40 research outputs found
Current State of Preeclampsia Mouse Models: Approaches, Relevance, and Standardization
Preeclampsia (PE) is a multisystemic, pregnancy-specific disorder and a leading cause of maternal and fetal death. PE is also associated with an increased risk for chronic morbidities later in life for mother and offspring. Abnormal placentation or placental function has been well-established as central to the genesis of PE; yet much remains to be determined about the factors involved in the development of this condition. Despite decades of investigation and many clinical trials, the only definitive treatment is parturition. To better understand the condition and identify potential targets preclinically, many approaches to simulate PE in mice have been developed and include mixed mouse strain crosses, genetic overexpression and knockout, exogenous agent administration, surgical manipulation, systemic adenoviral infection, and trophoblast-specific gene transfer. These models have been useful to investigate how biological perturbations identified in human PE are involved in the generation of PE-like symptoms and have improved the understanding of the molecular mechanisms underpinning the human condition. However, these approaches were characterized by a wide variety of physiological endpoints, which can make it difficult to compare effects across models and many of these approaches have aspects that lack physiological relevance to this human disorder and may interfere with therapeutic development. This report provides a comprehensive review of mouse models that exhibit PE-like symptoms and a proposed standardization of physiological characteristics for analysis in murine models of PE
Sequential and Batch Processing Methods of the EBP Learning Algorithm
Placental abnormalities can cause Pregnancy-Associated Disorders, including preeclampsia, intrauterine growth restriction, and placental insufficiency, resulting in complications for both the mother and fetus. Trophoblast cells within the labyrinthine layer of the placenta facilitate the exchange of nutrients, gases, and waste between mother and fetus; therefore, the development of this cell layer is critical for fetal development. As trophoblast cells differentiate, it is assumed their metabolism changes with their energy requirements. We hypothesize that proper regulation of trophoblast metabolism is a key component of normal placental development; therefore, we examined the role of AMP-activated kinase (AMPK, PRKAA1/2), a sensor of cellular energy status. Our previous studies have shown that AMPK knockdown alters both trophoblast differentiation and nutrient transport. In this study, AMPKα1/2 shRNA was used to investigate the metabolic effects of AMPK knockdown on SM10 placental labyrinthine progenitor cells before and after differentiation. Extracellular flux analysis confirmed that AMPK knockdown was sufficient to reduce trophoblast glycolysis, mitochondrial respiration, and ATP coupling efficiency. A reduction in AMPK in differentiated trophoblasts also resulted in increased mitochondrial volume. These data indicate that a reduction in AMPK disrupts cellular metabolism in both progenitors and differentiated placental trophoblasts. This disruption correlates to abortive trophoblast differentiation that may contribute to the development of Pregnancy-Associated Disorders
Mouse models of preeclampsia with preexisting comorbidities
Preeclampsia is a pregnancy-specific condition and a leading cause of maternal and fetal morbidity and mortality. It is thought to occur due to abnormal placental development or dysfunction, because the only known cure is delivery of the placenta. Several clinical risk factors are associated with an increased incidence of preeclampsia including chronic hypertension, diabetes, autoimmune conditions, kidney disease, and obesity. How these comorbidities intersect with preeclamptic etiology, however, is not well understood. This may be due to the limited number of animal models as well as the paucity of studies investigating the impact of these comorbidities. This review examines the current mouse models of chronic hypertension, pregestational diabetes, and obesity that subsequently develop preeclampsia-like symptoms and discusses how closely these models recapitulate the human condition. Finally, we propose an avenue to expand the development of mouse models of preeclampsia superimposed on chronic comorbidities to provide a strong foundation needed for preclinical testing
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The NeST (Neoadjuvant systemic therapy in breast cancer) study: National Practice Questionnaire of United Kingdom multi-disciplinary decision making
Abstract: Background: Neoadjuvant systemic therapy (NST) is increasingly used in the treatment of breast cancer, yet it is clear that there is significant geographical variation in its use in the UK. This study aimed to examine stated practice across UK breast units, in terms of indications for use, radiological monitoring, pathological reporting of treatment response, and post-treatment surgical management. Methods: Multidisciplinary teams (MDTs) from all UK breast units were invited to participate in the NeST study. A detailed questionnaire assessing current stated practice was distributed to all participating units in December 2017 and data collated securely usingREDCap. Descriptive statistics were calculated for each questionnaire item. Results: Thirty-nine MDTs from a diverse range of hospitals responded. All MDTs routinely offered neoadjuvant chemotherapy (NACT) to a median of 10% (range 5–60%) of patients. Neoadjuvant endocrine therapy (NET) was offered to a median of 4% (range 0–25%) of patients by 66% of MDTs. The principal indication given for use of neoadjuvant therapy was for surgical downstaging. There was no consensus on methods of radiological monitoring of response, and a wide variety of pathological reporting systems were used to assess tumour response. Twenty-five percent of centres reported resecting the original tumour footprint, irrespective of clinical/radiological response. Radiologically negative axillae at diagnosis routinely had post-NACT or post-NET sentinel lymph node biopsy (SLNB) in 73.0 and 84% of centres respectively, whereas 16% performed SLNB pre-NACT. Positive axillae at diagnosis would receive axillary node clearance at 60% of centres, regardless of response to NACT. Discussion: There is wide variation in the stated use of neoadjuvant systemic therapy across the UK, with general low usage of NET. Surgical downstaging remains the most common indication of the use of NAC, although not all centres leverage the benefits of NAC for de-escalating surgery to the breast and/or axilla. There is a need for agreed multidisciplinary guidance for optimising selection and management of patients for NST. These findings will be corroborated in phase II of the NeST study which is a national collaborative prospective audit of NST utilisation and clinical outcomes
Structural Attributes Dynamics of the Brazilian Broiler Production Chain
ABSTRACT Brazil is one of the world’s largest broiler meat exporters. Broiler meat is one of the most consumed meats worldwide. The most significant challenge for strategic business management when optimizing the financial returnis knowing exactly where to invest. The same happens in the broiler production chain. The present research aimed to investigate which were the most central actors in the broiler supply chain and the dynamics of the chain. The current study was done based on the poultry chain business relations, from 2000 to 2015, of the leading actors of the Brazilian broiler production chain. The centrality indicator was established through social network analysis (SNA) approach, to determine their positions in the chain as a whole. The most used indicators within network analysis are those designed to identify the extent to which one actor occupies a more central position than another. The Gephi® software was applied to calculate the structural attributes and indicators of the network. Results were estimated using the RapidMiner® software. A model was presented that shows one infrastructure indicator as an explanatory variable. The findings indicate that the centrality indicator was weakly influenced when compared to the other variables, such as market demand, wide variations on the scenario, and mergers or acquisitions
Current State of Preeclampsia Mouse Models: Approaches, Relevance, and Standardization
Preeclampsia (PE) is a multisystemic, pregnancy-specific disorder and a leading cause of maternal and fetal death. PE is also associated with an increased risk for chronic morbidities later in life for mother and offspring. Abnormal placentation or placental function has been well-established as central to the genesis of PE; yet much remains to be determined about the factors involved in the development of this condition. Despite decades of investigation and many clinical trials, the only definitive treatment is parturition. To better understand the condition and identify potential targets preclinically, many approaches to simulate PE in mice have been developed and include mixed mouse strain crosses, genetic overexpression and knockout, exogenous agent administration, surgical manipulation, systemic adenoviral infection, and trophoblast-specific gene transfer. These models have been useful to investigate how biological perturbations identified in human PE are involved in the generation of PE-like symptoms and have improved the understanding of the molecular mechanisms underpinning the human condition. However, these approaches were characterized by a wide variety of physiological endpoints, which can make it difficult to compare effects across models and many of these approaches have aspects that lack physiological relevance to this human disorder and may interfere with therapeutic development. This report provides a comprehensive review of mouse models that exhibit PE-like symptoms and a proposed standardization of physiological characteristics for analysis in murine models of PE
Brazilian chicken meat production chain:a 10-year overview
Brazil is the world's largest broiler meat exporter. Health control, knowledge and technology, as well as the natural aspects of the country are pointed out as the keys for the success of that product in the market. Brazilian broiler production grew significantly in the last decade; it creates jobs and has a significant social role in Brazilian economy. This study aimed at evaluating the Brazilian broiler meat supply chain from 2000 to 2010 using the social network analysis (SNA). Data from governmental and private sources were organized and analyzed. The focus of this study was the broiler production supply chain segment involving the hatchery, the broiler farm, the feed mill, the processing plant, and the government. The inputs considered were one-day-old chicks, pullet, feedstuff, and the infrastructure; and the outputs were broiler meat and taxes paid. The software UCINET was applied for calculating the structural attributes and indicators of the network. Results showed a relatively disorganized network in 2000 with the strongest tie between the farmer and the processing plant. The structural organization of the network improved until 2010. The density of the ties in the broiler meat production network increased steadily from 2000 to 2010 within a vertical cohesive supply chain structure. The success of Brazilian broiler meat production is attributed to the abundance of land, fertile soil, favorable climate, and the effort and investments in research and development by innovative companies in the last few years. The results of the present study showed that Brazilian broiler production evolved positively in the last ten years, and it was weakly influenced by international challenges