Antimutageno djelovanje vitamina C na oksidacijske promjene uzrokovane kinolonima

Quinolones are broad-spectrum antibiotics effective against both Gram-positive and Gram-negative bacteria. Reactive oxygen species (ROS) generated by quinolones may damage cell structures and could be a risk to health. The use of vitamin C to reduce such risks may have the opposite effects: vitamin C in the presence of divalent metal ions can induce the Fenton reaction, leading to hydroxyl radical (HO˙) generation and oxidative damage. The purpose of this study is to evaluate the antioxidant and prooxidant properties of vitamin C by measuring its effects on both lipid peroxidation and mutagenesis induced by quinolones nalidixic acid (NLX) or norfloxacin (NOR) in Salmonella typhimurium TA102. Mutagenicity was evaluated by the Ames test and the results were expressed as (histidine+ revertants/ng of quinolone), while lipoperoxidation was measured as thiobarbituric acid reactive substances (μmol malondialdehyde/(mL·h)). The effects of different concentrations of nalidixic acid (10–1000 ng) or norfloxacin (7–700 ng) on S. typhimurium TA102 were studied, employing the S9 mix (liver homogenate from rats pre-treated with Arochlor 1254) in the presence of 10–1000 μg of ascorbic acid (AA) with 0.1 mM FeCl3 or EDTA. Minimal inhibitory concentrations of NOR and NLX against 25 uropathogenic Escherichia coli strains were obtained using the plate dilution method in the presence of vitamin C. Vitamin C (1 mg) together with 0.1 mM FeCl3 showed a prooxidant effect in the S9 mix and enhanced the lipoperoxidation induced by either NOR or NLX. Mutagenic potency was also increased for both NOR and NLX. When metal ions were chelated with EDTA, ascorbate showed both antimutagenic and antioxidant properties. Mutagenic potency and lipoperoxidation were reduced for both NOR and NLX. The addition of vitamin C did not change the minimal in vitro inhibitory concentrations of NLX or NOR against the 25 uropathogenic E. coli strains. The antimutagenic and antioxidant effects of vitamin C were especially marked when the Salmonella strain was exposed to NOR or NLX in the presence of EDTA. In contrast, the vitamin C in the presence of FeCl3 increased ROS generation, enhancing both the mutagenic effect of the quinolones and malondialdehyde production from lipoperoxidation induced in the bacterial membranes. Therapeutic use of quinolones together with vitamin C and divalent cations might induce the Fenton reaction involving norfloxacin and nalidixic acid. However, our results suggest that vitamin C could be a good alternative for reducing the genotoxic risk of these therapeutic drugs if it is carefully handled.Kinoloni su antibiotici širokog spektra koji djeluju na Gram-pozitivne i Gram-negativne bakterije. Stvaraju reaktivne metabolite kisika što mogu oštetiti strukturu stanica i time narušiti zdravlje ljudi. Da bi se taj rizik smanjio, koristi se vitamin C koji međutim može imati i suprotno djelovanje: u prisutnosti dvovalentnih iona metala potiče Fentonovu reakciju, što dovodi do stvaranja hidroksil radikala (HO˙) koji oštećuju stanicu. Svrha je ovoga rada utvrditi antioksidativna i prooksidativna svojstva vitamina C ispitivanjem njegova utjecaja na peroksidaciju lipida i mutagenezu induciranu kinolonima poput nalidiksinske kiseline i norfloksacina iz soja bakterije Salmonella typhimurium TA102. Mutagenost je procijenjena Amesovim testom, a rezultati su izraženi kao broj revertanata histidin+/ng kinolona. Peroksidacija lipida mjerena je reakcijom produkata s tiobarbiturnom kiselinom, te izražena kao μmol malonaldehida/(mL·h). Istražen je utjecaj različitih koncentracija nalidiksinske kiseline (10-1000 ng) ili norfloksacina (7-700 ng) na bakteriju S. typhimurium TA102 pomoću mješavine S9 (homogenat jetre štakora tretiranih aroklorom 1254), 10-1000 μg vitamina C i 0,1 mM FeCl3 ili etilendiamintetraoctene kiseline (EDTA). Najmanje koncentracije norfloksacina i nalidiksinske kiseline, potrebne za inhibiciju 25 uropatogenih sojeva bakterije Escherichia coli, određene su metodom na agaru u prisutnosti vitamina C. Vitamin C (1 mg) uz 0,1 mM FeCl3 imao je prooksidativno djelovanje u mješavini S9, pospješio je peroksidaciju lipida uzrokovanu norfloksacinom ili nalidiksinskom kiselinom, te pojačao mutagenost oba kinolona. Stvaranje kelatnog kompleksa iona metala s EDTA potaknulo je antimutageno i antioksidativno djelovanje vitamina C, te smanjilo mutageno i lipoperoksidacijsko djelovanje norfloksacina i nalidiksinske kiseline. Dodatak vitamina C nije smanjio minimalnu koncentraciju nalidiksinske kiseline i norfloksacina in vitro, potrebnu za inhibiciju 25 uropatogenih sojeva bakterije E. coli. Antimutageno i antioksidativno djelovanje vitamina C bilo je osobito izraženo kada je soj bakterije Salmonella izložen djelovanju norfloksacina ili nalidiksinske kiseline u prisutnosti EDTA. Zajedno s FeCl3 vitamin C je ubrzao stvaranje reaktivnih metabolita kisika, pojačavajući time mutageno djelovanje kinolona te proizvodnju malondialdehida peroksidacijom lipida u membrani bakterija. Uporaba kinolona u kombinaciji s vitaminom C i dvovalentnim kationima pri liječenju bolesti mogla bi pokrenuti Fentonovu reakciju s norfloksacinom i nalidiksinskom kiselinom. Međutim, rezultati autora pokazuju da bi se vitamin C, pravilnom primjenom, mogao upotrijebiti kako bi se smanjila opasnost od genotoksičnog djelovanja tih lijekova

Utilización de objetos de aprendizaje en asignaturas heterogéneas de la Universidad Politécnica de Madrid. Resultados y valoración de la experiencia.

Durante el curso 2007/08 un grupo de profesores de distintas Escuelas de la UPM ha participado en un proyecto coordinado cuyo objetivo principal el la generación y adaptación de materiales didácticos para transformar de forma progresiva la docencia a formato semi-presencial o completamente a distancia. Como recursos educativos se han utilizado los Objetos de Aprendizaje. La novedad de las asignaturas implicadas, no sólo por su temática, sino en otros aspectos de gran importancia práctica como la diferenca en número y procedencia de los alumnos que las cursan, nivel en el Plan de Estudos , etc. En este trabajo se describe la experiencia y se muestran algunos de los materiales proparados. También se presentan los resultados académicos alcanzados por los alumnos y la valoración cualitativa que hacen los estudiantes respecto a disponer de objetos digitales de aprendizaje

Emakumeen presentzia euskal hedabideetan: GMMP monitorizazioaen 2020ko emaitzak Hego Euskal Herrian

1995eko urtarrilaren 18an, lehenengo aldiz, emakumeek hedabideetan zuten errepresentazioa neurtu zuen World Association for Christian Communication (WACC) elkarteak koordinatutako Global Media Monitoring Project delakoak, MediaWatch Canada elkartearekin batera. Harrezkero, bost urtero egin ohi da monitorizazio globala. Espainiako Estatuko erakundeek 2000. urteko neurketan parte hartu zuten lehenengo aldiz; lehenengo edizio hartan, 71 herritako zenbait ikertzailek hartu zuten parte, eta gaur egun 100dik gora dira herri parte-hartzaileak. Euskal Herritik 2015ean saiatu ginen neurketa sarean sartzen, baina ez ginen garaiz heldu. 2020an, berriz, lortu dugu: lehenengo aldiz, EAEko eta Nafarroako komunikabideak sartu dira emakumeen hedabideetako presentzia neurtzea xede duen monitorizazio globalean, beti ere GMMP Spain delakoaren antolaketak ezarritako irizpideen arabera. Hala ere, oinarri horietatik harago joanda, datu bilketan Euskal Herriko lagin oso bat aztertzea erabaki genuen —datu horiek ikerketa ofizialean sartuko ez diren arren, ikerketa orokorrarekin alderatu ahal izateko asmoz bildu genituen—

Transport and Health: A Look at Three Latin American Cities

Transport is associated with environmental problems, economic losses, health and social inequalities. A number of European and US cities have implemented initiatives to promote multimodal modes of transport. In Latin America changes are occurring in public transport systems and a number of projects aimed at stimulating non-motorized modes of transport (walking and cycling) have already been implemented. Based on articles from peer-reviewed academic journals, this paper examines experiences in Bogota (Colombia), Curitiba (Brazil), and Santiago (Chile), and identifies how changes to the transport system contribute to encourage active transportation. Bus rapid transit, ciclovias, bike paths/lanes, and car use restriction are initiatives that contribute to promoting active transportation in these cities. Few studies have been carried out on the relationship between transport and physical activity. Car ownership continues to increase. The public health sector needs to be a stronger activist in the transport policy decision-making process to incorporate health issues into the transport agenda in Latin America

Revista de las revista

A Propósito de la Clasificación de los Piroplasmas del Buey / Filariosis Cardiopulmonar / Observaciones sobre la enfermedad de Marek en el año de 1933, por el doctor Hartwigk / El comportamiento de la vitamina c en la enfermedad de Addison / La eliminación renal de vitamina C en la nefritis experimental  / Contribuciones clínicas al problema de las pigmentaciones morbosas de la piel / Sobre la correlación de las vitaminas A y D / La epizootia de encefalomielitis equina (tipo americano), sugiere que la enfermedad puede ser diseminada por insectos vectores / Lo que debe saberse sobre aborto / Control de la enfermedad en finca infectad

Etiología de la infección cérvico vaginal en pacientes del Hospital Juárez de México

Objetivo. Conocer la etiología de la infección cérvico vaginal, con el fin de establecer un diagnóstico acertado que permita ofrecer a las pacientes el tratamiento más apropiado. Material y métodos. De enero de 1995 a diciembre de 1999 se realizó un estudio bacteriológico a 6 811 muestras de exudado cérvico vaginal de pacientes del Hospital Juárez de México, de la Ciudad de México, con edades comprendidas entre los 13 y los 65 años, que referían leucorrea, prurito, hiperemia y dolor abdominal bajo. Resultados. La frecuencia de infección por cada germen fue G vaginalis, 22.65%, Candida spp, 19.13%, C albicans, 7.8%, T vaginalis, 1.5%, Streptococcus del grupo D, 11.78%, Streptococcus b haemolyticus, 4.59%, E coli, 13.46%, Klebsiella ssp, 2.0%, además de otras enterobacterias menos frecuentes como Citrobacter spp, Enterobacter spp, Pseudomonas spp, M morganii y P mirabilis. El 2.9% presentó anaerobios siempre asociados con G vaginalis. Se aislaron Neisseria spp y N weaveri en 0.15% de las muestras. La N gonorrhoeae no se encontró en ningún caso. Datos comparativos indican que, tanto Streptococcus hemoliticos como E coli tuvieron un marcado incremento en los dos últimos años, siendo el de esta última estadísticamente significativo (p<0.001). El método de ji cuadrada se aplicó para la evaluación de los datos. Conclusiones. Considerando la diversidad de la etiología de la infección se recomienda realizar cultivos de la secreción cérvico vaginal a todas las pacientes con sintomatología sugestiva de ella. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htm

Rolipram impairs NF-kappaB activity and MMP-9 expression in experimental autoimmune encephalomyelitis

Rolipram suppresses experimental autoimmune encephalomyelitis (EAE) and diminishes cell infiltration of the central nervous system (CNS). In Lewis rats with EAE, rolipram reduced matrix metalloproteinase-9 (MMP-9) gene expression in lymph node cells (LNCs) and spinal cord, decreased basal levels of nuclear (p50/p65) NF-kappaB in LNCs from treated rats, and impaired CD3 mediated NF-kappaB translocation. Rolipram reduced the luciferase activity directed by the NF-kappaB binding site of the MMP-9 gene in lymphocytes. It also diminished NF-kappaB activity and the ability of a myelin basic protein (MBP) specific cell line to migrate across artificial basement membranes. IL-2 induced MMP-9 proteolytic activity was only slightly reduced indicating that additional factors contribute to inhibit cell migration mediated by rolipram.S

Relaciones públicas enfocadas al sentido de pertenencia dentro de clase diamante

Seminario: Relaciones públicas estratégica