scholarly journals Specificity of manifestation of functional asymmetry microcirculation parameters at physical loads on the upper limbs

2019 ◽  
Vol 18 (4) ◽  
pp. 37-44
Author(s):  
L. V. Mezentseva
Keyword(s):  
Blood Flow ◽  
Standing Position ◽  
Functional Asymmetry ◽  
Upper Limbs ◽  
Initial State ◽  
Doppler Flowmetry ◽  
Flow Fluctuations ◽  
Left And Right ◽  
Specific Regulation ◽  
The Right

Purpose – the study the functional asymmetry of oscillatory processes of microcirculatory bed at physical loads on the upper limbs.Material and methods. Microcirculation parameters were measured in 5 healthy volunteers (men aged 50–55 years) by laser Doppler flowmetry (LDF). LDF signal sensors were fixed symmetrically on the lower parts of the right and left shoulders (3 cm above the elbow bend). Physical exercise consisted of machs left or right hand in the standing position for 1 min. Measurements were performed in 3 conditions: 1 – initial state, 2 – immediately after exercise, 3 – 5 min after load termination The changes in the mean perfusion value and the components of the amplitude-frequency spectrum of blood flow fluctuations (myogenic, neurogenic, respiratory and cardiac), as well as the correlation between the changes in all parameters of the right and left sides of the observation were evaluated.Results. Asymmetry of changes in microcirculation parameters and correlations between them under the physical loads on the upper limbs was revealed. It is shown that both left and right machs change the microcirculation parameters of both the left and right sides, and the changes on the left are more pronounced than on the right. It is shown that after the left machs the blood flow on the left and right increases, and after the right machs – reduced. After loads the right side is recovering more slowly than the left.Conclusions. Our results illustrate the specific regulation of blood flow in micro vessels of paired organs, which is associated with functional asymmetry. The physiological mechanisms for this asymmetry require further experimental and clinical studies.

scholarly journals Nonlinear analysis of fluctuations of microcirculation parameters in symmetrical organs of humans by laser doppler flowmetry

2019 ◽  
Vol 17 (4) ◽  
pp. 33-38 ◽  
Author(s):  
L. V. Mezentseva
Keyword(s):  
Nonlinear Dynamics ◽  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Coefficient Of Variation ◽  
Correlation Dimension ◽  
The Body ◽  
Doppler Flowmetry ◽  
Average Value ◽  
Flow Fluctuations ◽  
The Right

Purpose– the study the nonlinear dynamics of microcirculation parameters in human symmetrical organs.Material and Methods. Parameters of microcirculation were measured in healthy volunteers (aged between 50 and 70 years) by means of laser Doppler flowmetry (LDF). LDF signal transducers were fixed symmetrically on the lower parts of the right and left shoulders (3 cm above the elbow bend). The degree of chaoticity of microcirculation parameters as a nonlinear dynamic process was estimated using Hausdorff’s index, relative entropy and characteristics of phase portraits. Along with components of the amplitude-and-frequency range for blood flow fluctuations (myogenic, neurogenic, respiratory, and cardiac) was estimated and correlations between all characteristics of microcirculation in both sides of the body were done.Results.Asymmetry of correlation relationships of nonlinear dynamics parameters and components of the amplitude-andfrequency range for blood flow fluctuations of right and left sides of the body was revealed. Hausdorff index in the left side correlated not only with the average value of perfusion and with the coefficient of variation in the same side (r1 = –0,68; r2 =–0,51), but also with correlation dimension of chaos in the opposite side (r=0,49). Similarly, entropy in the left side correlated not only with the average value of perfusion and coefficient of variation in the left (r1 =0,43; r2 =0,60), but also with the entropy and correlation dimension of chaos in the right side (r1 =0,48; r2 =–0,41). The neurogenic component in the left side positively correlated with the myogenic component in the same side (r=0,71). A positive correlation was observed between the neurogenic component in right side and myogenic component in the opposite side (r=0,57). Asymmetry of correlation relationships was also revealed for the respiratory and cardiac components.Conclusions. Our results illustrate the specific regulation of blood flow in micro vessels of paired organs, which is associated with functional asymmetry. The physiological mechanisms for this asymmetry require further experimental and clinical studies. 

Role of oxygen-derived free radicals in free growth retardation induced by ischemia-reperfusion in rats

1997 ◽  
Vol 272 (2) ◽  
pp. H701-H705 ◽  
Author(s):  
H. Ishimoto ◽  
M. Natori ◽  
M. Tanaka ◽  
T. Miyazaki ◽  
T. Kobayashi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Free Radicals ◽  
Growth Retardation ◽  
Ischemia Reperfusion ◽  
Lipid Peroxides ◽  
Treated Group ◽  
Sprague Dawley ◽  
Doppler Flowmetry ◽  
Oxygen Derived Free Radicals ◽  
The Right

We investigated the involvement of oxygen-derived free radicals in the pathogenesis of the intrauterine growth retardation (IUGR) induced in Sprague-Dawley rats by ischemia-reperfusion. On day 17 of gestation, rats received saline, superoxide dismutase (SOD, 50,000 U/kg), catalase (CAT, 50,000 U/kg), or SOD + CAT subcutaneously 1 h before induction of 30 min of ischemia of the right uterine horn. On day 21 the placental level of lipid peroxides was significantly increased (P < 0.001 vs. sham-operated group) and IUGR was induced (P < 0.001 vs. left horn) in the saline-treated group n = 6). Pretreatment with SOD + CAT (n = 6) significantly inhibited the increase in placental lipid peroxides and prevented IUGR. The effect of ischemia-reperfusion on uterine blood flow, with or without pretreatment with radical scavengers, was investigated in separate experiments by laser-Doppler flowmetry. The induction of hypoperfusion 3 h after ischemia (blood flow -40 +/- 5%, n = 6, P < 0.05) was blocked by pretreatment with SOD + CAT (n = 6). Results indicate that oxygen-derived free radicals may be important in the development of postischemic uteroplacental hypoperfusion and of ischemia-reperfusion-induced IUGR in the rat.

Effect of the α2-Agonist Dexmedetomidine on Cerebral Neurotransmitter Concentrations during Cerebral Ischemia in Rats

2002 ◽  
Vol 96 (2) ◽  
pp. 450-457 ◽  
Author(s):  
Kristin Engelhard ◽  
Christian Werner ◽  
Susanne Kaspar ◽  
Oliver Möllenberg ◽  
Manfred Blobner ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Ischemia ◽  
Glutamate Release ◽  
Plasma Catecholamine ◽  
Doppler Flowmetry ◽  
Brain Norepinephrine ◽  
Arterial Blood ◽  
The Right ◽  
Plasma Catecholamine Concentrations

Background This study investigates whether neuroprotection seen with dexmedetomidine is associated with suppression of peripheral or central sympathetic tone. Methods Thirty fasted male Sprague-Dawley rats were intubated and ventilated with isoflurane and N2O/O2 (fraction of inspired oxygen = 0.33). Catheters were inserted into the right femoral artery and vein and into the right jugular vein. Cerebral blood flow was measured using laser Doppler flowmetry. Bilateral microdialysis probes were placed into the cortex and the dorsal hippocampus. At the end of preparation, the administration of isoflurane was replaced by fentanyl (bolus: 10 microg/kg; infusion: 25 microg x kg(-1) x h(-1)). Animals were randomly assigned to one of the following groups: group 1 (n = 10): control animals; group 2 (n = 10): 100 microg/kg dexmedetomidine administered intraperitoneally 30 min before ischemia; group 3 (n = 10): sham-operated rats. Ischemia (30 min) was produced by unilateral carotid artery occlusion plus hemorrhagic hypotension to a mean arterial blood pressure of 30-35 mmHg to reduce ipsilateral cerebral blood flow by 70%. Pericranial temperature, arterial blood gases, and pH were maintained constant. Cerebral catecholamine and glutamate concentrations and plasma catecholamine concentrations were analyzed using high-performance liquid chromatography. Results During ischemia, dexmedetomidine suppressed circulating norepinephrine concentrations by 95% compared with control animals. In contrast, brain norepinephrine and glutamate concentrations were increased irrespective of dexmedetomidine infusion before ischemia. Conclusions The current data show that the increase of circulating catecholamine concentrations during cerebral ischemia was suppressed with dexmedetomidine. In contrast, dexmedetomidine does not suppress elevation in brain norepinephrine and glutamate concentration associated with cerebral ischemia. This suggests that the neuroprotective effects of dexmedetomidine are not related to inhibition of presynaptic norepinephrine or glutamate release in the brain.

Functional Asymmetry in Body Perception and Ocular Dominance: A Study of Their Interactions

1981 ◽  
Vol 52 (3) ◽  
pp. 903-909 ◽  
Author(s):  
Vezio Ruggieri ◽  
Chiara Bergerone ◽  
Alberto Cei ◽  
Carla Valeri
Keyword(s):  
Ocular Dominance ◽  
Psychology Students ◽  
Functional Asymmetry ◽  
Body Perception ◽  
Perceptual Error ◽  
Interesting Connection ◽  
Undergraduate Female ◽  
Left And Right ◽  
The Difference ◽  
The Right

The relationships between ocular dominance and body perception (for the left and right body halves) were examined for 41 undergraduate female psychology students. The results indicate an interesting connection between the two phenomena. The four groups of subjects classified on the basis of ocular dominance (right, left, fluctuating and no dominance) showed statistically significant differences on one aspect of body perception, measured by the ‘Difference Deviation Scores.’ Also three groups of subjects classified on the basis of body perception (subjects with major perceptual error on the left or on the right, and subjects showing no difference in perception of the two body halves) showed statistically significant differences in ocular dominance.

scholarly journals Effects of tDCS Dose and Electrode Montage on regional cerebral blood flow and motor behavior

2021 ◽  
Author(s):  
Anant Shinde ◽  
Karl Lerud ◽  
Fanny Munsch ◽  
David C Alsop ◽  
Gottfried Schlaug
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Regions ◽  
Regional Cerebral Blood ◽  
Left Hand ◽  
Motor Region ◽  
Left And Right ◽  
The Right ◽  
Sequence Performance

AbstractWe used three dose levels (Sham, 2mA and 4mA) and two different electrode montages (unihemispheric or bihemispheric) to examine DOSE and MONTAGE effects on regional cerebral blood flow (rCBF) as a surrogate marker of neural activity, and on a finger sequence task, as a surrogate behavioral measure drawing on brain regions targeted by transcranial direct current stimulation (tDCS). We placed the anodal electrode over the right motor region (C4) while the cathodal or return electrode was placed either over a left supraorbital region (unihemispheric montage) or over the left motor region (C3 in the bihemispheric montage). Performance changes in the finger sequence task for both hands (left hand: p = 0.0026, and right hand: p = 0.0002) showed a linear tDCS dose response, but no effect of montage. rCBF in the the right hemispheric perirolandic area increased with dose under the anodal electrode (p = 0.027), while in the perirolandic ROI in the left hemisphere, rCBF showed a trend to increase with dose (p = 0.053), and significant effect of montage (p = 0.00004). The bihemispheric montage showed additional rCBF increases in frontomesial regions in the 4mA condition but not in the 2mA condition. Furthermore, we found correlations between rCBF changes in the right perirolandic region and improvements in the finger sequence task performance (FSP) for left and right hand. Our data support not only a strong direct tDCS dose effect for rCBF and FSP as surrogate measures of targeted brain regions, but also indirect effects on rCBF in functionally connected regions (e.g., frontomesial regions), particularly in the higher dose condition, and on FSP of the ipsilateral hand (to the anodal electrode). At higher dose and irrespective of polarity, a wider network of sensorimotor regions is positively affected by tDCS.Graphical AbstractHighlightstDCS-DOSE had linear effect on finger sequence performance for both handsrCBF changes in both perirolandic ROIs demonstrated tDCS-DOSE effects and left perirolandic ROI demonstrated tDCS-MONTAGE effects.Simulated current intensity in the left and right perirolandic ROI strongly correlated with the contralateral hand’s finger sequence performance.tDCS-Tolerability scores did not correlate with change in rCBF or finger sequence performance of the left hand.

scholarly journals Laser doppler flowmetry assessment of microcirculation in children of 6–7 years old

2021 ◽  
Vol 20 (3) ◽  
pp. 46-53
Author(s):  
V. I. Kozlov ◽  
V. N. Sakharov ◽  
O. A. Gurova ◽  
V. V. Sidorov
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Lower Limbs ◽  
Doppler Flowmetry ◽  
Flow Modulation ◽  
Left Hand ◽  
Flow Fluctuations ◽  
Ongoing Development

Introduction. The state of the blood flow within the capillaries and close blood vessels is highly important in practice for the revealing of pathogenetic mechanisms of both systemic and local circulatory disorders. Aim of the study was to define the parameters of microcirculation and the level of blood flow fluctuations (flux) in the distal segments of upper and lower limbs (in fingers of hands and toes of feet) in children of 6–7 years old; and to describe the possible differences in the mechanisms of blood flow modulation in boys and girls. Materials and methods. Skin microcirculation was assessed in middle fingers of hands and great toes of feet in children of 6-7 years old (14 girls and 7 boys in prone position) by means of laser doppler flowmetry. Results. The ranges for parameters of microcirculation (PM) for distal segments of upper and lower limbs in children of mentioned age group were defined, also it was shown that the PM are significantly lower in the lower limbs comparing to those of the upper limbs (both in groups of girls and boys). Asymmetry of PM in the feet was not found; the features of right hand-left hand asymmetry for PM in girls and boys are described. The analysis of modulation of blood flow fluctuations (fluxmotions) of different frequencies showed the profound role of vasomotor (myogenic) rhythm for regulation of microcirculation. Conclusion. Increased neurogenic influences on the modulation of fluxmotions in girls of 6-7 years old may be an evidence of the ongoing development of the mechanisms of blood flow regulation, particularly the association with the growth rate of girls is possible.

Left-right cortical asymmetries of regional cerebral blood flow during listening to words

1982 ◽  
Vol 48 (2) ◽  
pp. 458-466 ◽  
Author(s):  
Y. Nishizawa ◽  
T. S. Olsen ◽  
B. Larsen ◽  
N. A. Lassen
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Temporal Region ◽  
Regional Cerebral Blood ◽  
Left And Right ◽  
Sound Discrimination ◽  
Listening Task ◽  
The Right ◽  
Verbal Stimulation

1. Regional cerebral blood flow (rCBF) was measured during rest and during listening to simple words. The xenon-133 intracarotid technique was used and results were obtained from 254 regions of seven right hemispheres and seven left hemispheres. The measurements were performed just after carotid angiography, carried out to exclude space occupying lesions. In all subjects the angiogram was normal. All were right handed. 2. Mean hemispheric blood flow of both left and right hemispheres increased 10% from the resting measurement during the listening task. This increase was due in part to activation of the entire hemisphere. The focal rCBF increases were localized to the superior part of the temporal regions, the prefrontal regions, the frontal eye fields, and the orbitofrontal regions. Significant asymmetries were found in particular in the superior temporal region with the left side showing a more widespread and intense increase, averaging 29% as compared to 18% on the right side. This left-sided dominance during verbal stimulation should be compared to the right-sided dominance of rCBF during nonverbal sound discrimination reported by Roland et al. (25, 26), who used precisely the same technique as in the present study.

The azygos veins of the Weddell seal, Leptonychotes weddelli (Lesson)

1972 ◽  
Vol 50 (12) ◽  
pp. 1583-1587 ◽  
Author(s):  
A. G. Watson ◽  
David A. Dowd
Keyword(s):  
Blood Flow ◽  
Vena Cava ◽  
Weddell Seal ◽  
Venous System ◽  
Left And Right ◽  
The Right ◽  
Relationship Of ◽  
The Relationship

The azygos venous system of one Weddell seal (Leptonychotes weddelli) has been described. Both left and right azygos trunks were present with segmental anastomoses between them. The right azygos trunk was the larger and opened into the anterior vena cava; the left azygos trunk terminated in the left costocervical vein. At each segmental level the azygos trunks communicated with collecting sinuses into which drained blood from intercostal spaces and the extradural intravertebral vein. These collecting sinuses were themselves connected to each other by longitudinal anastomoses. The relationship of this system to blood flow during diving is briefly discussed.

scholarly journals Regional hypoxic cerebral vasodilation facilitated by diameter changes primarily in anterior versus posterior circulation

2016 ◽  
Vol 37 (6) ◽  
pp. 2025-2034 ◽  
Author(s):  
J Mikhail Kellawan ◽  
John W Harrell ◽  
Alejandro Roldan-Alzate ◽  
Oliver Wieben ◽  
William G Schrage
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Vascular Reactivity ◽  
Cerebral Arteries ◽  
Posterior Circulation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Left And Right ◽  
The Right

The inability to quantify cerebral blood flow and changes in macrocirculation cross-sectional area in all brain regions impedes robust insight into hypoxic cerebral blood flow control. We applied four-dimensional flow magnetic resonance imaging to quantify cerebral blood flow (ml • min−1) and cross-sectional area (mm2) simultaneously in 11 arteries. In healthy adults, blood pressure, O2 Saturation (SpO2), and end-tidal CO2 were measured at baseline and steady-state hypoxia (FiO2 = 0.11). We investigated left and right: internal carotid, vertebral, middle, anterior, posterior cerebral arteries, and basilar artery. Hypoxia (SpO2 = 80±2%) increased total cerebral blood flow from 621±38 to 742±50 ml • min−1 ( p < 0.05). Hypoxia increased cerebral blood flow, except in the right posterior cerebral arteries. Hypoxia increased cross-sectional area in the anterior arteries (left and right internal carotid arteries, left and right middle, p < 0.05; left and right anterior p = 0.08) but only the right vertebral artery of the posterior circulation. Nonetheless, relative cerebral blood flow distribution and vascular reactivity (Δ%cerebral blood flow • ΔSpO2−1) were not different between arteries. Collectively, moderate hypoxia: (1) increased cerebral blood flow, but relative distribution remains similar to normoxia, (2) evokes similar vascular reactivity between 11 arteries, and (3) increased cross-sectional area primarily in the anterior arteries. This study provides the first wide-ranging, quantitative, functional and structural data regarding intracranial arteries during hypoxia in humans, highlighting cerebral blood flow regulation of microcirculation and macrocirculation differs between anterior and posterior circulation.

scholarly journals Neurally Derived Tissues inXenopus laevisEmbryos Exhibit a Consistent Bioelectrical Left-Right Asymmetry

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Vaibhav P. Pai ◽  
Laura N. Vandenberg ◽  
Douglas Blackiston ◽  
Michael Levin
Keyword(s):  
Xenopus Laevis ◽  
Neural Crest ◽  
Transmembrane Potential ◽  
Functional Asymmetry ◽  
Embryonic Patterning ◽  
Eye Field ◽  
Left And Right ◽  
Left Right Asymmetry ◽  
The Right ◽  
Depolarizing Channel

Consistent left-right asymmetry in organ morphogenesis is a fascinating aspect of bilaterian development. Although embryonic patterning of asymmetric viscera, heart, and brain is beginning to be understood, less is known about possible subtle asymmetries present in anatomically identical paired structures. We investigated two important developmental events: physiological controls of eye development and specification of neural crest derivatives, inXenopus laevisembryos. We found that the striking hyperpolarization of transmembrane potential (Vmem) demarcating eye induction usually occurs in the right eye field first. This asymmetry is randomized by perturbing visceral left-right patterning, suggesting that eye asymmetry is linked to mechanisms establishing primary laterality. Bilateral misexpression of a depolarizing channel mRNA affects primarily the right eye, revealing an additional functional asymmetry in the control of eye patterning byVmem. The ATP-sensitive K+channel subunit transcript, SUR1, is asymmetrically expressed in the eye primordia, thus being a good candidate for the observed physiological asymmetries. Such subtle asymmetries are not only seen in the eye: consistent asymmetry was also observed in the migration of differentiated melanocytes on the left and right sides. These data suggest that even anatomically symmetrical structures may possess subtle but consistent laterality and interact with other developmental left-right patterning pathways.

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