143 research outputs found

    Brucella abortus–infected platelets modulate the activation of neutrophils

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    Brucellosis is a contagious disease caused by bacteria of the genus Brucella. Platelets (PLTs) have been widely involved in the modulation of the immune response. We have previously reported the modulation of Brucella abortus–mediated infection of monocytes. As a result, PLTs cooperate with monocytes and increase their inflammatory capacity, promoting the resolution of the infection. Extending these results, in this study we demonstrate that patients with brucellosis present slightly elevated levels of complexes between PLTs and both monocytes and neutrophils. We then assessed whether PLTs were capable of modulating functional aspects of neutrophils. The presence of PLTs throughout neutrophil infection increased the production of interleukin‐8, CD11b surface expression and reactive oxygen species formation, whereas it decreased the expression of CD62L, indicating an activated status of these cells. We next analyzed whether this modulation was mediated by released factors. To discriminate between these options, neutrophils were treated with supernatants collected from B. abortus–infected PLTs. Our results show that CD11b expression was induced by soluble factors of PLTs but direct contact between cell populations was needed to enhance the respiratory burst. Additionally, B. abortus–infected PLTs recruit polymorphonuclear (PMN) cells to the site of infection. Finally, the presence of PLTs did not modify the initial invasion of PMN cells by B. abortus but improved the control of the infection at extended times. Altogether, our results demonstrate that PLTs interact with neutrophils and promote a proinflammatory phenotype which could also contribute to the resolution of the infection.Fil: Trotta, Aldana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Milillo, MarĂ­a AyelĂ©n. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Serafino, Agustina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Castillo Montañez, Luis Alejandro. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Birnberg Weiss, Federico. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Delpino, MarĂ­a Victoria. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de InmunologĂ­a, GenĂ©tica y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de InmunologĂ­a, GenĂ©tica y Metabolismo; ArgentinaFil: Giambartolomei, Guillermo Hernan. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de InmunologĂ­a, GenĂ©tica y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de InmunologĂ­a, GenĂ©tica y Metabolismo; ArgentinaFil: FernĂĄndez, Cecilia Gabriela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Barrionuevo, Paula. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

    Early and late skin reactions to radiotherapy for breast cancer and their correlation with radiation-induced DNA damage in lymphocytes

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    INTRODUCTION: Radiotherapy outcomes might be further improved by a greater understanding of the individual variations in normal tissue reactions that determine tolerance. Most published studies on radiation toxicity have been performed retrospectively. Our prospective study was launched in 1996 to measure the in vitro radiosensitivity of peripheral blood lymphocytes before treatment with radical radiotherapy in patients with breast cancer, and to assess the early and the late radiation skin side effects in the same group of patients. We prospectively recruited consecutive breast cancer patients receiving radiation therapy after breast surgery. To evaluate whether early and late side effects of radiotherapy can be predicted by the assay, a study was conducted of the association between the results of in vitro radiosensitivity tests and acute and late adverse radiation effects. METHODS: Intrinsic molecular radiosensitivity was measured by using an initial radiation-induced DNA damage assay on lymphocytes obtained from breast cancer patients before radiotherapy. Acute reactions were assessed in 108 of these patients on the last treatment day. Late morbidity was assessed after 7 years of follow-up in some of these patients. The Radiation Therapy Oncology Group (RTOG) morbidity score system was used for both assessments. RESULTS: Radiosensitivity values obtained using the in vitro test showed no relation with the acute or late adverse skin reactions observed. There was no evidence of a relation between acute and late normal tissue reactions assessed in the same patients. A positive relation was found between the treatment volume and both early and late side effects. CONCLUSION: After radiation treatment, a number of cells containing major changes can have a long survival and disappear very slowly, becoming a chronic focus of immunological system stimulation. This stimulation can produce, in a stochastic manner, late radiation-related adverse effects of varying severity. Further research is warranted to identify the major determinants of normal tissue radiation response to make it possible to individualize treatments and improve the outcome of radiotherapy in cancer patients

    Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

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    Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

    The impact of positive psychological interventions on well-being in healthy elderly people

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    This systematic review aims to evaluate the impact of Positive Psychological Interventions (PPIs) on well-being in healthy older adults. Systematic review of PPIs obtained from three electronic databases (PsycINFO, Scopus, and Web of Science) was undertaken. Inclusion criteria were: that they were positive psychology intervention, included measurement of well-being, participants were aged over 60 years, and the studies were in English. The Cochrane Collaboration Guidelines dimensions of quality control, randomization, comparability, follow-up rate, dropout, blinding assessors are used to rate the quality of studies by two reviewers independently. The RE-AIM (Reach, Efficacy, Adoption, Implementation, and Maintenance) for evaluation of PPIs effectiveness was also applied. The final review included eight articles, each describing a positive psychological intervention study. The reminiscence interventions were the most prevalent type of PPIs to promote and maintain well-being in later life. Only two studies were rated as high quality, four were of moderate-quality and two were of low-quality. Overall results indicated that efficacy criteria (89%), reach criteria (85%), adoption criteria (73%), implementation criteria (67%), and maintenance criteria (4%) across a variety of RE-AIM dimensions. Directions for future positive psychological research related to RE-AIM, and implications for decision-making, are described

    Exploring the Gain of Function Contribution of AKT to Mammary Tumorigenesis in Mouse Models

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    Elevated expression of AKT has been noted in a significant percentage of primary human breast cancers, mainly as a consequence of the PTEN/PI3K pathway deregulation. To investigate the mechanistic basis of the AKT gain of function-dependent mechanisms of breast tumorigenesis, we explored the phenotype induced by activated AKT transgenes in a quantitative manner. We generated several transgenic mice lines expressing different levels of constitutively active AKT in the mammary gland. We thoroughly analyzed the preneoplastic and neoplastic mammary lesions of these mice and correlated the process of tumorigenesis to AKT levels. Finally, we analyzed the impact that a possible senescent checkpoint might have in the tumor promotion inhibition observed, crossing these lines to mammary specific p53(R172H) mutant expression, and to p27 knock-out mice. We analyzed the benign, premalignant and malignant lesions extensively by pathology and at molecular level analysing the expression of proteins involved in the PI3K/AKT pathway and in cellular senescence. Our findings revealed an increased preneoplastic phenotype depending upon AKT signaling which was not altered by p27 or p53 loss. However, p53 inactivation by R172H point mutation combined with myrAKT transgenic expression significantly increased the percentage and size of mammary carcinoma observed, but was not sufficient to promote full penetrance of the tumorigenic phenotype. Molecular analysis suggest that tumors from double myrAKT;p53(R172H) mice result from acceleration of initiated p53(R172H) tumors and not from bypass of AKT-induced oncogenic senescence. Our work suggests that tumors are not the consequence of the bypass of senescence in MIN. We also show that AKT-induced oncogenic senescence is dependent of pRb but not of p53. Finally, our work also suggests that the cooperation observed between mutant p53 and activated AKT is due to AKT-induced acceleration of mutant p53-induced tumors. Finally, our work shows that levels of activated AKT are not essential in the induction of benign or premalignant tumors, or in the cooperation of AKT with other tumorigenic signal such as mutant p53, once AKT pathway is activated, the relative level of activity seems not to determine the phenotype

    Baixa percepção de risco entre adolescentes espanhóis em relação ao consumo de ålcool

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    SegĂșn los estudios recientes, los adolescentes españoles muestran una baja percepciĂłn del riesgo asociado al consumo de alcohol. El objetivo de la presente investigaciĂłn es analizar los factores que favorecen esta baja percepciĂłn a partir de la opiniĂłn de un grupo de 32 profesionales/expertos en adolescencia, familia, escuela, medios de comunicaciĂłn y polĂ­ticas locales. Se utilizĂł una metodologĂ­a cualitativa, fundamentada en Grounded Theory, a partir de la informaciĂłn obtenida mediante 5 grupos de discusiĂłn guiados por entrevistas semiestructuradas. Se identificaron 12 factores o subcategorĂ­as agrupados en 4 categorĂ­as generales: riesgo a corto plazo, inmediatez y percepciĂłn de invulnerabilidad (categorĂ­a Âżpensamiento adolescenteÂż); concepciĂłn benĂ©vola del alcohol, normalizaciĂłn del consumo y binomio alcohol-diversiĂłn (categorĂ­a Âżnormas socialesÂż); consumo habitual en los padres, inconsistencia verbal-no verbal en el modelado parental, consumo sin riesgo en los medios, consumo con resultados positivos en los medios (categorĂ­a Âżmodelos socialesÂż); excesivo contenido sanitario, riesgo a largo plazo (categorĂ­a Âżdiscurso preventivoÂż). Tras discutir los resultados en el contexto de la literatura cientĂ­fica actual, se realizan varias propuestas con el objetivo de aumentar la percepciĂłn del riesgo en los adolescentes: incidir con mayor fuerza en contenidos sobre los riesgos a corto plazo del alcohol; orientar las estrategias educativas dirigidas al adolescente, tambiĂ©n hacia los agentes de socializaciĂłn, especialmente los padres; incidir en polĂ­ticas centradas en la sustancia y en reducir la oferta.According to recent studies, Spanish adolescents show low perception of risk in alcohol consumption. The current study aims to analyze the factors that favor this low perception based on the opinion of a group of 32 professional experts on adolescence, family, school, mass media, and local policies. A qualitative methodology was used, based on Grounded Theory, using information from 5 focus groups guided by semi-structured interviews. Twelve factors or subcategories were identified, grouped in 4 general categories: short-term risk, immediacy, and perception of invulnerability (Âżadolescent thinkingÂż category); benevolent view of alcohol, normalization of consumption, and alcohol-entertainment binomial (Âżsocial normsÂż category); parentsÂż habitual consumption, verbal/non-verbal inconsistency in parental model, risk-free consumption depicted in the mass media, consumption with positive results in the media (Âżsocial modelsÂż category); and excessive health content, long-term risk (Âżpreventive discourseÂż category). After discussing the results in the context of the current scientific literature, the article offers various proposals for increasing risk perception in adolescents: stronger impact of contents on short-term risks of alcohol; educational strategies targeted to adolescents to include agents of socialization, especially parents; and policies centered on the substance and reduction of supply.De acordo com estudos recentes, os adolescentes espanhĂłis mostram baixa percepção de risco em relação ao consumo de ĂĄlcool. O estudo tem como objetivo analisar os fatores associados com a baixa percepção de risco, com base nas opiniĂ”es de um grupo de 32 especialistas em adolescĂȘncia, famĂ­lia, escola, mĂ­dia e polĂ­ticas locais. Foi utilizada uma metodologia qualitativa, baseada na Teoria Fundamentada, usando informaçÔes de cinco grupos focais orientados por entrevistas semi-estruturadas. Foram identificados 12 fatores ou subcategorias, agrupados em quatro categorias gerais: risco no curto prazo, imediatismo e percepção de invulnerabilidade (categoria de Âżpensamento adolescenteÂż); visĂŁo benevolente em relação ao ĂĄlcool, normalização do consumo e binĂŽmio ĂĄlcool-entretenimento (categoria de Âżnormas sociaisÂż); consumo habitual pelos pais, inconsistĂȘncia na comunicação verbal versus nĂŁo verbal no modelo representado pelos pais, consumo isento de risco retratado pela mĂ­dia, consumo com resultados positivos na mĂ­dia (categoria de Âżmodelos sociaisÂż) e excesso de conteĂșdo relacionado Ă  saĂșde, risco no longo prazo (categoria de Âżdiscurso preventivoÂż). Depois de discutir os resultados no contexto da literatura cientĂ­fica atual, o artigo oferece vĂĄrias propostas para aumentar a percepção de risco entre os adolescentes: impacto mais forte de conteĂșdos sobre os riscos do ĂĄlcool no curto prazo; estratĂ©gias educativas orientadas aos adolescentes para incluir os agentes da socialização, especialmente os pais, alĂ©m de polĂ­ticas centradas na substĂąncia e na redução da oferta.Departamento de EducaciĂłn y PsicologĂ­a SocialVersiĂłn del edito

    Successional Change in Phosphorus Stoichiometry Explains the Inverse Relationship between Herbivory and Lupin Density on Mount St. Helens

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    The average nitrogen-to-phosphorus ratio (N?P) of insect herbivores is less than that of leaves, suggesting that P may mediate plant-insect interactions more often than appreciated. We investigated whether succession-related heterogeneity in N and P stoichiometry influences herbivore performance on N-fixing lupin (Lupinus lepidus) colonizing primary successional volcanic surfaces, where the abundances of several specialist lepidopteran herbivores are inversely related to lupin density and are known to alter lupin colonization dynamics. We examined larval performance in response to leaf nutritional characteristics using gelechiid and pyralid leaf-tiers, and a noctuid leaf-cutter.Apple JL, Wink M, Wills SE, Bishop JG (2009) Successional Change in Phosphorus Stoichiometry Explains the Inverse Relationship between Herbivory and Lupin Density on Mount St. Helens. PLoS ONE 4(11): e7807. doi:10.1371/journal.pone.000780

    Pubertal high fat diet: effects on mammary cancer development

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    INTRODUCTION: Epidemiological studies linking dietary fat intake and obesity to breast cancer risk have produced inconsistent results. This may be due to the difficulty of dissociating fat intake from obesity, and/or the lack of defined periods of exposure in these studies. The pubertal mammary gland is highly sensitive to cancer-causing agents. We assessed how high fat diet (HFD) affects inflammation, proliferative, and developmental events in the pubertal gland, since dysregulation of these can promote mammary tumorigenesis. To test the effect of HFD initiated during puberty on tumorigenesis, we utilized BALB/c mice, for which HFD neither induces obesity nor metabolic syndrome, allowing dissociation of HFD effects from other conditions associated with HFD. METHODS: Pubertal BALB/c mice were fed a low fat diet (12% kcal fat) or a HFD (60% kcal fat), and subjected to carcinogen 7,12-dimethylbenz[a]anthracene (DMBA)-induced tumorigenesis. RESULTS: HFD elevated mammary gland expression of inflammatory and growth factor genes at 3 and 4 weeks of diet. Receptor activator of nuclear factor kappa-B ligand (RANKL), robustly induced at 4 weeks, has direct mitogenic activity in mammary epithelial cells and, as a potent inducer of NF-ÎșB activity, may induce inflammatory genes. Three weeks of HFD induced a transient influx of eosinophils into the mammary gland, consistent with elevated inflammatory factors. At 10 weeks, prior to the appearance of palpable tumors, there were increased numbers of abnormal mammary epithelial lesions, enhanced cellular proliferation, increased growth factors, chemokines associated with immune-suppressive regulatory T cells, increased vascularization, and elevated M2 macrophages. HFD dramatically reduced tumor latency. Early developing tumors were more proliferative and were associated with increased levels of tumor-related growth factors, including increased plasma levels of HGF in tumor-bearing animals. Early HFD tumors also had increased vascularization, and more intra-tumor and stromal M2 macrophages. CONCLUSIONS: Taken together in this non-obesogenic context, HFD promotion of inflammatory processes, as well as local and systemically increased growth factor expression, are likely responsible for the enhanced tumorigenesis. It is noteworthy that although DMBA mutagenesis is virtually random in its targeting of genes in tumorigenesis, the short latency tumors arising in animals on HFD showed a unique gene expression profile, highlighting the potent overarching influence of HFD

    A theoretical framework to describe communication processes during medical disability assessment interviews

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    BACKGROUND: Research in different fields of medicine suggests that communication is important in physician-patient encounters and influences satisfaction with these encounters. It is argued that this also applies to the non-curative tasks that physicians perform, such as sickness certification and medical disability assessments. However, there is no conceptualised theoretical framework that can be used to describe intentions with regard to communication behaviour, communication behaviour itself, and satisfaction with communication behaviour in a medical disability assessment context. OBJECTIVE: The objective of this paper is to describe the conceptualization of a model for the communication behaviour of physicians performing medical disability assessments in a social insurance context and of their claimants, in face-to-face encounters during medical disability assessment interviews and the preparation thereof. CONCEPTUALIzATION: The behavioural model, based on the Theory of Planned Behaviour (TPB), is conceptualised for the communication behaviour of social insurance physicians and claimants separately, but also combined during the assessment interview. Other important concepts in the model are the evaluation of communication behaviour (satisfaction), intentions, attitudes, skills, and barriers for communication. CONCLUSION: The conceptualization of the TPB-based behavioural model will help to provide insight into the communication behaviour of social insurance physicians and claimants during disability assessment interviews. After empirical testing of the relationships in the model, it can be used in other studies to obtain more insight into communication behaviour in non-curative medicine, and it could help social insurance physicians to adapt their communication behaviour to their task when performing disability assessment

    Controversies in the management of advanced prostate cancer

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    For advanced prostate cancer, the main hormone treatment against which other treatments are assessed is surgical castration. It is simple, safe and effective, however it is not acceptable to all patients. Medical castration by means of luteinizing hormone-releasing hormone (LH-RH) analogues such as goserelin acetate provides an alternative to surgical castration. Diethylstilboestrol, previously the only non-surgical alternative to orchidectomy, is no longer routinely used. Castration reduces serum testosterone by around 90%, but does not affect androgen biosynthesis in the adrenal glands. Addition of an anti-androgen to medical or surgical castration blocks the effect of remaining testosterone on prostate cells and is termed combined androgen blockade (CAB). CAB has now been compared with castration alone (medical and surgical) in numerous clinical trials. Some trials show advantage of CAB over castration, whereas others report no significant difference. The author favours the view that CAB has an advantage over castration. No study has reported that CAB is less effective than castration. Of the anti-androgens which are available for use in CAB, bicalutamide may be associated with a lower incidence of side-effects compared with the other non-steroidal anti-androgens and, in common with nilutamide, has the advantage of once-daily dosing. Only one study has compared anti-androgens within CAB: bicalutamide plus LH-RH analogue and flutamide plus LH-RH analogue. At 160-week follow-up, the groups were equivalent in terms of survival and time to progression. However, bicalutamide caused significantly less diarrhoea than flutamide. Withdrawal and intermittent therapy with anti-androgens extend the range of treatment options. © 1999 Cancer Research Campaig
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