Dietary patterns of Sonoran breastfeeding women are associated to exclusive or partial breastfeeding regimes / Los patrones dietarios de mujeres sonorenses amamantando se asocian con los regímenes de lactancia exclusiva o parcial

Abstract Background: During breastfeeding, the maternal diet ensures mothers and infants health. Therefore, it is necessary to update information about the diet of exclusively or partially breastfeeding women in each population. We evaluated the diet of Sonoran breastfeeding women, identified their dietary patterns, and examined their association with the breastfeeding regime. Methods: In this cross-sectional study, 62 women breastfeeding exclusively (n = 43) or partially (n = 19) participated. The diet was assessed using a food frequency questionnaire, and patterns were identified through principal component analysis. Results: Overall, fats and sodium intake were higher, while potassium intake was lower than recommended. Two dietary patterns were identified: "regional" (n = 36) and "prudent" (n = 26). Women following the "prudent" pattern consumed more protein, calcium, and potassium than those following the "regional" pattern (p < 0.05). The probability of exclusively breastfeeding women having a "prudent" dietary pattern was higher than that of partially breastfeeding women (adjusted odds ratios = 7.29, p = 0.019). Conclusions: Exclusive breastfeeding possibly motivated mothers to follow a more prudent diet than those who partially breastfed. Therefore, it is crucial to promote a healthy diet among breastfeeding mothers.

Resumen Introducción: Durante el amamantamiento, la dieta garantiza la salud materno-infantil. Por esto, es necesario contar con información actualizada sobre la dieta de quienes amamantan exclusiva o parcialmente en cada población. El objetivo de este trabajo fue evaluar la dieta de mujeres sonorenses amamantando, identificar sus patrones dietarios y buscar su asociación con el régimen de lactancia. Métodos: En este estudio transversal participaron 62 mujeres amamantando de forma exclusiva (n = 43) o parcialmente (n = 19). Se evaluó la dieta con un cuestionario de frecuencia de consumo de alimentos y los patrones se identificaron a través del análisis de componentes principales. Resultados: En general, la ingestión de grasas y sodio fue superior y la de potasio inferior a las cantidades recomendadas. Se identificaron dos patrones dietarios: "regional" (n = 36) y "prudente" (n = 26). Las mujeres con patrón "prudente" ingirieron más proteína, calcio y potasio que las del patrón "regional" (p < 0.05). La probabilidad de que las mujeres que amamantaban en exclusiva siguieran un patrón dietario "prudente" fue mayor que la de aquellas que amamantaban parcialmente (razón de momios ajustada (AOR) = 7.29, p = 0.019). Conclusiones: La lactancia exclusiva posiblemente motivó a las madres a seguir una dieta más prudente que la de aquellas que amamantaban parcialmente. Es necesario promover una dieta saludable entre las madres amamantando.

Immunomodulatory effects of testosterone and letrozole during Plasmodium berghei ANKA infection.

Introduction: Malaria is one of the leading health problems globally. Plasmodium infection causes pronounced sexual dimorphism, and the lethality and severity are more remarkable in males than in females. To study the role of testosterone in the susceptibility and mortality of males in malaria, it is common to increase its concentration. However, this strategy does not consider the enzyme CYP19A1 aromatase, which can transform it into oestrogens. Methods: To avoid the interference of oestrogens, we inhibited in vivo CYP19A1 aromatase with letrozole and increased the testosterone level by exogen administration before infection with Plasmodium berghei ANKA. We measured the impact on free testosterone, 17ß-oestradiol and dehydroepiandrosterone levels in plasma; additionally, we evaluated parasitaemia, body temperature, body mass, glucose levels and haemoglobin concentration. Furthermore, we evaluated the effects of testosterone on the immune response; we quantified the CD3+/CD4+, CD3+/CD8+, CD19+, Mac-3+ and NK cells in the spleen and the plasma concentrations of the cytokines IL-2, IL-4, IL-6, IFN-, IL-10, TNF-α and IL-17A. Finally, we quantified the levels of antibodies. Results: We found that mice treated with the combination of letrozole and testosterone and infected with Plasmodium berghei ANKA had increased concentrations of free testosterone and DHEA but decreased levels of 17ß-oestradiol. As a result, parasitaemia increased, leading to severe anaemia. Interestingly, testosterone increased temperature and decreased glucose concentration as a possible testosterone-mediated regulatory mechanism. The severity of symptomatology was related to critical immunomodulatory effects generated by free testosterone; it selectively increased CD3+CD8+ T and CD19+ cells but decreased Mac-3+. Remarkably, it reduced IL-17A concentration and increased IL-4 and TNF-α. Finally, it increased IgG1 levels and the IgG1/IgG2a ratio. In conclusion, free testosterone plays an essential role in pathogenesis in male mice by increasing CD8+ and decreasing Mac3+ cells and mainly reducing IL-17A levels, which is critical in the development of anaemia. Our results are important for understanding the mechanisms that regulate the exacerbated inflammatory response in infectious diseases and would be useful for the future development of alternative therapies to reduce the mortality generated by inflammatory processes.

Testosterone induces sexual dimorphism during infection with Plasmodium berghei ANKA.

Malaria is the most lethal parasitic disease worldwide; men exhibit higher mortality and more severe symptomatology than women; however, in most studies of immune response in malaria, sex is not considered a variable. Sex hormones 17ß-oestradiol and testosterone are responsible for the main physiological differences between sexes. When interacting with their receptors on different immune cells, they modify the expression of genes that modulate cell proliferation, differentiation, and synthesis of cytokines. The immunosuppressive activity of testosterone is well accepted; however, its participation in the sexual dimorphism of the immune response to malaria has not been studied. In this work, we analysed whether altering the concentration of testosterone, through increasing the concentration of this hormone for exogenous administration for three weeks, or gonadectomy before infection with Plasmodium berghei ANKA affects different cells of the immune response necessary for parasite clearance. We also assessed the concentration of pro-and anti-inflammatory cytokines in male and female CBA/Ca mice infected or not with the parasite. Our results show that testosterone changes affect females more than males, resulting in sex-associated patterns. Testosterone administration increased parasitaemia in intact males while reducing it in intact females leading to a dimorphic pattern. In addition, gonadectomy increased parasitaemia in both sexes. Moreover, testosterone administration prevented both weight loss caused by the infection in females and hypothermia in gonadectomized mice of both sexes. Boosting testosterone concentration increased CD3+ and CD8+ populations but decreased the B220+ cells exclusively in females. Additionally, testosterone reduced IFN-γ concentration and increased IL-6 levels only in females, while in males, testosterone increased the number of NK cells. Finally, gonadectomy decreased TNF-α concentration in both sexes. Our results demonstrate that testosterone induces different patterns depending on sex and testosterone concentration. The results of this work contribute to understanding the impact of modifying testosterone concentration on the immune response specific against Plasmodium and the participation of this hormone in sexual dimorphism in malaria.

Tamoxifen Suppresses the Immune Response to Plasmodium berghei ANKA and Exacerbates Symptomatology.

Malaria is the most lethal parasitic disease in the world. Mortality and severity in symptoms are higher in men than women, suggesting that oestrogens, which are in higher concentration in females than in males, may regulate the immune response against malaria. Tamoxifen, a selective oestrogen receptor modulator used in breast cancer treatment due to its antagonistic effect on oestrogen receptors α and ß, is also studied because of its potential therapeutic use for several parasitic diseases. However, most studies, including one in malaria, have not addressed the immunomodulatory role of tamoxifen. In this work, we evaluated the effect of tamoxifen on the immune response of CBA/Ca mice against Plasmodium berghei ANKA. This study showed for the first time that tamoxifen increased parasite load, aggravated symptoms by decreasing body temperature and body weight, and worsened anaemia. Additionally, tamoxifen significantly increased the splenic index and the percentages of CD4+ and NK+ cells on day eight post-infection. By contrast, tamoxifen decreased both CD8+ and B220+ populations in the spleen and decreased the serum levels of IL-2, IL-6, and IL-17. Our findings support the notion that tamoxifen is a potent immunomodulator in malaria-infected mice and suggest caution when administering it to malaria-infected women with breast cancer.

Planificación del flujo de caja de proyectos de construcción basada en BIM y dinámica de sistemas / Cash flow planning of construction projects based on BIM and system dynamics / Planeamento do fluxo de caixa de projectos de construção baseados em BIM e System Dynamics

RESUMEN La planificación del flujo de caja de un proyecto de construcción es una actividad decisiva para garantizar los recursos financieros que son necesarios para el desarrollo de las actividades de obra. Debido a la importancia, en la industria de la construcción se observa la necesidad de metodologías de análisis de flujo caja de adaptación fácil a las modificaciones, y con altos niveles de detalle, las cuales propicien mejoras en la precisión de las estimaciones y en la anticipación de situaciones problemáticas. Considerando esta necesidad, en este artículo se propone un nuevo esquema metodológico para la planificación del flujo de caja de proyectos de construcción, el cual está basado en la integración de modelos del proceso constructivo BIM 5D (Building Information Modeling 5D), y dinámica de sistemas. El esquema que es propuesto consta de seis etapas principales: 1) modelo BIM 3D, cantidades y rendimientos, 2) estructura desglosada del trabajo, 3) estimación de costos, 4) modelado y simulación digital BIM 5D, 5) análisis del flujo de caja, y 6) implementación de la alternativa. La aplicación del esquema indica que la rapidez, visualización y automatización, con la que se desarrolla la planificación del flujo de caja, propicia el análisis de varias alternativas; lo cual fortalece los procesos de toma de decisiones, y mejora los resultados de la planificación.

ABSTRACT Cash flow planning of a construction project is a crucial activity to guarantee the financial resources necessary for construction activities development. Due to the importance, there is a need for cash flow analysis methodologies that are easy to adapt to modifications and involve high levels of detail, which allow improving precision in estimations and anticipating possible problematic events. Considering this need, this paper proposes a new methodological scheme for cash flow planning of construction projects, which is based on construction process models BIM 5D (Building Information Modeling 5D), and system dynamics. The proposed scheme consists of six main stages: 1) BIM 3D model and quantities, 2) work breakdown structure, 3) cost estimation, 4) BIM 5D digital modeling and simulation, 5) cash flow analysis, and 6) implementation. The application of the proposed scheme indicates that the speed, visualization, and automation, with which the cash flow planning is developed, favors the analysis of several alternatives, which strengthens decision-making processes, and improves planning results.

RESUMO O planeamento do fluxo de caixa de um projecto de construção é uma actividade decisiva para garantir os recursos financeiros necessários para o desenvolvimento das actividades de trabalho. Devido à sua importância, na indústria da construção há necessidade de metodologias de análise de fluxo de caixa que sejam facilmente adaptáveis às mudanças e com elevados níveis de detalhe, que permitam melhorar a precisão das estimativas e a antecipação de situações problemáticas. Considerando esta necessidade, este documento propõe um novo esquema metodológico para o planeamento do fluxo de caixa dos projectos de construção, que se baseia na integração do BIM 5D (Building Information Modeling 5D) e modelos de dinâmica do sistema do processo de construção. O esquema proposto consiste em seis fases principais: 1) modelo BIM 3D, quantidades e desempenhos, 2) estrutura de repartição do trabalho, 3) estimativa de custos, 4) modelação e simulação digital BIM 5D, 5) análise do fluxo de caixa, e 6) implementação da alternativa. A aplicação do esquema indica que a rapidez, visualização e automatização, com a qual o planeamento do fluxo de caixa é desenvolvido, é conducente à análise de várias alternativas; o que reforça os processos de tomada de decisão, e melhora os resultados do planeamento.

17ß-Estradiol Is Involved in the Sexual Dimorphism of the Immune Response to Malaria.

Malaria is the leading cause of parasitic infection-related death globally. Additionally, malaria-associated mortality is higher in men than in women, and this sexual dimorphism reflects differences in innate and adaptive immune responses that are influenced by sex hormones. Normally, females develop more robust immune responses against parasites than males. However, most clinical and laboratory studies related to the immune response to malaria do not consider sex as a variable, and relatively few studies have compared the sex-dependent role of 17ß-estradiol in this process. In this study, we decreased in vivo the levels of 17ß-estradiol by gonadectomy or administered 17ß-estradiol to intact or gonadectomized male and female CBA/Ca mice infected with Plasmodium berghei ANKA. Subsequently, we assessed the effects of 17ß-estradiol on parasite load; the percentages of different immune cells in the spleen; the plasma levels of antibodies and pro- and anti-inflammatory cytokines; and the mRNA expression levels of cytokine-encoding genes in the brain. The results showed that the administration of 17ß-estradiol increased parasitemia and decreased body weight in intact female mice. Moreover, intact females exhibited higher levels of CD8+ T cells and lower levels of NK1.1+ cells than their male counterparts under the same condition. Gonadectomy increased IFN-γ and decreased TNF-α concentrations only in intact female mice. Additionally, IL-10 levels were higher in intact females than in their male counterparts. Finally, the mRNA expression levels of cytokines coding genes in the brain showed a dimorphic pattern, i.e., gonadectomy upregulated Tnf, Il1b, and Il10 expression in males but not in females. Our findings explain the sexual dimorphism in the immune response to malaria, at least in part, and suggest potential sex-dependent implications for the efficacy of vaccines or drugs targeting malaria.

Dimorphic effect of 17ß-oestradiol on pathology and oxidative stress in experimental malaria.

Malaria is the parasitic disease with the highest mortality worldwide; males exhibit higher mortality and more severe symptomatology than females, suggesting the participation of sexual hormones in protection and pathology. We have documented that gonadectomy modifies oxidative stress in Plasmodium berghei ANKA-infected mice in a dimorphic manner. However, gonadectomy decreases all sexual steroids levels, making it difficult to determine the contribution of each hormone to the results. This study aimed to explore the participation of 17ß-oestradiol (E2) in oxidative stress in the blood, spleen, liver and brain of P. berghei-infected female and male mice. E2 was administered to intact or gonadectomized (GX) male and female mice to assess their effects on parasitaemia, body weight loss and hypothermia. We also measured the effect of E2 on the specific activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and on malondialdehyde (MDA) levels in the blood, spleen, liver and brain of CBA/Ca male and female mice infected with P. berghei ANKA. We detected the effects of E2 and sexual dimorphism on all tissues and variables analysed. Administration of E2 increased parasitaemia in intact mice. However, reconstitution of GX female mice with E2 decreased parasitaemia. E2 decreased body weight and differentially modulated oxidative stress depending on the sex, infection and tissue analysed. Low antioxidant activity was detected in the brain, suggesting additional protective antioxidant mechanisms in the brain independent of antioxidant enzymes. Our results explained, at least in part, the sexual dimorphism in this experimental model of malaria.

Laboratory measures of coagulation among trauma patients on NOAs: results of the AAST-MIT.

BACKGROUND: Warfarin is associated with poor outcomes after trauma, an effect correlated with elevations in the international normalized ratio (INR). In contrast, the novel oral anticoagulants (NOAs) have no validated laboratory measure to quantify coagulopathy. We sought to determine if use of NOAs was associated with elevated activated partial thromboplastin time (aPTT) or INR levels among trauma patients or increased clotting times on thromboelastography (TEG). METHODS: This was a post-hoc analysis of a prospective observational study across 16 trauma centers. Patients on dabigatran, rivaroxaban, or apixaban were included. Laboratory data were collected at admission and after reversal. Admission labs were compared between medication groups. Traditional measures of coagulopathy were compared with TEG results using Spearman's rank coefficient for correlation. Labs before and after reversal were also analyzed between medication groups. RESULTS: 182 patients were enrolled between June 2013 and July 2015: 50 on dabigatran, 123 on rivaroxaban, and 34 apixaban. INR values were mildly elevated among patients on dabigatran (median 1.3, IQR 1.1-1.4) and rivaroxaban (median 1.3, IQR 1.1-1.6) compared with apixaban (median 1.1, IQR 1.0-1.2). Patients on dabigatran had slightly higher than normal aPTT values (median 35, IQR 29.8-46.3), whereas those on rivaroxaban and apixaban did not. Fifty patients had TEG results. The median values for R, alpha, MA and lysis were normal for all groups. Prothrombin time (PT) and aPTT had a high correlation in all groups (dabigatran p=0.0005, rivaroxaban p<0.0001, and apixaban p<0.0001). aPTT correlated with the R value on TEG in patients on dabigatran (p=0.0094) and rivaroxaban (p=0.0028) but not apixaban (p=0.2532). Reversal occurred in 14%, 25%, and 18% of dabigatran, rivaroxaban, and apixaban patients, respectively. Both traditional measures of coagulopathy and TEG remained within normal limits after reversal. DISCUSSION: Neither traditional measures of coagulation nor TEG were able to detect coagulopathy in patients on NOAs. LEVEL OF EVIDENCE: Level IV.

Planificación de recursos humanos a partir de la simulación del proceso constructivo en modelos BIM 5D / Planning of human resources from the simulation of the construction process in BIM 5D models / Planejamento de recursos humanos a partir da simulação do processo construtivo em modelos BIM 5D

RESUMEN La planificación de recursos humanos de un proyecto de construcción es una actividad de gran importancia para el desarrollo exitoso de este tipo de actividades. Resulta una labor zcompleja que requiere de herramientas y metodologías automatizadas que permiten la optimización de variables relacionadas con tiempo y costos. Building Information Modeling (BIM) es una base de datos digital que proporciona una réplica virtual del proceso constructivo a partir de cinco variables: i) el tiempo; ii) el costo; y tres dimensiones: x, y z; el modelo se conoce como BIM 5D. En este artículo se propone una metodología para la planificación de recursos humanos que tome como referencia la simulación del proceso constructivo BIM 5D. Se expone un conjunto de técnicas para la planificación del recurso humano en proyectos de construcción y se realiza la planificación de un caso de estudio a partir del enfoque BIM 5D. Con base en los resultados se formaliza un método para el diseño de la planificación del recurso humano. Comparado con otras metodologías, la propuesta presenta ventajas como la automatización del proceso y la posibilidad para la evaluación de distintas alternativas en tiempos reducidos.

ABSTRACT The human resources planning of a construction project is an activity of great importance for the successful development of construction activities. It is a complex task that requires automated tools and methodologies that allow the optimization of variables related to time and costs. Building Information Modeling (BIM) is a digital database that allows to obtain a virtual replication constructive process from five variables: i) time; ii) costs; and three dimensions x, y, z; model that is known as BIM 5D. In this paper it proposes a methodology for the planning of human resources based on the simulation of the BIM 5D construction processes. A set of techniques for the planning of the human resource in construction projects is presented and planning of a case study is carried out from the BIM 5D approach. Taking in account the results, it formalized a method for human resource planning. Compared to other methodologies, it presents advantages such as automation and the possibility of evaluating different alternatives in reduced times.

RESUMO O planejamento de recursos humanos de um projeto de construção é uma atividade de grande importância para o desenvolvimento bem-su-cedido deste tipo de atividades. É uma tarefa complexa que requer ferramentas e metodologias automatizadas que permitem a otimização de variáveis relacionadas com tempo e custos. Building Information Modeling (BIM), em português, Modelagem da Informação da Construção, é um banco de dados digital que fornece uma réplica virtual do processo de construção com base em cinco variáveis: i) tempo; ii) o custo; e três dimensões: x, y, z; o modelo é conhecido como BIM 5D. Este artigo propõe uma metodologia para o planejamento de recursos humanos que toma como referência a simulação do processo de construção do BIM 5D. Expõe-se um conjunto de técnicas para o planejamento de recursos humanos em projetos de construção e realiza-se o planejamento de um estudo de caso com base na abordagem BIM 5D. baseado nos resultados, formaliza-se um método para o planejamento de recursos humanos. Em comparação com outras metodologias, a proposta apresenta vantagens como automatização do processo e a possibilidade de avaliação de diferentes alternativas em tempos reduzidos.

An AAST-MITC analysis of pancreatic trauma: Staple or sew? Resect or drain?

INTRODUCTION: Pancreatic trauma results in high morbidity and mortality, in part caused by the delay in diagnosis and subsequent organ dysfunction. Optimal operative management strategies remain unclear. We therefore sought to determine CT accuracy in diagnosing pancreatic injury and the morbidity and mortality associated with varying operative strategies. METHODS: We created a multicenter, pancreatic trauma registry from 18 Level 1 and 2 trauma centers. Adult, blunt or penetrating injured patients from 2005 to 2012 were analyzed. Sensitivity and specificity of CT scan identification of main pancreatic duct injury was calculated against operative findings. Independent predictors for mortality, adult respiratory distress syndrome (ARDS), and pancreatic fistula and/or pseudocyst were identified through multivariate regression analysis. The association between outcomes and operative management was measured. RESULTS: We identified 704 pancreatic injury patients of whom 584 (83%) underwent a pancreas-related procedure. CT grade modestly correlated with OR grade (r 0.39) missing 10 ductal injuries (9 grade III, 1 grade IV) providing 78.7% sensitivity and 61.6% specificity. Independent predictors of mortality were age, Injury Severity Score (ISS), lactate, and number of packed red blood cells transfused. Independent predictors of ARDS were ISS, Glasgow Coma Scale score, and pancreatic fistula (OR 5.2, 2.6-10.1). Among grade III injuries (n = 158, 22.4%), the risk of pancreatic fistula/pseudocyst was reduced when the end of the pancreas was stapled (OR 0.21, 95% CI 0.05-0.9) compared with sewn and was not affected by duct stitch placement. Drainage alone in grades IV (n = 25) and V (n = 24) injuries carried increased risk of pancreatic fistula/pseudocyst (OR 8.3, 95% CI 2.2-32.9). CONCLUSION: CT is insufficiently sensitive to reliably identify pancreatic duct injury. Patients with grade III injuries should have their resection site stapled instead of sewn and a duct stitch is unnecessary. Further study is needed to determine if drainage alone should be employed in grades IV and V injuries. LEVEL OF EVIDENCE: Epidemiologic/Diagnostic study, level III.

Novel oral anticoagulants and trauma: The results of a prospective American Association for the Surgery of Trauma Multi-Institutional Trial.

BACKGROUND: The number of anticoagulated trauma patients is increasing. Trauma patients on warfarin have been found to have poor outcomes, particularly after intracranial hemorrhage (ICH). However, the effect of novel oral anticoagulants (NOAs) on trauma outcomes is unknown. We hypothesized that patients on NOAs would have higher rates of ICH, ICH progression, and death compared with patients on traditional anticoagulant and antiplatelet agents. METHODS: This was a prospective observational trial across 16 trauma centers. Inclusion criteria was any trauma patient admitted on aspirin, clopidogrel, warfarin, dabigatran, rivaroxaban, or apixaban. Demographic data, admission vital signs, mechanism of injury, injury severity scores, laboratory values, and interventions were collected. Outcomes included ICH, progression of ICH, and death. RESULTS: A total of 1,847 patients were enrolled between July 2013 and June 2015. Mean age was 74.9 years (SD ± 13.8), 46% were female, 77% were non-Hispanic white. At least one comorbidity was reported in 94% of patients. Blunt trauma accounted for 99% of patients, and the median Injury Severity Score was 9 (interquartile range, 4-14). 50% of patients were on antiplatelet agents, 33% on warfarin, 10% on NOAs, and 7% on combination therapy or subcutaneous agents.Patients taking NOAs were not at higher risk for ICH on univariate (24% vs. 31%) or multivariate analysis (incidence rate ratio, 0.78; confidence interval 0.61-1.01, p = 0.05). Compared with all other agents, patients on aspirin (90%, 81 mg; 10%, 325 mg) had the highest rate (35%) and risk (incidence rate ratio, 1.27; confidence interval, 1.13-1.43; p < 0.001) of ICH. Progression of ICH occurred in 17% of patients and was not different between medication groups. Study mortality was 7% and was not significantly different between groups on univariate or multivariate analysis. CONCLUSION: Patients on NOAs were not at higher risk for ICH, ICH progression, or death. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III.

Bortezomib reverses a post-translational mechanism of tumorigenesis for patched1 haploinsufficiency in medulloblastoma.

BACKGROUND: Tumor initiation has been attributed to haploinsufficiency at a single locus for a large number of cancers. Patched1 (Ptc1) was one of the first such loci, and Ptc1 haploinsufficiency has been asserted to lead to medulloblastoma and rhabdomyosarcoma in mice. PROCEDURE: To study the role of Ptc1 in cerebellar tumor development and to create a preclinical therapeutic platform, we have generated a conditional Ptc1 haploinsufficiency model of medulloblastoma by inactivating Ptc1 in Pax7-expressing cells of the cerebellum. RESULTS: These mice developed exclusively medulloblastoma. We show that despite the presence of transcription of Ptc1, Ptc1 protein is nearly undetectable or absent in tumors. Our results suggest that Ptc1 loss of function is complete, but achieved at the protein level rather than by the classic genetic two-hit mechanism or a strict half-dosage genetic haploinsufficiency mechanism. Furthermore, we found that bortezomib, a 26S proteasome inhibitor, had a significant anti-tumor activity in vitro and in vivo, which was accompanied by restoration of Ptc1 protein and downregulation of the hedgehog signaling pathway. The same effect was seen for both human and mouse medulloblastoma tumor cell growth. CONCLUSIONS: These results suggest that proteasome inhibition is a potential new therapeutic approach in medulloblastoma.

Role of the promyelocytic leukemia body in the dynamic interaction between the androgen receptor and steroid receptor coactivator-1 in living cells.

The dynamic interaction between the androgen receptor (AR) and steroid receptor coactivator-1 (SRC-1) was explored in living cells expressing chimeric forms of the receptor and the coactivator containing two spectral variants of jellyfish fluorescent protein. Laser scanning confocal imaging of transfected cells expressing fluorescently labeled SRC-1 revealed that in an unsynchronized cell population, the coactivator is distributed in approximately 40% cells as nuclear bodies of 0.2-1.0 microm in diameter. Immunostaining of cyan fluorescent protein-labeled SRC-1 (CFP-SRC1)-expressing cells with antibody to promyelocytic leukemia (PML) protein showed significant overlap of the CFP fluorescence with the antibody stain. Cotransfection of cells with a plasmid expressing the CFP conjugate of Sp100 (another marker protein for the PML nuclear body) also showed colocalization of the yellow fluorescent protein (YFP)-SRC1 containing nuclear foci with the PML bodies in living cells. Analysis of the three-dimensional structure revealed that the PML bodies are round to elliptical in shape with multiple satellite bodies on their surface. Some of these satellite bodies contain the SRC-1. Activation and nuclear import of CFP-AR by the agonistic ligand 5alpha-dihydrotestosterone, but not by the antagonist casodex, transferred YFP-SRC1 from the PML bodies to an interlacing filamentous structure. In a single living cell, agonist-activated AR caused a time-dependent movement of YFP-SRC1 from the PML bodies to this filamentous structure. Additionally, coexpression of a constitutively active mutant of AR (AR-deltaligand binding domain) also displaced YFP-SRC1 from the PML bodies to this intranuclear filamentous structure. The fluorescence recovery after photobleaching approach was used to examine changes in the kinetics of movement of YFP-SRC1 during its mobilization from the PML bodies to the intranuclear filamentous structure by the agonist-activated AR. Results of the relative half-times (t(1/2)) of replacement of YFP-SRC1 within the photobleached region of a single PML body from its surrounding nuclear space supported the conclusion that SRC-1 is actively transported from the PML bodies to the intranuclear filamentous structure by the ligand-activated AR. This observation also suggests an interaction between AR and SRC-1 before its binding to the target gene. The PML bodies have been implicated as a cross-road for multiple regulatory pathways that control cell proliferation, cellular senescence, and apoptosis. Our present results along with other recent reports expand the role of this subnuclear structure to include the regulation of steroid hormone action.