Mauricius Marques dos Santos

Bio: Mauricius Marques dos Santos is an academic researcher from University of Arizona. The author has contributed to research in topics: Medicine & Chemistry. The author has an hindex of 2, co-authored 2 publications receiving 594 citations.

Innate Immunity and Asthma Risk in Amish and Hutterite Farm Children

Abstract: BackgroundThe Amish and Hutterites are U.S. agricultural populations whose lifestyles are remarkably similar in many respects but whose farming practices, in particular, are distinct; the former follow traditional farming practices whereas the latter use industrialized farming practices. The populations also show striking disparities in the prevalence of asthma, and little is known about the immune responses underlying these disparities. MethodsWe studied environmental exposures, genetic ancestry, and immune profiles among 60 Amish and Hutterite children, measuring levels of allergens and endotoxins and assessing the microbiome composition of indoor dust samples. Whole blood was collected to measure serum IgE levels, cytokine responses, and gene expression, and peripheral-blood leukocytes were phenotyped with flow cytometry. The effects of dust extracts obtained from Amish and Hutterite homes on immune and airway responses were assessed in a murine model of experimental allergic asthma. ResultsDespite the...

Rapid direct injection LC-MS/MS method for analysis of prioritized indicator compounds in wastewater effluent

Abstract: Trace organic compounds (TOrCs) have been detected in drinking water sources for several years, raising concerns due to their potential risks to public health. The main contributor of TOrCs to drinking water is through wastewater discharges. However, there are several hundred TOrCs currently known with numerous new organic chemicals being released daily, making it unfeasible to monitor each one in water. This study used a detailed literature review and scoring system to establish a list of twenty priority indicator TOrCs in US wastewaters. Next, a rapid direct injection LC-MS/MS method for analysis of these compounds was developed without the need for an extraction step and only 80 μL sample volume while providing method reporting limits of 3–39 ng L−1 for all but one TOrC (sucralose: 302 ng L−1). The elimination of an extraction step reduced matrix effects considerably making the method suitable for wastewater analysis. Method validation including matrix spike recoveries, linearity of calibration curve and inter- and intra-day variability was successfully performed. Finally, the twenty indicator TOrCs were evaluated in four different wastewater treatment plant (WWTP) effluents through four sample campaigns spread across a year. The occurrence data indicated that all indicator TOrCs were detected in at least three out of the four WWTP effluents. Sucralose, iohexol, TCPP, acesulfame and gemfibrozil were detected in all samples at the four WWTPs indicating they could be used as indicators of wastewater influence in receiving waters. DEET, caffeine, triclosan, iopromide and others are effective indicators at showing seasonal variations, treatment process efficacy, and consumption patterns. Overall, the impact of this study will help develop more effective monitoring programs for TOrCs in water reuse schemes.

The Human Intestinal Microbiome in Health and Disease

Abstract: The large majority of studies on the role of the microbiome in the pathogenesis of disease are correlative and preclinical; several have influenced clinical practice.

Current understanding of the human microbiome.

Abstract: Our understanding of the link between the human microbiome and disease, including obesity, inflammatory bowel disease, arthritis and autism, is rapidly expanding. Improvements in the throughput and accuracy of DNA sequencing of the genomes of microbial communities that are associated with human samples, complemented by analysis of transcriptomes, proteomes, metabolomes and immunomes and by mechanistic experiments in model systems, have vastly improved our ability to understand the structure and function of the microbiome in both diseased and healthy states. However, many challenges remain. In this review, we focus on studies in humans to describe these challenges and propose strategies that leverage existing knowledge to move rapidly from correlation to causation and ultimately to translation into therapies.

Gut microbiota and IBD: causation or correlation?

Abstract: A general consensus exists that IBD is associated with compositional and metabolic changes in the intestinal microbiota (dysbiosis). However, a direct causal relationship between dysbiosis and IBD has not been definitively established in humans. Findings from animal models have revealed diverse and context-specific roles of the gut microbiota in health and disease, ranging from protective to pro-inflammatory actions. Moreover, evidence from these experimental models suggest that although gut bacteria often drive immune activation, chronic inflammation in turn shapes the gut microbiota and contributes to dysbiosis. The purpose of this Review is to summarize current associations between IBD and dysbiosis, describe the role of the gut microbiota in the context of specific animal models of colitis, and discuss the potential role of microbiota-focused interventions in the treatment of human IBD. Ultimately, more studies will be needed to define host-microbial relationships relevant to human disease and amenable to therapeutic interventions.

Does the epithelial barrier hypothesis explain the increase in allergy, autoimmunity and other chronic conditions?

Abstract: There has been a steep increase in allergic and autoimmune diseases, reaching epidemic proportions and now affecting more than one billion people worldwide. These diseases are more common in industrialized countries, and their prevalence continues to rise in developing countries in parallel to urbanization and industrialization. Intact skin and mucosal barriers are crucial for the maintenance of tissue homeostasis as they protect host tissues from infections, environmental toxins, pollutants and allergens. A defective epithelial barrier has been demonstrated in allergic and autoimmune conditions such as asthma, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, eosinophilic esophagitis, coeliac disease and inflammatory bowel disease. In addition, leakiness of the gut epithelium is also implicated in systemic autoimmune and metabolic conditions such as diabetes, obesity, multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis and autoimmune hepatitis. Finally, distant inflammatory responses due to a ‘leaky gut’ and microbiome changes are suspected in Alzheimer disease, Parkinson disease, chronic depression and autism spectrum disorders. This article introduces an extended ‘epithelial barrier hypothesis’, which proposes that the increase in epithelial barrier-damaging agents linked to industrialization, urbanization and modern life underlies the rise in allergic, autoimmune and other chronic conditions. Furthermore, it discusses how the immune responses to dysbiotic microbiota that cross the damaged barrier may be involved in the development of these diseases. In this review, Cezmi Akdis discusses how epithelial barrier-damaging agents linked to industrialization, urbanization and modern life may explain the increased prevalence of allergic disease as well as a wide range of autoimmune and metabolic conditions in which immune responses to translocated bacteria have systemic effects.