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Results for “Physiology”

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bioRxiv2017

Immediate effects of psychosocial stress on attention depend on subjective experience and not directly on stress-related physiological changes

Acute psychosocial stress is associated with physiological, subjective and cognitive changes. In particular, attention, which is considered one of the main processes driving cognition, has been related to different stress outcomes, such as anxiety, cortisol levels and autonomic responses, individually. Nonetheless, their specific contributions to and association with attention is still not fully understood. To study this association, 42 male participants were asked to perform an attentional task just before and immediately after being exposed to either an experimental treatment designed to induce psychosocial stress using the Trier Social Stress Test (TSST) or a matching stress-free control condition. The salivary cortisol concentration, heart rate, and self-reported anxiety were measured to assess the physiological response to stress and the subjective experience during the protocol. As expected, psychosocial stress induced increases in heart rate, salivary cortisol levels and anxiety. The behavioral analysis revealed that members of the control group performed better on the attentional task after the protocol, while members of the TSST group showed no changes. Moreover, after dividing the stress group into sub-groups of participants with high and low anxiety, we observed that participants in the high-anxiety group not only failed to perform better but also performed worse. Finally, after testing several single-level mediation models, we found that anxiety is sufficient to explain the changes in attention and that it mediates the effects between heart rate and cortisol levels on attention. Our results suggest that the immediate effects of acute psychosocial stress on attention are highly dependent on the participants subjective experience, which, in turn, is affected and can mediate stress-related physiological changes.

neuroscience↗

bioRxiv2018

Seasonal physiological responses to heat in an alpine range-restricted bird: the Cape Rockjumper

Hot, dry summer conditions impose physiological stress on endotherms, yet we have a poor understanding of how endotherms seasonally adjust their costs of thermoregulation under hot conditions. We determined whether seasonal phenotypic plasticity in evaporative cooling capacity at high temperatures explained how the range-restricted Cape Rockjumper (Chaetops frenatus; hereafter \"Rockjumper\"), copes with hot and dry summer temperatures of the temperate mountain peaks of southwest South Africa. We measured evaporative water loss (EWL), resting metabolic rate (RMR), and body temperature (Tb) at high air temperatures (30 to 42{degrees}C) of individuals from a wild population of Rockjumpers during winter and summer (n = 11 winter, 4 females, 7 males; n = 10 summer, 6 females, 4 males). We found Rockjumper evaporative cooling in summer imposes higher EWL (i.e. greater water costs) compared to winter, although an accompanying lack of change in RMR resulted in increased summer cooling efficiency. These patterns are similar to those observed in species that inhabit regions where summer temperatures are routinely hot but not water stressed. Our findings show that avian seasonal physiological adjustments to heat can be diverse. Further seasonal studies on thermoregulation in the heat will greatly improve our knowledge of the functional value traits such as evaporative cooling efficiency and heat tolerance hold and how they contribute to the physiological stress organisms experience in heterogenous environments.

zoology↗

bioRxiv2018

When metabolism meets physiology: Harvey and Harvetta

Precision medicine is an emerging paradigm that requires realistic, mechanistic models capturing the complexity of the human body. We present two comprehensive molecular to physiological-level, gender-specific whole-body metabolism (WBM) reconstructions, named Harvey, in recognition of William Harvey, and Harvetta. These validated, knowledge-based WBM reconstructions capture the metabolism of 20 organs, six sex organs, six blood cells, the gastrointestinal lumen, systemic blood circulation, and the blood-brain barrier. They represent 99% of the human body weight, when excluding the weight of the skeleton. Harvey and Harvetta can be parameterized based on physiological, dietary, and omics data. They correctly predict inter-organ metabolic cycles, basal metabolic rates, and energy use. We demonstrate the integration of microbiome data thereby allowing the assessment of individual-specific, organ-level modulation of host metabolism by the gut microbiota. The WBM reconstructions and the individual organ reconstructions are available under http://vmh.life. Harvey and Harvetta represent a pivotal step towards virtual physiological humans.

systems biology↗

bioRxiv2018

Physiology and lipid accumulation capacity of different Yarrowia lipolytica and Rhodosporidium toruloides strains on glycerol

ObjectiveTo compare physiological and process parameters, as well as lipid accumulation capacity, of six strains of Yarrowia lipolytica and two strains of Rhodosporidium toruloides in media containing glycerol as the main carbon and energy source.\n\nResultsThe strains Y. lipolytica IMUFRJ 50678, Po1g, W29 and CCT 5443 displayed very similar physiological parameters, with {micro}max, [Formula] and [Formula] average values of 0.31 h-1, 0.53 (g DW/g S), 0.60 (g S/g DW.h) and 0.46 (g DW/g S), respectively. The two strains of R. toruloides presented physiological and process parameters with no significant difference, with average values of 0.084 h-1, 0.53 (g DW/g S), 0.17 (g S/g DW.h) and 0.44 (g DW/g S). Among all Y. lipolytica strains, Y. lipolytica CCT 5443 strain presented the highest YLip/S, 0.054 (g Lip/g S), and PLipof 0.040 (g Lip/l.h). Among all investigated strains (Y. lipolytica and R. toruloides), the yeast R. toruloides CCT 7815 displayed the highest lipid accumulation capacity, with YLip/Sequal to 0.11 (g Lip/g S) and PLipequal to 0.10 (g Lip/l.h).\n\nConclusionAmong all strains investigated in our study, the yeast strain R. toruloides CCT 7815 presents the most promising characteristics for industrial single cell oil production.\n\nList of abbreviations

microbiology↗

bioRxiv2018

Physiological Characteristics of Viable-but-nonculturable Vibrio parahaemolyticus upon Prolonged Exposure to the Refrigerator Temperature

Although it has been reported that viable-but-nonculturable (VBNC) cells of Vibrio parahaemolyticus can be developed by a prolonged duration of cold-starvation there are restricted cellular characteristics available on understanding the exact mechanisms governing the entry of pathogens into the VBNC state. Therefore, this research was aimed at determining the cellular profile of VBNC cells of V. parahaemolyticus upon exposure to the refrigerator temperature. Strains of V. parahaemolyticus were incubated in artificial sea water (ASW) microcosms (pH 6) added with different amounts of NaCl at 4{degrees}C until these pathogens entered into such a dormant state. At a regular time-interval, both culturability and viability of these bacteria were enumerated, and then cellular profiling were carried out in terms of cellular membrane permeability, enzymatic activity, hydrophobicity, fatty acid composition, and morphological changes after cells of V. parahaemolyticus became the VBNC state. Three strains of V. parahaemolyticus used in this study showed that VBNC cells retained the strong virulent properties to Vero and CACO-2 cell lines, re-gained the cytotoxicity even after resuscitation, became permeabilized in terms of the outer membrane, showed lower levels of enzymatic (catalase and glutathione-S-transferase) activities, exerted the increasing hydrophobicity, and then exhibited increasing amounts of saturated fatty acids.\n\nIMPORTANCETo the current best knowledge, there are restricted information available on understanding the physiological characterization of viable-but-nonculturable cells. Most previous studies are still making a degree of efforts in discovering the causative effector causing microorganisms to be induced into the VBNC state. Herein, the present study showed that pathogenic V. parahaemolyticus can enter into the VBNC state when challenged by a certain environmental stress where higher amounts of NaCl combined with acidic pHs was artificially controlled. Importantly, it was indicated that VBNC V. parahaemolyticus maintained peculiarly different physiological characteristics. Furthermore, this study proposed a novel approach on the transient/stepwise conversion of the bacteria into the VBNC state. Specific alternative tools for measuring and controlling the incidence of VBNC pathogens on food are not established until now. In this aspect, results obtained from this study will used to provide an effective insight in determining physiological properties of viable-but-nonculturable V. parahaemolyticus.

microbiology↗

bioRxiv2018

Protein nitration is a physiological regulator of cardiac lactate dehydrogenase active site loop mobility and activity

Protein tyrosine nitration is a hallmark of oxidative stress related disease states, commonly detected as anti-nitrotyrosine immunoreactivity. The precise reactive oxygen sources, mechanisms of nitration as well as the modified target proteins and functional consequences, however, remain often unclear. Here we explore protein tyrosine nitration under basal conditions and find surprisingly physiologically nitrated proteins. Upon purifying a prominent physiologically nitrotyrosine immunopositive in hearts from mouse, rat and pig, we identify it as lactate dehydrogenase (LDH). Mechanistically, LDHs degree of basal nitration depended on two canonical sources, NO synthase (NOS) and myeloperoxidase (MPO), respectively. When validating the nitrated amino acid by MALDI-TOF mass spectrometry, we, surprisingly, located LDH nitration not to a tyrosine but the C-terminal tryptophan, Trp324. Molecular dynamics simulations suggested that Trp324 nitration restricts the interaction of the active site loop with the C-terminal -helix essential for activity. This prediction was confirmed by enzyme kinetics revealing an apparent lower Vmax of nitrated LDH, although yet unidentified concurrent oxidative modifications may contribute. Protein nitration is, thus, not a by definition disease marker but reflects also physiological signaling by eNOS/NO, MPO/nitrite and possibly other pathways. The commonly used assay of anti-nitrotyrosine immunoreactivity is apparently cross-reactive to nitrotryptophan requiring a reevaluation of the protein nitration literature. In the case of LDH, nitration of Trp324 is aggravated under cardiac metabolic stress conditions and functionally limits maximal enzyme activity. Trp324-nitrated LDH may serve both as a previously not recognized disease biomarker and possibly mechanistic lead to understand the metabolic changes under these conditions.

biochemistry↗

bioRxiv2018

Cognitive self-regulation influences pain-related physiology

Cognitive self-regulation can shape pain experience, but its effects on autonomic responses to painful events are unclear. In this study, participants (N = 41) deployed a cognitive strategy based on reappraisal and imagination to regulate pain up or down on different trials while skin conductance responses (SCR) and electrocardiogram (ECG) activity were recorded. Using a machine learning approach, we first developed stimulus-locked SCR and ECG physiological markers predictive of pain ratings. The physiological markers demonstrated high sensitivity and moderate specificity in predicting pain across two datasets, including an independent test dataset (N = 84). When we tested the markers on the cognitive self-regulation data, we found that cognitive self-regulation had significant impacts on both pain ratings and pain-related physiology in accordance with regulatory goals. These findings suggest that self-regulation can impact autonomic nervous system responses to painful stimuli and provide pain-related autonomic profiles for future studies.

neuroscience↗

bioRxiv2018

Noninvasive Vagus Nerve Stimulation Alters Neural Response and Physiological Autonomic Tone to Noxious Thermal Challenge

The mechanisms by which noninvasive vagal nerve stimulation (nVNS) affect central and peripheral neural circuits that subserve pain and autonomic physiology are not clear, and thus remain an area of intense investigation. Effects of nVNS vs sham stimulation on subject responses to five noxious thermal stimuli (applied to left lower extremity), were measured in 30 healthy subjects (n=15 sham and n=15 nVNS), with fMRI and physiological galvanic skin response (GSR). With repeated noxious thermal stimuli a group x time analysis showed a significantly (p < .001) decreased response with nVNS in bilateral primary and secondary somatosensory cortices (SI and SII), left dorsoposterior insular cortex, bilateral paracentral lobule, bilateral medial dorsal thalamus, right anterior cingulate cortex, and right orbitofrontal cortex. A group x time x GSR analysis showed a significantly decreased response in nVNS group (p < .0005) in bilaterally in SI, lower and mid medullary brainstem, and inferior occipital cortex. Finally, nVNS treatment showed decreased activity in pronociceptive brainstem nuclei (e.g. the reticular nucleus and rostral ventromedial medulla) and key autonomic integration nuclei (e.g. the rostroventrolateral medulla, nucleus ambiguous, and dorsal motor nucleus of the vagus nerve). In aggregate, noninvasive vagal nerve stimulation reduced the physiological response to noxious thermal stimuli and impacted neural circuits important for pain processing and autonomic output.

neuroscience↗

bioRxiv2018

A physiology-based model of bile acid metabolism shows altered tissue concentrations after drug administration and in specific genotype subgroups

Drug-induced liver injuries (DILI) are an important issue in drug development and patient safety and often lead to termination of drug-development programs or late withdrawals of drugs. Since DILI events are hard to diagnose in preclinical settings, a need for alternative prediction methods such as computational modeling emerges. Impairment of bile acid (BA) metabolism, known as cholestasis, is a frequent form of DILI. Being rather a systemic then a single organ related disease, whole-body physiology-based modeling is a predestined approach for cholestasis modeling. The objectives of the presented study were 1) the development of a physiology-based model for human bile acid metabolism, 2) model validation and characterization for a virtual population, and 3) prediction and quantification of the effects of genetic predispositions and drug interaction on bile acid metabolism. The developed physiology-based bile acid (PBBA) model is based on the standard PBPK model of PKSim(R) and describes the bile acid circulation in a healthy reference individual. Active processes such as the hepatic synthesis, gallbladder emptying upon meal intake, transition through the gastrointestinal tract, reabsorption into the liver, distribution within the body, and excretion are included. The kinetics of active processes for the surrogate BA glycochenodeoxycholic acid were fitted to time-concentration profiles of blood BA levels reported in literature. The robustness of our PBBA model is underlined by the comparison of simulated plasma BA concentrations in a virtual population of 1,000 healthy individuals with reported data. In addition to plasma concentrations, the PBBA model allows simulations of BA exposure in relevant tissues like the liver and can therefore enhance the mechanistic understanding of cholestasis. This feature was used to analyse the reported increased risk of cholestatic DILI in Benign Recurrent Intrahepatic Cholestasis type 2 (BRIC2) patients. Simulations of the PBBA model suggest a higher susceptibility of BRIC2 patients towards cholestatic DILI due to BA accumulation in hepatocytes. Apart from these intrinsic effects, drug-interactions and their effect on the systemic bile acid metabolism were simulated by combining the PBBA model with a drug PBPK model of cyclosporine A (CsA). The results of which confirmed the reported higher risk of developing DILI as a consequence of CsA intake. Altogether, the presented model enhances our mechanistic understanding of cholestasis, allows the identification of drug-interactions leading to altered BA levels in blood and organs, and could be used to prevent clinical cases of cholestasis and enhance patient safety.

systems biology↗

bioRxiv2026

Cross-Kingdom Control: Yeast Prion Protein Modulates Host Physiology in Drosophila

Prions, once mainly studied for their pathogenic roles, are now gaining recognition as adaptive elements in microbial physiology. Over one-third of wild yeast isolates harbor prion proteins, yet their impact on host-microbe interactions remains poorly characterized. Given the ecological dominance of yeasts in the Drosophila mycobiome, we leveraged the Drosophila melanogaster-Saccharomyces cerevisiae system to investigate how the mycobiome-derived prion, [MRPL10+], modulates host physiology. We show that flies exposed to [MRPL10+] yeast exhibit significantly enhanced cold tolerance and increased locomotor activity. This effect persists with heat-killed yeast and diluted culture, suggesting a stable, potent bioactive factor. Using the genetically diverse Drosophila Global Diversity Lines (GDL), we identified natural variation in responsiveness to [MRPL10+] yeast. Genome-wide association and functional RNAi screening revealed a gut-brain signaling axis involving genes critical for digestion, intercellular communication, transcription regulation, and neural transmission. Notably, serotonin and octopamine pathways were essential for [MRPL10+]-induced changes in cold tolerance and locomotion, implicating neuromodulatory circuits in prion-mediated microbial signaling. Our findings establish a mechanistic link between a fungal prion and host metabolic and neural adaptation. This work provides the first genetic dissection of a prion-mediated host-microbe interaction, laying the groundwork for investigating beneficial prions in complex microbial communities and highlighting a new dimension of the mycobiomes influence on animal physiology.

evolutionary biology↗

bioRxiv2016

The Divisive-Normalization Model of V1 Neurons: A Comprehensive Comparison of Physiological Data and Model Predictions

The physiological responses of simple and complex cells in the primary visual cortex (V1) have been studied extensively and modeled at different levels. At the functional level, the divisive normalization model (DNM, Heeger, 1992) has accounted for a wide range of single-cell recordings in terms of a combination of linear filtering, nonlinear rectification, and divisive normalization. We propose standardizing the formulation of the DNM and implementing it in software that takes static grayscale images as inputs and produces firing-rate responses as outputs. We also review a comprehensive suite of 30 empirical phenomena and report a series of simulation experiments that qualitatively replicate dozens of key experiments with a standard parameter set consistent with physiological measurements. This systematic approach identifies novel falsifiable predictions of the DNM. We show how the model simultaneously satisfies the conflicting desiderata of flexibility and falsifiability. Our key idea is that, while adjustable parameters are needed to accommodate the diversity across neurons, they must be fixed for a given individual neuron. This requirement introduces falsifiable constraints when this single neuron is probed with multiple stimuli. We also present mathematical analyses and simulation experiments that explicate some of these constraints.

physiology↗

bioRxiv2018

Effects of different load on physiological, hematological, biochemical, cytokines indices of Zanskar ponies at high altitude

High altitude people required high endurance pack animals for load carrying and riding at prevalent mountainous terrains and rugged region. So far no studies have been taken to evaluate effect of loads on physiology of ponies in high altitude region. So, in this view we evaluated variation in physiological, hematological, biochemical, and cytokines indices of Zanskar ponies during load carrying at high altitude. Total twelve (12) numbers of Zanskar ponies, mare, age 4-6 years, were divided into three groups; group-A (without load), group-B (60 kg), and group-C (80 kg) of back pack loads. Track was very narrow and slippery with gravel, uneven with rocky surface and has a steep gradient of 4 km uphill at altitude 3291 to 3500 m. When we evaluate these parameters, it is understood that the heart rate, pulse rate and respiration rate was significantly (p<0.05) increased in 80 kg group among the three groups. The hematology parameters viz. hemoglobin, PCV, lymphocytes, monocytes%, ESR and eosinophil% significantly (p<0.05) changed in 80 kg group after load carrying among the three groups which was followed by control and 60 kg group. In biochemical parameters viz. LA, LDH, TP, HK, CORT, T3, CRT, AST, CK-MB, GPx, FRAP and IL-6 significantly (p<0.05) changed in 80 kg group after load carrying among the three groups which was followed by control and 60 kg group. The ALT, ALB, GLB, UR and UA significantly (p<0.05) changed in 80 kg group before and after load carrying among the three groups which was followed by control and 60 kg group. It has been concluded that, this result has revealed strong correlation of change in biomarkers level with performance in ponies during load carry. Hence, these parameters might be use for performance of endurance of Zanskar ponies in high mountain region.

physiology↗

bioRxiv2016

Physiological reason for ceasing growth of unfertilized eggs produced by unmated queens in the subterranean termite Reticulitermes chinensis

In Reticulitermes chinensis, a close relative of R. speratus with asexual queen succession, unfertilized eggs can be produced but are not incubated. To explain this phenomenon, we analysed the physiological differences between unfertilized eggs/unmated queens and fertilized eggs/mated queens. Fertilized eggs consumed significantly larger quantities of five amino acids (Cys, Met, Ile, Leu and Tyr), Ca, protein and cholesterol during incubation. The higher levels of four trace elements (Na, K, Zn and Fe) in fertilized eggs and their lower levels in mated queens indicated that mated queens might transfer these trace elements to fertilized eggs to complete incubation. The higher levels of Mn, triglycerides and serotonin in mated queens and higher levels of Mn and glucose in fertilized eggs suggested that these substances are very important for normal ovarian and embryonic growth. The different expression of three reproductive genes (vtgl, rabil and JHE1) suggested that they might be involved in the regulation of ovarian and embryonic growth. Overall, changes in these physiological indices may substantially affect ovarian and embryonic growth and prohibit the incubation of unfertilized eggs in R. chinensis.

Zoology↗

bioRxiv2016

When the Good Guy Becomes the Bad Boy: Social Information Modulates the Neural, Physiological and Subjective Responses to Emotional Facial Expressions

In the past decade, different studies have suggested that high-order factors could influence the perceptual processing of emotional stimuli. In this study, we aimed to evaluate the effect of congruent vs. incongruent social information (positive, negative or no information related to the character of the target) on subjective (perceived and felt valence and arousal), physiological (facial mimicry) as well as on neural (P100 and N170) responses to dynamic emotoional facial expressions (EFE) that varied from neutral to one of the six basic emotions. Across three studies, the results showed (1) reduced valence and arousal evaluation of EFE when associated with incongruent social information (Study 1), (2) increased electromyographical responses (Study 2) and significant modulation of P100 and N170 components (Study 3) when EFE were associated with social (positive and negative) information (vs. no information). These studies revealed that positive or negative social information reduced subjective responses to incongruent EFE and produces a similar neural and physiological boost of the early perceptual processing of EFE irrespective of their congruency. In conclusion, this study suggested that social context (positive or negative) enhances the necessity to be alert to any subsequent cues.

Neuroscience↗

bioRxiv2016

A unified coarse-grained theory of bacterial physiology explains the relationship between cell size, growth rate and proteome composition under various growth limitations

Universal observations in Biology are sometimes described as "laws". In E. coli, experimental studies performed over the past six decades have revealed major growth laws relating ribosomal mass fraction and cell size to the growth rate. Because they formalize complex emerging principles in biology, growth laws have been instrumental in shaping our understanding of bacterial physiology. Here, we discovered a novel size law that connects cell size to the inverse of the metabolic proteome mass fraction and the active fraction of ribosomes. We used a simple whole-cell coarse-grained model of cell physiology that combines the proteome allocation theory and the structural model of cell division. The model captures all available experimental data connecting the cell proteome composition, ribosome activity, division size and growth rate in response to nutrient quality, antibiotic treatment and increased protein burden. Finally, a stochastic extension of the model explains non-trivial correlations observed in single cell experiments including the adder principle. This work provides a simple and robust theoretical framework for studying the fundamental principles of cell size determination in unicellular organisms.

Biophysics↗

bioRxiv2017

The collective influence of 1, 25-dihydroxyvitamin D3 with physiological fluid shear stress on osteoblasts

1, 25-dihydroxyvitamin D3 (1, 25 (OH)2 D3) and mechanical stimuli in physiological environment play an important role in the pathogenesis of osteoporosis. The effects of 1, 25-dihydroxyvitamin D3 alone and mechanical stimuli alone on osteoblasts have been widely investigated. This study reports the collective influences of 1, 25-dihydroxyvitamin D3 and flow shear stress (FSS) on biological functions of osteoblasts. 1, 25 (OH)2 D3 were constructed in various kinds of concentration (0, 1, 10, 100 nmmol/L), while physiological fluid shear stress (12 dynes/cm2) were produced by using a parallel-plate fluid flow system. 1, 25 (OH)2 D3 affects the responses of ROBs to FSS, including the inhibition of NO releases and cell proliferation as well as the promotion of PGE2 releases and cell differentiation. These findings provide a possible mechanism by which 1, 25(OH)2 D3 influences osteoblasts responses to FSS and may provide guidance for the selection of 1, 25(OH)2 D3 concentration and mechanical loading in order to in vitro produce functional bone tissues.

cell biology↗

bioRxiv2017

Massive Phenotypic Measurements Reveal Complex Physiological Consequences Of Differential Translation Efficacies

AO_SCPCAPBSTRACTC_SCPCAPControl of protein biosynthesis is at the heart of resource allocation and cell adaptation to fluctuating environments. One genes translation often occurs at the expense of anothers, resulting in global energetic and fitness trade-offs during differential expression of various functions. Patterns of ribosome utilization--as controlled by initiation, elongation and release rates--are central to this balance. To disentangle their respective determinants and physiological impacts, we complemented measurements of protein production with highly parallelized quantifications of transcripts abundance and decay, ribosome loading and cellular growth rate for 244,000 precisely designed sequence variants of an otherwise standard reporter. We find highly constrained, non-monotonic relationships between measured phenotypes. We show that fitness defects derive either from protein overproduction, with efficient translation initiation and heavy ribosome flows; or from unproductive ribosome sequestration by highly structured, slowly initiated and overly stabilized transcripts. These observations demonstrate physiological impacts of key sequence features in natural and designed transcripts.

synthetic biology↗

bioRxiv2018

Physiological motion of the carotid atherosclerotic plaque quantified using ultrasound B-Mode image analysis

BackgroundPhysical motion throughout the cardiac cycle may contribute to the rupture of the atherosclerotic carotid plaque, resulting in ischaemic stroke. The purpose of this study was to quantify the physiological motion of the atherosclerotic carotid plaque and to investigate any relationship between the quantified motion parameters and the degree of stenosis, greyscale plaque characteristics, and the presence of cerebrovascular symptoms.\n\nMethodsDisplacement, velocity and acceleration of 81 plaques (51% symptomatic, stenosis range 10%-95%) from 51 patients were measured using an automated system employing a block matching algorithm relative to the ultrasound probe and relative to the periadventitial tissues, over a mean duration of 5 cardiac cycles.\n\nResultsAveraged across all plaques, the displacement amplitude was 1.2 mm relative to the probe, and 0.35 mm relative to the periadventitial tissues. Maximum and mean plaque velocities were 4.7 and 1.3 mm/s relative to the ultrasound probe, and 2.4 and 0.70 mm/s relative to the periadventitial tissues. The corresponding acceleration magnitudes were 69 and 22 mm/s2 relative to the probe, and 57 and 18 mm/s2 relative to the periadventitial tissues. There were no significant differences in any of the motion parameters, with respect to the presence of cerebrovascular symptoms, and none of the parameters showed a statistically significant relationship to the degree of stenosis, and the greyscale plaque characteristics (p[≤]0.05). The technique used was able to detect plaque motion amplitudes above 50m.\n\nConclusionsThis study provides quantitative data on the physiological motion of the atherosclerotic carotid plaque in-vivo. No significant relationship was found between the measured motion parameters and the presence of cerebrovascular symptoms, the degree of stenosis, and the greyscale plaque characteristics.

biophysics↗