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Staphylea, also called bladdernuts, is a genus of plants belonging to the family Staphyleaceae, widespread in tropical or temperate climates of America, Europe, and the Far East. Staphylea spp. produce bioactive metabolites with antioxidant properties, including polyphenols which have not been completely investigated for their phytotherapeutic potential, even though they have a long history of use for food. Here, we report the isolation of six flavonol glycosides from the hydroalcoholic extract of aerial parts of Staphylea pinnata L., collected in Italy, using a solid-phase extraction technique. They were identified using spectroscopic, spectrometric, and optical methods as three quercetin and three isorhamnetin glycosides. Among the flavonol glycosides isolated, isoquercetin and quercetin malonyl glucoside showed powerful antioxidant, antimicrobial, and wound healing promoting activity and thus are valuable as antiaging ingredients for cosmeceutical applications and for therapeutic applications in skin wound repair.
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Antioxidantes , Flavonoles , Glicósidos , Extractos Vegetales , Glicósidos/farmacología , Glicósidos/química , Glicósidos/aislamiento & purificación , Flavonoles/farmacología , Flavonoles/química , Flavonoles/aislamiento & purificación , Antioxidantes/farmacología , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/farmacología , Cicatrización de Heridas/efectos de los fármacos , Quercetina/farmacología , Quercetina/química , Quercetina/análogos & derivados , Quercetina/aislamiento & purificación , Humanos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , AnimalesRESUMEN
In the search for new alternative biocontrol strategies, phytopathogenic fungi could represent a new frontier for weed management. In this respect, as part of our ongoing work aiming at using fungal pathogens as an alternative to common herbicides, the foliar pathogen Nigrospora sphaerica has been evaluated to control buffelgrass (Cenchrus ciliaris). In particular, in this work, the isolation and structural elucidation of two new biosynthetically related metabolites, named nigrosphaeritriol (3-(hydroxymethyl)-2-methylpentane-1,4-diol) and nigrosphaerilactol (3-(1-hydroxyethyl)-4-methyltetrahydrofuran-2-ol), from the phytotoxic culture filtrate extract were described, along with the identification of several known metabolites. Moreover, the absolute stereochemistry of (3R,4S,5S)-nigrosphaerilactone, previously reported as (3S,4R,5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone, was determined for the first time by X-ray diffraction analysis. Considering their structural relationship, the determination of the absolute stereochemistry of nigrosphaerilactone allowed us to hypothesize the absolute stereochemistry of nigrosphaeritriol and nigrosphaerilactol.
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Ascomicetos , Cenchrus , Malezas , Cristalografía por Rayos XRESUMEN
Diplodia corticola is one of the most aggressive fungal pathogens of Quercus species involved in the decline of Mediterranean oak forests. In this study, three strains of D. corticola associated with holm (Quercus ilex) and cork (Quercus suber) oak trees exhibiting dieback symptoms and cankers in Algeria were selected to investigate the production of secondary metabolites. Metabolomic analyses revealed the production of several known compounds, such as sphaeropsidins, diplopyrones and diplofuranones. Moreover, the comparative investigation of secondary metabolites produced by the analyzed strains with different degrees of virulence revealed possible implications of these compounds in the fungal virulence. In particular, sphaeropsidins seem to be the main phytotoxic compounds of D. corticola involved in the infections of Quercus species, with a possible synergistic influence of the less representative compounds in the fungal virulence.
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Ascomicetos , Quercus , Virulencia , ArgeliaRESUMEN
Furan is a volatile compound that is formed in foods during thermal processing. It is classified as a possible human carcinogen by international authorities based on sufficient evidence of carcinogenicity from studies in experimental animals. Although a vast number of studies both in vitro and in vivo have been performed to investigate furan genotoxicity, the results are inconsistent, and its carcinogenic mode of action remains to be clarified. Here, we address the mutagenic and clastogenic activity of furan and its prime reactive metabolite cis-2 butene-1,4-dial (BDA) in mammalian cells in culture and in mouse animal models in a search for DNA lesions responsible of these effects. To this aim, Fanconi anemia-derived human cell lines defective in the repair of DNA inter-strand crosslinks (ICLs) and Ogg1-/- mice defective in the removal of 8-hydroxyguanine from DNA, were used. We show that both furan and BDA present a weak (if any) mutagenic activity but are clear inducers of clastogenic damage. ICLs are strongly indicated as key lesions for chromosomal damage whereas oxidized base lesions are unlikely to play a critical role.
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Aberraciones Cromosómicas/inducido químicamente , Furanos/efectos adversos , Mutación/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Carcinógenos , Línea Celular , Daño del ADN/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Furanos/toxicidad , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Ratones , Micronúcleos con Defecto Cromosómico/inducido químicamente , Mutágenos , Oxidación-ReducciónRESUMEN
"Patient-centred care" is the recent response to the malaise produced in the field of health care from the point of view both of a technical mentality and the paternalistic model. The interest in the story-telling approach shown by both the humanities and the social sciences has favoured a "narrative turn" in medicine too, where the new ethics of therapeutic relationship consider the hermeneutic method a means by which to integrate evidence and subjectivity, scientific data and patient experience. The aim of this paper is to show how Ricoeur's theory of "threefold mimesis" makes a conceptual contribution to the use of narrative interviews in nursing and also be successfully transferred into and applied in the field of healthcare in general. First, the paper examines how this narrative approach might open up new possibilities for the acquisition of in-depth knowledge of patients' life experiences, a condition indispensable for the improvement of the quality of care. Secondly, it highlights how this Ricoeurian method seems capable of provide an opportunity for healthcare professionals to review their own understanding of the caregiver-patient therapeutic relationship, beginning with their confrontation with the patient's world as revealed by the narrative they provide.
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Conocimiento , Narración , Hermenéutica , Humanos , Atención Dirigida al Paciente , Proyectos de InvestigaciónRESUMEN
Although there have been some studies that explore the meaning of aging and give voice to older people, the impact that the aging experience can have on them justifies continued research in this area. In this study, with a hermeneutic phenomenological design and an interpretation method inspired by the philosophy of Ricoeur, we conducted in-depth interviews with 14 elderly people at a social day center in Rome (Italy). The analysis revealed three central themes associated with the experience of being old: changes and limitations related with being aged, the experience that comes from having lived a long life, and an awareness of death. The findings could help health professionals, families and caregivers to achieve a deeper understanding of what old age entails, and may also serve as a platform for interventions that seek to enable older people to experience aging as a meaningful and positive process.
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Envejecimiento , Actitud Frente a la Muerte , Hermenéutica , Anciano , Anciano de 80 o más Años , Cuidadores/estadística & datos numéricos , Femenino , Humanos , Entrevistas como Asunto , Masculino , Investigación Cualitativa , Ciudad de RomaRESUMEN
The MUTYH DNA-glycosylase is indirectly engaged in the repair of the miscoding 7,8-dihydro-8-oxo-2'-deoxyguanine (8-oxodG) lesion by removing adenine erroneously incorporated opposite the oxidized purine. Inherited biallelic mutations in the MUTYH gene are responsible for a recessive syndrome, the MUTYH-associated polyposis (MAP), which confers an increased risk of colorectal cancer. In this study, we functionally characterized the Q338H variant using recombinant proteins, as well as cell-based assays. This is a common variant among human colorectal cancer genes, which is generally considered, unrelated to the MAP phenotype but recently indicated as a low-penetrance allele. We demonstrate that the Q338H variant retains a wild-type DNA-glycosylase activity in vitro, but it shows a reduced ability to interact with the replication sensor RAD9:RAD1:HUS1 (9-1-1) complex. In comparison with Mutyh(-)(/)(-) mouse embryo fibroblasts expressing a wild-type MUTYH cDNA, the expression of Q338H variant was associated with increased levels of DNA 8-oxodG, hypersensitivity to oxidant and accumulation of the population in the S phase of the cell cycle. Thus, an inefficient interaction of MUTYH with the 9-1-1 complex leads to a repair-defective phenotype, indicating that a proper communication between MUTYH enzymatic function and the S phase checkpoint is needed for effective repair of oxidative damage.
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ADN Glicosilasas/fisiología , Reparación del ADN , Sustitución de Aminoácidos , Animales , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , ADN Glicosilasas/genética , ADN Glicosilasas/metabolismo , Ratones , Ratones Noqueados , Mutación , Estrés Oxidativo , Proteínas Recombinantes/metabolismoRESUMEN
The plant Centaurea cineraria L. subsp. cineraria has been investigated as a potential source of inhibitors of broomrape radicle growth. The latter are weeds that pose a threat to agriculture and for which there are few methods available for the control of infestations. Four sesquiterpene lactones have been isolated from C. cineraria L. subsp. cineraria aerial parts and identified as isocnicin, cnicin, salonitenolide, and 11ß,13-dihydrosalonitenolide using spectroscopic, spectrometric, and optical methods. Salonitenolide and 11ß,13-dihydrosalonitenolide have been isolated for the first time from this plant. Tested at 1.0-0.1 mM against the broomrape species Phelipanche ramosa, Orobanche minor, Orobanche crenata, and Orobanche cumana, isocnicin, cnicin, and salonitenolide demonstrated remarkable inhibitory activity (over 80% in most of the cases) at the highest concentrations. Structure-activity relationship conclusions indicated the significance of the α,ß-unsaturated lactone ring. In addition, the synthetic acetylated derivative of salonitenolide showed the strongest activity among all compounds tested, with inhibitions close to 100% at different concentrations, which has been related to a different lipophilicity and the absence of H-bond donor atoms in its structure. Neither the extracts nor the compounds exhibited the stimulating activity of broomrape germination (induction of suicidal germination). These findings highlight the potential of C. cineraria to produce bioactive compounds for managing parasitic weeds and prompt further studies on its sesquiterpene lactones as tools in developing natural product-based herbicides.
RESUMEN
Huntington disease (HD) is a neurodegenerative disease caused by expansion of CAG repeats in the huntingtin (Htt) gene. The expression of hMTH1, the human hydrolase that degrades oxidized purine nucleoside triphosphates, grants protection in a chemical HD mouse model in which HD-like features are induced by the mitochondrial toxin 3-nitropropionic acid (3-NP). To further examine the relationship between oxidized dNTPs and HD-like neurodegeneration, we studied the effects of hMTH1 expression in a genetic cellular model for HD, such as striatal cells expressing mutant htt (Hdh(Q111)). hMTH1 expression protected these cells from 3-NP and H2O2-induced killing, by counteracting the mutant htt-dependent increased vulnerability and accumulation of nuclear and mitochondrial DNA 8-hydroxyguanine levels. hMTH1 expression reverted the decreased mitochondrial membrane potential characteristic of Hdh(Q111) cells and delayed the increase in mitochondrial reactive oxygen species associated with 3-NP treatment. Further indications of hMTH1-mediated mitochondrial protection are the partial reversion of 3-NP-induced alterations in mitochondrial morphology and the modulation of DRP1 and MFN1 proteins, which control fusion/fission rates of mitochondria. Finally, in line with the in vitro findings, upon 3-NP in vivo treatment, 8-hydroxyguanine levels in mitochondrial DNA from heart, muscle and brain are significantly lower in transgenic hMTH1-expressing mice than in wild-type animals.
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Enzimas Reparadoras del ADN/metabolismo , Enfermedad de Huntington/fisiopatología , Mitocondrias/fisiología , Monoéster Fosfórico Hidrolasas/metabolismo , Animales , Encéfalo/patología , Encéfalo/fisiopatología , Muerte Celular/efectos de los fármacos , Muerte Celular/fisiología , Línea Celular , Células Cultivadas , ADN Mitocondrial/metabolismo , Modelos Animales de Enfermedad , Humanos , Proteína Huntingtina , Enfermedad de Huntington/patología , Peróxido de Hidrógeno/toxicidad , Potencial de la Membrana Mitocondrial/fisiología , Ratones Transgénicos , Mitocondrias/patología , Músculo Esquelético/metabolismo , Mutación , Miocardio/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Nitrocompuestos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Propionatos/toxicidad , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Dothiorella species are fungal plant pathogens associated with Botryosphaeria dieback of grapevine. Symptoms caused by these fungi on grapevines suggest possible implication of phytotoxic metabolites in the infection mechanisms. However, few studies were conducted to investigate the secondary metabolism of these fungi. In this study, 6-methylpyridione analogues were isolated and identified for the first time in liquid cultures of Dothiorella sarmentorum isolated from symptomatic grapevine in Algeria.
RESUMEN
BACKGROUND: Antiretroviral therapy has increasingly improved management of HIV infection, ensuring long-term efficacy and tolerability. Each class of antiretrovirals has, however, different characteristics and different tolerability profiles. The literature data show that protease inhibitors (PIs) are associated with a higher incidence of dyslipidemia. The aim of our study was to evaluate whether patients treated with PIs have both greater dyslipidemia and increased intima media thickness (IMT) and atheromatous plaques compared to patients treated without PIs. MATERIALS AND METHODS: A total of 110 HIV-experienced patients screened with Doppler ultrasonography of the supra-aortic trunks in December 2019 were enrolled in a retrospective cross-sectional observational study. Patients were divided into two groups: 59 in the PI-based group, treated with PIs, and 51 in the PI-sparing group. In the two groups, we evaluated lipids, cardiovascular risk factors (smoking, BMI, age, hypertension), increased pathological IMT (a value > 1 mm), and possible atheromatous plaque. RESULTS: Serum LDL (p 0.04) and percentage of patients with hypercholesterolemia (p 0.03) were higher in the PI-based than in the PI-sparing group. Doppler data showed a trend in increase of IMT > 1 in the PI-based group, which appeared statistically significant for the section of the left common carotid artery (p 0.03). However, in multivariate logistic regression models, none of the evaluated variables were significantly associated with IMT > 1. CONCLUSIONS: Our real-life data show that patients treated with PIs have a trend of developing both greater dyslipidemia and increased pathological IMT and atheromatous plaques These findings may be useful to optimize antiretrovirals for patients with cardiovascular risk factors.
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Alternaria alternata is one of the most devastating phytopathogenic fungi. This microorganism causes black spots in many fruits and vegetables worldwide, generating significant post-harvest losses. In this study, an A. alternata strain, isolated from infected pears (Pyrus communis) harvested in Italy, was characterized by focusing on its pathogenicity mechanisms and competitive exclusion in the presence of another pathogen, Botrytis cinerea. In in vitro assays, the fungus produces strong enzymatic activities such as amylase, xylanase, and cellulase, potentially involved during the infection. Moreover, it secretes four different toxins purified and identified as altertoxin I, alteichin, alternariol, and alternariol 4-methyl ether. Only alteichin generated necrotic lesions on host-variety pears, while all the compounds showed moderate to slight necrotic activity on non-host pears and other non-host fruit (lemon, Citrus limon), indicating they are non-host toxins. Interestingly, A. alternata has shown competitive exclusion to the competitor fungus Botrytis cinerea when co-inoculated in host and non-host pear fruits, inhibiting its growth by 70 and 65%, respectively, a result not observed in a preliminary characterization in a dual culture assay. Alteichin and alternariol 4-methyl ether tested against B. cinerea had the best inhibition activity, suggesting that the synergism of these toxins and enzymatic activities of A. alternata are probably involved in the competitive exclusion dynamics in host and non-host pear fruits.
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The purpose of this qualitative study was to analyse nurses' professional dignity in their everyday working lives. We explored the factors that affect nursing professional dignity in practice that emerge in relationships with health professionals, among clinical nurses working in hospitals and in community settings in central Italy. The main themes identified were: (i) nursing professional dignity perceived as an achievement; (ii) recognition of dignity beyond professional roles. These two concepts are interconnected. This study provides insights into professional dignity in nursing being perceived as an achievement linked to the intrinsic dignity of every human being. The 'nursing professional dignity perceived as an achievement' was perceived as having declined in different social factors. Some factors of nursing professional dignity perceived as an achievement were attained more easily in community settings. 'Recognition of dignity beyond professional roles' underpins the intrinsic dignity as an expression of humanity, embedded in persons regardless of any profession, and values, such as: respect, moral integrity, humility, working conscientiously and kindness.
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Logro , Enfermería en Salud Comunitaria/ética , Educación en Enfermería/ética , Relaciones Interprofesionales/ética , Enfermeras Clínicas/psicología , Personeidad , Desarrollo de Personal/ética , Lugar de Trabajo/psicología , Adulto , Competencia Clínica , Enfermería en Salud Comunitaria/educación , Educación en Enfermería/normas , Femenino , Grupos Focales , Humanos , Italia , Masculino , Persona de Mediana Edad , Enfermeras Clínicas/estadística & datos numéricos , Autonomía Profesional , Rol Profesional/psicología , Investigación Cualitativa , Desarrollo de Personal/normas , Encuestas y CuestionariosRESUMEN
Several human neurodegenerative disorders are characterized by the accumulation of 8-oxo-7,8-dihydroguanine (8-oxodG) in the DNA of affected neurons. This can occur either through direct oxidation of DNA guanine or via incorporation of the oxidized nucleotide during replication. Hydrolases that degrade oxidized purine nucleoside triphosphates normally minimize this incorporation. hMTH1 is the major human hydrolase. It degrades both 8-oxodGTP and 8-oxoGTP to the corresponding monophosphates. To investigate whether the incorporation of oxidized nucleic acid precursors contributes to neurodegeneration, we constructed a transgenic mouse in which the human hMTH1 8-oxodGTPase is expressed. hMTH1 expression protected embryonic fibroblasts and mouse tissues against the effects of oxidants. Wild-type mice exposed to 3-nitropropionic acid develop neuropathological and behavioural symptoms that resemble those of Huntington's disease. hMTH1 transgene expression conferred a dramatic protection against these Huntington's disease-like symptoms, including weight loss, dystonia and gait abnormalities, striatal degeneration, and death. In a complementary approach, an in vitro genetic model for Huntington's disease was also used. hMTH1 expression protected progenitor striatal cells containing an expanded CAG repeat of the huntingtin gene from toxicity associated with expression of the mutant huntingtin. The findings implicate oxidized nucleic acid precursors in the neuropathological features of Huntington's disease and identify the utilization of oxidized nucleoside triphosphates by striatal cells as a significant contributor to the pathogenesis of this disorder.
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Cuerpo Estriado/metabolismo , Guanina/análogos & derivados , Enfermedad de Huntington/metabolismo , Enfermedades Neurodegenerativas/metabolismo , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Daño del ADN , Enzimas Reparadoras del ADN/genética , Enzimas Reparadoras del ADN/metabolismo , ADN Complementario/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Embrión de Mamíferos/metabolismo , Fibroblastos/metabolismo , Guanina/metabolismo , Humanos , Proteína Huntingtina , Enfermedad de Huntington/genética , Ratones , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Enfermedades Neurodegenerativas/genética , Nitrocompuestos/toxicidad , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Monoéster Fosfórico Hidrolasas/genética , Monoéster Fosfórico Hidrolasas/metabolismo , Propionatos/toxicidad , Células Madre/metabolismoRESUMEN
MUTYH-associated polyposis (MAP) is a colorectal cancer syndrome, due to biallelic mutations of MUTYH. This Base Excision Repair gene encodes for a DNA glycosylase that specifically mitigates the high mutagenic potential of the 8-hydroxyguanine (8-oxodG) along the DNA. Aim of this study was to characterize the biological effects, in a mammalian cell background, of human MUTYH mutations identified in MAP patients (137insIW [c.411_416dupATGGAT; p.137insIleTrp]; R171W [c.511C>T; p.Arg171Trp]; E466del [c.1395_1397delGGA; p.Glu466del]; Y165C [c.494A>G; p.Tyr165Cys]; and G382D [c.1145G>A; p.Gly382Asp]). We set up a novel assay in which the human proteins were expressed in Mutyh(-/-) mouse defective cells. Several parameters, including accumulation of 8-oxodG in the genome and hypersensitivity to oxidative stress, were then used to evaluate the consequences of MUTYH expression. Human proteins were also obtained from Escherichia coli and their glycosylase activity was tested in vitro. The cell-based analysis demonstrated that all MUTYH variants we investigated were dysfunctional in Base Excision Repair. In vitro data complemented the in vivo observations, with the exception of the G382D mutant, which showed a glycosylase activity very similar to the wild-type protein. Our cell-based assay can provide useful information on the significance of MUTYH variants, improving molecular diagnosis and genetic counseling in families with mutations of uncertain pathogenicity.
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Poliposis Adenomatosa del Colon/enzimología , Poliposis Adenomatosa del Colon/genética , ADN Glicosilasas/genética , Pruebas de Enzimas/métodos , Fibroblastos/enzimología , Predisposición Genética a la Enfermedad , Mutación/genética , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Bromatos/farmacología , Muerte Celular/efectos de los fármacos , Muerte Celular/efectos de la radiación , Línea Celular , ADN Glicosilasas/aislamiento & purificación , Reparación del ADN/efectos de los fármacos , Reparación del ADN/efectos de la radiación , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Fibroblastos/efectos de los fármacos , Fibroblastos/efectos de la radiación , Técnica del Anticuerpo Fluorescente , Rayos gamma , Humanos , Cinética , Ratones , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Transporte de Proteínas/efectos de los fármacos , Transporte de Proteínas/efectos de la radiaciónRESUMEN
Oxidative DNA damage can be the consequence of endogenous metabolic processes and exogenous insults and several DNA repair enzymes provide protection against the toxic effects of oxidized DNA bases. Here we review the increasing knowledge on the relationship between an oxidized dNTPs pool and genome instability. The review also describes some important progress toward understanding the role of oxidative DNA damage and its repair in neurodegenerative diseases. In particular the hMTH1 hydrolase destroys oxidized nucleic acid precursors to prevent their harmful incorporation into DNA and RNA. Based on results obtained in our transgenic mouse overexpressing hMTH1 in the brain we discussed the mechanisms by which this hydrolase protects against neurodegeneration in Huntington disease models.
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Nucleótidos de Desoxiguanina/metabolismo , Inestabilidad Genómica , Enfermedades Neurodegenerativas/metabolismo , Nucleótidos de Purina/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Animales , Daño del ADN , Reparación del ADN , Enzimas Reparadoras del ADN/metabolismo , Humanos , Estrés Oxidativo , Monoéster Fosfórico Hidrolasas/metabolismoRESUMEN
Background: The medication process in the Neonatal Intensive Care Unit (NICU), can be challenging in terms of costs, time, and the risk of errors. Newborns, especially if born preterm, are more vulnerable to medication errors than adults. Recently, robotic medication compounding has reportedly improved the safety and efficiency of the therapeutic process. In this study, we analyze the advantages of using the I.V. Station® system in our NICU, compared to the manual preparation of injectable drugs in terms of accuracy, cost, and time. Method: An in vitro experimental controlled study was conducted to analyze 10 injectable powdered or liquid drugs. Accuracy was calculated within a 5% difference of the bottle weight during different stages of preparation (reconstitution, dilution, and final product). The overall cost of manual and automated preparations were calculated and compared. Descriptive statistics for each step of the process are presented as mean ± standard deviation or median (range). Results: The median error observed during reconstitution, dilution, and final therapy of the drugs prepared by the I.V. Station® ranged within ±5% accuracy, with narrower ranges of error compared to those prepared manually. With increasing preparations, the I.V. Station® consumed less materials, reduced costs, decreased preparation time, and optimized the medication process, unlike the manual method. In the 10 drugs analyzed, the time saved from using the I.V. Station® ranged from 16 s for acyclovir to 2 h 57 min for teicoplanin, and cost savings varied from 8% for ampicillin to 66% for teicoplanin. These advantages are also capable of continually improving as the total amount of final product increases. Conclusions: The I.V. Station® improved the therapeutic process in our NICU. The benefits included increased precision in drug preparation, improved safety, lowered cost, and saved time. These advantages are particularly important in areas such as the NICU, where the I.V. Station® could improve the delivery of the high complexity of care and a large amount of intravenous therapy typically required. In addition, these benefits may lead to the reduction in medication errors and improve patient and family care; however, additional studies will be required to confirm this hypothesis.
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Oxidation is a common form of DNA damage to which purines are particularly susceptible. We previously reported that oxidized dGTP is potentially an important source of DNA 8-oxodGMP in mammalian cells and that the incorporated lesions are removed by DNA mismatch repair (MMR). MMR deficiency is associated with a mutator phenotype and widespread microsatellite instability (MSI). Here, we identify oxidized deoxynucleoside triphosphates (dNTPs) as an important cofactor in this genetic instability. The high spontaneous hprt mutation rate of MMR-defective msh2(-/-) mouse embryonic fibroblasts was attenuated by expression of the hMTH1 protein, which degrades oxidized purine dNTPs. A high level of hMTH1 abolished their mutator phenotype and restored the hprt mutation rate to normal. Molecular analysis of hprt mutants showed that the presence of hMTH1 reduced the incidence of mutations in all classes, including frameshifts, and also implicated incorporated 2-oxodAMP in the mutator phenotype. In hMSH6-deficient DLD-1 human colorectal carcinoma cells, overexpression of hMTH1 markedly attenuated the spontaneous mutation rate and reduced MSI. It also reduced the incidence of -G and -A frameshifts in the hMLH1-defective DU145 human prostatic cancer cell line. Our findings indicate that incorporation of oxidized purines from the dNTP pool may contribute significantly to the extreme genetic instability of MMR-defective human tumors.
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Daño del ADN , Enzimas Reparadoras del ADN , Reparación del ADN/genética , Desoxirribonucleótidos/metabolismo , Inestabilidad Genómica , Oxidación-Reducción , Animales , Secuencia de Bases , Ratones , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Monoéster Fosfórico Hidrolasas/genética , Monoéster Fosfórico Hidrolasas/metabolismoRESUMEN
Oxidative DNA damage is one of the most common threats to genome stability and DNA repair enzymes provide protection from the effects of oxidized DNA bases. In mammalian cells, base excision repair (BER) mediated by the OGG1 and MYH DNA glycosylases prevents the accumulation of 8-oxoguanine (8-oxoG) in DNA. When steady-state levels of DNA 8-oxoG were measured in myh(-/-) and myh(-/-)/ogg1(-/-) mice, an age-dependent accumulation of the oxidized purine was found in lung and small intestine of doubly defective myh(-/-)/ogg1(-/-) mice. Since there is an increased incidence of lung and small intestinal cancer in myh(-/-)/ogg1(-/-) mice, these findings are consistent with a causal role for unrepaired oxidized DNA bases in cancer development. We previously presented in vitro evidence that mismatch repair (MMR) participates in the repair of oxidative DNA damage and msh2(-/-) mouse embryo fibroblasts also have increased steady state levels of DNA 8-oxoG. To investigate whether DNA 8-oxoG also accumulates in vivo, basal levels were measured in several organs of 4-month-old msh2(-/-) mice and their wild-type counterparts. Msh2(-/-) mice had significantly increased levels of DNA 8-oxoG in spleen, heart, liver, lung, kidney and possibly small intestine but not in bone marrow, thymus or brain. The tissue-specificity of DNA 8-oxoG accumulation in msh2(-/-) and other DNA repair defective mice suggests that DNA protection of different organs is mediated by different combinations of repair pathways.
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Reparación del ADN/fisiología , Guanina/análogos & derivados , Animales , Daño del ADN , ADN Glicosilasas/deficiencia , ADN Glicosilasas/genética , Reparación del ADN/genética , Guanina/metabolismo , Humanos , Ratones , Ratones Noqueados , Proteína 2 Homóloga a MutS/deficiencia , Proteína 2 Homóloga a MutS/genética , Oxidación-ReducciónRESUMEN
DNA polymerase (Pol) beta null mouse embryonic fibroblasts provide a useful cell system to investigate the effects of alterations in base excision repair (BER) on genome stability. These cells are characterized by hypersensitivity to the cytotoxic effects of methyl methanesulfonate (MMS) and by decreased repair of the MMS-induced DNA single strand breaks (SSB). Here, we show that, in the absence of Pol beta, SSB accumulate in G1 phase cells, accompanied by the formation of proliferating cell nuclear antigen foci in the nuclei. When replicating Pol beta null cells are treated with MMS, a rapid phosphorylation of histone H2AX is detected in the nuclei of S phase cells, indicating that double strand breaks (DSB) are formed in response to unrepaired SSB. This is followed by relocalization within the nuclei of Rad51 protein, which is essential for homologous recombination (HR). These findings are compatible with a model where, in mammalian cells, unrepaired SSB produced during BER are substrates for the HR pathway via DSB formation. This is an example of a coordinated effort of two different repair pathways, BER and HR, to protect mammalian cells from alkylation-induced cytotoxicity.