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European Journal of Clinical Nutrition Feb 2019Body mass in humans and animals is strongly associated with the rate of heat production as defined by resting energy expenditure (REE). Beginning with the ancient Greeks... (Review)
Review
Body mass in humans and animals is strongly associated with the rate of heat production as defined by resting energy expenditure (REE). Beginning with the ancient Greeks up to the present time, philosophers and scientists have endeavored to understand the nature and sources of bodily heat. Today we recognize that body mass consists of organs and tissues, each of which produces a specified amount of heat at rest. An individual organ's REE can now be estimated in vivo as the product of its assumed mass-specific metabolic rate and its imaging-derived mass; whole-body REE reflects the sum of organ and tissue metabolic rates. The sizes of organs and total body mass in adults are governed by two main factors, a person's stature or height, and their level of adiposity. With greater body size, as represented by adult height independent of adiposity, organs remain stable or increase in mass according to distinct "scaling" patterns. Similarly, with greater relative adiposity organs adaptively accommodate to the increase in imposed mechanical and metabolic loading conditions. Through a detailed analysis of these stature and adiposity effects, we show how classical statistical REE prediction models can be mechanistically understood at the anatomic body composition level.
Topics: Body Composition; Energy Metabolism; Humans
PubMed: 30254244
DOI: 10.1038/s41430-018-0319-3 -
Annual Review of Cell and Developmental... Oct 2022Although tissue homeostasis-the steady state-implies stability, our organs are in a state of continual, large-scale cellular flux. This flux underpins an organ's ability... (Review)
Review
Although tissue homeostasis-the steady state-implies stability, our organs are in a state of continual, large-scale cellular flux. This flux underpins an organ's ability to homeostatically renew, to non-homeostatically resize upon altered functional demand, and to return to homeostasis after resizing or injury-in other words, to be dynamic. Here, I examine the basic unit of organ-scale cell dynamics: the cellular life cycle of birth, differentiation, and death. Focusing on epithelial organs, I discuss how spatial patterns and temporal kinetics of life cycle stages depend upon lineage organization and tissue architecture. I review how signaling between stages coordinates life cycle dynamics to enforce homeostasis, and I highlight how particular stages are transiently unbalanced to drive organ resizing or repair. Finally, I offer that considering organs as a collective of not cells but rather cell life cycles provides a powerful vantage for deciphering homeostatic and non-homeostatic tissue states.
Topics: Cell Differentiation; Homeostasis; Signal Transduction
PubMed: 35850152
DOI: 10.1146/annurev-cellbio-120420-114855 -
Frontiers in Behavioral Neuroscience 2022Benefits of physical exercise for brain functions are well documented in mammals, including humans. In this review, we will summarize recent research on the effects of... (Review)
Review
Benefits of physical exercise for brain functions are well documented in mammals, including humans. In this review, we will summarize recent research on the effects of species-specific intense locomotion on behavior and brain functions of different invertebrates. Special emphasis is made on understanding the biological significance of these effects as well as underlying cellular and molecular mechanisms. The results obtained in three distantly related clades of protostomes, Nematodes, Molluscs and Artropods, suggest that influence of intense locomotion on the brain could have deep roots in evolution and wide adaptive significance. In , improved learning, nerve regeneration, resistance to neurodegenerative processes were detected after physical activity; in -facilitation of decision making in the novel environment, in -increased endurance, improved sleep and feeding behavior, in -improved orientation in conspecific phonotaxis, enhanced aggressiveness, higher mating success, resistance to some disturbing stimuli. Many of these effects have previously been described in mammals as beneficial results of running, suggesting certain similarity between distantly-related species. Our hypothesis posits that the above modulation of cognitive functions results from changes in the organism's predictive model. Intense movement is interpreted by the organism as predictive of change, in anticipation of which adjustments need to be made. Identifying the physiological and molecular mechanisms behind these adjustments is easier in experiments in invertebrates and may lead to the discovery of novel neurobiological mechanisms for regulation and correction of cognitive and emotional status.
PubMed: 35836487
DOI: 10.3389/fnbeh.2022.928093 -
Current Biology : CB Oct 2011For organisms that fly or swim, movement results from the combined effects of the moving medium - air or water - and the organism's own locomotion. For larger organisms,... (Review)
Review
For organisms that fly or swim, movement results from the combined effects of the moving medium - air or water - and the organism's own locomotion. For larger organisms, propulsion contributes significantly to progress but the flow usually still provides significant opposition or assistance, or produces lateral displacement ('drift'). Animals show a range of responses to flows, depending on the direction of the flow relative to their preferred direction, the speed of the flow relative to their own self-propelled speed, the incidence of flows in different directions and the proportion of the journey remaining. We here present a classification of responses based on the direction of the resulting movement relative to flow and preferred direction, which is applicable to a range of taxa and environments. The responses adopted in particular circumstances are related to the organisms' locomotory and sensory capacities and the environmental cues available. Advances in biologging technologies and particle tracking models are now providing a wealth of data, which often demonstrate a striking level of convergence in the strategies that very different animals living in very different environments employ when moving in a flow.
Topics: Air; Animal Migration; Animals; Aquatic Organisms; Arthropods; Cues; Fishes; Grasshoppers; Larva; Locomotion; Movement; Orientation; Swimming; Tidal Waves
PubMed: 22032194
DOI: 10.1016/j.cub.2011.08.014 -
Developmental Biology Jul 2019Tissue remodeling is broadly defined as the reorganization or restoration of existing tissues. Tissue remodeling processes are responsible for directing the development... (Review)
Review
Tissue remodeling is broadly defined as the reorganization or restoration of existing tissues. Tissue remodeling processes are responsible for directing the development and maintenance of tissues, organs, and overall morphology of an organism. Therefore, studying the regulatory and mechanistic aspects of tissue remodeling allows one to decipher how tissue structure and function is manipulated in animals. As such, research focused on investigating natural tissue reorganization in animal model organisms has great potential for advancing medical therapies, in conjunction with tissue engineering and regenerative medicine. Here we discuss the molecular and cellular mechanisms responsible for tissue remodeling events that occur across several animal phyla. Notably, this review emphasizes the molecular and cellular mechanisms involved in embryonic and postnatal physiological tissue remodeling events, ranging from metamorphosis to bone remodeling during functional adaptation.
Topics: Animal Structures; Animals; Biological Evolution; Extracellular Matrix; Humans; Metamorphosis, Biological; Models, Animal; Regeneration; Signal Transduction; Tissue Engineering
PubMed: 30974103
DOI: 10.1016/j.ydbio.2019.04.001 -
History and Philosophy of the Life... Aug 2021Both concepts of the holobiont and the immune system are at the heart of an ongoing scientific and philosophical examination concerning questions of the organism's...
Both concepts of the holobiont and the immune system are at the heart of an ongoing scientific and philosophical examination concerning questions of the organism's individuality and identity as well as the relations between organisms and their environment. Examining the holobiont, the question of boundaries and individuality is challenging because it is both an assemblage of organisms with physiological cohesive aspects. I discuss the concept of immunity and the immune system function from the holobiont perspective. Because of the host-microbial close relations of codependence and interdependence, the holobiont is more often than not confused with the host, as the host is the domain in which this entity exists. I discuss the holobiont unique ecological characteristics of microbial assemblages connected to a host in a network of interactions in which the host is one of the organisms in the community but also its landscape. Therefore, I suggest viewing the holobiont as a host-ecosystem and discuss the implication of such a view on the concept of immunity and the meaning of protection. Furthermore, I show that viewing the holobiont as a host ecosystem opens the possibility of using the same ecological definition of boundaries and immunity dealing with an ecological system. Thus, the holobiont's boundaries and immunity are defined by the persistence of its complex system of interactions integrating existing and new interactions. This way of thinking presents a notion of immunity that materializes as the result of the complex interdependence relations between the different organisms composing the holobiont similar to that of an ecosystem. Taking this view further, I discuss the notion of immunogenicity that is ontologically heterogeneous with various causal explanations of the processes of tolerance and targeted immune response. Finally, I discuss the possible conceptualization of already existing and new biomedical practices.
Topics: Host Microbial Interactions; Immune System; Immunity
PubMed: 34370107
DOI: 10.1007/s40656-021-00454-y -
Frontiers in Microbiology 2021Neonicotinoids are synthetic pesticides widely used for the control of various pests in agriculture throughout the world. They mainly attack the nicotinic acetylcholine... (Review)
Review
Neonicotinoids are synthetic pesticides widely used for the control of various pests in agriculture throughout the world. They mainly attack the nicotinic acetylcholine receptors, generate nervous stimulation, receptor clot, paralysis and finally cause death. They are low volatile, highly soluble and have a long half-life in soil and water. Due to their extensive use, the environmental residues have immensely increased in the last two decades and caused many hazardous effects on non-target organisms, including humans. Hence, for the protection of the environment and diversity of living organism's the degradation of neonicotinoids has received widespread attention. Compared to the other methods, biological methods are considered cost-effective, eco-friendly and most efficient. In particular, the use of microbial species makes the degradation of xenobiotics more accessible fast and active due to their smaller size. Since this degradation also converts xenobiotics into less toxic substances, the various metabolic pathways for the microbial degradation of neonicotinoids have been systematically discussed. Additionally, different enzymes, genes, plasmids and proteins are also investigated here. At last, this review highlights the implementation of innovative tools, databases, multi-omics strategies and immobilization techniques of microbial cells to detect and degrade neonicotinoids in the environment.
PubMed: 34925268
DOI: 10.3389/fmicb.2021.759439 -
Frontiers in Immunology 2021The scopes related to the interplay between stem cells and the immune system are broad and range from the basic understanding of organism's physiology and ecology to... (Review)
Review
The scopes related to the interplay between stem cells and the immune system are broad and range from the basic understanding of organism's physiology and ecology to translational studies, further contributing to (eco)toxicology, biotechnology, and medicine as well as regulatory and ethical aspects. Stem cells originate immune cells through hematopoiesis, and the interplay between the two cell types is required in processes like regeneration. In addition, stem and immune cell anomalies directly affect the organism's functions, its ability to cope with environmental changes and, indirectly, its role in ecosystem services. However, stem cells and immune cells continue to be considered parts of two branches of biological research with few interconnections between them. This review aims to bridge these two seemingly disparate disciplines towards much more integrative and transformative approaches with examples deriving mainly from aquatic invertebrates. We discuss the current understanding of cross-disciplinary collaborative and emerging issues, raising novel hypotheses and comments. We also discuss the problems and perspectives of the two disciplines and how to integrate their conceptual frameworks to address basic equations in biology in a new, innovative way.
Topics: Allergy and Immunology; Aquatic Organisms; Cell Communication; Genomics; Immune System; Immunity, Innate; Marine Biology; Signal Transduction; Stem Cells; Systems Biology
PubMed: 34276677
DOI: 10.3389/fimmu.2021.688106 -
The Journal of Antimicrobial... Feb 2020Candida albicans is an opportunistic yeast and the major human fungal pathogen in the USA, as well as in many other regions of the world. Infections with C. albicans can... (Review)
Review
Candida albicans is an opportunistic yeast and the major human fungal pathogen in the USA, as well as in many other regions of the world. Infections with C. albicans can range from superficial mucosal and dermatological infections to life-threatening infections of the bloodstream and vital organs. The azole antifungals remain an important mainstay treatment of candidiasis and therefore the investigation and understanding of the evolution, frequency and mechanisms of azole resistance are vital to improving treatment strategies against this organism. Here the organism C. albicans and the genetic changes and molecular bases underlying the currently known resistance mechanisms to the azole antifungal class are reviewed, including up-regulated expression of efflux pumps, changes in the expression and amino acid composition of the azole target Erg11 and alterations to the organism's typical sterol biosynthesis pathways. Additionally, we update what is known about activating mutations in the zinc cluster transcription factor (ZCF) genes regulating many of these resistance mechanisms and review azole import as a potential contributor to azole resistance. Lastly, investigations of azole tolerance in C. albicans and its implicated clinical significance are reviewed.
Topics: Antifungal Agents; Azoles; Candida albicans; Candidiasis; Drug Resistance, Fungal; Fungal Proteins; Humans; Microbial Sensitivity Tests; Transcription Factors
PubMed: 31603213
DOI: 10.1093/jac/dkz400