Toxicity Evaluation of Anti-cholinesterasic Amphibian Extracts by MTT and an Optimized Artemia salina Test.

The amphibian skin is an important source of bioactive compounds. Recently, our workgroup reported the bioactivity of new extracts from the Hylidae, Microhylidae and Leptodactylidae families against several pathways involved in Alzheimer's disease. However, since cytotoxicity can be a limiting factor for their applicability, we evaluated the toxicity of nine amphibian skin extracts with reported anticholinesterase activity, using the traditional MTT assay and an optimized Artemia salina test. The proposed improvement, guided by experimental design, aims to reduce the amount of biological sample needed. Overall, we proved that the active extracts were non-toxic at effective concentration against cholinesterases (AChE/BChE), positioning the amphibian skin as a promising and preliminary safe source of bioactive compounds in the anti-Alzheimer's treatment. Interestingly, we demonstrated that both toxicity assays can discriminate between toxic and non-toxic samples. We propose the A. salina bioassay as a reliable and cost-effective alternative for early toxicity screening.

Acetylcholine hydrolytic activity of fibrillated ß-amyloid (1-40) peptide.

Alzheimer's disease is characterized by the presence of senile plaques composed of ß-amyloid peptide (Aß) aggregates with toxic effects that are still not fully understood. Recently, it was discovered that Aß(1-42) fibrils possess catalytic activity on acetylcholine hydrolysis. Catalytic amyloids are an emerging and exciting field of research. In this study, we examined the catalytic activity of the fibrils formed by Aß(1-40), the most abundant Aß variant, on acetylcholine hydrolysis. Our findings reveal that Aß(1-40) fibrils exhibit moderate enzymatic activity, indicating that natural peptide aggregates could serve as biocatalysts and provide new insights into the potential role of Aß in neurological disorders.

Inhibition of Human Cholinesterases and in†vitro ß-Amyloid Aggregation by Rationally Designed Peptides.

The multifactorial nature of Alzheimer's disease (AD) is now widely recognized, which has increased the interest in compounds that can address more than one AD-associated targets. Herein, we report the inhibitory activity on the human cholinesterases (acetylcholinesterase, hAChE and butyrylcholinesterase, hBChE) and on the AChE-induced ß-amyloid peptide (Aß) aggregation by a series of peptide derivatives designed by mutating aliphatic residues for aromatic ones. We identified peptide W3 (LGWVSKGKLL-NH2 ) as an interesting scaffold for the development of new anti-AD multitarget-directed drugs. It showed the lowest IC50 value against hAChE reported for a peptide (0.99±0.02 µM) and inhibited 94.2 %±1.2 of AChE-induced Aß aggregation at 10 µM. Furthermore, it inhibited hBChE (IC50 , 15.44±0.91 µM), showed no in vivo toxicity in brine shrimp and had shown moderated radical scavenging and Fe2+ chelating capabilities in previous studies. The results are in line with multiple reports showing the utility of the indole moiety for the development of cholinesterase inhibitors.

Natural multi-target modulators of pathological pathways in Alzheimer's disease isolated from the Rhinella arenarum skin.

The skin of anuran amphibians is a rich source of compounds with great medicinal potential. Alzheimer's disease (AD) is a complex disease associated with numerous pathological pathways, making their simultaneous modulation necessary. Nowadays the development of anti-AD drugs is focused on a Multi-Target Directed Ligands strategy. Herein we report the bioactivity of the skin extracts of the toad Rhinella arenarum obtained by an invasive and non-invasive methods, against five AD pathological targets (AChE, BChE, MAO-B, antioxidant and chelating activities). The extract derived from the non-invasive technique showed the highest biological activity, being capable of acting on all or almost all the pathological targets of AD, while also avoiding harm to the animal.

Rational design and synthesis of modified natural peptides from Boana pulchella (anura) as acetylcholinesterase inhibitors and antioxidants.

The use of acetylcholinesterase (AChE) inhibitors, antioxidants or multitarget compounds are among the main strategies against Alzheimer's disease (AD). Between AChE inhibitors, those targeting the peripheral anionic site (PAS) are of special interest. Here, we describe the rational design and synthesis of peptide analogs of a natural PAS-targeting sequence that we recently discovered, aiming at increasing its activity against AChE. We also tested their radical scavenging and metal chelating properties. Our design strategy was based on the position-specific, computer-aided insertion of aromatic residues. The analog named as W3 showed a 30-fold higher inhibitory activity than the original sequence and an improved antioxidant activity. W3 is the most potent modified natural peptide against Electrophorus electricus AChE ever reported with an IC50 of 10.42 µM (± 1.02). In addition, it showed a radical scavenging activity of 47.00% ± 3.11 at 50 µM and 93.47% ± 1.53 at 400 µM. Since peptides are receiving increasing interest as drugs, we propose the W3 analog as an attractive sequence for the development of new peptide-based multitarget drugs for AD. Besides, this work sheds light on the importance of the aromatic residues in the modulation of AChE activity and their effect on the radical scavenging activity of a peptide.

[Infant mortality and social inequalities in Argentina, 1980-2017]. / Mortalidad infantil y desigualdades sociales en Argentina, 1980-2017.

OBJECTIVE: To estimate the trend in infant mortality, inequality between jurisdictions and inequality associated with social conditions in Argentina between 1980 and 2017. METHODS: Ecological and time series study of infant mortality and its inequality. Official data on infant mortality, births and unmet basic needs were obtained; the infant mortality rate, the Gini index and the concentration index were calculated. The trend was also analyzed with a linear regression model and the regression coefficient and its statistical significance were calculated. RESULTS: Infant mortality was reduced by 71.2% (from 32.41 to 9.34 per 1 000 live births). Inequality by jurisdiction also decreased, and the Gini index fell from 0,163 to 0,09. Inequality associated with social conditions also showed a reduction, and the concentration index was reduced from -0.153 to -0.079. Although infant mortality declined throughout the period, this decline was not always accompanied by a reduction in the Gini index and the concentration index. CONCLUSIONS: The trend in the infant mortality rate decreased while the inequality in its distribution by jurisdiction and the inequality associated with social conditions did not always accompany this reduction.

Adoptando un modelo de gestión territorial integral para mejorar las prácticas en el primer nivel de atención de la salud: experiencia en los servicios de salud públicos de la ciudad de Villa María, Córdoba, Argentina / A comprehensive territorial management model to improve practices at primary healthcare: describing the experience in the public health services of the city of Villa María, Córdoba, Argentina

Este artículo relata la experiencia de la Secretaría de Salud (de la ciudad de Villa María, provincia de Córdoba, Argentina), frente a la implementación de una estrategia de abordaje integral de la salud en los servicios de atención primaria, basada en la territorialidad, la interdisciplinariedad, la participación comunitaria, la integralidad y la intersectorialidad denominada "Programa de Gestión Territorial Integral" (PGTI). Su implementación se realizó utilizando la estrategia de Educación Permanente en Salud (EPS). El programa incluyó la elaboración y difusión periódica, a través del Observatorio de Salud de indicadores construidos por los equipos. La puesta en marcha del PGTI fortaleció la coordinación con distintas áreas gubernamentales y no gubernamentales que resultaron en: la adopción del programa por Ordenanza del Consejo Deliberante Municipal, un convenio con la Universidad Nacional de Villa María, un plan conjunto de trabajo con el Hospital Provincial de la ciudad y la incorporación de la rendición de cuentas periódicas de los resultados por parte del ejecutivo municipal al Consejo Deliberante a partir del monitoreo continuo del Observatorio de Salud.El desarrollo hasta aquí logrado conforma un estímulo sustancial para sostener este proceso de formación y gestión colectiva e invita a nuevos desafíos (AU)

This article shows the experience of the Ministry of Health of the city of Villa María, province of Córdoba, Argentina, of implementing a strategy of comprehensive health care approach to in primary health care services, based on territoriality, interdisciplinarity, community participation, comprehensiveness and intersectorality, named the Comprehensive Territorial Management Program (CTMP). Its implementation was carried out using the strategy of Permanent Health Education (PHE). The program included the elaboration and periodic dissemination, through the Health Observatory, of indicators built by the health teams. The implementation of the CTMP strengthened the coordination between the health services and different governmental and non-governmental areas that resulted in the adoption of the program by Ordinance of the Municipal Deliberative Council, an agreement with the National University of Villa María, a joint work plan with the Provincial Hospital of the city and the inclusion of the periodic accountability of the results by the municipal executive to the Deliberative Council. The development achieved thus far constitutes a substantial stimulus to sustain this process of training and collective management and invite new challenges (AU)

Acetylcholinesterase inhibitory activity of a naturally occurring peptide isolated from Boana pulchella (Anura: Hylidae) and its analogs.

Alzheimer's disease (AD), the most common form of dementia, is a growing problem worldwide, with 10 million incident cases registered every year. The complex etiology of AD has not been clarified yet and represents an active research topic. In this work, we studied the inhibitory properties of Hp-1935, a natural peptide extracted from the skin secretions of an Argentinian frog (Boana pulchella). It was initially isolated as an antimicrobial peptide by our group, but we later discovered its anti-AChE action. Since not many peptides with this activity have been reported, we focused on defining the basis of its inhibitory mechanism against acetylcholinesterase (AChE) and on finding the primary portion for the inhibitory activity in its sequence, through the combination of an experimental strategy of design and synthesis with molecular dynamics simulations. We also tested its cytotoxicity. We found that Hp-1935 is an interesting sequence for the development of new AChE inhibitors. This peptide is a peripheral anionic site inhibitor with an inhibitory activity that collocates it between the most potent natural amino acids peptides against AChE reported. We also demonstrate that its inhibitory activity is concentrated on the central part of the sequence.

[Result of a strategy using reminders before and after date of vaccination to improve timeliness of vaccination at six month]. / Resultado de una estrategia de recordatorios previos y posteriores a la fecha de vacunación para mejorar la oportunidad de la vacunación a los seis meses.

The impact of immunization depends on timely application of the vaccines, especially relevant in children. Successful strategies for improving timeliness include the use of nominalized records and follow-up mechanisms. This study assessed the result of reminders before and after the scheduled date of vaccination to improve timely vaccination at six months. A before-and-after intervention study was performed with a time series and comparator group with 1,856 children from Villa María, Córdoba, Argentina. The strategy was implemented in the city's public services and consisted of preparing weekly vaccination schedules, performing follow-up, and contacting and/or making active searches for no-show cases. Assessment of the result used the percentage of timely vaccination with the third dose of the pentavalent vaccine. Time series were built for each group, before and after, and were analyzed with a simple linear model. Means of the percentages were calculated with their confidence intervals, using bootstrap, and compared with the permutation method. In the intervention group, the mean percentage of timely vaccination increased significantly by 2.6 times, reaching 61.7% (56.2; 78.1). No significant increase occurred in the comparator group: p = 0.1101. The mean rates were similar before the implementation. Timely vaccination improved in children receiving the intervention. The results indicate that the proposed strategy to use nominalized records can reduce the delay in application of vaccines.

El impacto de la inmunización depende de que las vacunas se apliquen oportunamente, aspecto aún más relevante en los niños. Las estrategias exitosas para mejorar la oportunidad incluyen el uso de registros nominalizados y mecanismos de seguimiento. En este estudio se evaluó el resultado del uso de recordatorios previos, y posteriores a la fecha de vacunación, para mejorar la vacunación oportuna a los seis meses. Se realizó un estudio de intervención antes-después, con serie cronológica y grupo de comparación, con 1.856 niños de Villa María, Córdoba, Argentina. La estrategia se implementó en los servicios públicos de la ciudad y consistió en confeccionar agendas de vacunación semanalmente, realizar el seguimiento y contactar y/o realizar búsqueda activa en los casos de no concurrencia. Para evaluar el resultado se utilizó el porcentaje de vacunados oportunamente con tercera dosis de quíntuple. Se construyeron series cronológicas para cada grupo, antes y después, y se analizaron con un modelo lineal simple. Se calculó la media de los porcentajes y sus intervalos de confianza utilizando bootstrap y se compararon con el método de permutaciones. En el grupo de intervención, la media del porcentaje de vacunación oportuna aumentó significativamente 2,6 veces, llegando a 61,7% (56,2; 78,1). En el de comparación no hubo un incremento significativo: p = 0,1101. Antes de la implementación sus medias eran similares. Se mejoró la vacunación oportuna de los niños bajo intervención. Los resultados indican que la estrategia propuesta para utilizar los registros nominalizados puede reducir la demora en la aplicación de las vacunas.

O impacto da imunização depende de quais vacinas se aplicaram no momento oportuno, característica ainda mais relevante nas crianças. As estratégias bem sucedidas para melhorar a oportunidade incluem o uso de registros nominalizados e mecanismos de monitoramento. Neste estudo foi avaliado o resultado da utilização de avisos prévios, e posteriores a data de vacinação, para melhorar a vacinação num prazo de seis meses. Foi realizado um estudo de intervenção antes e depois, com série cronológica e grupo de comparação, com 1.856 crianças da Villa Maria, Córdoba, Argentina. A estratégia foi implementada nos serviços públicos da cidade e consistiu em elaborar agendas de vacinação semanalmente, fazer monitoramento, contatar e desenvolver uma pesquisa ativa nos casos de não concorrência. Para avaliar o resultado foi utilizada a porcentagem de vacinados adequadamente com a terceira dose de quíntupla. Foram construídas séries cronológicas para cada grupo, antes e depois, foram analisadas com um modelo lineal simples. Foi calculada a media das porcentagens e seus intervalos de confiança usando bootstrap e foram comparados com o método de permutações. No grupo de intervenção, a média de porcentagem de vacinação oportuna aumentou significativamente 2,6 vezes, chegando a 61,7% (56,2; 78,1). No grupo de comparação não ouve um incremento significativo: p = 0,1101. Antes da implementação as médias eram similares. Foi melhorada a vacinação oportuna das crianças sob intervenção. Os resultados indicam que a estratégia proposta para utilizar os registros nominalizados pode reduzir a demora nas aplicações das vacinas.

Natural Multi-Target Inhibitors of Cholinesterases and Monoamine Oxidase Enzymes with Antioxidant Potential from Skin Extracts of Hypsiboas cordobae and Pseudis minuta (Anura: Hylidae).

Alzheimer's disease (AD) is the most common cause of dementia, characterized by loss of selective neuronal and normal brain functions. Every year, ten million new cases are diagnosed worldwide. AD is a complex disease associated with all kind of different pathways, making their simultaneous modulation necessary. Nowadays anti-AD treatments are focused on enzymatic inhibitors. The study of the amphibians' skin had acquired great importance in the fields of biology and human health and represents an attractive and novel source for natural compounds with high potential in the development of new drugs. The present work exhibits the power of amphibian skins as a source of bioactive compounds. Herein we report the activity of extracts of two species from Hylidae family (H. cordobae and P. minuta) as reversible inhibitors of acetylcholinesterase and butyrylcholinesterase enzymes. Furthermore, the extracts inhibit MAO-B enzyme and showed antioxidant activities, acting on four important pathways of AD.