolite 5-FDHU at the therapeutic level as well as at reduced test dose levels to obtain pharmacokinetic data to be used as reference values for the identification of patients at risk of major 5-FU toxicity due to impaired metabolism to 5-FDHU.