-
Journal of Visceral Surgery Feb 2013Acute calculous cholecystitis may progress in a variety of ways from mild cases treatable with (or even without) oral antibiotics to severe cases complicated by bile... (Review)
Review
Acute calculous cholecystitis may progress in a variety of ways from mild cases treatable with (or even without) oral antibiotics to severe cases complicated by bile peritonitis that require emergency surgical or radiological intervention. A sample of bile should always be sent for microbial cultures to identify aerobic and anaerobic bacterial organisms. Empirically selected broad spectrum antibiotic therapy (with a defined duration, dosage and administration route) should be prescribed according to the severity of the cholecystitis, an associated history of recent antibiotic therapy, and local bacterial susceptibility patterns. As soon as causative organisms have been identified, antibiotic therapy should be adjusted to a narrower spectrum antimicrobial agent based on the specific micro-organism(s) and the results of sensitivity testing.
Topics: Anti-Bacterial Agents; Bile; Cholecystectomy; Cholecystitis, Acute; Combined Modality Therapy; Drug Administration Schedule; Gallstones; Humans; Perioperative Care
PubMed: 23433832
DOI: 10.1016/j.jviscsurg.2013.01.004 -
Frontiers in Psychology 2020The enactive and ecological approaches to embodied cognitive science are on a collision course. While both draw inspiration from similar views in psychology and... (Review)
Review
The enactive and ecological approaches to embodied cognitive science are on a collision course. While both draw inspiration from similar views in psychology and phenomenology, the two approaches initially held seemingly contradictory views and points of focus. Early enactivists saw value in the ecological approach but insisted that the two schools remain distinct. While ecological psychology challenged the common foes of mental representation and mind-body dualism, it seemingly did so at the cost of the autonomy of the agent. This is evidence that the early enactive and ecological approaches told different stories about how agents and environments interact. Whereas the enactive approach broadly focuses on agency and the organism's resilience to environmental perturbations, the ecological approach insists that organisms are best understood in terms of the organism-environment system and at the ecological scale. Historically, this tension created space for harsh criticisms from both sides and for some ecological psychologists to dismiss enactivism altogether. Despite their differences, both approaches use dynamic systems theory to explain the interactions between embodied agents and the environment or contextual milieu in which they are embedded. This has led some scholars to focus on the complementary elements of each approach and argue that the two schools are allies, thus rejecting the historical disagreements between the two approaches and calling for an ecological-enactive synthesis. The attempts to synthesize the approaches are noteworthy and should be considered steps in the right direction but are potentially problematic. If the two schools are merely synthesized to some form of ecological-enactivism, then something of value from both approaches could be lost. This is analogous to the hasty comparison between two seemingly similar schools of thought found in early attempts at East-West comparative philosophy. I argue that the relationship between the enactive and ecological approaches is both complementary and contrary and is thus best understood in terms of complementarity. Given the complexity of complementarity I will unpack the notion in steps. I will begin with the exploration of analogous concepts in Japanese Philosophy and gradually build a lens through which both agent environment and ecological enactive complementarities can be understood.
PubMed: 32903774
DOI: 10.3389/fpsyg.2020.01347 -
International Journal of Molecular... Mar 2019Circadian timekeeping allows appropriate temporal regulation of an organism's internal metabolism to anticipate and respond to recurrent daily changes in the... (Review)
Review
Circadian timekeeping allows appropriate temporal regulation of an organism's internal metabolism to anticipate and respond to recurrent daily changes in the environment. Evidence from animal genetic models and from humans under circadian misalignment (such as shift work or jet lag) shows that disruption of circadian rhythms contributes to the development of obesity and metabolic disease. Inappropriate timing of food intake and high-fat feeding also lead to disruptions of the temporal coordination of metabolism and physiology and subsequently promote its pathogenesis. This review illustrates the impact of genetically or environmentally induced molecular clock disruption (at the level of the brain and peripheral tissues) and the interplay between the circadian system and metabolic processes. Here, we discuss some mechanisms responsible for diet-induced circadian desynchrony and consider the impact of nutritional cues in inter-organ communication, with a particular focus on the communication between peripheral organs and brain. Finally, we discuss the relay of environmental information by signal-dependent transcription factors to adjust the timing of gene oscillations. Collectively, a better knowledge of the mechanisms by which the circadian clock function can be compromised will lead to novel preventive and therapeutic strategies for obesity and other metabolic disorders arising from circadian desynchrony.
Topics: Animals; Circadian Clocks; Circadian Rhythm Signaling Peptides and Proteins; Energy Metabolism; Humans; Metabolic Diseases
PubMed: 30935034
DOI: 10.3390/ijms20071597 -
Frontiers in Cell and Developmental... 2022Epithelial tissues are vital to the function of most organs, providing critical functions such as secretion, protection, and absorption. Cells within an epithelial layer... (Review)
Review
Epithelial tissues are vital to the function of most organs, providing critical functions such as secretion, protection, and absorption. Cells within an epithelial layer must coordinate to create functionally distinct apical, lateral, and basal surfaces in order to maintain proper organ function and organism viability. This is accomplished through the careful targeting of polarity factors to their respective locations within the cell, as well as the strategic placement of post-mitotic cells within the epithelium during tissue morphogenesis. The process of establishing and maintaining epithelial tissue integrity is conserved across many species, as important polarity factors and spindle orientation mechanisms can be found in many phyla. However, most of the information gathered about these processes and players has been investigated in bilaterian organisms such as , and vertebrate species. This review discusses the advances made in the field of epithelial polarity establishment from more basal organisms, and the advantages to utilizing these simpler models. An increasing number of cnidarian model organisms have been sequenced in recent years, such as and . It is now feasible to investigate how polarity is established and maintained in basal organisms to gain an understanding of the most basal requirements for epithelial tissue morphogenesis.
PubMed: 35433674
DOI: 10.3389/fcell.2022.854373 -
The Biochemical Journal Aug 2013The modern synthesis of evolutionary theory and genetics has enabled us to discover underlying molecular mechanisms of organismal evolution. We know that in order to... (Review)
Review
The modern synthesis of evolutionary theory and genetics has enabled us to discover underlying molecular mechanisms of organismal evolution. We know that in order to maximize an organism's fitness in a particular environment, individual interactions among components of protein and nucleic acid networks need to be optimized by natural selection, or sometimes through random processes, as the organism responds to changes and/or challenges in the environment. Despite the significant role of molecular networks in determining an organism's adaptation to its environment, we still do not know how such inter- and intra-molecular interactions within networks change over time and contribute to an organism's evolvability while maintaining overall network functions. One way to address this challenge is to identify connections between molecular networks and their host organisms, to manipulate these connections, and then attempt to understand how such perturbations influence molecular dynamics of the network and thus influence evolutionary paths and organismal fitness. In the present review, we discuss how integrating evolutionary history with experimental systems that combine tools drawn from molecular evolution, synthetic biology and biochemistry allow us to identify the underlying mechanisms of organismal evolution, particularly from the perspective of protein interaction networks.
Topics: Biochemistry; Biological Evolution; Evolution, Molecular; Protein Interaction Maps; Synthetic Biology
PubMed: 23849056
DOI: 10.1042/BJ20130205 -
Disease Models & Mechanisms Mar 2022Whole-body health relies on complex inter-organ signalling networks that enable organisms to adapt to environmental perturbations and to changes in tissue homeostasis.... (Review)
Review
Whole-body health relies on complex inter-organ signalling networks that enable organisms to adapt to environmental perturbations and to changes in tissue homeostasis. The intestine plays a major role as a signalling centre by producing local and systemic signals that are relayed to the body and that maintain intestinal and organismal homeostasis. Consequently, disruption of intestinal homeostasis and signalling are associated with systemic diseases and multi-organ dysfunction. In recent years, the fruit fly Drosophila melanogaster has emerged as a prime model organism to study tissue-intrinsic and systemic signalling networks of the adult intestine due to its genetic tractability and functional conservation with mammals. In this Review, we highlight Drosophila research that has contributed to our understanding of how the adult intestine interacts with its microenvironment and with distant organs. We discuss the implications of these findings for understanding intestinal and whole-body pathophysiology, and how future Drosophila studies might advance our knowledge of the complex interplay between the intestine and the rest of the body in health and disease.
Topics: Animals; Drosophila; Drosophila melanogaster; Homeostasis; Intestines; Mammals; Signal Transduction
PubMed: 35344037
DOI: 10.1242/dmm.049332 -
Philosophical Transactions of the Royal... Mar 2021We advance an account that grounds cognition, specifically decision-making, in an activity all organisms as autonomous systems must perform to keep themselves...
We advance an account that grounds cognition, specifically decision-making, in an activity all organisms as autonomous systems must perform to keep themselves viable-controlling their production mechanisms. Production mechanisms, as we characterize them, perform activities such as procuring resources from their environment, putting these resources to use to construct and repair the organism's body and moving through the environment. Given the variable nature of the environment and the continual degradation of the organism, these production mechanisms must be regulated by control mechanisms that select when a production is required and how it should be carried out. To operate on production mechanisms, control mechanisms need to procure information through measurement processes and evaluate possible actions. They are making decisions. In all organisms, these decisions are made by multiple different control mechanisms that are organized not hierarchically but heterarchically. In many cases, they employ internal models of features of the environment with which the organism must deal. Cognition, in the form of decision-making, is thus fundamental to living systems which must control their production mechanisms. This article is part of the theme issue 'Basal cognition: conceptual tools and the view from the single cell'.
Topics: Cognition; Eukaryotic Cells; Prokaryotic Cells
PubMed: 33487110
DOI: 10.1098/rstb.2019.0751 -
Oxidative Medicine and Cellular... 2014Liver ischemia/reperfusion injury has been extensively studied during the last decades and has been implicated in the pathophysiology of many clinical entities following... (Review)
Review
Liver ischemia/reperfusion injury has been extensively studied during the last decades and has been implicated in the pathophysiology of many clinical entities following hepatic surgery and transplantation. Apart from its pivotal role in the pathogenesis of the organ's post reperfusion injury, it has also been proposed as an underlying mechanism responsible for the dysfunction and injury of other organs as well. It seems that liver ischemia and reperfusion represent an event with "global" consequences that influence the function of many remote organs including the lung, kidney, intestine, pancreas, adrenals, and myocardium among others. The molecular and clinical manifestation of these remote organs injury may lead to the multiple organ dysfunction syndrome, frequently encountered in these patients. Remote organ injury seems to be in part the result of the oxidative burst and the inflammatory response following reperfusion. The present paper aims to review the existing literature regarding the proposed mechanisms of remote organ injury after liver ischemia and reperfusion.
Topics: Heart Injuries; Humans; Intestinal Mucosa; Intestines; Ischemia; Kidney; Liver; Lung Injury; Oxidative Stress; Pancreas; Reactive Oxygen Species; Reperfusion Injury
PubMed: 24799983
DOI: 10.1155/2014/906965