Dasha Fuentes

Systemic and Skin Toxicity in Cercopithecus aethiops sabaeus Monkeys Treated During 26 Weeks with a High Intravenous Dose of the Anti- Epidermal Growth Factor Receptor Monoclonal Antibody Nimotuzumab

Nimotuzumab (h-R3) is a humanized anti-epidermal growth factor receptor monoclonal antibody (mAb) registered for treating head and neck tumours. The present study was designed to evaluate the systemic and skin toxicity of chronic intravenous administration of the h-R3 in a relevant species demonstrated by comparing the h-R3 binding affinity constants (Kd) in microsomal placental fractions from Homo sapiens and Cercopithecus aethiops monkeys using an EGF-Receptor radioligand competition assay. The Kd obtained for Nimotuzumab were 9.1x10-8 M for monkeys and 4.5x10-8 M for humans. Monkeys (n=18) were distributed into 3 groups with 3 animals of each sex in each group. Group I received saline; group II received 2.85 mg/kg of h-R3; and group III received 28.57 mg/kg of the h-R3, which represent 1 and 10 times the human dose, and they were weekly intravenously treated during 26 weeks. During the study there were no deaths. Electroneurophysiological, sanguine chemistry and haematological results did not evidence alterations. Areas of haematomas, probably related with the administration procedure, were observed at the administration zones of all animals. The electrocardiography study showed at the end of the study a slight increase in the cardiac frequency of 4 treated animals without others signs. Unexpectedly, skin biopsies and a detailed clinical inspection of the animals did not detect the presence of cutaneous rash or any other skin toxicity sign reported for the majority of the anti-EGF-R monoclonal antibodies. It is concluded that doses up to 28.5 mg/kg of h-R3, intravenously administered during 26 weeks to Cercopithecus aethiops monkeys, do not produce considerable toxic effects.

Hematological, biochemical, respiratory, cardiovascular and electroneurophysiological parameters in African green monkeys (Cercopithecus aethiops sabaeus). Its use in non-clinical toxicological studies.

Background  The purpose of this study is to better characterize the hematological, biochemical, respiratory, cardiovascular and electroneurophysiological parameters in young adult Cercopithecus aethiops sabaeus of both sexes. The rhesus and cynomolgus monkeys are widely used as experimental primate models. However, only few articles have been published testing toxicological effects of pharmaceuticals on African green monkey.

Effects of an epidermal growth factor receptor-based cancer vaccine on wound healing and inflammation processes in murine experimental models.

Anti‐epidermal growth factor receptor (EGFR) therapies have been proven clinically effective for a variety of epithelial tumours. Vaccination of mice with the extracellular domain (ECD) of autologous EGFR overcomes the tolerance to self‐EGFR and has antimetastatic effect on EGFR+ tumour. Because EGF/EGFR‐signalling plays an important role in the inflammation stage of wound healing, the main objective of this study was to explore the possible role of murine (m) EGFR‐ECD vaccine in the croton‐oil‐induced ear oedema and wound healing process in mice as autologous experimental models, mimicking the possible post‐surgical wound complication in patients treated with human EGFR‐ECD/VSSP vaccine. Mice were intramuscularly immunised four times; biweekly with the mEGFR‐ECD/VSSP/Mont. Seven days later, an 8 mm diameter, full‐thickness skin wound was created on the back of each animal. Immunisation induced a strong specific humoral response against the mEGFR‐ECD protein and a DTH dose–response curve but interestingly, animals treated with mEGFR‐ECD/VSSP/Mont had similar inflammatory and healing speed responses compared to control ones. These data suggest that application of mEGFR‐ECD/VSSP vaccine as a therapeutic approach in cancer patients could not elicit a poor healing process after surgery.

Age-Related Changes in the Behavior of Apolipoprotein E Knockout Mice

The knockout mouse model, B6.129P2-Apoetm1Unc is homozygotic for the Apolipoprotein E (ApoE) deletion; thus, it is capable of developing hyperlipidemia and atherosclerosis but ApoE is also a lipid-transport protein abundantly expressed in most neurons in the central nervous system, so these animals could also be models of neurodegenerative diseases. The aim of this study was to determine age-related changes in spontaneous behavior and in learning and memory of Apolipoprotein E knockout mice. Spontaneous behavioral measurements included sleeping pattern, motor coordination and balance by rotarod and open field activity, whereas learning and memory tests included forced alternation in Y-maze, novel object recognition and passive avoidance conditioning. Significant behavioral differences between aged knockout mice and age-matched wild type strain, C57Bl/6 were found in all the behavioral tests, except for the rotarod test. Genetically’ modified mice exhibited less huddling contact during sleeping, decreased locomotor activity in novel environments and in learning and memory deficits. These results are consistent with the cognitive impairment and memory loss seen as the earliest clinical symptoms in neurodegenerative disorders such as Alzheimer’s disease. The ApoE knockout mice might therefore be an appropriate model for studying the underlying mechanisms involved in behavioral changes caused by neurodegenerative diseases as well as for evaluating new therapies for these pathologies.

Toxicity assay in repeated doses of Dermatophagoides siboney allergen extract in mice

Allergen extracts are used for hyposensitivity and immunotherapy treatments, reducing significantly clinical symptoms of allergic diseases. Because of its wide use in immunoallergen therapy, we evaluated the Dermatophagoides siboney allergen extract to establish the potential toxicity following repeated subcutaneous dosing in Cenp:NMRI mice. Animals were randomly distributed into two groups, control (vehicle) and treated (166.6 UB/animal), and they were observed daily for clinical signs of toxicity following treatment. Body weight was weekly measured. At the end of the study, blood samples were collected for hematology and serum chemistry analysis and animals were euthanized for gross necropsy and histological examination of tissues. There were not significant differences in body weight or hematology parameters between control and treated animals. Differences were noted in uric acid, blood urea nitrogen and glucose; however, these alterations were not considered to be of biologic relevance. Pathology evaluations demonstrated hemorrhagic and inflammatory lesions at the administration site in both experimental groups. We conclude that repeated dosing of 166.6 UB did not cause significant toxic effects in the mouse model.