Stars of the Tactile World

Secret Worlds ◽  
2021 ◽  
pp. 107-135
Author(s):  
Martin Stevens
Keyword(s):  
High Sensitivity ◽  
Microscopic Level ◽  
Sensory Cells ◽  
Prey Detection ◽  
Tactile Information ◽  
Mechanical Information ◽  
Physical Forces ◽  
And Function ◽  
Eimer's Organ ◽  
Slit Sensilla

This chapter addresses the supreme level of refinement found in many animals for analysing tactile and pressure information. It begins by looking at the sensory organ of the star-nosed mole. The mole’s star-shaped organ is used purely for collecting tactile information. The chapter then considers the Eimer’s organs which cover every appendage that comprises the nose, some of which are used for initial prey detection, while others are for identification. Owing to the number of Eimer’s organs, their tiny size, and the way that the sensory cells respond to patterns of stimulation across parts of each individual Eimer’s organ, the mole obtains exquisite detail on texture, almost to a microscopic level. The chapter also discusses the highly refined tactile sense of spiders, looking at how they rely on vibrations transmitted through the ground, the silk web strands, or the surface waves and air for prey detection and capture. Spiders are equipped with a variety of sensors to detect mechanical information, including fine hairs sensitive to wind movement and touch, and special organs called slit sensilla around the joints of legs that measure physical forces acting on the exoskeleton. Finally, the chapter studies the nature and function of integumentary sense organs or ISOs in both crocodiles and alligators. The heavily built bodies of crocodiles and alligators belie a high sensitivity, being able to detect the slightest changes in touch and pressure.

Abstract 4336: Interrogating the Human Myocardial Interstitium during Myocardial Arrest and Reperfusion: Dynamic Changes in Cytokines and Protease Activity

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Robert E Stroud ◽  
Christine N Koval ◽  
Isabelle Gengler ◽  
Anne M Deschamps ◽  
John S Ikonomidis ◽  
...  
Keyword(s):  
Detection System ◽  
Ischemia Reperfusion ◽  
Dynamic Assessment ◽  
High Sensitivity ◽  
Fluorescent Detection ◽  
Suspension Array ◽  
Cytokine Analysis ◽  
And Function ◽  
Inflammatory Molecules ◽  
Pulmonary Bypass

Background. Cytokines, such as the interleukins (IL1β, IL2, IL6) and tumor necrosis factor (TNF) can modulate myocardial structure and function with ischemia/reperfusion (I/R) but dynamic assessment of these biological molecules within the human myocardial interstitium with I/R has not been performed, and the inter-relationship to matrix metalloproteinases activity (MMPact) remains unexplored. Accordingly, a fluorogenic microdialysis method was used to simultaneously measure myocardial interstitial cytokine levels and MMPact in patients during and following I/R. Methods . MMPact was measured in patients (n=13) undergoing cardio-pulmonary bypass (CPB) at baseline, during myocardial arrest and CPB (on-CPB), and immediately following reperfusion and separation from CPB (post-CPB) by a validated in-line microdialysis fluorescent detection system. Myocardial interstitial fluid was subjected to cytokine analysis by high sensitivity multiplex suspension array. Results . Interstitial MMPact increased by over 30% post-CPB and was accompanied by a specific change in cytokine profiles (Figure ). The classical pro-inflammatory molecules such as TNF and IL6 were either not detectable or unchanged, whereas IL1β and IL2 which can be proinflammatory, were increased. Conclusions. These unique results demonstrated that a dynamic cytokine signature occurs within the human myocardial interstitium following I/R and is temporally related to heightened MMP activity. Direct interrogation of the human myocardial interstitium may provide a unique insight into critical signaling pathways which may evoke adverse structural and functional events following I/R.

scholarly journals Expression of an epidermal keratin protein in liver of transgenic mice causes structural and functional abnormalities.

1995 ◽  
Vol 128 (1) ◽  
pp. 157-169 ◽  
Author(s):  
K M Albers ◽  
F E Davis ◽  
T N Perrone ◽  
E Y Lee ◽  
Y Liu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cell Structure ◽  
Structure And Function ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Inflammatory Infiltration ◽  
Intermediate Filament Proteins ◽  
And Function

To examine the role of keratin intermediate filament proteins in cell structure and function, transgenic mice were isolated that express a modified form of the human K14 keratin protein in liver hepatocytes. A modified K14 cDNA (K14.P) sequence was linked downstream of the mouse transthyretin (TTR) gene promoter and enhancer elements to achieve targeted expression in hepatocytes. Hepatocytes expressing high levels of the transgene were found to have abnormal keratin filament networks as detected by indirect immunofluorescence using an antibody specific for the transgene product. Light and electron microscopic level histological analysis of isolated liver tissue showed in many cases degenerative changes that included inflammatory infiltration, ballooning degeneration, an increase in fat containing vacuoles, and glycogen accumulation. These changes were most evident in older mice over four months of age. No indication of typical Mallory body structures were identified at either the light or electron microscopic level. To evaluate secretory function in transgenic livers, bile acid secretion rates were measured in isolated perfused liver and found to be approximately twofold lower than aged-matched controls. These findings indicate that expression of an abnormal keratin in liver epithelial cells in the in vivo setting can alter the structure and function of a tissue and suggest a role of the keratin network in cellular secretion.

Questionnaire on sexual attitude and function 2009: a novel clinical and epidemiological computer based tool

2011 ◽  
Vol 26 (S2) ◽  
pp. 1553-1553
Author(s):  
K.K. Pirkalani ◽  
Z. Talaee Rad
Keyword(s):  
Sensitivity And Specificity ◽  
Computer Software ◽  
High Sensitivity ◽  
Sexual Attitude ◽  
Sexual Problems ◽  
Medical Documentation ◽  
Face To Face ◽  
Icd 10 ◽  
Almost All ◽  
And Function

ObjectiveTo study sexual problems of our patients and standardizing it for patients with or without religious and cultural restrains we developed a questionnaire with 240 phrases that were extracted from a pool of 1400 sentences addressing sexual problems. Sixty four scales under four headings (sexual general characteristics, deviations, dysfunctions and psychodynamic syndromes) (16 items each) were evaluated based on criteria of DSM-IV and ICD 10. Five validity scales (honesty, desirability, debasement, guilt feeling and overall validity) were also used for better assessment.MethodsA total of 1300 patients in the four variants of the test were evaluated during a time span of 7 years. The questions were presented to examinees at 8th. Grade and higher in a calm environment and the results were evaluated by a computer software specifically developed for this purpose.ResultsThe last version of the test was completed by 734 patients with excellent compliance. It was of nice politeness and comprehensiveness. For almost all scales the sensitivity and specificity were around 85 and 92% respectively.ConclusionWe conclude that QSAF 2009 is an excellent tool both in clinics (diagnosis and follow up) and epidemiology with high sensitivity and specificity. It has also application in cross cultural studies, medico - legal issues and medical documentation. It prevents face to face interviews, breaks patients’ resistance and is less time consuming than scheduled interviews.

scholarly journals Spontaneous and coordinated Ca2+ activity of cochlear sensory and non-sensory cells drives the maturation of OHC afferent innervation

2018 ◽  
Author(s):  
Federico Ceriani ◽  
Aenea Hendry ◽  
Jing-Yi Jeng ◽  
Stuart L. Johnson ◽  
Jennifer Olt ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Outer Hair Cells ◽  
Fine Tuning ◽  
Sensory Cells ◽  
Early Postnatal Development ◽  
Acoustic Stimuli ◽  
Ribbon Synapses ◽  
Immature Development ◽  
Afferent Innervation

Outer hair cells (OHCs) are highly specialized sensory cells conferring the fine tuning and high sensitivity of the mammalian cochlea to acoustic stimuli. Here, by genetically manipulating spontaneous Ca2+ signalling in vivo, through a period of early postnatal development, we find that the refinement of OHC afferent innervation is regulated by complementary spontaneous Ca2+ signals originating in OHCs and non-sensory cells. OHCs fire spontaneous Ca2+ spikes during a narrow period of immature development. Simultaneously, waves of Ca2+ activity in the non-sensory greater epithelial ridge act, via ATP-induced activation of P2X receptors, to synchronize OHC firing, resulting in the refinement of their afferent innervation. In the absence of connexin channels Ca2+ waves are impaired, leading to a reduction in the number of ribbon synapses and afferent fibres on OHCs. We propose that the correct maturation of the afferent connectivity in OHCs requires experience-independent Ca2+ signals from sensory and non-sensory cells.

scholarly journals Expression and function of receptors for stem cell factor and erythropoietin during lineage commitment of human hematopoietic progenitor cells

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1594-1607 ◽  
Author(s):  
J Olweus ◽  
LW Terstappen ◽  
PA Thompson ◽  
F Lund-Johansen
Keyword(s):  
Stem Cell ◽  
Progenitor Cells ◽  
Stem Cell Factor ◽  
Progenitor Cell ◽  
High Sensitivity ◽  
Receptor Expression ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cells ◽  
Fluorescence Measurements ◽  
And Function

The aim of the present study was to determine whether stem cell factor (SCF) and erythropoietin (EPO) act differently on defined subsets of progenitor cells, and if potential differences correlate with the receptor density on each subset. To investigate this possibility directly, we optimized conditions for the identification and purification of homogeneous progenitor cell subpopulations from human bone marrow. Populations containing 40% and 44% colony forming cells (CFCs) with 99% and 95% purity for the granulomonocytic and erythroid lineage, respectively, were sorted on the basis of differential expression of CD34, CD64, and CD71. In addition, a population containing 67% CFCs, of which 29–43% were CFU-MIX, was sorted from CD34hi CD38loCD50+ cells. Purified progenitor cell subsets were compared directly for responsiveness to SCF and EPO using a short-term proliferation assay. Expression of the receptors for SCF and EPO were then examined on each subset using a flow cytometer modified for high- sensitivity fluorescence measurements. The results show that EPO induces extensive proliferation of erythroid progenitor cells, but has no effect on the proliferation or survival of primitive or granulomonocytic progenitors, even when used in combination with other cytokines. The majority of erythroid progenitor cells furthermore stained positively with anti-EPO receptor (EPO-R) monoclonal antibodies, whereas other progenitor cells were negative. SCF alone induced extensive proliferation of erythroid progenitor cells, and had a stronger synergistic effect on primitive than on granulo-monocytic progenitors. In spite of these differences in SCF activity, there were no significant differences in SCF-R expression between the progenitor subsets. These results suggest that the selective action of EPO on erythropoiesis is determined by lineage-restricted receptor expression, whereas there are additional cell-type specific factors that influence progenitor cell responses to SCF.

Outer Hair Cells Provide Active Tuning in the Organ of Corti

Physiology ◽  
1998 ◽  
Vol 13 (3) ◽  
pp. 107-111 ◽  
Author(s):  
Mats Ulfendahl ◽  
Åke Flock
Keyword(s):  
Mechanical Behavior ◽  
Hair Cells ◽  
Organ Of Corti ◽  
High Sensitivity ◽  
Outer Hair Cells ◽  
Sensory Cells ◽  
Effector Cells ◽  
Hearing Organ

The detection of sound by the mammalian hearing organ, the organ of Corti, is far from a passive process with the sensory cells acting as mere receptors. The high sensitivity and sharp tuning of the auditory apparatus are very much dependant on the active mechanical behavior of the outer hair cells, acting as effector cells.

A Laboratory Exercise to Explore Sustained Gravitational-Force Tolerance by Insects

2015 ◽  
Vol 77 (9) ◽  
pp. 707-709
Author(s):  
W. Wyatt Hoback ◽  
Adrianne Pursley ◽  
Kerri Farnsworth-Hoback ◽  
Leon G. Higley
Keyword(s):  
Gravitational Force ◽  
Structure And Function ◽  
Background Information ◽  
Biological Processes ◽  
Scientific Process ◽  
Laboratory Exercise ◽  
Physical Forces ◽  
And Function

This exercise examines the correlation between gravitational-force (g-force) tolerance and the sizes of organisms, emphasizing differences between vertebrates and invertebrates, particularly the effects of size and scale on biological processes. Students form a hypothesis based on background information and then test it by spinning subjects in a centrifuge. Class results can be graphed, analyzed, and compared to human tolerance. The activity engages students in scientific process while investigating the effects of physical forces on structure and function.

scholarly journals Mechanosignaling in the vasculature: emerging concepts in sensing, transduction and physiological responses

2015 ◽  
Vol 308 (12) ◽  
pp. H1451-H1462 ◽  
Author(s):  
Shampa Chatterjee ◽  
Keigi Fujiwara ◽  
Néstor Gustavo Pérez ◽  
Masuko Ushio-Fukai ◽  
Aron B. Fisher
Keyword(s):  
Cellular Proliferation ◽  
Signaling Cascades ◽  
Physical Force ◽  
Society Meeting ◽  
Receptor Kinases ◽  
Final Response ◽  
Pan American ◽  
Physical Forces ◽  
And Function ◽  
Cellular Components

Cells are constantly exposed to mechanical forces that play a role in modulating cellular structure and function. The cardiovascular system experiences physical forces in the form of shear stress and stretch associated with blood flow and contraction, respectively. These forces are sensed by endothelial cells and cardiomyocytes and lead to responses that control vascular and cardiac homeostasis. This was highlighted at the Pan American Physiological Society meeting at Iguassu Falls, Brazil, in a symposium titled “Mechanosignaling in the Vasculature.” This symposium presented recent research that showed the existence of a vital link between mechanosensing and downstream redox sensitive signaling cascades. This link helps to transduce and transmit the physical force into an observable physiological response. The speakers showcased how mechanosensors such as ion channels, membrane receptor kinases, adhesion molecules, and other cellular components transduce the force via redox signals (such as reactive oxygen species and nitric oxide) to receptors (transcription factors, growth factors, etc.). Receptor activated pathways then lead to cellular responses including cellular proliferation, contraction, and remodeling. These responses have major relevance to the physiology and pathophysiology of various cardiovascular diseases. Thus an understanding of the complex series of events, from the initial sensing through the final response, is essential for progress in this field. Overall, this symposium addressed some important emerging concepts in the field of mechanosignaling and the eventual pathophysiological responses.

Sign in / Sign up

Export Citation Format

Share Document