Trend to replacement of Experimental Animals

Para la aprobación, registro y comercialización de medicamentos, agroquímicos, productos de uso doméstico y sustancias cosméticas es necesario estudiar e informar al organismo regulador la potencial toxicidad. Por motivos éticos y económicos, en los últimos años se ha disminuido la utilización de animales de experimentación y se ha fomentado el desarrollo de metodologías alternativas. En el proceso de migración, la OCDE validó procedimientos para evaluar irritación y corrosión ocular y dérmica, mutagenicidad, fototoxicidad, sensibilización y absorción dérmica. Hoy en día es un área en constante investigación y desarrollo ya que aún no se ha logrado reemplazar completamente la calidad de los datos obtenidos en animales. Si bien la tendencia mundial al reemplazo de animales es clara, en Argentina aún no hemos dado el primer paso: no contamos con una ley que regule el uso de animales de experimentación. Las agencias reguladoras (SENASA y ANMAT) continúan solicitando ensayos con animales, pero han manifestado su interés en aceptar evidencia toxicológica obtenida por métodos alternativos. Desde el Laboratorio de Métodos Alternativos al uso de Animales de Experimentación que forma parte de la Plataforma Tecnológica EBAL nos hemos propuesto trabajar en el desarrollo, ejecución, perfeccionamiento y transferencia de metodología alternativa.For the approval, registration and commercialization of drugs, agrochemicals, household products and cosmetics substances is necessary to study and inform the regulatory organism about thepotential toxicity. Due to ethical and economic reasons, the use of experimental animals has decreased in the last years and the development of alternative methods has been improved. During the process of replacement, the OECD validated procedures to testdermal and ocular irritation and corrosion, mutagenicity, phototoxicity, dermal sensitization and absorption. Nowadays this area is in constant investigation and development as it has not been already possible to completely replace data quality obtained in animals. Even though the global trend to replace animals is clear, in Argentina the first step has not been taken yet as there is not a law that restraint the use of experimental animals. Although procedures with animals are still requested by the regulatory agencies (SENASA and ANMAT), they have shown interest in accepting toxicological evidence obtained by alternative methods. In our Laboratory of Alternative Methods to the use of Experimental Animals which belongs to the EBAL Technological Platform we have proposed to work in development, execution, improvement and transference of alternative methods.Fil: Rivero, Martín Nicolás. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Lenze, Mariela Belén. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Izaguirre, Mercedes. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Wikinski, Silvia Ines. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Gutiérrez, María Laura. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Comparison between HET-CAM protocols and a product use clinical study for eye irritation evaluation of personal care products including cosmetics according to their surfactant composition

The hen´s egg test on chorioallantoic membrane (HET-CAM) is one of the most frequently used alternative tests for prediction of ocular irritation of cosmetic products. There are different HET-CAM protocols widely accepted, but there is no information about which of the protocols better correlates with the results obtained in product use clinical study under the conditions of use. Two Fix Time Methods (FTM) -Lüepke and the ICCVAM guideline - and two Reaction Time Methods (RTM) -ECVAM DBALM Prot. No. 47 and No. 96- were employed to test 18 cosmetic products. Simultaneously, they were evaluated by an ophthalmological clinical test. A unified classification system was used, and products were classified into four irritation levels: non-irritant, weak, moderate and severe irritant. The duration of use (rinse-off or leave-on), and the concentration and type of surfactants were taken into account in the analysis. All the products that were classified as non-irritant by any HET-CAM protocols were also safe in the product use clinical study. The product that was found to be non-safe in the product use clinical evaluation was also unsuitable by most of the HET-CAM protocols. These results were employed to develop an algorithm that allows selecting the appropriate HET-CAM protocol for each type of product to be tested.Fil: Rivero, Martín Nicolás. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lenze, Mariela Belén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Farmacología; ArgentinaFil: Izaguirre, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Farmacología; ArgentinaFil: Pérez Damonte, Silvia H. Claim; ArgentinaFil: Aguilar, Alejandro. Claim; ArgentinaFil: Wikinski, Silvia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Farmacología; ArgentinaFil: Gutierrez, Maria Laura. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Body mass index, waist circumference, insulin, and leptin plasma levels differentiate between clozapine-responsive and clozapine-resistant schizophrenia

Background: Between 25% and 50% of patients suffering from treatment-resistant schizophrenia fail to achieve a clinical response with clozapine. The rapid identification and treatment of this subgroup of patients represents a challenge for healthcare practice. Aims: To evaluate the relationship between metabolic alterations and the clinical response to clozapine. Methods: A multicenter, observational, case–control study was performed. Patients diagnosed with schizophrenia treated with clozapine were eligible (minimum dose 400 mg/d for at least 8 weeks and/or clozapine plasma levels ⩾ 350 µg/mL). According to the Positive and Negative Syndrome Scale (PANSS) total score, patients were classified as clozapine-responsive (CR) (<80 points) or clozapine non-responsive (CNR) (⩾80 points). Groups were compared based on demographic and treatment-related characteristics, together with body mass index (BMI), waist circumference, insulin, leptin, and C-reactive protein plasma levels. Plasma levels of clozapine and its main metabolite, nor-clozapine, were measured in all the participants. In addition, the potential relationship between PANSS scores and leptin or insulin plasma levels was assessed. Results: A total of 46 patients were included: 25 CR and 21 CNR. BMI and waist circumference, fasting insulin and leptin plasma levels were lower in the CNR group, while C-reactive protein was not different. Moreover, significant negative correlations were observed between PANSS positive and general psychopathology subscores, on one hand, and insulin and leptin plasma levels, on the other hand, as well as between PANSS negative subscores and leptin plasma levels. Conclusions: Our results suggest that the lack of metabolic effect induced by clozapine is associated with the lack of clinical response.Fil: Hönig, Guillermo. Gobierno de la Ciudad de Buenos Aires; ArgentinaFil: Daray, Federico Manuel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodante, Demián. Gobierno de la Ciudad de Buenos Aires; ArgentinaFil: Drucaroff, Lucas Javier. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutiérrez, María Laura. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lenze, Mariela Belén. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García Bournissen, Facundo. Western University; CanadáFil: Wikinski, Silvia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentin

Advancing ocular safety research: A comprehensive examination of benzocaine acute exposure without animal testing

Benzocaine is a widely employed local anaesthetic; however, there is a notable dearth of preclinical and clinical evidence regarding its safety in ophthalmological products. To address this, a comprehensive strategy incorporating in silico and in vitro methodologies was proposed for assessing benzocaine´s ocular toxicity without animal testing. To collect the in silico evidence, the QSAR Toolbox (v4.5) was used. A single exposure to two benzocaine concentrations (2% and 20%) was evaluated by in vitro methods. Hen’s Egg Chorioallantoic Membrane Test (HET-CAM) was performed to evaluate the effects on the conjunctiva. To study corneal integrity, Short Time Exposure test (STE) and Bovine Corneal Opacity and Permeability (BCOP) assay, followed by histopathological analysis, were carried out. Results from both in silico and in vitro methodologies categorize benzocaine as non-irritating. The histopathological analysis further affirms the safety of using benzocaine in eye drops, as no alterations were observed in evaluated corneal strata. This research proposes a useful combined strategy to provide evidence on the safety of local anaesthetics and particularly show that 2% and 20% benzocaine solutions do not induce eye irritation or corneal damage, supporting the potential use of benzocaine in the development of ophthalmic anesthetic products.Fil: Lenze, Mariela Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Benedetti, Martina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Roco, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Ramírez, Pedro Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Blanco, Raúl. Laboratorio Labyes; ArgentinaFil: Yaceszen, Sol. Laboratorio Labyes; ArgentinaFil: Corrales, Carlos. Laboratorio Labyes; ArgentinaFil: Wikinski, Silvia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; ArgentinaFil: Gutiérrez, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Farmacologia; Argentin