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BACKGROUND: Mexico has experienced a significant reduction in malaria cases over the past two decades. Certification of localities as malaria-free areas (MFAs) has been proposed as a steppingstone before elimination is achieved throughout the country. The Mexican state of Quintana Roo is a candidate for MFA certification. Monitoring the status of insecticide susceptibility of major vectors is crucial for MFA certification. This study describes the susceptibility status of Anopheles albimanus, main malaria vector, from historically important malaria foci in Quintana Roo, using both phenotypic and genotypic approaches. METHODS: Adult mosquito collections were carried out at three localities: Palmar (Municipality of Othon P. Blanco), Buenavista (Bacalar) and Puerto Morelos (Puerto Morelos). Outdoor human-landing catches were performed by pairs of trained staff from 18:00 to 22:00 during 3-night periods at each locality during the rainy season of 2022. Wild-caught female mosquitoes were exposed to diagnostic doses of deltamethrin, permethrin, malathion, pirimiphos-methyl or bendiocarb using CDC bottle bioassays. Mortality was registered at the diagnostic time and recovery was assessed 24 h after exposure. Molecular analyses targeting the Voltage-Gated Sodium Channel (vgsc) gene and acetylcholinesterase (ace-1) gene were used to screen for target site polymorphisms. An SNP analysis was carried out to identify mutations at position 995 in the vgsc gene and at position 280 in the ace-1 gene. RESULTS: A total of 2828 anophelines were collected. The main species identified were Anopheles albimanus (82%) and Anopheles vestitipennis (16%). Mortalities in the CDC bottle bioassay ranged from 99% to 100% for all the insecticides and mosquito species. Sequence analysis was performed on 35 An. albimanus across the three localities; of those, 25 were analysed for vgsc and 10 for ace-1 mutations. All individuals showed wild type alleles. CONCLUSION: The results demonstrated that An. albimanus populations from historical malaria foci in Quintana Roo are susceptible to the main insecticides used by the Ministry of Health.

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Germination is an effective strategy to improve the nutritional and functional quality of Andean grains such as quinoa (Chenopodium quinoa Willd.); it helps reduce anti-nutritional components and enhance the digestibility and sensory aspects of the germinated. This work aimed to evaluate the effect of germination (0, 24, 48, and 72 h) on the physicochemical properties, content of bioactive compounds, and antioxidant capacity of three varieties of quinoa: white, red, and black high Andean from Peru. Color, nutritional composition, mineral content, phenolic compounds, flavonoids, and antioxidant activity were analyzed. Additionally, infrared spectra were obtained to elucidate structural changes during germination. The results showed color variations and significant increases (p < 0.05) in proteins, fiber, minerals, phenolic compounds, flavonoids, and antioxidant capacity after 72 h of germination, attributed to the activation of enzymatic pathways. In contrast, the infrared spectra showed a decrease in the intensity of functional groups -CH-, -CH2-, C-OH, -OH, and C-N. Correlation analysis showed that flavonoids mainly contributed to antioxidant activity (r = 0.612). Germination represents a promising alternative to develop functional ingredients from germinated quinoa flour with improved nutritional and functional attributes.

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INTRODUCTION: During the first months of the COVID-19 pandemic in Latin America, countries like Ecuador, Peru and Colombia experienced chaotic scenarios with public health systems collapsing and lack of testing capacity to control the spread of the virus. In main cities like Guayaquil in Ecuador, dramatic situations such as corpses in the streets were internationally broadcasted. METHODS: While the COVID-19 pandemic was devastating South America, SARS-CoV-2 transmission was successfully managed in the Galapagos Islands due to the implementation of a massive screening strategy including hospitalized and community-dwelling populations, and travel restrictions facilitated by its geographical location (972 km from the Ecuadorian continental territory). Floreana Island was one of the few locations in the world that remained COVID-19 free during 2020. RESULTS: In this study, we retrospectively analyzed the data related to SARS-CoV-2 massive testing campaigns from April to September 2020 in the Galapagos Islands, and found this territory to have the lowest positivity rate in South America (4.8-6.7%) and the highest testing ratio among Ecuadorian provinces (9.87% of the population, which is 2480 out of 25 124 inhabitants) during the first wave of the COVID-19 pandemic. CONCLUSION: This story of success was possible because of the interinstitutional collaboration between the regional government of Galapagos Islands (Consejo de Gobierno), the local authorities (Gobiernos Autonomos Descentralizados de Santa Cruz, San Cristobal and Isabela), the regional authorities from Ecuadorian Ministry of Health, the Agencia de Regulación y Control de la Bioseguridad y Cuarentena para Galápagos and Universidad de Las Américas.

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Sand flies have expanded their areas of distribution, thereby increasing the risk of pathogen transmission in non-endemic areas. To establish efficient prevention and control strategies for the transmission of vector-borne pathogens, it is important to understand seasonal dynamics of their vectors. In Mexico, there are several areas where the contact between sand flies, hosts and reservoirs favours the transmission of the pathogen. We compared sand fly communities in a forest management area and a conserved area in Noh-Bec, Quintana Roo, Mexico. The analysis included species diversity, activity peaks and molecular detection of pathogens. Sand flies were collected from November to December 2021 and April to May 2022, during 84 night-traps. The conserved area showed higher numbers and greater species heterogeneity of sand flies as compared with the other sites. The ß-diversity analysis revealed that sites disturbed by logging (S1, S2, S3) had greater similarity (90%) in their sand fly species composition than a conserved area (S4) (similarity = 36%). Although none of the specimens were infected with Leishmania, we detected Wolbachia (19.4%) in all four sites, as well as Bartonella (3.25%) only in the disturbed sites. Further studies on the dynamics of sand fly populations and their association with pathogens are necessary.

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Background: The SARS-CoV-2 gold standard detection method is an RT-qPCR with a previous step of viral RNA extraction from the patient sample either by using commercial automatized or manual extraction kits. This RNA extraction step is expensive and time demanding. Objective: The aim of our study was to evaluate the clinical performance of a simple SARS-CoV-2 detection protocol based on a fast and intense sample homogenization followed by direct RT-qPCR. Results: 388 nasopharyngeal swabs were analyzed in this study. 222 of them tested positive for SARS-CoV-2 by the gold standard RNA extraction and RT-qPCR method, while 166 tested negative. 197 of those 222 positive samples were also positive for the homogenization protocol, yielding a sensitivity of 88.74% (95% IC; 83.83 - 92.58). 166 of those negative samples were also negative for the homogenization protocol, so the specificity obtained was 97% (95% IC; 93.11 - 99.01). For Ct values below 30, meaning a viral load of 103 copies/uL, only 4 SARS-CoV-2 positive samples failed for the RNA extraction free method; for that limit of detection, the homogenizer-based method had a sensitivity of 97.92% (95% CI; 96.01 - 99.83). Conclusions: Our results show that this fast and cheap homogenization method for the SARS-CoV-2 detection by RT-qPCR is a reliable alternative of high sensitivity for potentially infectious SARS-CoV-2 positive patients. This RNA extraction free protocol would help to reduce diagnosis time and cost, and to overcome the RNA extraction kits shortage experienced during COVID-19 pandemic.

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Through the methodology of optical surface design based on concentric rings, this paper proposes the design of freeform mirrors, initially by employing segmented rings, each of them with different spherical radii of curvature, and then by employing segmented conic rings with different conic constants in each of the segments. These surfaces will then produce the desired images. For the case of segmented spherical rings, mathematical expressions were deduced to obtain the image points as a function of the radii of curvature. Furthermore, it is shown that in the case where conic rings were used, there is a decrease in spherical aberration, which allows the manipulation of the generated image. Finally, several proposals are presented for the design of mirrors to generate both the desired size of the image and the desired distribution of energy, together with their analyses.

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Understanding the grazing process and animal response to sward structures (e.g., sward height) is key to setting targets for efficient grazing management. We hypothesized that the short-term intake rate (STIR) of dry matter (DM) and digestible organic matter (OM) by dairy heifers is maximized with Kikuyu grass (Cenchrus clandestinus-Hochst. ex Chiov.) of intermediate sward heights. The treatments consisted of five pre-grazing sward heights (10, 15, 20, 25, and 30 cm) randomly assigned to two of ten paddocks. The experimental design included two measurements of each paddock at different periods and times of day. Three Holstein heifers (440 ± 42 kg body weight) were used to determine the STIR, which was estimated using the double-weighing technique with correction for insensible weight losses. The bite mass (BM), bite rate (BR), sward structural characteristics, and nutritional value of herbage samples were assessed. The data were analyzed using mixed models with a factorial arrangement of five sward heights, two times of day, and two evaluation periods. The sward height of Kikuyu grass that maximized both STIRs was approximately 20 cm. The STIR of the DM was 30% and 15% lower than the maximum in the shortest and tallest swards tested, respectively. In swards shorter than 20 cm, the STIR was lower because the BM decreased with sward height, whereas in those greater than 20 cm, the lower BM and STIR of DM was explained by a decrease in bulk density and bite volume. The top stratum was composed mainly of highly digestible leaf blades with similar nutrient content across sward heights; therefore the STIR of digestible OM was also maximized at 20 cm. Hence, the optimal pre-grazing sward height of Kikuyu grass should be managed at 20 cm under rotational stocking systems to maximize nutrient intake rate of dairy heifers.

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Anopheles darlingi is considered the main vector of malaria in the Neotropical region, so knowledge of its distribution in the Americas is highly relevant for the design of strategies for prevention and control of the illness. In Mexico, An. darlingi was recorded for the first time in 1943, and currently its distribution covers the states of Campeche, Chiapas, Quintana Roo, and Tabasco. In this study, new distribution data and observations of the abundance of An. darlingi in 14 localities of Quintana Roo, southeastern Mexico, are presented.

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This paper describes the effects of laser pulse rate and solution flow rate on the determination of lithium at high pressure for water and 2.5% sodium chloride solutions using laser-induced breakdown spectroscopy (LIBS). Preliminary studies were performed with 0-40 mg L-1 Li solutions, at ambient pressure and at 210 bar, and in static and flowing (6 mL · min-1) regimes, for a combination of four different measurement conditions. The sensitivity of calibration curves depended on the pressure and the flow rate, as well as the laser pulse rate. The sensitivity of the calibration curve increased about 10% and 18% when the pressure was changed from 1 to 210 bar for static and flowing conditions, respectively. However, an effect of flow rate at high pressure for both 2 and 10 Hz laser pulse rates was observed. At ambient pressure, the effect of flow rate was negligible, as the sensitivity of the calibration curve decreased around 2%, while at high pressure the sensitivity increased around 4% when measurements were performed in a flow regime. Therefore, it seems there is a synergistic effect between pressure and flow rate, as the sensitivity increases significantly when both changes are considered. When the pulse rate is changed from 2 to 10 Hz, the sensitivity increases 26-31%, depending on the pressure and flow conditions. For lithium detection limit studies, performed with a laser pulse energy of 2.5 mJ, repetition rate of 10 Hz, gate delay of 500 ns, gate width of 1000 ns, and 1000 accumulations, a value around 40 µg L-1 was achieved for Li solutions in pure water for all four measurement conditions, while a detection limit of about 92 µg L-1 was determined for Li in 2.5% sodium chloride solutions, when high pressure and flowing conditions were employed. The results obtained in the present work demonstrate that LIBS is a powerful tool for the determination of Li in deep ocean conditions such as those found around hydrothermal vent systems.

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The intensity and frequency of grazing affect the defoliating strategy of ruminants, their daily nutrient intake, thus nutrition and physiological status. Italian ryegrass (Lolium multiflorum Lam.) pastures were grazed by sheep either under a low-intensity/high-frequency grazing strategy (Rotatinuous stocking; RN) with nominal pre- and post-grazing sward heights of 18 and 11 cm, respectively, or under a high-intensity/low-frequency strategy (traditional rotational stocking; RT) with nominal pre- and post-grazing sward heights of 25 and 5 cm, respectively. Treatments were arranged under a complete randomized design and evaluated over two periods, in different years. In 2017, the aim was to depict the type of bites that sheep perform during the grazing-down and associate them to the grazing management strategy according to their relative contribution to the diet ingested. In 2018 we estimated the total nutrient intake and evaluated blood indicators of the nutritional status and immune response to stress of sheep. The bite types accounting the most for the diet ingested by RN sheep were those performed on the "top stratum" of plants with around 20, 15, and 25 cm, whereas the type of bites accounting the most for the diet of RT sheep were those performed on "grazed plants" with around 10, 5, and ≤ 3 cm. In 2018, the RN sheep increased by 18% the total organic matter (OM) intake and by 20-25% the intake of soluble nutrients (i.e., crude protein, total soluble sugars, crude fat), digestible OM and of metabolizable energy, and had 17.5, 18, and 6.1% greater blood concentration of glucose, urea nitrogen (BUN) and albumin, respectively, but 17% lower blood neutrophil-to-lymphocyte (N:L) ratio. Sheep grazing vegetative Italian ryegrass pastures under the low-intensity/high-frequency grazing strategy (RN) ingested a diet of better quality from bites allocated on the top stratum of plants, had greater intake of soluble nutrients and blood parameters positively associated with nutritional status and immune response to stress.

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BACKGROUND: The COVID-19 pandemic has caused significant supply shortages worldwide for SARS-CoV-2 molecular diagnosis, like RNA extraction kits. OBJECTIVE: The aim of our study was to evaluate the clinical performance and analytical sensitivity of a simple SARS-CoV-2 diagnosis protocol based on heat shock without RNA extraction using both "CDC" (N gene) and "Charite" (E gene) RT-qPCR protocols. RESULTS: 1,036 nasopharyngeal samples, 543 of them SARS-CoV-2 positive, were analyzed. The heat shock method correctly identified 68.8% (232/337) and 89.4% (202/226) of SARS-CoV-2 positive samples for N gene and E gene, respectively. Analytical sensitivity was assessed for heat shock method using the CDC RT-qPCR protocol, obtaining sensitivity values of 98.6%, 93.3% and 84.8% for limit of detection of 100.000, 50.000 and 20.000 viral RNA copies/mL of sample. CONCLUSIONS: Our findings show that a simple heat shock SARS-CoV-2 RT-qPCR diagnosis method without RNA extraction is a reliable alternative for potentially infectious SARS-CoV-2 positive patients at the time of testing. This affordable protocol can help overcome the cost and supply shortages for SARS-CoV-2 diagnosis, especially in developing countries. In Ecuador, it has been used already by laboratories in the public health system for more than 100.000 specimens.

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COVID-19 pandemic has challenged public health systems worldwide, particularly affecting developing countries in Latin America like Ecuador. In this report, we exposed the fundamental role of the Ecuadorian universities to improve COVID-19 surveillance in the country, with an overall contribution over 15% of the total SARS-CoV-2 RT-PCR tests done. We highlight the role of our university during the first semester of the COVID-19 pandemic, contributing to a massive free SARS-CoV-2 testing up to almost 10% of the total diagnosis completed in the country, mainly focus on underserved urban, rural and indigenous communities. Finally, we described our contribution to a high quality and low-cost SARS-CoV-2 RT-PCR diagnostic in Ecuador.

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Antimicrobial resistance is a growing problem in human and veterinary medicine. Here we show that 6.25% of the guinea pigs studied in Ecuador, raised as livestock, carry methicillin resistant Staphylococcus aureus (MRSA) in the nasopharynx and therefore may potentially play a role in the transmission of MRSA in the Andean Region of South America.

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RESUMEN: El objetivo de este trabajo consistió en determinar la frecuencia de aceptación de creencias populares sobre la salud oral de embarazadas atendidas en los servicios de obstetricia de los hospitales Luis Albrecht y Belén de Trujillo, La Libertad - Perú. Se trabajó con 320 gestantes atendidas entre los meses de octubre y noviembre de 2016, usando el método de selección no probabilístico accidental. Para determinar la confiabilidad de la encuesta se empleó el estadístico Kuder-Richardson Formula 20, encontrando una confiabilidad de 0.765 (p<0.05); además, fue validado por juicio de expertos. Se usó la estadística descriptiva para la presentación de los resultados. La creencia popular de aceptación más frecuente fue "Mi bebé le quita calcio y flúor a mis dientes durante el embarazo" con un 55,94 %, mientras que la menos frecuente fue "Si veo un relámpago o rayo mi hijo nacerá con labio partido", con un 3,13 %. Según nivel educativo, la más aceptada fue "Mi bebé le quita calcio y flúor a mis dientes durante el embarazo" con un 68 % en aquellas de nivel de instrucción secundario; según rango de edad, la más frecuente fue "El calcio de mi leche saldrá de mis dientes cuando amamante a mi bebé", con un 53,3 % entre las edades de 15-29 años; mientras que, la creencia más aceptada según hospital fue "El calcio de mi leche saldrá de mis dientes cuando amamante a mi bebé", con un 53,1 % en las gestantes del hospital Belén de Trujillo. La creencia popular de aceptación más frecuente fue "Mi bebé le quita calcio y flúor a mis dientes durante el embarazo", mientras que la menos frecuente fue "Si veo un relámpago o rayo mi hijo nacerá con labio partido". La aceptación de creencias populares sobre la pérdida de calcio durante la gestación son las más frecuentes según nivel educativo, rango de edad y hospital.

ABSTRACT: The aim of this work was to determine the frequency of acceptance of popular beliefs about the oral health of pregnant women attended at the obstetric services of the Luis Albrecht and Belén hospitals in Trujillo, La Libertad - Peru. We worked with 320 pregnant women attended between October and November 2016, using the accidental non-probabilistic selection method. To determine the reliability of the survey, the Kuder-Richardson Formula 20 statistic was used, finding a reliability of 0.765 (p <0.05); In addition, it was validated by expert judgment. Descriptive statistics was used to present the results. The popular belief of more frequent acceptance was "My baby takes calcium and fluoride from my teeth during pregnancy" with 55.94 %, while the least frequent was "If I see a lightning or lightning, my son will be born with a split lip", with 3.13 %. According to educational level, the most accepted was "My baby takes calcium and fluoride from my teeth during pregnancy" with 68 % in those of secondary education level; according to age range, the most frequent was "The calcium in my milk will come out of my teeth when I breastfeed my baby", with 53.3 % between the ages of 15 - 29 years; while, the most accepted belief according to hospital was "The calcium of my milk will come out of my teeth when I breastfeed my baby", with 53.1 % in the pregnant women of Bethlehem hospital in Trujillo. The popular belief of more frequent acceptance was "My baby takes calcium and fluoride from my teeth during pregnancy", while the least frequent was "If I see a lightning or lightning, my son will be born with a split lip". The acceptance of popular beliefs about the loss of calcium during pregnancy are the most frequent according to educational level, age range and hospital.

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RESUMEN: El objetivo de este estudio fue comparar los hilos de sutura de seda negra y la sutura nylon con respecto a la adhesión bacteriana post extracción dental simple de piezas posteriores. El presente trabajo se desarrolló en la Clínica Odontológica y el Laboratorio de Microbiología de la Unidad de Ciencias Biomédicas y Biotecnología de la Universidad Privada Antenor Orrego (Trujillo, Perú), entre agosto y setiembre de 2014. Se trabajó con 19 unidades de muestreo para hilo de seda negra y 19 para nylon. El procedimiento de exodoncia para todos los pacientes fue estandarizado. Luego de la extracción, se procedió a suturar la herida quirúrgica, colocando dos puntos circunferenciales, uno con cada tipo de hilo. A los 7 días, los hilos fueron retirados y sometidos a análisis microbiológico. La adhesión bacteriana de los hilos de sutura seda negra y nylon fue comparada empleando el test de Wilcoxon. Además la adhesión bacteriana de cada hilo fue comparada con la adhesión en hilos estériles (control) empleando el test de Mann-Whitney para una p<0,005. Al comparar la adhesión bacteriana de ambos hilos, se encontró diferencia entre ellos (p=0,027), correspondiendo mayor adhesión al hilo de nylon. La adhesión bacteriana fue mayor en el hilo de sutura de nylon comparado con el hilo de sutura de seda negra.

ABSTRACT: The objective of the study was to compare black silk suture threads and nylon suture with respect to bacterial adhesion after simple dental extraction of posterior pieces. The present study was developed in the Clínica Estomatológica and the Laboratorio de Microbiología of the Unidad de Ciencias Biomédicas y Biotecnología de la Universidad Privada Antenor Orrego (Trujillo, Peru), between August and September 2014. We worked with 19 units sampling for black silk thread and 19 for nylon. The procedure of exodontia for all patients was standardized. After the extraction, the surgical wound was sutured, placing two circumferential points, one with each type of thread. After 7 days, the threads were removed and subjected to microbiological analysis. The bacterial adhesion of the black silk and nylon suture strands was compared using the Wilcoxon test. In addition, the bacterial adhesion of each strand was compared with the adhesion in sterile strands (control) using the Mann-Whitney test for p <0.005. When comparing the bacterial adhesion of both threads, a difference was found between them (p = 0.027), corresponding greater adhesion to the nylon thread. Bacterial adhesion was higher in nylon suture compared to black silk suture.

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RESUMEN: El objetivo de este trabajo fue determinar la efectividad analgésica de paracetamol post-cirugía mucogingival. El estudio, prospectivo, longitudinal, comparativo y experimental, se desarrolló en la Clínica Odontológica de la Universidad Privada Antenor Orrego (Trujillo, Perú) con los pacientes de la asignatura Periodoncia II. Se incluyeron 39 pacientes, quienes fueron distribuidos de manera aleatoria en 2 grupos de 19 y 20 cada uno, según los criterios establecidos. La medicación se inició 20 minutos después de concluida la cirugía, y se mantuvo por 24 horas. Para determinar la efectividad analgésica se usó la escala visual analógica (0-100 mm) y se recogió la información que fue procesada, utilizando la prueba de U Mann-Whitney con un nivel de significancia del 5 %. No existe diferencia en cuanto a la efectividad analgésica post-cirugías mucogingivales entre paracetamol y el control a las 2 horas (p=0.415), 8 horas (p=0.279) y 24 horas (p=0.736). Paracetamol es efectivo como analgésico post-cirugía mucogingival.

ABSTRACT: The objective of this study was to determine the analgesic effectiveness of paracetamol after mucogingival surgery. This prospective, longitudinal, comparative and experimental study was developed in the Stomatology Clinic of the Universidad Privada Antenor Orrego (Trujillo, Perú) with the patients of the Periodontics II subject. We included 39 patients, who were randomly distributed into 2 groups of 19 and 20 each, according to the established criteria. The medication was started 20 minutes after the surgery was completed, and was maintained for 24 hours. To determine the analgesic effectiveness, the analogue visual scale (0-100 mm) was used and the information that was processed was collected, using the U Mann-Whitney test with a level of significance of 5 %. There is no difference in terms of analgesic effectiveness post-mucogingival surgery between paracetamol and control at 2 hours (p = 0.415), 8 hours (p = 0.279) and 24 hours (p = 0.736). Paracetamol is effective as a mucogingival post-surgery analgesic.

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Fifteen plant species from a protected cloud forest (CF) in Veracruz, Mexico, were screened for their in vitro capacity to inhibit the growth of the phytopathogenic bacteria Chryseobacterium sp., Pseudomonas cichorii, Pectobacterium carotovorum and Pantoea stewartii, causal agents of damage to crops like 'chayote', lettuce, potato and corn. As a result, the bioactivity of Turpinia insignis and Leandra cornoides is reported for the first time against Chryseobacterium sp. and P. cichorii. In addition, 24 and 18 compounds not described for these species were dereplicated by an UPLC/MS-MS method, respectively. The identified compounds included simple phenols, hydroxycinnamic acids, flavonoids and coumarins. The antibacterial assay of 12 of them demonstrated the bacteriostatic effect of vanillin, trans-cinnamic acid, scopoletin and umbelliferone against Chryseobacterium sp. These findings confirm for the first time the value of the CF plants from Veracruz as sources of bioactive natural products with antimicrobial properties against phytopathogenic bacteria.

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In the last few decades, genomic manipulation has made significant progress as a result of the development of recombinant DNA technologies; however, more often than not, these techniques have been costly and labor intensive. In contrast, recently developed next-generation sequencing (NGS) technologies have provided a cheaper, faster, and easier process to study genomics. In particular, an NGS technique emerged from bacterial CRISPR-associated protein-9 nuclease (Cas9) as a revolutionary method to modify, regulate, or mark specific genomic sequences on virtually any organism. A later adaptation of this bacterial defense mechanism that successfully and permanently edits dysfunctional genes and corrects missing proteins has resulted in a new era for disease genetic engineering. Clinical trials using this technique are already being performed, and the applicability of CRISPR-Cas9 techniques is actively being investigated using in vivo studies. However, the concept of genome correction poses great concerns from a regulatory perspective, especially in terms of security, so principles for the regulation of these methodologies are being established. We delved into CRISPR-Cas9 from its natural and ortholog origins to its engineered variants and behaviors to present its notable and diverse applications in the fields of biotechnology and human therapeutics.

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AIMS: Anti-neoplastic activity induced by cannabinoids has been extensively documented for a number of cancer cell types; however, this topic has been explored in gastric cancer cells only in a limited number of approaches. Thus, the need of integrative and comparative studies still persists. MATERIALS AND METHODS: In this study we tested and compared the effects of three different cannabinoid receptor agonists-anandamide (AEA), (R)-(+)-methanandamide (Meth-AEA) and CP 55,940 (CP)- on gastric cancer cell morphology, viability and death events in order to provide new insights to the use of these agents for therapeutic purposes. KEY FINDINGS: The three agents tested exhibited similar concentration-dependent effects in the induction of changes in cell morphology and cell loss, as well as in the decrease of cell viability and DNA laddering in the human gastric adenocarcinoma cell line (AGS). Differences among the cannabinoids tested were mostly observed in the density of cells found in early and late apoptosis and necrosis, favoring AEA and CP as the more effective inducers of apoptotic mechanisms, and Meth-AEA as a more effective inducer of necrosis through transient and rapid apoptosis. SIGNIFICANCE: Through a comparative approach, our results support and confirm the therapeutic potential that cannabinoid receptor agonists exert in gastric cancer cells and open possibilities to use cannabinoids as part of a new gastric cancer therapy.

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Cannabinoid receptor (CBs) agonists affect the growth of tumor cells via activation of deadly cascades. The spectrum of action of these agents and the precise role of the endocannabinoid system (ECS) on oncogenic processes remain elusive. Herein we compared the effects of synthetic (CP 55-940 and WIN 55,212-2) and endogenous (anandamide or AEA) CBs agonists (10-20 µM) on morphological changes, cell viability, and induction of apoptosis in primary astrocytes and in two glioblastoma cell lines (C6 and U373 cells) in order to characterize their possible differential actions on brain tumor cells. None of the CBs agonist tested induced changes in cell viability or morphology in primary astrocytes. In contrast, CP 55-940 significantly decreased cell viability in C6 and U373 cells at 5 days of treatment, whereas AEA and WIN 55,212-2 moderately decreased cell viability in both cell lines. Treatment of U373 and C6 for 3 and 5 days with AEA or WIN 55,212-2 produced discrete morphological changes in cell bodies, whereas the exposure to CP 55-940 induced soma degradation. CP 55-940 also induced apoptosis in both C6 and U373 cell lines. Our results support a more effective action of CP 55-940 to produce cell death of both cell lines through apoptotic mechanisms. Comparative aspects between cannabinoids with different profiles are necessary for the design of potential treatments against glial tumors.

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