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1.
J Cell Mol Med ; 27(2): 222-231, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36545841

RESUMEN

Incidence of Malignant Melanoma has become the 5th in the UK. To date, the major anticancer therapeutics include cell therapy, immunotherapy, gene therapy and nanotechnology-based strategies. Recently, extracellular vesicles, especially exosomes, have been highlighted for their therapeutic benefits in numerous chronic diseases. Exosomes display multifunctional properties, including inhibition of cancer cell proliferation and initiation of apoptosis. In the present in vitro study, the antitumour effect of cord blood stem cell (CBSC)-derived exosomes was confirmed by the CCK-8 assay (p < 0.05) on CHL-1 melanoma cells and improve the repair mechanism on lymphocytes from melanoma patients. Importantly, no significant effect was observed in healthy lymphocytes when treated with the exosome concentrations at 24, 48 and 72 h. Comet assay results (OTM and %Tail DNA) demonstrated that the optimal exosome concentration showed a significant impact (p < 0.05) in lymphocytes from melanoma patients whilst causing no significant DNA damage in lymphocytes of healthy volunteers was 300 µg/ml. Similarly, the Comet assay results depicted significant DNA damage in a melanoma cell line (CHL-1 cells) treated with CBSC-derived exosomes, both the cytotoxicity of CHL-1 cells treated with CBSC-derived exosomes exhibited a significant time-dependent decrease in cell survival. Sequencing analysis of CBSC exosomes showed the presence of the let-7 family of miRNAs, including let-7a-5p, let-7b-5p, let-7c-5p, let-7d-3p, let-7d-5p and two novel miRNAs. The potency of CBSC exosomes in inhibiting cancer progression in lymphocytes from melanoma patients and CHL-1 cells whilst causing no harm to the healthy lymphocytes makes it a potential candidate as an anticancer therapy.


Asunto(s)
Exosomas , Vesículas Extracelulares , Melanoma , MicroARNs , Humanos , Exosomas/metabolismo , Sangre Fetal/metabolismo , MicroARNs/metabolismo , Melanoma/genética , Vesículas Extracelulares/metabolismo , Células Madre/metabolismo , Melanoma Cutáneo Maligno
2.
J Appl Res Intellect Disabil ; 35(1): 112-122, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34297441

RESUMEN

BACKGROUND: The aim was to pilot an adapted manualised weight management programme for persons with mild-moderate intellectual disabilities affected by overweight or obesity ('Shape Up-LD'). METHOD: Adults with intellectual disabilities were enrolled in a 6-month trial (3-month active intervention and 3-month follow-up) and were individually randomised to Shape Up-LD or a usual care control. Feasibility outcomes included recruitment, retention, initial effectiveness and cost. RESULTS: Fifty people were enrolled. Follow-up rates were 78% at 3 months and 74% at 6 months. At 3 and 6 months, controlling for baseline weight, no difference was observed between groups (3 months: ß: -0.34, 95% confidence interval [CI]: -2.38, 1.69, 6 months: ß: -0.55, 95%CI -4.34, 3.24). CONCLUSION: It may be possible to carry out a trial of Shape Up-LD, although barriers to recruitment, carer engagement and questionnaire completion need to be addressed, alongside refinements to the intervention.


Asunto(s)
Discapacidad Intelectual , Programas de Reducción de Peso , Adulto , Estudios de Factibilidad , Humanos , Discapacidad Intelectual/terapia , Sobrepeso/terapia , Aumento de Peso
3.
Drug Metab Rev ; 53(4): 604-617, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33989097

RESUMEN

The field of nanotechnology has allowed for increasing nanoparticle (NP) exposure to the male reproductive system. Certain NPs have been reported to have adverse consequences on male germ and somatic cells. Germ cells are the bridge between generations and are responsible for the transmission of genetic and epigenetic information to future generations. A number of NPs have negative impacts on male germ and somatic cells which could ultimately affect fertility or the ability to produce healthy offspring. These impacts are related to NP composition, modification, concentration, agglomeration, and route of administration. NPs can induce severe toxic effects on the male reproduction system after passing through the blood-testis barrier and ultimately damaging the spermatozoa. Therefore, understanding the impacts of NPs on reproduction is necessary. This review will provide a comprehensive overview on the current state of knowledge derived from the previous in vivo and in vitro research on effects of NPs on the male reproductive system at the genetic, cellular, and molecular levels.


Asunto(s)
Nanopartículas , Genitales Masculinos , Humanos , Masculino , Nanopartículas/toxicidad , Nanotecnología , Reproducción
4.
Arch Toxicol ; 95(1): 337-343, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33128380

RESUMEN

Evading apoptosis and chemo-resistance are considered as very important factors which help tumour progression and metastasis. Hence, to overcome chemo-resistance, there is an urgent requirement for emergence of more effective treatment options. Myricetin, a naturally occurring flavonoid, is present in various plant-derived foods and shows antitumour potential in different cancers. In the present in vitro study, results from the comet assay demonstrated that myricetin bulk (10 µM) and nano (20 µM) forms exhibited a non-significant level of genotoxicity in lymphocytes from multiple myeloma patients when compared to those from healthy individuals. Western blot results showed a decrease in Bcl-2/Bax ratio and an increase in P53 protein levels in lymphocytes from myeloma patients, but not in lymphocytes from healthy individuals. A significant increase in intracellular reactive oxygen species level was also observed, suggesting that regulation of apoptotic proteins triggered by myricetin exposure in lymphocytes from myeloma patients occurred through P53 and oxidative stress-dependent pathways. The potency of myricetin against lymphocytes from myeloma patients marks it a potential candidate to be considered as an alternative to overcome chemo-resistance in cancer therapies.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Flavonoides/farmacología , Linfocitos/efectos de los fármacos , Mieloma Múltiple/tratamiento farmacológico , Nanopartículas , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Células Cultivadas , Resistencia a Antineoplásicos , Femenino , Humanos , Linfocitos/metabolismo , Linfocitos/patología , Masculino , Persona de Mediana Edad , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Estrés Oxidativo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteína X Asociada a bcl-2/metabolismo
5.
JAAPA ; 34(6): 20-25, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34031309

RESUMEN

ABSTRACT: Narcolepsy continues to be a significantly underdiagnosed/misdiagnosed condition worldwide. According to the National Institutes of Health (NIH), an estimated 135,000 to 200,000 patients in the United States are living with narcolepsy. However, due to the number of patients who either do not seek medical advice for their symptoms or receive an incorrect initial diagnosis at onset, this number may be higher. This article reviews the different subtypes of narcolepsy along with the pathophysiology, screening guidelines, clinical features, diagnosis, and management of the disorder. Educational awareness from a healthcare and patient standpoint can enhance early detection and accurate diagnosis of narcolepsy and improve patient quality of life.


Asunto(s)
Narcolepsia , Calidad de Vida , Errores Diagnósticos , Diagnóstico Precoz , Humanos , Narcolepsia/diagnóstico , Narcolepsia/terapia
6.
J Toxicol Environ Health B Crit Rev ; 23(3): 91-106, 2020 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-32046612

RESUMEN

Male germ stem cells are responsible for transmission of genetic information to the next generation. Some chemicals exert a negative impact on male germ cells, either directly, or indirectly affecting them through their action on somatic cells. Ultimately, these effects might inhibit fertility, and may exhibit negative consequences on future offspring. Genotoxic anticancer agents may interact with DNA in germ cells potentially leading to a heritable germline mutation. Experimental information in support of this theory has not always been reproducible and suitable in vivo studies remain limited. Thus, alternative male germ cell tests, which are now able to detect phase specificity of such agents, might be used by regulatory agencies to help evaluate the potential risk of mutation. However, there is an urgent need for such approaches for identification of male reproductive genotoxins since this area has until recently been dependent on in vivo studies. Many factors drive alternative approaches, including the (1) commitment to the principles of the 3R's (Replacement, Reduction, and Refinement), (2) time-consuming nature and high cost of animal experiments, and (3) new opportunities presented by new molecular analytical assays. There is as yet currently no apparent appropriate model of full mammalian spermatogenesis in vitro, under the REACH initiative, where new tests introduced to assess genotoxicity and mutagenicity need to avoid unnecessary testing on animals. Accordingly, a battery of tests used in conjunction with the high throughput STAPUT gravity sedimentation was recently developed for purification of male germ cells to investigate genotoxicity for phase specificity in germ cells. This system might be valuable for the examination of phases previously only available in mammals with large-scale studies of germ cell genotoxicity in vivo. The aim of this review was to focus on this alternative approach and its applications as well as on chemicals of known in vivo phase specificities used during this test system development.


Asunto(s)
Células Germinativas/efectos de los fármacos , Pruebas de Mutagenicidad/métodos , Mutágenos/toxicidad , Animales , Apoptosis/efectos de los fármacos , Daño del ADN/efectos de los fármacos , Mutación de Línea Germinal/efectos de los fármacos , Humanos , Técnicas In Vitro , Masculino , Mutagénesis/efectos de los fármacos , Medición de Riesgo , Sensibilidad y Especificidad
7.
Arch Toxicol ; 94(4): 1229-1239, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32107588

RESUMEN

We investigated the protective role of myricetin bulk and nanoforms, against reactive oxygen species (ROS)-induced oxidative stress caused by hydrogen peroxide and tertiary-butyl hydro peroxide in lymphocytes in vitro from healthy individuals and those from pre-cancerous patients suffering with monoclonal gammopathy of undetermined significance (MGUS). The change in intracellular reactive oxygen species was measured once cells were treated with myricetin bulk forms and nanoforms with and without either hydrogen peroxide or tertiary-butyl hydro peroxide co-supplementation. The direct and indirect antioxidant activity of myricetin was spectrofluometrically measured using the fluorescent dye 2',7'-dichlorofluorescin diacetate and using the Comet assay, respectively. Hydrogen peroxide (50 µM) and tertiary-butyl hydro peroxide (300 µM) induced a higher level of reactive oxygen species-related DNA damage and strand breaks. Addition of myricetin nanoform (20 µM) and bulk (10 µM) form could, however, significantly prevent hydrogen peroxide- and tertiary-butyl hydro peroxide-induced oxidative imbalances and the nanoform was more effective. Glutathione levels were also quantified using a non-fluorescent dye. Results suggest that myricetin treatment had no significant effect on the cellular antioxidant enzyme, glutathione. The current study also investigates the effect of myricetin on the induction of double-strand breaks by staining the gamma-H2AX foci immunocytochemically. It was observed that myricetin does not induce double-strand breaks at basal levels rather demonstrated a protective effect.


Asunto(s)
Antioxidantes/farmacología , Flavonoides/farmacología , Linfocitos/fisiología , Gammopatía Monoclonal de Relevancia Indeterminada , Especies Reactivas de Oxígeno/toxicidad , Ensayo Cometa , Daño del ADN , Glutatión , Humanos , Peróxido de Hidrógeno , Oxidación-Reducción , Estrés Oxidativo
8.
Arch Toxicol ; 94(7): 2349-2357, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32342131

RESUMEN

2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) is a central dietary mutagen, produced when proteinaceous food is heated at very high temperatures potentially causing DNA strand breaks. This study investigates the protective potential of a well-researched flavonoid, myricetin in its bulk and nano-forms against oxidative stress induced ex vivo/in vitro by PhIP in lymphocytes from pre-cancerous monoclonal gammopathy of undetermined significance (MGUS) patients and those from healthy individuals. The results from the Comet assay revealed that in the presence of myricetin bulk (10 µM) and myricetin nano (20 µM), the DNA damage caused by a high dose of PhIP (100 µM) was significantly (P < 0.001) reduced in both groups. However, nano has shown better protection in lymphocytes from pre-cancerous patients. Consistent results were obtained from the micronucleus assay where micronuclei frequency in binucleated cells significantly decreased upon supplementing PhIP with myricetin bulk (P < 0.01) and myricetin nano (P < 0.001), compared to the PhIP treatment alone. To briefly determine the cellular pathways involved in the protective role of myricetin against PhIP, we studied gene expression of P53 and ATR kinase (ATM- and Rad3-related), using the real-time PCR technique.


Asunto(s)
Antimutagênicos/farmacología , Daño del ADN/efectos de los fármacos , Flavonoides/farmacología , Imidazoles/toxicidad , Linfocitos/efectos de los fármacos , Micronúcleos con Defecto Cromosómico/efectos de los fármacos , Gammopatía Monoclonal de Relevancia Indeterminada/sangre , Mutágenos/toxicidad , Nanopartículas , Adulto , Anciano , Anciano de 80 o más Años , Antioxidantes/farmacología , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Ensayo Cometa , Femenino , Humanos , Linfocitos/metabolismo , Linfocitos/patología , Masculino , Micronúcleos con Defecto Cromosómico/inducido químicamente , Pruebas de Micronúcleos , Persona de Mediana Edad , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal , Proteína p53 Supresora de Tumor/metabolismo , Adulto Joven
9.
J Gen Intern Med ; 34(2): 312-316, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30361916

RESUMEN

The volume and rigor of evidence-based design have increasingly grown over the last three decades since the field's inception, supporting research-based designs to improve patient outcomes. This movement of using evidence from engineering and the hard sciences is not necessarily new, but design-based health research launched with the demonstration that post-operative patients with window views towards nature versus a brick wall yielded shorter lengths of hospital stay and less analgesia use, promoting subsequent investigations and guideline development. Architects continue to base healthcare design decisions on credible research, with a recent shift in physician involvement in the design process by introducing clinicians to design-thinking methodologies. In parallel, architects are becoming familiar with research-based practice, allowing for further rigor and clinical partnership. This cross-pollination of fields could benefit from further discussion surrounding the ethics of hospital architecture as applied to current building codes and guidelines. Historical precedents where the building was used as a form of treatment can inform future concepts of ethical design practice when applied to current population health challenges, such as design for dementia care. While architecture itself does not necessarily provide a cure, good design can act as a preventative tool and enhance overall quality of care.


Asunto(s)
Accesibilidad Arquitectónica/métodos , Arquitectura y Construcción de Hospitales/métodos , Hospitales , Principios Morales , Accesibilidad Arquitectónica/normas , Toma de Decisiones , Arquitectura y Construcción de Hospitales/normas , Hospitales/normas , Humanos
10.
Environ Res ; 166: 10-15, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29807314

RESUMEN

Chronic obstructive pulmonary disease (COPD) in humans, describes a group of lung conditions characterised by airflow limitation that is poorly reversible. The airflow limitation usually progresses slowly and is related to an abnormal inflammatory response of the lung to toxic particles. COPD is characterised by oxidative stress and an increased risk of lung carcinoma. The 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) is one of a number of mutagenic/carcinogenic heterocyclic amines found mainly in well-cooked meats which are thus part of the regular diet. Antioxidants are very important in order to protect the cells against oxidative damage. The aim of the present study was to assess the effects of IQ on the level of DNA damage and susceptibility to a potent mutagen in peripheral blood cells of COPD patients. DNA damage and the frequency of micronuclei (MNi) were evaluated using the Comet and micronucleus assays, respectively. Differential expressions of both mRNA and protein of the endogenous antioxidant enzyme catalase were evaluated with quantitative polymerase chain reaction (qPCR) and Western blot analysis, respectively. Furthermore, the effect of bulk and nano forms of quercetin and their combination with IQ were examined. Results of the present study clearly demonstrated that MNi frequency in the peripheral blood lymphocytes exhibited a positive correlation with the DNA damage as evident from the different Comet assay parameters. Increase of the endogenous antioxidant catalase also showed there was a stimulation of this enzyme system by IQ. Whereas, the endogenous antioxidant quercetin significantly reduced oxidative stress in COPD patients and healthy individuals.


Asunto(s)
Daño del ADN , Mutágenos/toxicidad , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Quercetina/farmacología , Quinolonas/toxicidad , Catalasa/análisis , Ensayo Cometa , Humanos , Linfocitos , Pruebas de Micronúcleos , Estrés Oxidativo
11.
Risk Anal ; 38(7): 1321-1331, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29240986

RESUMEN

Societies worldwide are investing considerable resources into the safe development and use of nanomaterials. Although each of these protective efforts is crucial for governing the risks of nanomaterials, they are insufficient in isolation. What is missing is a more integrative governance approach that goes beyond legislation. Development of this approach must be evidence based and involve key stakeholders to ensure acceptance by end users. The challenge is to develop a framework that coordinates the variety of actors involved in nanotechnology and civil society to facilitate consideration of the complex issues that occur in this rapidly evolving research and development area. Here, we propose three sets of essential elements required to generate an effective risk governance framework for nanomaterials. (1) Advanced tools to facilitate risk-based decision making, including an assessment of the needs of users regarding risk assessment, mitigation, and transfer. (2) An integrated model of predicted human behavior and decision making concerning nanomaterial risks. (3) Legal and other (nano-specific and general) regulatory requirements to ensure compliance and to stimulate proactive approaches to safety. The implementation of such an approach should facilitate and motivate good practice for the various stakeholders to allow the safe and sustainable future development of nanotechnology.

12.
Crit Care Nurs Q ; 41(1): 60-67, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29210767

RESUMEN

Advanced informatics systems can help improve health care delivery and the environment of care for critically ill patients. However, identifying, testing, and deploying advanced informatics systems can be quite challenging. These processes often require involvement from a collaborative group of health care professionals of varied disciplines with knowledge of the complexities related to designing the modern and "smart" intensive care unit (ICU). In this article, we explore the connectivity environment within the ICU, middleware technologies to address a host of patient care initiatives, and the core informatics concepts necessary for both the design and implementation of advanced informatics systems.


Asunto(s)
Unidades de Cuidados Intensivos/organización & administración , Informática Médica/instrumentación , Informática Médica/tendencias , Seguridad del Paciente/normas , Cuidados Críticos/organización & administración , Monitoreo del Ambiente/instrumentación , Monitoreo del Ambiente/métodos , Diseño de Equipo/normas , Humanos , Unidades de Cuidados Intensivos/tendencias , Interfaz Usuario-Computador
13.
Crit Care Nurs Q ; 41(1): 3-9, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29210762

RESUMEN

There is controversy today about whether decentralized intensive care unit (ICU) designs featuring alcoves and multiple sites for charting are effective. There are issues relating to travel distance, visibility of patients, visibility of staff colleagues, and communications among caregivers, along with concerns about safety risk. When these designs became possible and popular, many ICU designs moved away from the high-visibility circular, semicircular, or box-like shapes and began to feature units with more linear shapes and footprints similar to acute bed units. Critical care nurses on the new, linear units have expressed concerns. This theory and opinion article relies upon field observations in unrelated research studies and consulting engagements, along with material from the relevant literature. It leads to a challenging hypothesis that criticism of decentralized charting alcoves may be misplaced, and that the associated problem may stem from corridor design and unit size in contemporary ICU design. The authors conclude that reliable data from research investigations are needed to confirm the anecdotal reports of nurses. If problems are present in current facilities, organizations may wish to consider video monitoring, expanded responsibilities in the current buddy system, and use of greater information sharing during daily team huddles. New designs need to involve nurses and carefully consider these issues.


Asunto(s)
Enfermería de Cuidados Críticos/métodos , Arquitectura y Construcción de Hospitales/tendencias , Política , Comunicación , Humanos , Unidades de Cuidados Intensivos/organización & administración , Seguridad del Paciente , Recursos Humanos
14.
Mutagenesis ; 32(5): 517-524, 2017 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-29040706

RESUMEN

Chemotherapy drugs usually inflict a lethal dose to tumour cells with the consequence that these cells are being killed by cell death. However, each round of chemotherapy also causes damage to normal somatic cells. The DNA cross-linking agent oxaliplatin (OXP), which causes DNA double-strand breaks, and vinflunine (VFN), which disrupts the mitotic spindle, are two of these chemotherapy drugs which were evaluated in vitro using peripheral lymphocytes from colorectal cancer patients and healthy individuals to determine any differential response. Endpoints examined included micronucleus (MN) induction using the cytokinesis-blocked micronucleus (CBMN) assay and pancentromeric fluorescence in situ hybridisation. Also, survivin expression was monitored since it regulates the mitotic spindle checkpoint and inhibits apoptosis. OXP produced cytogenetic damage (micronuclei in binucleated cells) via its clastogenic but also previously unknown aneugenic action, possibly through interfering with topoisomerase II, whilst VFN produced micronuclei in mononucleated cells because of incomplete karyokinesis. Survivin expression was found to be significantly reduced in a concentration-dependent manner by not only OXP but surprisingly also VFN. This resulted in large numbers of multinucleated cells found with the CBMN assay. As survivin is upregulated in cancers, eliminating apoptosis inhibition might provide a more targeted chemotherapy approach; particularly, when considering VFN, which only affects cycling cells by inhibiting their mitotic spindle, and alongside possibly other pro-apoptotic compounds. Hence, these newly found properties of VFN -the inhibition of survivin expression-might demonstrate a promising chemotherapeutic approach as VFN induces less DNA damage in normal somatic cells compared to other chemotherapeutic compounds.


Asunto(s)
Neoplasias del Colon/tratamiento farmacológico , Proteínas Inhibidoras de la Apoptosis/efectos de los fármacos , Linfocitos/efectos de los fármacos , Micronúcleos con Defecto Cromosómico/inducido químicamente , Compuestos Organoplatinos/efectos adversos , Vinblastina/análogos & derivados , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Regulación de la Expresión Génica , Humanos , Hibridación Fluorescente in Situ , Proteínas Inhibidoras de la Apoptosis/genética , Linfocitos/metabolismo , Masculino , Pruebas de Micronúcleos , Mutágenos/efectos adversos , Mutágenos/uso terapéutico , Compuestos Organoplatinos/uso terapéutico , Oxaliplatino , Survivin , Vinblastina/efectos adversos , Vinblastina/uso terapéutico
16.
J Am Chem Soc ; 137(23): 7371-8, 2015 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-25946518

RESUMEN

Experiments and density functional calculations were used to quantify the impact of the Pd-Ti interaction in the cationic heterobimetallic Cl2Ti(N(t)BuPPh2)2Pd(η(3)-methallyl) catalyst 1 used for allylic aminations. The catalytic significance of the Pd-Ti interaction was evaluated computationally by examining the catalytic cycle for catalyst 1 with a conformation where the Pd-Ti interaction is intact versus one where the Pd-Ti interaction is severed. Studies were also performed on the relative reactivity of the cationic monometallic (CH2)2(N(t)BuPPh2)2Pd(η(3)-methallyl) catalyst 2 where the Ti from catalyst 1 was replaced by an ethylene group. These computational and experimental studies revealed that the Pd-Ti interaction lowers the activation barrier for turnover-limiting amine reductive addition and accelerates catalysis up to 10(5). The Pd-Ti distance in 1 is the result of the N(t)Bu groups enforcing a boat conformation that brings the two metals into close proximity, especially in the transition state. The turnover frequency of classic Pd π allyl complexes was compared to that of 1 to determine the impact of P-Pd-P coordination angle and ligand electronic properties on catalysis. These experiments identified that cationic (PPh3)2Pd(η(3)-CH2C(CH3)CH2) catalyst 3 performs similarly to 1 for allylic aminations with diethylamine. However, computations and experiment reveal that the apparent similarity in reactivity is due to very fast reaction kinetics. The higher reactivity of 1 versus 3 was confirmed in the reaction of methallyl chloride and 2,2,6,6-tetramethylpiperidine (TMP). Overall, experiments and calculations demonstrate that the Pd-Ti interaction induces and is responsible for significantly lower barriers and faster catalysis for allylic aminations.

17.
FASEB J ; 28(10): 4563-70, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25063845

RESUMEN

Lymphocyte responses from 208 individuals: 20 with melanoma, 34 with colon cancer, and 4 with lung cancer (58), 18 with suspected melanoma, 28 with polyposis, and 10 with COPD (56), and 94 healthy volunteers were examined. The natural logarithm of the Olive tail moment (OTM) was plotted for exposure to UVA through 5 different agar depths (100 cell measurements/depth) and analyzed using a repeated measures regression model. Responses of patients with cancer plateaued after treatment with different UVA intensities, but returned toward control values for healthy volunteers. For precancerous conditions and suspected cancers, intermediate responses occurred. ROC analysis of mean log OTMs, for cancers plus precancerous/suspect conditions vs. controls, cancer vs. precancerous/suspect conditions plus controls, and cancer vs. controls, gave areas under the curve of 0.87, 0.89, and 0.93, respectively (P<0.001). Optimization allowed test sensitivity or specificity to approach 100% with acceptable complementary measures. This modified comet assay could represent a stand-alone test or an adjunct to other investigative procedures for detecting cancer.


Asunto(s)
Detección Precoz del Cáncer/métodos , Genoma Humano , Linfocitos/efectos de la radiación , Neoplasias/diagnóstico , Tolerancia a Radiación , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Interpretación Estadística de Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Rayos Ultravioleta
18.
Mutagenesis ; 30(2): 237-45, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25381309

RESUMEN

Zinc oxide (ZnO) nanoparticles are the mostly used engineered metal oxide nanoparticles in consumer products. This has increased the likelihood of human exposure to this engineered nanoparticle (ENPs) through different routes. At present, the majority of the studies concerning ZnO ENPs toxicity have been conducted using in vitro and in vivo systems. In this study, for the first time we assessed the effect of ZnO ENPs on the major cellular pathways in the lymphocytes of healthy individuals as well as in susceptible patients suffering from lung cancer, chronic obstructive pulmonary disease (COPD) and asthma. Using the differential expression analysis, we observed a significant (P < 0.05) dose-dependent (10, 20 and 40 µg/ml for 6h) increase in the expression of tumour suppressor protein p53 (40, 60 and 110%); Ras p21 (30, 52 and 80%); c-Jun N-terminal kinases; JNKs) (28, 47 and 78%) in lung cancer patient samples treated with ZnO ENPs compared to healthy controls. A similar trend was also seen in COPD patient samples where a significant (P < 0.05) dose-dependent increase in the expression of tumour suppressor protein p53 (26, 45 and 84%), Ras p21 (21, 40 and 77%), JNKs (17, 32 and 69%) was observed after 6h of ZnO ENPs treatment at the aforesaid concentrations. However, the increase in the expression profile of tested protein was not significant in the asthma patients as compared to controls. Our results reiterate the concern about the safety of ZnO ENPs in consumer products and suggest the need for a complete risk assessment of any new ENPs before its use.


Asunto(s)
Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Nanopartículas del Metal/toxicidad , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Enfermedades Respiratorias/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Óxido de Zinc/toxicidad , Adulto , Anciano , Anciano de 80 o más Años , Asma/metabolismo , Células Cultivadas , Femenino , Humanos , Neoplasias Pulmonares/metabolismo , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/metabolismo
20.
Mutagenesis ; 29(6): 393-400, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25296962

RESUMEN

The use of biomarkers of early genetic effects, predictive for cancer, such as micronuclei (MN) in lymphocytes, may help to investigate the association between diet and cancer. We hypothesised that the presence of mutagens in the diet may increase MN formation. A 'pooled' standardised analysis was performed by applying the same experimental protocol for the cytokinesis block micronucleus assay in 625 young healthy women after delivery from five European study populations (Greece, Denmark, UK, Spain and Norway). We assessed MN frequencies in mono- and binucleated T-lymphocytes (MNMONO and MNBN) and the cytokinesis blocked proliferation index using a semi-automated image analysis system. Food frequency questionnaires (FFQs) were used to estimate intake of fatty acids and a broad range of immunotoxic and genotoxic/carcinogenic compounds through the diet. Pooled difference based on delivery type revealed higher MNMONO frequencies in caesarean than in vaginal delivery (P = 0.002). Statistical analysis showed a decrease in MNMONO frequencies with increasing calculated omega-6 PUFA concentrations and a decrease in MNBN frequencies with increasing calculated omega-3 PUFA concentrations. The expected toxic compounds estimated by FFQs were not associated with MN formation in mothers after delivery. In pregnant women, an omega-3 and -6 rich diet estimated by FFQ is associated with lower MN formation during pregnancy and delivery.


Asunto(s)
Dieta , Conducta Alimentaria , Micronúcleos con Defecto Cromosómico , Encuestas y Cuestionarios , Población Blanca , Adulto , Proliferación Celular/efectos de los fármacos , Estudios de Cohortes , Citocinesis/efectos de los fármacos , Femenino , Humanos , Modelos Lineales , Persona de Mediana Edad , Mutágenos/toxicidad , Embarazo , Linfocitos T/metabolismo
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