-
Journal of Medicine and Life 2010Acute stress increases resistance to infection. The alteration of this mechanism in chronically stressed people impairs the organism's ability to mount a strong immune... (Review)
Review
Acute stress increases resistance to infection. The alteration of this mechanism in chronically stressed people impairs the organism's ability to mount a strong immune response with a resultant increase in morbidity. Acute stress induces a probable sympatho-adrenergically mediated increase in chemotaxis and adhesion molecules expression, thus promoting immune cells migration to sites of infection and/or inflammation, while chronic stress impairs this mechanism. Protracted stressful conditions decrease NK cytotoxic capacity. There is a substance P, which under stressful circumstances mediates the increase in macrophage cytokine production. Acute stress increases T cell mobilization through a beta2-adrenergically mediated process, which is blunted during chronic stress. Psychological stress impairs the immune system's ability to produce antibodies in response to a vaccine, thereby making the organism more vulnerable to infections.
Topics: Chemotaxis; Humans; Immune System; Immunity, Cellular; Immunity, Humoral; Killer Cells, Natural; Stress, Psychological; T-Lymphocytes
PubMed: 20302192
DOI: No ID Found -
Microbiological Reviews Sep 1991The gram-positive bacterium Listeria monocytogenes is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in... (Review)
Review
The gram-positive bacterium Listeria monocytogenes is an ubiquitous, intracellular pathogen which has been implicated within the past decade as the causative organism in several outbreaks of foodborne disease. Listeriosis, with a mortality rate of about 24%, is found mainly among pregnant women, their fetuses, and immunocompromised persons, with symptoms of abortion, neonatal death, septicemia, and meningitis. Epidemiological investigations can make use of strain-typing procedures such as DNA restriction enzyme analysis or electrophoretic enzyme typing. The organism has a multifactorial virulence system, with the thiol-activated hemolysin, listeriolysin O, being identified as playing a crucial role in the organism's ability to multiply within host phagocytic cells and to spread from cell to cell. The organism occurs widely in food, with the highest incidences being found in meat, poultry, and seafood products. Improved methods for detecting and enumerating the organism in foodstuffs are now available, including those based on the use of monoclonal antibodies, DNA probes, or the polymerase chain reaction. As knowledge of the molecular and applied biology of L. monocytogenes increases, progress can be made in the prevention and control of human infection.
Topics: Animals; Food Microbiology; Humans; Listeria monocytogenes; Listeriosis; Virulence
PubMed: 1943998
DOI: 10.1128/mr.55.3.476-511.1991 -
Journal of Biophotonics Dec 2019Visible light synchronizes the human biological clock in the suprachiasmatic nuclei of the hypothalamus to the solar 24-hour cycle. Short wavelengths, perceived as blue... (Review)
Review
Visible light synchronizes the human biological clock in the suprachiasmatic nuclei of the hypothalamus to the solar 24-hour cycle. Short wavelengths, perceived as blue color, are the strongest synchronizing agent for the circadian system that keeps most biological and psychological rhythms internally synchronized. Circadian rhythm is important for optimum function of organisms and circadian sleep-wake disruptions or chronic misalignment often may lead to psychiatric and neurodegenerative illness. The beneficial effect on circadian synchronization, sleep quality, mood, and cognitive performance depends not only on the light spectral composition but also on the timing of exposure and its intensity. Exposure to blue light during the day is important to suppress melatonin secretion, the hormone that is produced by the pineal gland and plays crucial role in circadian rhythm entrainment. While the exposure to blue is important for keeping organism's wellbeing, alertness, and cognitive performance during the day, chronic exposure to low-intensity blue light directly before bedtime, may have serious implications on sleep quality, circadian phase and cycle durations. This rises inevitably the need for solutions to improve wellbeing, alertness, and cognitive performance in today's modern society where exposure to blue light emitting devices is ever increasing.
Topics: Aging; Behavior; Circadian Rhythm; Color; Humans; Light; Retina
PubMed: 31433569
DOI: 10.1002/jbio.201900102 -
Clinical Microbiology Reviews Oct 2004Mycoplasma pneumoniae is a unique bacterium that does not always receive the attention it merits considering the number of illnesses it causes and the degree of... (Review)
Review
Mycoplasma pneumoniae is a unique bacterium that does not always receive the attention it merits considering the number of illnesses it causes and the degree of morbidity associated with it in both children and adults. Serious infections requiring hospitalization, while rare, occur in both adults and children and may involve multiple organ systems. The severity of disease appears to be related to the degree to which the host immune response reacts to the infection. Extrapulmonary complications involving all of the major organ systems can occur in association with M. pneumoniae infection as a result of direct invasion and/or autoimmune response. The extrapulmonary manifestations are sometimes of greater severity and clinical importance than the primary respiratory infection. Evidence for this organism's contributory role in chronic lung conditions such as asthma is accumulating. Effective management of M. pneumoniae infections can usually be achieved with macrolides, tetracyclines, or fluoroquinolones. As more is learned about the pathogenesis and immune response elicited by M. pneumoniae, improvement in methods for diagnosis and prevention of disease due to this organism may occur.
Topics: Asthma; Humans; Mycoplasma pneumoniae; Pneumonia, Mycoplasma
PubMed: 15489344
DOI: 10.1128/CMR.17.4.697-728.2004 -
Biochemistry and Molecular Biology... Mar 2018Disrupting a gene to determine its effect on an organism's phenotype is an indispensable tool in molecular biology. Such techniques are critical for understanding how a... (Review)
Review
Disrupting a gene to determine its effect on an organism's phenotype is an indispensable tool in molecular biology. Such techniques are critical for understanding how a gene product contributes to the development and cellular identity of organisms. The explosion of genomic sequencing technologies combined with recent advances in genome-editing techniques has elevated the possibilities of genetic manipulations in numerous organisms in which these experiments were previously not readily accessible or possible. Introducing the next generation of molecular biologists to these emerging techniques is key in the modern biology classroom. This comprehensive review introduces undergraduates to CRISPR/Cas9 editing and its uses in genetic studies. The goals of this review are to explain how CRISPR functions as a prokaryotic immune system, describe how researchers generate mutations with CRISPR/Cas9, highlight how Cas9 has been adapted for new functions, and discuss ethical considerations of genome editing. Additionally, anticipatory guides and questions for discussion are posed throughout the review to encourage active exploration of these topics in the classroom. Finally, the supplement includes a study guide and practical suggestions to incorporate CRISPR/Cas9 experiments into lab courses at the undergraduate level. © 2018 The Authors Biochemistry and Molecular Biology Education published by Wiley Periodicals, Inc. on behalf of International Union of Biochemistry and Molecular Biology, 46(2):195-205, 2018.
Topics: CRISPR-Cas Systems; Gene Editing; Molecular Biology; Students; Universities
PubMed: 29381252
DOI: 10.1002/bmb.21108 -
Genetics Nov 2015Fruit flies of the genus Drosophila have been an attractive and effective genetic model organism since Thomas Hunt Morgan and colleagues made seminal discoveries with...
Fruit flies of the genus Drosophila have been an attractive and effective genetic model organism since Thomas Hunt Morgan and colleagues made seminal discoveries with them a century ago. Work with Drosophila has enabled dramatic advances in cell and developmental biology, neurobiology and behavior, molecular biology, evolutionary and population genetics, and other fields. With more tissue types and observable behaviors than in other short-generation model organisms, and with vast genome data available for many species within the genus, the fly's tractable complexity will continue to enable exciting opportunities to explore mechanisms of complex developmental programs, behaviors, and broader evolutionary questions. This primer describes the organism's natural history, the features of sequenced genomes within the genus, the wide range of available genetic tools and online resources, the types of biological questions Drosophila can help address, and historical milestones.
Topics: Animals; Drosophila; Models, Biological; Models, Genetic
PubMed: 26564900
DOI: 10.1534/genetics.115.183392 -
Psychoneuroendocrinology Apr 2019An organism's capacity to cope with stressful experiences is dependent on its ability to appropriately engage central and peripheral systems, such as the...
An organism's capacity to cope with stressful experiences is dependent on its ability to appropriately engage central and peripheral systems, such as the hypothalamic-pituitary-adrenal (HPA) axis, to adapt to changing environmental demands. The HPA axis is a primary neuroendocrine mediator of neural and behavioral responses to stress, and dysfunction of this system is linked to increased risk for developing mental health disorders such as depression, anxiety, and post-traumatic stress disorder. However, the mechanisms by which dysregulated HPA function results in abnormal behavioral responses to stress are poorly understood. Here, we tested how corticosterone (CORT)-induced HPA axis disruption affects behavioral responses to stress in male C57BL/6 N mice, and probed correlates of these behaviors in the brain. We show that chronic HPA disruption blunts acute stress-induced grooming and rearing behaviors in the open field test, effects which were accompanied by decreased FOS immunoreactivity in the paraventricular nucleus of the hypothalamus (PVH) and paraventricular nucleus of the thalamus (PVT). Blockade of CORT secretion with metyrapone injection prior to acute stress did not recapitulate the effects of chronic HPA disruption on open field behavior, and acute CORT replacement did not rescue normal behavioral stress responses following chronic HPA disruption. This suggests that under acute conditions, CORT is not necessary for these responses normally, nor sufficient to rescue the deficits of chronic HPA dysregulation. Together, these findings support the hypothesis that chronic HPA dysregulation causes adaptation in stress-related brain circuits and demonstrate that these changes can influence an organism's behavioral response to stress exposure.
Topics: Animals; Anxiety; Anxiety Disorders; Corticosterone; Depression; Depressive Disorder; Disease Models, Animal; Hypothalamo-Hypophyseal System; Hypothalamus; Male; Mice; Mice, Inbred C57BL; Neurosecretory Systems; Pituitary Gland; Pituitary-Adrenal System; Stress, Psychological
PubMed: 30594817
DOI: 10.1016/j.psyneuen.2018.12.010 -
Biosensors Dec 2022Organs-on-chips (OoCs) are microfluidic devices that contain bioengineered tissues or parts of natural tissues or organs and can mimic the crucial structures and... (Review)
Review
Organs-on-chips (OoCs) are microfluidic devices that contain bioengineered tissues or parts of natural tissues or organs and can mimic the crucial structures and functions of living organisms. They are designed to control and maintain the cell- and tissue-specific microenvironment while also providing detailed feedback about the activities that are taking place. Bioprinting is an emerging technology for constructing artificial tissues or organ constructs by combining state-of-the-art 3D printing methods with biomaterials. The utilization of 3D bioprinting and cells patterning in OoC technologies reinforces the creation of more complex structures that can imitate the functions of a living organism in a more precise way. Here, we summarize the current 3D bioprinting techniques and we focus on the advantages of 3D bioprinting compared to traditional cell seeding in addition to the methods, materials, and applications of 3D bioprinting in the development of OoC microsystems.
Topics: Tissue Engineering; Bioprinting; Microphysiological Systems; Biocompatible Materials; Printing, Three-Dimensional
PubMed: 36551101
DOI: 10.3390/bios12121135