Green synthesis of ethyl cinnamates under microwave irradiation: photophysical properties, cytotoxicity, and cell bioimaging.

A simple and green method for the synthesis of six ethyl cinnamates was performed via Horner-Wadsworth-Emmons reaction under microwave irradiation. The photoluminescent properties of all compounds in ethyl acetate solutions were evaluated demonstrating that all compounds exhibit fluorescence. Five compounds exhibited blue emissions in the 369-442 nm range, and another compound exhibited blue-green emission at 504 nm. This last compound showed the largest Stokes shift (134 nm), and the highest quantum yield (17.8%). Two compounds showed extinction coefficient values (ε) higher than 30 000 M-1 cm-1, which are appropriate for cell bioimaging applications. In this sense, cytotoxicity assays were performed using Vero cells at different concentrations; the results showed that these compounds were not cytotoxic at the highest concentration tested (20 µg mL-1). Finally, the analysis by fluorescence microscopy for localization and cellular staining using Vero cells demonstrated that the compounds stained the cytoplasm and the nuclei in a selective way.

Frank's sign associated with the severity of ischemic heart disease in patients under 65 years old / Signo de Frank asociado con la gravedad de la cardiopatía isquémica en adultos de edad inferior o igual a 65 años

Background and objective Frank's sign is the diagonal ear fold which has been associated with ischemic heart disease. The objective of this work was to evaluate the relationship of Frank's sign with severity of ischemic heart disease in adults ≤ 65 years old in the northeast of Mexico. Patients and methods A cross-sectional study was conducted in patients ≤ 65 years old who underwent coronary angiography consecutively over a period of 5 months in 2022. Severe coronary artery disease (CAD) was associated with Frank's sign and other common cardiovascular risks. To determine the association, bivariate and multivariate analysis was performed using logistic regression that included variables with a value of p<0.05. Statistical analysis was performed with SPSS version 22. Results We included 311 patients ≤ 65 years, of whom 80% were men. The median age was 57 years (range 28–65). Frank's sign was positive in 62% of the population. The main clinical characteristics in patients with Frank's sign were type 2 diabetes mellitus (55%), p=0.003, dyslipidemia (53%), p=0.026 and smoking (68%), p=0.002. In the multivariate analysis, the independent variables associated with severe CAD were Frank's Sign OR 3.26; 95% CI (1.98–5.38), p≤0.001, male gender OR 2.28; 95% CI (1.20–4.35), p=0.012, and dyslipidemia OR 1.81; 95% CI (1.11–2.97), p=0.017. Conclusions There is an independent association between Frank's sign with the presence of severe CAD in patients ≤ 65 years old, which may be useful for screening and prevention (AU)

Antecedentes y objetivo El signo de pliegue diagonal de la oreja o signo de Frank se ha asociado con cardiopatía isquémica. El objetivo de este trabajo fue evaluar la relación del signo de Frank con la gravedad de la cardiopatía isquémica en adultos≤65años en el noreste de México. Pacientes y métodos Se realizó un estudio transversal en pacientes ≤65años sometidos a coronariografía de manera consecutiva en un periodo de 5 meses en 2022. Se relacionó la enfermedad arterial coronaria (EAC) grave con el signo de Frank y los factores de riesgo cardiovascular tradicionales. Para determinar la asociación se realizó análisis bivariado y multivariado mediante regresión logística que incluyó las variables con valor de p<0,05. El análisis estadístico se realizó con el programa SPSS versión 22. Resultados Se incluyeron 311 pacientes≤65años, de los cuales el 80% fueron hombres. La mediana de edad fue 57 años (rango de 28-65 años). El 62% de los pacientes presentó el signo de Frank. Las principales características clínicas en pacientes con signo de Frank fueron diabetes mellitus tipo 2 (55%), p=0,003, dislipidemia (53%), p=0,026 y tabaquismo (68%), p=0,002. En el análisis multivariado las variables independientes asociadas a EAC grave fueron el signo de Frank (OR: 3,26; IC 95%: 1,98-5,38; p≤0,001), sexo masculino (OR: 2,28; IC 95%: 1,20-4,35; p=0,012) y dislipidemia (OR: 1,81; IC 95%: 1,11-2,97; p=0,017). Conclusiones Existe asociación independiente del signo de Frank con la presencia de EAC grave en pacientes≤65años, que puede ser útil para el cribado y la prevención (AU)

Breast Cancer Tissue Explants: An Approach to Develop Personalized Therapy in Public Health Services.

Breast cancer is one of the main causes of death worldwide. Lately, there is great interest in developing methods that assess individual sensitivity and/or resistance of tumors to antineoplastics to provide personalized therapy for patients. In this study we used organotypic culture of human breast tumor slices to predict the experimental effect of antineoplastics on the viability of tumoral tissue. Samples of breast tumor were taken from 27 patients with clinically advanced breast cancer; slices were obtained and incubated separately for 48 h with paclitaxel, docetaxel, epirubicin, 5-fluorouracil, cyclophosphamide, and cell culture media (control). We determined an experimental tumor sensitivity/resistance (S/R) profile by evaluating tissue viability using the Alamar Blue® metabolic test, and by structural viability (histopathological analyses, necrosis, and inflammation). These parameters were related to immunohistochemical expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. The predominant histological type found was infiltrating ductal carcinoma (85.2%), followed by lobular carcinoma (7.4%) and mixed carcinoma (7.4%). Experimental drug resistance was related to positive hormone receptor status in 83% of samples treated with cyclophosphamide (p = 0.027). Results suggest that the tumor S/R profile can help to predict personalized therapy or optimize chemotherapeutic treatments in breast cancer.

[Educational intervention on organ and tissue donation at UMAE No. 34]. / Intervención educativa sobre donación de órganos y tejidos en la UMAE No. 34.

Background: The lack of information associated with donation is devastating for those patients in need of a transplant and requires a solution based on changing social perception through educational interventions. Objective: Determine the level of knowledge of the general population after an educational intervention about organ and tissue donation at the Hospital de Cardiología UMAE No. 34. Methods: Educational intervention study with measurement before and after, prospective. Instrument validated using the Kuder-Richardson formula with a reliability coefficient of 0.74. The study population was made up of the general population in the waiting rooms at UMAE No. 34, only the associations with values of p < 0.05 were considered statistically significant. Results: 266 evaluation instruments were applied to 133 participants. The educational intervention contributed to an increase in the level of knowledge (p = 0.0001). The level of knowledge after the intervention was higher in the younger participants (p = 0.013) and in those with a university studies (p = 0.0001). The relation between age and the level of subsequent knowledge showed favorable significance in the intention to donate in younger participants with high subsequent knowledge (p = 0.046). Conclusions: An educational intervention on donation of organs and tissues for transplant purposes is an effective strategy to increase and reinforce the knowledge of the general population.

Introducción: la falta de información relacionada con la donación de órganos y tejidos resulta devastadora para aquellos pacientes en necesidad de un trasplante, y requiere de una solución basada en el cambio de percepción social mediante intervenciones educativas. Objetivo: determinar el nivel de conocimiento de la población general posterior a una intervención educativa sobre la donación de órganos y tejidos en el Hospital de Cardiología No. 34. Métodos: estudio de intervención educativa con medición antes y después, prospectivo. Instrumento validado mediante fórmula de Kuder-Richardson con coeficiente de fiabilidad de 0.74. La población de estudio se conformó por la población general en las salas de espera de la UMAE No. 34. Las asociaciones con valores de p < 0.05 se consideraron estadísticamente significativas. Resultados: se aplicaron 266 instrumentos de evaluación en 133 participantes. La intervención educativa contribuyó a aumentar el nivel de conocimiento (p = 0.0001). El nivel de conocimiento posterior a la intervención fue mayor en los participantes jóvenes (p = 0.013) y en aquellos con estudios universitarios (p = 0.0001). La relación entre la edad y el nivel de conocimiento posterior mostró significancia favorable en la intención de donación en jóvenes con conocimiento posterior alto (p = 0.046). Conclusiones: una intervención educativa sobre la donación de órganos y tejidos con fines de trasplantes es una estrategia eficaz para aumentar y reforzar el conocimiento de la población general.

Frank's sign associated with the severity of ischemic heart disease in patients under 65 years old.

BACKGROUND AND OBJECTIVE: Frank's sign is the diagonal ear fold which has been associated with ischemic heart disease. The objective of this work was to evaluate the relationship of Frank's sign with severity of ischemic heart disease in adults ≤ 65 years old in the northeast of Mexico. PATIENTS AND METHODS: A cross-sectional study was conducted in patients ≤ 65 years old who underwent coronary angiography consecutively over a period of 5 months in 2022. Severe coronary artery disease (CAD) was associated with Frank's sign and other common cardiovascular risks. To determine the association, bivariate and multivariate analysis was performed using logistic regression that included variables with a value of p<0.05. Statistical analysis was performed with SPSS version 22. RESULTS: We included 311 patients ≤ 65 years, of whom 80% were men. The median age was 57 years (range 28-65). Frank's sign was positive in 62% of the population. The main clinical characteristics in patients with Frank's sign were type 2 diabetes mellitus (55%), p=0.003, dyslipidemia (53%), p=0.026 and smoking (68%), p=0.002. In the multivariate analysis, the independent variables associated with severe CAD were Frank's Sign OR 3.26; 95% CI (1.98-5.38), p≤0.001, male gender OR 2.28; 95% CI (1.20-4.35), p=0.012, and dyslipidemia OR 1.81; 95% CI (1.11-2.97), p=0.017. CONCLUSIONS: There is an independent association between Frank's sign with the presence of severe CAD in patients ≤ 65 years old, which may be useful for screening and prevention.

Metformin May Alter the Metabolic Reprogramming in Cancer Cells by Disrupting the L-Arginine Metabolism: A Preliminary Computational Study.

Metabolic reprogramming in cancer is considered to be one of the most important hallmarks to drive proliferation, angiogenesis, and invasion. AMP-activated protein kinase activation is one of the established mechanisms for metformin's anti-cancer actions. However, it has been suggested that metformin may exert antitumoral effects by the modulation of other master regulators of cellular energy. Here, based on structural and physicochemical criteria, we tested the hypothesis that metformin may act as an antagonist of L-arginine metabolism and other related metabolic pathways. First, we created a database containing different L-arginine-related metabolites and biguanides. After that, comparisons of structural and physicochemical properties were performed employing different cheminformatic tools. Finally, we performed molecular docking simulations using AutoDock 4.2 to compare the affinities and binding modes of biguanides and L-arginine-related metabolites against their corresponding targets. Our results showed that biguanides, especially metformin and buformin, exhibited a moderate-to-high similarity to the metabolites belonging to the urea cycle, polyamine metabolism, and creatine biosynthesis. The predicted affinities and binding modes for biguanides displayed good concordance with those obtained for some L-arginine-related metabolites, including L-arginine and creatine. In conclusion, metabolic reprogramming in cancer cells by metformin and biguanides may be also driven by metabolic disruption of L-arginine and structurally related compounds.

Antidiabetic Drugs and their Potential Use in COVID-19: A Mechanistic Approach.

Many therapies have been developed against COVID-19 since it first appeared in December 2019. Antivirals, antimalarials, cephalosporins, colchicine, anticoagulants, and corticosteroids, among others, have been evaluated as protecting agents against antibacterial complications due to their anti-inflammatory and immunomodulatory effects against thrombosis and cell death caused by infection with SARS-CoV-2. Nevertheless, the overall balance in their application has not been found to be satisfactory. On the other hand, developing and applying several vaccines against this virus have marked an important watershed in preventive and prophylactic medicine in the new millennium. However, given the regular efficacy reported of some of them, the still scarce affordability, and the emergency of new strains for which no drug has been evaluated, the search for new pharmacological therapy alternatives still represents an essential component in the clinical management of COVID-19, and the rapid identification of drugs with potential antiviral and/or immunomodulatory properties is needed. In the present review, a potential therapeutic effect of metformin and other antidiabetic therapies for the management of COVID-19 are proposed and discussed from the viewpoint of their in vitro and in vivo immunomodulatory effects. Given that acute inflammation is an important component of COVID-19, antidiabetic therapies could be promising alternatives in its management and reducing the disease's severity. In order to understand how metformin and other antidiabetic therapies could work in the context of COVID-19, here we review the possible mechanisms of action through a detailed description of cellular and molecular events.

Comparative Biomonitoring of Arsenic Exposure in Mothers and Their Neonates in Comarca Lagunera, Mexico.

Multiple comorbidities related to arsenic exposure through drinking water continue to be public problems worldwide, principally in chronically exposed populations, such as those in the Comarca Lagunera (CL), Mexico. In addition, this relationship could be exacerbated by an early life exposure through the placenta and later through breast milk. This study conducted a comparative analysis of arsenic levels in multiple biological samples from pregnant women and their neonates in the CL and the comparison region, Saltillo. Total arsenic levels in placenta, breast milk, blood, and urine were measured in pregnant women and their neonates from rural areas of seven municipalities of the CL using atomic absorption spectrophotometry with hydride generation methodology. The average concentrations of tAs in drinking water were 47.7 µg/L and 0.05 µg/L in the exposed and non-exposed areas, respectively. Mean levels of tAs were 7.80 µg/kg, 77.04 µg/g-Cr, and 4.30 µg/L in placenta, blood, urine, and breast milk, respectively, in mothers, and 107.92 µg/g-Cr in neonates in the exposed group, which were significantly higher than those in the non-exposed area. High levels of urinary arsenic in neonates were maintained 4 days after birth, demonstrating an early arsenic exposure route through the placenta and breast milk. In addition, our study suggested that breastfeeding may reduce arsenic exposure in infants in arsenic-contaminated areas. Further studies are necessary to follow up on comorbidities later in life in neonates and to provide interventions in this region.

Phenolic Profiles and Biological Activities of Extracts from Edible Wild Fruits Ehretia tinifolia and Sideroxylon lanuginosum.

Ehretia tinifolia Linnaeus (Boraginacea) and Sideroxylon lanuginosum Michaux (Sapotaceae) are wild fruits consumed in North America and are appreciated for their pleasant flavor and sweet taste. However, details regarding their composition and biological properties in the available literature are scarce. This study reports the phenolic composition, antioxidant, antiproliferative activities, and digestive enzymatic inhibition of amberlite-retained methanolic extracts from both fruits. Results revealed that these wild fruit extracts are rich in antioxidants. S. lanuginosum had lower phenolic but higher flavonoid contents (21.4 ± 1.5 mg GAE/100 g FW and 6.42 ± 0.9 mg CE/100 g FW) than E. tinifolia (64.7 ± 2.6 mg GAE/100 g FW and 5.1 ± 0.4 mg CE/100 g FW). HPLC-DAD-MS/MS analysis showed rosmarinic acid as a major polyphenol in E. tinifolia and quercetin glucoside in S. lanuginosum. Polyphenols content in E. tinifolia was related to a significant free radical scavenging ability: DPPH (EC50 = 0.32 ± 0.03 mg/mL), TEAC (4134 ± 9.7 µM TE/g dry extract), and hemolysis inhibition (IC50 = 58.55 ± 2.4 µg/mL). Both extracts were capable of inhibiting α-glucosidase, partially inhibiting α-amylase, and showed no inhibition against lipase, while showing antiproliferative activity against HeLa, HT-29 and MCF-7 cancer cell lines. Our study revealed that these wild fruit extracts are rich in health-beneficial phytochemicals and hold significant potential for elaborating functional foods.

Transgenerational effects in DNA methylation, genotoxicity and reproductive phenotype by chronic arsenic exposure.

An emerging concern is the influences of early life exposure to environmental toxicants on offspring characteristics in later life. Since recent evidence suggests a transgenerational transference of aberrant phenotypes from exposed-parents to non-exposed offspring related to adult-onset diseases including reproductive phenotype. The transgenerational potential of arsenic a well know genotoxic and epigenetic modifier agent has not been assessed in mammals until now. In this experimental study, we evaluated the transgenerational effects of arsenic in a rat model with chronic exposure to arsenic. Rats chronically exposed to arsenic in drinking water (1 mg As2O3/mL) (F0) were mated to produce the arsenic lineage (F1, F2, and F3). The arsenic toxic effects on were evaluated over the four generations by analyzing the DNA methylation percentage, genotoxicity in WBC and physical and reproductive parameters, including sperm quality parameters and histopathological evaluation of the gonads. Chronic exposure to arsenic caused genotoxic damage (F0-F3) different methylation patterns, alterations in physical and reproductive parameters, aberrant morphology in the ovaries (F0 and F1) and testicles (F1-F3), and a decrease in the quality of sperm (F0-F3, except F2). Parental chronic arsenic exposure causes transgenerational genotoxicity and changes in global DNA methylation which might be associated with reproductive defects in rats. Combined with recent studies reveal that disturbances in the early life of an individual can affect the health of later generations.

Enhanced in vitro anticancer activity of yeast expressed recombinant glucose oxidase versus commercial enzyme.

Cancer treatments continue to have many disadvantages. Reactive oxygen species, such as H2O2, in high concentrations, can cause cytotoxicity to cells, being even greater in cancer cells. One of the H2O2-producing enzymes is glucose oxidase; its application in cancer treatment should be explored. In this work, the extracellular expression of the mutated recombinant enzyme glucose oxidase was carried out in the eukaryotic expression system Pichia pastoris SMD1168, through the modification and optimization of the gox gene of Aspergillus niger to improve its expression in yeast and its purification. Also, the secretion signal of the alpha-mating factor from Saccharomyces cerevisiae was added to the gene for extracellular expression, and it was inserted into the expression vector pPIC3.5k. The extracellular expression of the enzyme facilitated purification by anion exchange chromatography; the purification was corroborated by SDS-PAGE, with a molecular weight of its subunit between 63 kDa and 100 kDa. The mutated recombinant enzyme glucose oxidase showed greater anticancer activity compared to the commercial glucose oxidase and could have potential for cancer treatment. KEY POINTS: • Pichia pastoris is an excellent eukaryotic expression system for proteins that need post-translational modifications. • Extracellular expression facilitates protein purification. • Glucose oxidase has potential application in cancer treatment.

Ex vivo infection of murine precision-cut lung tissue slices with Mycobacterium abscessus: a model to study antimycobacterial agents.

BACKGROUND: Multidrug-resistant infections due to Mycobacterium abscessus often require complex and prolonged regimens for treatment. Here, we report the evaluation of a new ex vivo antimicrobial susceptibility testing model using organotypic cultures of murine precision-cut lung slices, an experimental model in which metabolic activity, and all the usual cell types of the organ are found while the tissue architecture and the interactions between the different cells are maintained. METHODS: Precision cut lung slices (PCLS) were prepared from the lungs of wild type BALB/c mice using the Krumdieck® tissue slicer. Lung tissue slices were ex vivo infected with the virulent M. abscessus strain L948. Then, we tested the antimicrobial activity of two drugs: imipenem (4, 16 and 64 µg/mL) and tigecycline (0.25, 1 and 4 µg/mL), at 12, 24 and 48 h. Afterwards, CFUs were determined plating on blood agar to measure the surviving intracellular bacteria. The viability of PCLS was assessed by Alamar Blue assay and corroborated using histopathological analysis. RESULTS: PCLS were successfully infected with a virulent strain of M. abscessus as demonstrated by CFUs and detailed histopathological analysis. The time-course infection, including tissue damage, parallels in vivo findings reported in genetically modified murine models for M. abscessus infection. Tigecycline showed a bactericidal effect at 48 h that achieved a reduction of > 4log10 CFU/mL against the intracellular mycobacteria, while imipenem showed a bacteriostatic effect. CONCLUSIONS: The use of this new organotypic ex vivo model provides the opportunity to test new drugs against M. abscessus, decreasing the use of costly and tedious animal models.

Synthesis, trypanocidal and anti-leishmania activity of new triazole-lapachol and nor-lapachol hybrids.

A new library of twenty triazole-lapachol and nor-lapachol derivatives was synthesized. The compounds were evaluated against the epimastigotes form of Trypanosoma cruzi and promastigotes of Leishmania braziliensis and L. infantum. The cytotoxicity of the compounds was determined on murine fibroblasts and used to assess the selectivity index. The introduction of triazole rings in the naphthoquinone derivatives improved activity against the parasitic protozoa T. cruzi and Leishmania species. Some of the derivatives were three to six times more potent than benznidazole against T. cruzi, with similar or slightly better selectivity indexes. The results against L. braziliensis showed that the derivatives 5b and 5e were the most selective compounds. However, they were less selective than the reference compound, miltefosine. Among all products, the derivative 3a was the most selective compound against L. infantum. Nevertheless, it was less potent and less selective than miltefosine. Also, the minimum inhibitory concentration values of the derivatives against nine different bacteria were determined. Moderate antibacterial activity was observed for compound 5c against Staphylococcus aureus.

Antimycobacterial Activity of Laurinterol and Aplysin from Laurencia johnstonii.

Marine environments represent a great opportunity for the discovery of compounds with a wide spectrum of bioactive properties. Due to their large variety and functions derived from natural selection, marine natural products may allow the identification of novel drugs based not only on newly discovered bioactive metabolites but also on already known compounds not yet thoroughly investigated. Since drug resistance has caused an increase in infections by Mycobacterium tuberculosis and nontuberculous mycobacteria, the re-evaluation of known bioactive metabolites has been suggested as a good approach to addressing this problem. In this sense, this study presents an evaluation of the in vitro effect of laurinterol and aplysin, two brominated sesquiterpenes isolated from Laurencia johnstonii, against nine M. tuberculosis strains and six nontuberculous mycobacteria (NTM). Laurinterol exhibited good antimycobacterial activity, especially against nontuberculous mycobacteria, being remarkable its effect against Mycobacterium abscessus, with minimum inhibitory concentration (MIC) values lower than those of the reference drug imipenem. This study provides further evidence for the antimycobacterial activity of some sesquiterpenes from L. johnstonii, which can be considered interesting lead compounds for the discovery of novel molecules to treat NTM infections.

Curcumin Attenuates the Pathogenicity of Entamoeba histolytica by Regulating the Expression of Virulence Factors in an Ex-Vivo Model Infection.

Infection with the enteric protozoan Entamoeba histolytica is still a serious public health problem, especially in developing countries. Amoebic liver abscess (ALA) is the most common extraintestinal manifestation of the amoebiasis, and it can lead to serious and potentially life-threatening complications in some people. ALA can be cured by metronidazole (MTZ); however, because it has poor activity against luminal trophozoites, 40-60% of treated patients get repeated episodes of invasive disease and require repeated treatments that can induce resistance to MTZ, this may emerge as an important public health problem. Anti-virulence strategies that impair the virulence of pathogens are one of the novel approaches to solving the problem. In this study, we found that low doses of curcumin (10 and 50 µM) attenuate the virulence of E. histolytica without affecting trophozoites growth or triggering liver injury. Curcumin (CUR) decreases the expression of genes associated with E. histolytica virulence (gal/galnac lectin, ehcp1, ehcp5, and amoebapore), and is correlated with significantly lower amoebic invasion. In addition, oxidative stress is critically involved in the etiopathology of amoebic liver abscess; our results show no changes in mRNA expression levels of superoxide dismutase (SOD) and catalase (CAT) after E. histolytica infection, with or without CUR. This study provides clear evidence that curcumin could be an anti-virulence agent against E. histolytica, and makes it an attractive potential starting point for effective treatments that reduce downstream amoebic liver abscess.

Development of a Novel Ex-vivo 3D Model to Screen Amoebicidal Activity on Infected Tissue.

Amoebiasis is a parasitic disease that causes thousands of deaths every year, its adverse effects and resistance to conventional treatments have led to the search of new treatment options, as well as the development of novel screening methods. In this work, we implemented a 3D model of intestine and liver slices from hamsters that were infected ex vivo with virulent E. histolytica trophozoites. Results show preserved histology in both uninfected tissues as well as ulcerations, destruction of the epithelial cells, and inflammatory reaction in intestine slices and formation of micro abscesses, and the presence of amoebae in the sinusoidal spaces and in the interior of central veins in liver slices. The three chemically synthetized compounds T-001, T-011, and T-016, which act as amoebicides in vitro, were active in both infected tissues, as they decreased the number of trophozoites, and provoked death by disintegration of the amoeba, similar to metronidazole. However, compound T-011 induced signs of cytotoxicity to liver slices. Our results suggest that ex vivo cultures of precision-cut intestinal and liver slices represent a reliable 3D approach to evaluate novel amoebicidal compounds, and to simultaneously detect their toxicity, while reducing the number of experimental animals commonly required by other model systems.

Protective effects of phenolic acids on mercury-induced DNA damage in precision-cut kidney slices.

OBJECTIVES: Precision-cut tissue slices are considered an organotypic 3D model widely used in biomedical research. The comet assay is an important screening test for early genotoxicity risk assessment that is mainly applied on in vitro models. The aim of the present study was to provide a 3D organ system for determination of genotoxicity using a modified method of the comet assay since the stromal components from the original tissue make this technique complicated. MATERIALS AND METHODS: A modified comet assay technique was validated using precision-cut hamster kidney slices to analyze the antigenotoxic effect of the phenolic compounds caffeic acid, chlorogenic acid, and rosmarinic acid in tissue slices incubated with 15 µM HgCl2. Cytotoxicity of the phenolic compounds was studied in Vero cells, and by morphologic analysis in tissue slices co-incubated with HgCl2 and phenolic compounds. RESULTS: A modification of the comet assay allows obtaining better and clear comet profiles for analysis. Non-cytotoxic concentrations of phenolic acids protected kidney tissue slices against mercury-induced DNA damage, and at the same time, were not nephrotoxic. The highest protection was provided by 3 µg/ml caffeic acid, although 6 µg/ml rosmarinic and 9 µg/ml chlorogenic acids also exhibited protective effects. CONCLUSION: This is the first time that a modification of the comet assay technique is reported as a tool to visualize the comets from kidney tissue slices in a clear and simple way. The phenolic compounds tested in this study provided protection against mercury-induced genotoxic damage in precision-cut kidney slices.

Antitumoral Effect of Laurinterol on 3D Culture of Breast Cancer Explants.

Macroalgae represent an important source of bioactive compounds with a wide range of biotechnological applications. Overall, the discovery of effective cytotoxic compounds with pharmaceutical potential is a significant challenge, mostly because they are scarce in nature or their total synthesis is not efficient, while the bioprospecting models currently used do not predict clinical responses. Given this context, we used three-dimensional (3D) cultures of human breast cancer explants to evaluate the antitumoral effect of laurinterol, the major compound of an ethanolic extract of Laurencia johnstonii. To this end, we evaluated the metabolic and histopathological effects of the crude extract of L. johnstonii and laurinterol on Vero and MCF-7 cells, in addition to breast cancer explants. We observed a dose-dependent inhibition of the metabolic activity, as well as morphologic and nuclear changes characteristic of apoptosis. On the other hand, a reduced metabolic viability and marked necrosis areas were observed in breast cancer explants incubated with the crude extract, while explants treated with laurinterol exhibited a heterogeneous response which was associated with the individual response of each human tumor sample. This study supports the cytotoxic and antitumoral effects of laurinterol in in vitro cell cultures and in ex vivo organotypic cultures of human breast cancer explants.

Telomere length analysis in residents of a community exposed to arsenic.

Differentiated cells telomere length is an indicator of senescence or lifespan; however, in peripheral blood leukocytes the relative shortening of the telomere has been considered as a biological marker of aging, and lengthening telomere as an associated risk to cancer. Individual's age, type of tissue, lifestyle, and environmental factors make telomere length variable. The presence of environmental carcinogens such as arsenic (As) influence as causal agents of these alterations, the main modes of action for As described are oxidative stress, reduction in DNA repair capacity, overexpression of genes, alteration of telomerase activity, and damage to telomeres. The telomeres of leukocytes resulting a finite capacity of replication due to the low or no activity of the telomerase enzyme, therefore, elongation telomere in this kind of cells is a potential biological marker associated with the development of chronic diseases and carcinogenesis.