Stereochemical Preference Toward Oncotarget: Design Synthesis and in Vitro Anticancer Evaluation of Diastereomeric B-Lactams

Purpose: In the battle against cancer discovery of new and novel chemotherapeutic agent demands extreme obligation. Development of anticancer compounds with higher potency and reduced side-effects is timely and challenging. Experimental Design: A small series of fourteen diastereomeric β-lactams (seven pairs) were synthesized through multi-step process exploring [2+2] ketene-imine cycloaddition as the key step. Comparative stereochemical preferences were studied through computational docking and validated by in vitro evaluation. β-tubulin was considered as possible molecular target and in vitro anticancer evaluation was conducted against SiHa, B16F10, K562 and Chang cell lines. Caspase-3 activation assay and hematoxylin/eosin staining of the cells were also accomplished. Results: Better docking scores of the cis- over the trans-β-lactams indicated favorable β-lactam—β-tubulin interactions in cis-geometry. In vitro (IC50) evaluation confirmed better anticancer activity of the cis-diastereoisomers. Apoptosis-induced cell death was supported by caspase-3 activation study. A cis-β-lactam [(±)-Cis-3-amino-1-phenyl-4-(p-tolyl) azetidin-2-one, 6C] was found to be more active (in vitro) than the marketed natural drug colchicine against SiHa and B16F10 (six times higher potency) cell lines. Reduced toxicity (compared to colchicine) in Chang cells confirmed better site-selectivity (accordingly less side-effects) of 6C than colchicine. Aside from 6C, most of the reported molecules demonstrated good to strong in vitro anticancer activity against SiHa and B16F10 cancer cell lines. Conclusions: Stereochemical preferences of the cis-β-lactams over their trans-counterparts, toward the molecular target β-tubulin, was confirmed by docking studies and in vitro anticancer evaluation. Apoptosis was identified as the cause of cell death. The lead 6C exhibited higher potency and selectivity than the marketed drug colchicine both in silico as well as in vitro

“Aplicación del mantenimiento preventivo, para mejorar la disponibilidad de flota de montacargas en la empresa Grúas Luguensi S.A.C - Chimbote, 2018”

La presente investigación titulada Aplicación del Mantenimiento Preventivo, para mejorar la Disponibilidad de flota de montacargas en la empresa Grúas Luguensi S.A.C - Chimbote, 2018; empleó una investigación de tipo correlacional, con diseño de investigación de carácter experimental en la categoría pre-experimental, donde la población estuvo compuesta por la flota de montacargas de la empresa Grúas Luguensi S.A.C y la muestra fueron los equipos críticos de flota de montacargas. Se empleó como herramientas la auditoría de gestión de mantenimiento, el reporte de fallas, el formato de tiempo medio entre fallas, el formato de tiempo medio de reparación, el formato de disponibilidad y el plan de mantenimiento preventivo para los montacargas en investigación. De ésta manera, se obtuvo como primer resultado la situación inicial de la gestión de mantenimiento y para ello se utilizó una auditoría que aplicada evidenció un valor inicial de 50.16% mostrando según los índices de conformidad un nivel aceptable pero mejorable y una vez aplicado el estímulo ascendió a 62.54% demostrando un buen sistema de mantenimiento, por lo que este incremento se evidencio en la disponibilidad, ya que percibió un valor inicial en los sistemas de motor, sistema hidráulico, sistema eléctrico y sistema de dirección de los montacargas Caterpillar, Komatsu, Hancha y Yale de 79.75% y una vez elaborado el plan de mantenimiento preventivo la disponibilidad final acrecentó a 89.87%. Finalmente, se concluyó que gracias al plan elaborado la disponibilidad incrementó en 10.12% comprobándose la hipótesis alternativa

Stereochemical preference toward oncotarget: Design, synthesis and <i>in vitro</i> anticancer evaluation of diastereomeric &#x3B2;-lactams

ABSTRACT Purpose: In the battle against cancer discovery of new and novel chemotherapeutic agent demands extreme obligation. Development of anticancer compounds with higher potency and reduced side-effects is timely and challenging. Experimental Design: A small series of fourteen diastereomeric β-lactams (seven pairs) were synthesized through multi-step process exploring [2+2] ketene-imine cycloaddition as the key step. Comparative stereochemical preferences were studied through computational docking and validated by in vitro evaluation. β-tubulin was considered as possible molecular target and in vitro anticancer evaluation was conducted against SiHa, B16F10, K562 and Chang cell lines. Caspase-3 activation assay and hematoxylin/eosin staining of the cells were also accomplished. Results: Better docking scores of the cis- over the trans-β-lactams indicated favorable β-lactam—β-tubulin interactions in cis-geometry. In vitro (IC50) evaluation confirmed better anticancer activity of the cis-diastereoisomers. Apoptosis-induced cell death was supported by caspase-3 activation study. A cis-β-lactam [(±)-Cis3-amino-1-phenyl-4-(p-tolyl) azetidin-2-one, 6C] was found to be more active (in vitro) than the marketed natural drug colchicine against SiHa and B16F10 (six times higher potency) cell lines. Reduced toxicity (compared to colchicine) in Chang cells confirmed better site-selectivity (accordingly less side-effects) of 6C than colchicine. Aside from 6C, most of the reported molecules demonstrated good to strong in vitro anticancer activity against SiHa and B16F10 cancer cell lines. Conclusions: Stereochemical preferences of the cis-β-lactams over their transcounterparts, toward the molecular target β-tubulin, was confirmed by docking studies and in vitro anticancer evaluation. Apoptosis was identified as the cause of cell death. The lead 6C exhibited higher potency and selectivity than the marketed drug colchicine both in silico as well as in vitr

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

Cytological effects of pulsed electromagnetic fields and static magnetic fields induced by a therapeutic device on in vivo exposed rats

Background: There is a trend towards the use of magnetic fields in medicine. Pulsed electromagnetic fields (PEMFs) technology was based upon 20 years of fundamental studies on the electromechanical properties of bone and other connective tissues. More recently, these magnetic fields have been used to treat several health conditions. There remains continuing concern that exposure to electromagnetic devices may cause adverse effects. The aim of the present study was to investigate the cytological effects induced in rats exposed in a patented medical device that uses PEMFs combined with static magnetic fields (SMFs).Material and Methods: Thirty sexually mature 14-week-old male and female Sprague Dawley rats were distributed into three groups: (a) 5 males and 5 females (independently) exposed to PEMFs combined with SMFs, (b) animals treated with SMFs only, and (c) non-exposed animals. Acridine orange fluorescent-staining micronucleus test and male germ cells analysis were performed according to standardized techniques.Results: A lack of evidence for alterations on micronucleus frequency, on polychromatic erythrocytes percentage, and on sperm counts and morphological characteristics of male germ cells were found in mature rats exposed to PEMFs medical device compared to non-exposed animals.Conclusions: This study suggests that the applied magnetic field generated in a therapeutic device did not have any detectable cytotoxic or genotoxic effect in exposed rats. In view of these findings and the contradictory reports in the literature, it is necessary to carry out more research to help clarify the controversy concerning cytogenotoxic risk associated with therapeutic magnetic fields exposures.Keywords: Cytotoxicity, pulsed electromagnetic fields, static magnetic fields, micronuclei, sperm abnormalitie

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

Objective(s): 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

Organotypic culture of breast tumor explants as a multicellular system for the screening of natural compounds with antineoplastic potential

Breast cancer is the leading cause of death in women worldwide. The search for novel compounds with antitumor activity, with less adverse effects and higher efficacy, and the development of methods to evaluate their toxicity is an area of intense research. In this study we implemented the preparation and culture of breast tumor explants, which were obtained from precision-cut breast tumor slices. In order to validate the model we are proposing to screen antineoplastic effect of natural compounds, we selected caffeic acid, ursolic acid, and rosmarinic acid. Using the Krumdieck tissue slicer, precision-cut tissue slices were prepared from breast cancer samples; from these slices, 4 mm explants were obtained and incubated with the selected compounds. Viability was assessed by Alamar Blue assay, LDH release, and histopathological criteria. Results showed that the viability of the explants cultured in the presence of paclitaxel (positive control) decreased significantly

Sperm chromatin dispersion by formaldehyde in Wistar rats

Formaldehyde (FA) is an environmental xenobiotic, which is genotoxic and carcinogenic to humans and animals; it induces DNA damage, mutations, and clastogenicity during critical cytogenetic events. FA-mediated oxidative stress is an important mechanism that has been associated with the induction of cytotoxic and genotoxic damage. Therefore, the objective of this study was to evaluate the dispersion of sperm chromatin and reproductive parameters induced by exposure to different concentrations of FA in Wistar rats. Compared to the percentage of sperm with fragmented DNA in the control group (18.10 ± 8.62%), the percentage of sperm with fragmented DNA increased following exposure to 5, 10, and 30 mg FA/kg body weight (29.60 ± 8.44, 85.20 ± 20.94 and 96.0 ± 7.87, respectively; P = 0.0001). Histopathological alterations were evident, especially in the seminiferous tubules. In conclusion, this study provides experimental evidence concerning the genotoxicity of FA, with particular reference to the decreased sperm concentration and motility and increased dispersion of DNA chromatin in rats