Search

The use of laboratory animals should be preceded by the recognition that the use of a living being always requires an ethical choice and each decision is inherently linked with the full understanding of the norms that regulate such use. This chapter analyses the significance of ethical evaluation and proposes a detailed analysis of European legislation regulating the use of animals in scientific research.

Stage 4 neuroblastoma (NB) is a devastating childhood cancer whose poor outcome has remained essentially unchanged in the last 20 years. Receptor tyrosine kinases have important roles in the control of proliferation, differentiation and apoptosis of NB cells. Thus, we tested the activity of second-generation tyrosine kinase inhibitor Dasatinib in human NB cell lines in vitro and in an orthotopic mouse model. Dasatinib inhibited cell viability with an IC(50) in the submicromolar range in 7 of 10 tested cell lines. In sensitive cells, Dasatinib reduced anchorage-independent growth and, in some instances, induced senescence and apoptosis. In HTLA-230 cells, Dasatinib treatment caused down-regulation of c-Kit and c-Src phosphorylation in conjunction with strong inhibition of Erk1/2 and Akt activity. To test the efficacy of Dasatinib in vivo, HTLA-230 and SY5Y cells were orthotopically injected in the adrenal gland of nude mice and drug treatments carried out until day 40. In mice injected with HTLA-230 cells, tumour growth was significantly inhibited at the dose of 30 mg/(kg day) when treatment was started 7 days after injection. In animals injected with SY5Y cells that were exquisitely sensitive in vitro (IC(50)= 92 nM), the antitumour effect of Dasatinib was observed at the dose of 60 mg/(kg day) but only when treatment was started 1 day after injection. However, the anti-tumour effect of Dasatinib in vivo was partial in both orthotopic models, emphasizing the importance of testing candidate new drugs in animal environments closely mimicking the human tumour.

The aim of this study was to evaluate the cochlear functionality of Sprague-Dawley rats exposed to electromagnetic fields at 900 MHz and to gentamicin by distortion product otoacoustic emissions, which are a well-known indicator of the status of the cochlea's outer hair cells. A population of 32 rats was divided into four groups: group 1 was treated with daily intramuscular injections of 150 mg/kg body weight gentamicin for 15 days; group 2 was treated with daily intramuscular injections of 150 mg/kg body weight gentamicin for 15 days and exposed to electromagnetic fields; group 3 was exposed to electromagnetic fields; group 4 was sham-exposed. Rats were exposed 2 h/day, 5 days/week for 4 weeks at a local SAR of 4 W/kg in the ear (continuous wave at 900 MHz). Distortion product otoacoustic emissions tests were carried out before, during and after the combined exposure. The analysis of the data showed no subchronic exposure to electromagnetic fields on the inner auditory system of rats in either normal ears or ears exposed to a well-recognized pathological agent.

UMTS communication devices are becoming common in everyday use. This could raise public concern about their possible detrimental effects on human health. The aim of this study, in the framework of the EMF nEAR Project, was to evaluate possible influence of UMTS electromagnetic fields (EMF) exposure on cochlear outer hair cells' (OHCs) functionality in laboratory animals. Forty-eight male Sprague–Dawley rats were locally exposed (right ear) or sham-exposed to a controlled UMTS EMF, frequency of 1946 MHz, at SAR level of 10 W/kg, 2 h a day, 5 days a week, for 4 weeks. A group of 12 rats treated with kanamycin (KM) was also included as positive control. Rats were tested by recording Distortion Product Otaoacoustic Emissions (DPOAEs), a non-invasive test capable of assessing the status of the OHCs in the inner ear. DPOAEs were performed before, during (one or three times a week) and after (1-week) exposure to the EMF. The analysis of the data shows that no statistically significant differences were found between the audiological signals recorded from the different experimental groups. The ototoxic effect of KM has been confirmed. Bioelectromagnetics 30:385–392, 2009. © 2009 Wiley-Liss, Inc.

In recent years, the widespread use of mobile phones has been accompanied by public debate about possible adverse consequences on human health. The auditory system is a major target of exposure to electromagnetic fields (EMF) emitted by cellular telephones; the aim of this study was the evaluation of possible effects of cellular phone-like emissions on the functionality of rat's cochlea. Distortion Products OtoAcoustic Emission (DPOAE) amplitude was selected as cochlea's outer hair cells (OHC) status indicator. A number of protocols, including different frequencies (the lower ones in rat's cochlea sensitivity spectrum), intensities and periods of exposure, were used; tests were carried out before, during and after the period of treatment. No significant variation due to exposure to microwaves has been evidenced.

Multimodality therapy is considered of great interest in the treatment of locally advanced solid tumours. In previous experiments, paclitaxel (TX) and epirubicin (EP) were combined with different schedules, obtaining a superadditive effect on the growth of a murine mammary carcinoma. In the present study, the authors have analysed the possible use of hyperthermia (HT) to increase the efficacy of TX and EP combinations. Tumours were transplanted into the right hind foot of female hybrid (C3D2F1) mice. Both TX and EP were administered i.p in two different doses. Hyperthermia was applied using a water bath at 43.2 degrees C for 1 h. Results were analysed in terms of Tumour Growth Delay (TGD). The maximum tolerated doses in combined protocols were TX 45 mg/kg and EP 9 mg/kg, with an interval time of 24h between the two administrations. TGDs of some of the schedules performed are reported: EP + HT = 11 days, TX + HT = 16 days, TX + EP (with an interval time of 24 h) = 14 days, and TX + EP + HT = 22 days. In the experimental model, HT significantly increases the effects of both TX and EP. TX + EP + HT treatment is the most effective (significantly different from TX + EP), but not in a significant way when compared to TX + HT treatment. These results suggest the possible use of a TX + HT protocol for local tumour response, whereas EP could be added in order to achieve a better systemic control.

The purpose of this paper is to present the experimental device and the work in progress performed in search for objective organic correlation of damage to hearing, examining possible acoustic otofunctional effects on the cochlear epithelium of the rat due to exposure to microwaves (900 MHz). Two experiments using male Sprague-Dawley rats were carried out with a far-field exposure in a cubic chamber. No statistically significant evidence was obtained at both specific absorption rate (SAR) values. The exposure system and the diagnostic apparatus are extremely useful to investigate a potential effect on the auditory system: however, with the parameters applied in these experiments, no evidence was observed.

Among the strategies targeting vector control, the exploitation of the endosymbiont Wolbachia to produce sterile males and/or invasive females with reduced vector competence seems to be promising. A new Aedes albopictus transinfection (ARwP-M) was generated by introducing wMel Wolbachia in the ARwP line which had been established previously by replacing wAlbA and wAlbB Wolbachia with the wPip strain. Various infection and fitness parameters were studied by comparing ARwP-M, ARwP and wild-type (SANG population) Ae. albopictus sharing the same genetic background. Moreover, the vector competence of ARwP-M related to chikungunya, dengue and zika viruses was evaluated in comparison with ARwP. ARwP-M showed a 100% rate of maternal inheritance of wMel and wPip Wolbachia. Survival, female fecundity and egg fertility did not show to differ between the three Ae. albopictus lines. Crosses between ARwP-M males and SANG females were fully unfertile regardless of male age while egg hatch in reverse crosses increased from 0 to about 17% with SANG males aging from 3 to 17 days. When competing with SANG males for SANG females, ARwP-M males induced a level of sterility significantly higher than that expected for an equal mating competitiveness (mean Fried index of 1.71 instead of 1). The overall Wolbachia density in ARwP-M females was about 15 fold higher than in ARwP, mostly due to the wMel infection. This feature corresponded to a strongly reduced vector competence for chikungunya and dengue viruses (in both cases, 5 and 0% rates of transmission at 14 and 21 days post infection) with respect to ARwP females. Results regarding Zika virus did not highlight significant differences between ARwP-M and ARwP. However, none of the tested ARwP-M females was capable at transmitting ZIKV. These findings are expected to promote the exploitation of Wolbachia to suppress the wild-type Ae. albopictus populations., Author summary Aedes albopictus is one of the major human disease vectors and, despite substantial control efforts, it is rapidly spreading worldwide and increasing its epidemiological role. Thus, innovative approaches to fight this mosquito are urgently needed. Among the available control strategies, the exploitation of the endosymbiotic bacterium Wolbachia seems to be promising. In nature, the infection by Wolbachia is generally not detrimental, instead, it causes a series of modifications in host physiology promoting the spread of the infection in uninfected populations. Herein, we report on the artificial transinfection of specific Wolbachia strains in Ae. albopictus to replace its native Wolbachia infection type. This manipulation aimed at exploiting the expected modifications in the reproductive biology and vector competence of the species to contribute to reduce its epidemiological role. Specifically, we found that the new double Wolbachia infection did not affect Ae. albopictus fitness. The males belonging to the manipulated line, ARwP-M, induced full egg infertility in the wild-type females they mate with and showed increased male mating competitiveness. Remarkably, the ARwP-M females demonstrated significantly reduced competence for chikungunya and dengue viruses while both tested Ae. albopictus lines showed a very low susceptibility for Zika virus. These findings may encourage the use of ARwP-M Ae. albopictus as a highly efficient and safe biocide to suppress the wild-type populations.