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PeerJ 2022The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense... (Review)
Review
The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense mechanisms used to deal with the pandemic. It then discusses different categories of defense mechanisms and their roles in managing the impacts of psychological distress. The aim of this review is to highlight the various psychological defense mechanisms individuals use to deal with the pandemic and to discuss how adjustment mechanisms can protect individuals from internal and external threats by shielding the integrity of the ego (the mind) and helping individuals maintain their self-schema.
Topics: Humans; COVID-19; Pandemics; Psychological Distress; Defense Mechanisms
PubMed: 35186458
DOI: 10.7717/peerj.12811 -
Psychodynamic Psychiatry Dec 2015Understanding defense mechanisms is an important part of psychotherapy. In this article, we trace the history of the concept of defense, from its origin with Freud to... (Review)
Review
Understanding defense mechanisms is an important part of psychotherapy. In this article, we trace the history of the concept of defense, from its origin with Freud to current views. The issue of defense as an unconscious mechanism is examined. The question of whether defenses are pathological, as well as their relation to pathology, is discussed. The effect of psychotherapy on the use of defenses, and their relation to a therapeutic alliance is explored. A series of empirical research studies that demonstrate the functioning of defense mechanisms and that support the theory is presented. Research also shows that as part of normal development, different defenses emerge at different developmental periods, and that gender differences in defense use occur.
Topics: Defense Mechanisms; History, 19th Century; History, 20th Century; Humans; Psychological Theory; Psychotherapy
PubMed: 26583439
DOI: 10.1521/pdps.2015.43.4.523 -
Trends in Parasitology Dec 2022Toxoplasma gondii encysts preferentially within neurons in the central nervous system, establishing lifelong persistence. Despite recent discoveries, this neuronal...
Toxoplasma gondii encysts preferentially within neurons in the central nervous system, establishing lifelong persistence. Despite recent discoveries, this neuronal preference was thought, in part, to be secondary to a lack of neuronal cell-autonomous immunity. By showing that neurons can mount interferon-gamma (IFN-γ)-mediated cell-autonomous anti-T. gondii defenses, Chandrasekaran et al. have challenged long held assumptions.
Topics: Toxoplasma; Interferon-gamma; Neurons; Immunity, Cellular; Defense Mechanisms
PubMed: 36280528
DOI: 10.1016/j.pt.2022.10.001 -
Phytopathology Apr 2023One important discovery in plant pathology over recent decades is the natural antiviral defense mechanism mediated by RNA interference (RNAi). In antiviral RNAi, virus... (Review)
Review
One important discovery in plant pathology over recent decades is the natural antiviral defense mechanism mediated by RNA interference (RNAi). In antiviral RNAi, virus infection triggers Dicer processing of virus-specific double-stranded RNA into small interfering RNAs (siRNAs). Frequently, further amplified by host enzyme and cofactors, these virus-derived siRNAs direct specific virus clearance in an Argonaute protein-containing effector complex. The siRNAs derived from viruses and viroids accumulate to very high levels during infection. Because they overlap extensively in nucleotide sequence, this allows for deep sequencing and bioinformatics assembly of total small RNAs for rapid discovery and identification of viruses and viroids. Antiviral RNAi acts as the primary defense mechanism against both RNA and DNA viruses in plants, yet viruses still successfully infect plants. They do so because all currently recognized plant viruses combat the RNAi response by encoding at least one protein as a viral suppressor of RNAi (VSR) required for infection, even though plant viruses have small genome sizes with a limited coding capacity. This review article will recapitulate the key findings that have revealed the genetic pathway for the biogenesis and antiviral activity of viral siRNAs and the specific role of VSRs in infection by antiviral RNAi suppression. Moreover, early pioneering studies on transgene silencing, RNAi, and virus-plant/virus-virus interactions paved the road to the discovery of antiviral RNAi.
Topics: RNA, Small Interfering; RNA Interference; RNA, Double-Stranded; Antiviral Agents; Plant Diseases; Plants; Viroids; Transgenes; Defense Mechanisms
PubMed: 36441873
DOI: 10.1094/PHYTO-10-22-0358-IA -
PLoS Biology May 2023The gasdermins are a family of pore-forming proteins involved in various cellular processes such as cell death and inflammation. A new study in PLOS Biology explores the...
The gasdermins are a family of pore-forming proteins involved in various cellular processes such as cell death and inflammation. A new study in PLOS Biology explores the evolutionary history of gasdermins across metazoans, highlighting the conservation and divergence of gasdermin E.
Topics: Animals; Pyroptosis; Lancelets; Gasdermins; Neoplasm Proteins; Defense Mechanisms
PubMed: 37141191
DOI: 10.1371/journal.pbio.3002103 -
BMJ Open Respiratory Research Jul 2023Epidemiological and clinical studies have indicated an association between particulate matter (PM) exposure and acute and chronic pulmonary inflammation, which may be... (Review)
Review
Epidemiological and clinical studies have indicated an association between particulate matter (PM) exposure and acute and chronic pulmonary inflammation, which may be registered as increased mortality and morbidity. Despite the increasing evidence, the pathophysiology mechanism of these PMs is still not fully characterised. Pulmonary alveolar macrophages (PAMs), as a predominant cell in the lung, play a critically important role in these pathological mechanisms. Toxin exposure triggers events associated with macrophage activation, including oxidative stress, acute damage, tissue disruption, remodelling and fibrosis. Targeting macrophage may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections. Biological toxins, their sources of exposure, physical and other properties, and their effects on the individuals are summarised in this article. Inhaled particulates from air pollution and toxic gases containing chemicals can interact with alveolar epithelial cells and immune cells in the airways. PAMs can sense ambient pollutants and be stimulated, triggering cellular signalling pathways. These cells are highly adaptable and can change their function and phenotype in response to inhaled agents. PAMs also have the ability to polarise and undergo plasticity in response to tissue damage, while maintaining resistance to exposure to inhaled agents.
Topics: Humans; Macrophages, Alveolar; Air Pollution; Gases; Lung; Defense Mechanisms
PubMed: 37479504
DOI: 10.1136/bmjresp-2022-001589 -
Journal of Agricultural and Food... Mar 2022Pepper mild mottle virus (PMMoV), an RNA virus, is one of the most devastating pathogens in pepper crops and has a significant influence on global crop yields. PMMoV...
Pepper mild mottle virus (PMMoV), an RNA virus, is one of the most devastating pathogens in pepper crops and has a significant influence on global crop yields. PMMoV poses a major threat to the global shortage of pepper plants and other Solanaceae crops due to the lack of an effective antiviral agent. In this study, we have developed a plant immune inducer (vanisulfane), as a "plant vaccine" that boosts plant immunity against PMMoV, and studied its resistance mechanism. The protective activity of vanisulfane against PMMoV was 59.4%. Vanisulfane can enhance the activity of defense enzymes and improve the content of chlorophyll, flavonoids, and total phenols for removing harmful free radicals from plants. Furthermore, vanisulfane was found to enhance defense genes. Label-free quantitative proteomics would tackle disease resistance pathways of vanisulfane. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, differentially abundant proteins (DAPs) are mainly involved in starch and sucrose metabolism, photosynthesis, MAPK signaling pathway, and oxidative phosphorylation pathway. These results are crucial for the discovery of new pesticides, understanding the improvement of plant immunity and the antiviral activity of plant immune inducers.
Topics: Capsicum; Defense Mechanisms; Plant Diseases; Tobamovirus
PubMed: 35297641
DOI: 10.1021/acs.jafc.2c00659 -
Journal of Affective Disorders Aug 2008Evolutionary perspectives on bipolar disorders can further our understanding of the origins of these conditions, and assist clinicians in distinguishing normal from... (Review)
Review
OBJECTIVE
Evolutionary perspectives on bipolar disorders can further our understanding of the origins of these conditions, and assist clinicians in distinguishing normal from abnormal states. Hypomania is unique amongst bipolar conditions in that it seems to have beneficial aspects and can be difficult to diagnose, in contrast to full-blown mania and depression. A theoretical perspective regarding the evolution of hypomania as a defense mechanism is presented.
METHOD
Literature review focused on the fitness reducing aspects of depression and the fitness enhancing aspects of hypomania/mania.
RESULTS
Of all the adversity inherent in depression, inhibition of physical and mental activity-depressive inhibition-has the most detrimental consequences, and throughout our evolution would have significantly reduced fitness. It is proposed that hypomania evolved as a depressive inhibition override defense mechanism, typically operating in a short-term time frame, to restore physical and mental activity to fitness sustaining or enhancing levels. Over-activity and not mood enhancement enabled hypomania to function as a defense mechanism against the fitness reducing state of depressive inhibition. Contributing to depressive inhibition are the Behavioral Activation System (BAS) and the Behavioral Inhibition System (BIS), two basic motivational systems. Depressive inhibition consists to some extent of low BAS and high BIS. As human intelligence evolved cognitions inhibiting BAS and activating BIS became amplified, resulting in intensified depressive inhibition.
LIMITATIONS
A theoretical perspective.
CONCLUSIONS
Given its ability to override depressive inhibition hypomania might be viewed as a natural treatment as opposed to a problem to treat, producing maximal improvement in areas where functioning has suffered the most while typically enhancing social behavior.
Topics: Adaptation, Psychological; Bipolar Disorder; Defense Mechanisms; Depression; Diagnostic and Statistical Manual of Mental Disorders; Humans; Inhibition, Psychological
PubMed: 18325598
DOI: 10.1016/j.jad.2008.01.028 -
The New Phytologist Feb 2021Algal viruses are important contributors to carbon cycling, recycling nutrients and organic material through host lysis. Although viral infection has been described as a...
Algal viruses are important contributors to carbon cycling, recycling nutrients and organic material through host lysis. Although viral infection has been described as a primary mechanism of phytoplankton mortality, little is known about host defense responses. We show that viral infection of the bloom-forming, planktonic diatom Chaetoceros socialis induces the mass formation of resting spores, a heavily silicified life cycle stage associated with carbon export due to rapid sinking. Although viral RNA was detected within spores, mature virions were not observed. 'Infected' spores were capable of germinating, but did not propagate or transmit infectious viruses. These results demonstrate that diatom spore formation is an effective defense strategy against viral-mediated mortality. They provide a possible mechanistic link between viral infection, bloom termination, and mass carbon export events and highlight an unappreciated role of viruses in regulating diatom life cycle transitions and ecological success.
Topics: DNA Viruses; Defense Mechanisms; Diatoms; Phytoplankton; Viruses
PubMed: 32978816
DOI: 10.1111/nph.16951 -
Current Biology : CB Nov 2023The aerial surfaces of quinoa (Chenopodium quinoa) and common ice plant (Mesembryanthemum crystallinum) are covered with a layer of epidermal bladder cells (EBCs), which...
The aerial surfaces of quinoa (Chenopodium quinoa) and common ice plant (Mesembryanthemum crystallinum) are covered with a layer of epidermal bladder cells (EBCs), which are modified non-glandular trichomes previously considered to be key to the extreme salt and drought tolerance of these plants. Here, however, we find that EBCs of these plants play only minor roles, if any, in abiotic stress tolerance and in fact are detrimental under conditions of water deficit. We report that EBCs instead function as deterrents to a broad range of generalist arthropod herbivores, through their combined function of forming both a chemical and a physical barrier, and they also serve a protective function against a phytopathogen. Our study overturns current models that link EBCs to salt and drought tolerance and assigns new functions to these structures that might provide novel possibilities for protecting crops from arthropod pests.
Topics: Herbivory; Urinary Bladder; Sodium Chloride; Plants; Defense Mechanisms
PubMed: 37852262
DOI: 10.1016/j.cub.2023.09.063