scholarly journals Statistical analysis of coronary blood flow monitoring data for hemodynamic assessment of the degree of coronary artery stenosis

2020 ◽  
Keyword(s):  
Blood Flow ◽  
Negative Correlation ◽  
High Frequency ◽  
Surgical Intervention ◽  
Coronary Artery Stenosis ◽  
Flow Monitoring ◽  
Hemodynamic Assessment ◽  
Before And After ◽  
Statistical Relationships

Statistical relationships between the pressure curves Pa(t), Pd(t) and blood flow velocity Va(t), recorded in vivo in the coronary arteries of patients before and after stenosis, as part of the standard clinical procedure for calculating dynamic indices FFR, HSR, CFR, and a number of other ones generally accepted in surgical practice are studied. It is shown that in the case of insignificant stenosis that does not require surgical intervention, there is a correlation between the curves, and their spectrum is represented by three main harmonics. In the case of significant stenosis requiring immediate stenting, the positive correlation between Pa(t) and Pd(t) is less pronounced, and there is a negative correlation with the Va(t) curve. The spectrum of the curves is much more complex and contains high-frequency harmonics. For patients from the so-called “gray zone”, an expert decision on the need for stenting can be made based on the appearance of additional harmonics in the spectrum and a negative correlation between the Pa(t), Pd(t) and Va(t) curves. The proposed approach can be used for automatic decision-making based on machine learning and the development of appropriate mathematical models.

Аpplying of high-frequency monopolar diathermocoagulation in the treatment of chronic pulpitis

2020 ◽  
Vol 1 (12) ◽  
pp. 40-42
Author(s):  
F. Yu. Daurova ◽  
D. I. Tomaeva ◽  
S. V. Podkopaeva ◽  
Yu. A. Taptun
Keyword(s):  
Root Canal ◽  
High Frequency ◽  
Antibacterial Effect ◽  
Comparison Group ◽  
Poor Quality ◽  
Endodontic Treatment ◽  
Root Canals ◽  
The Third ◽  
Before And After

Relevance: the reason for the development of complications in endodontic treatment is poor-quality instrumental treatment root canals.Aims: a study of the animicrobial action and clinical efficacy of high-frequency monopolar diathermocoagulation in the treatment of chronic forms of pulpitis.Materials and methods: 102 patients with various chronic forms of pulpitis were divided into three groups of 34 patients each. In the first two groups, high-frequency monopolar diathermocoagulation was used in endodontic treatment in different modes. In the third group, endodontic treatment was carried out without the use of diathermocoagulation (comparison group). The root canal microflora in chronic pulpitis in vivo was studied twice-before and after diathermocoagulation.Results: it was established that high-frequency monopolar diathermocoagulation in the effect mode is 3, power is 4 (4.1 W) and effect is 4, power is 4 (5.4 W) with an exposure time of 3 seconds, it has a pronounced antibacterial effect on all presented pathogenic microflora obtained from the root canals of the teeth.

Hemodynamic effects of leukotriene C4 in ovine fetus

1990 ◽  
Vol 259 (6) ◽  
pp. E851-E855
Author(s):  
B. A. Meyer ◽  
S. W. Walsh ◽  
V. M. Parisi
Keyword(s):  
Blood Flow ◽  
Vena Cava ◽  
Cardiovascular Effects ◽  
In Vivo Studies ◽  
Leukotriene C4 ◽  
Blood Flows ◽  
Before And After ◽  
Placental Blood ◽  
Near Term

Leukotrienes are synthesized during pregnancy and produce cardiovascular effects in adults. We hypothesized that leukotriene C4 would cause vasoconstriction in the fetus and placenta. Eight near-term, unanesthetized ovine fetuses were studied before and after infusion of 10 micrograms leukotriene C4 (LTC4) into the fetal vena cava. Cardiovascular monitoring of maternal and fetal arterial pressures and heart rates was performed. Fetal blood flows were measured by the radioactive-microsphere technique. Sustained elevations in systolic and diastolic blood pressure and decreased fetal heart rate began by 1 min and returned to baseline by 30 min. Arterial pH fell from 7.33 +/- 0.01 to 7.29 +/- 0.01 at 15 min (P less than 0.05) and to 7.29 +/- 0.01 at 30 min (P less than 0.05), with a significant increase in base deficit from 0.7 +/- 0.7 to 3.5 +/- 0.7 at 15 min (P less than 0.05) and to 2.9 +/- 1.0 at 30 min (P less than 0.05). Fetal PO2 and PCO2 were unchanged. Significant decreases in blood flow and resistance were seen in the umbilical placental circulation as well as in fetal skeletal muscle and intestine. Blood flow and resistance were unchanged in the renal and adrenal vascular beds. Fetal administration of LTC4 caused no changes in maternal cardiovascular parameters. These findings represent the first in vivo studies of the effects of a lipoxygenase metabolite on fetal-placental blood flow.

In vivo imaging of blood flow in the mouse Achilles tendon using high-frequency ultrasound

Ultrasonics ◽  
2009 ◽  
Vol 49 (2) ◽  
pp. 226-230 ◽  
Author(s):  
Chih-Kuang Yeh ◽  
Jia-Jiun Chen ◽  
Meng-Lin Li ◽  
Jer-Junn Luh ◽  
Jia-Jin Jason Chen
Keyword(s):  
Blood Flow ◽  
Achilles Tendon ◽  
In Vivo Imaging ◽  
High Frequency ◽  
High Frequency Ultrasound ◽  
Frequency Ultrasound

Ultrasonographic Bioinformatics Analysis of Uterus After Myomectomy

2020 ◽  
Vol 10 (6) ◽  
pp. 1374-1378
Author(s):  
Lili Jiang ◽  
Chuanxin Cheng ◽  
Xinmei Sheng
Keyword(s):  
Blood Flow ◽  
Bioinformatics Analysis ◽  
Uterine Wall ◽  
Before And After ◽  
The Mean

Objective: The myomectomy will affect the shape of uterine wall. Ultrasound can analyze the bioinformatics characteristics of uterus such as shape and blood flow in vivo. The aim of this study is to analyze the ultrasonographic bioinformatics of uterus after myomectomy. Methods: A total of 127 patients underwent myomectomy were examined by ultrasonography before operation, and 7 d, 1 m, 3 m, and 6 m after operation. The changes of uterine echo and blood signals were observed and recorded. Results: The mean volume of uterus was (152 ± 64) cm3 before myomectomy. During 6 m after operation, the uterus volume in all patients was decreased gradually. At 7 d and 1 m after operation, the mean volume of uterus was (73 ± 22) cm3 and (54 ± 23) cm3, respectively (about 48% and 36% of volume before operation). Different degree of scar echo appeared in 43 patients (33.8%). The diameter of scars was decreased remarkably during 6 months after myomectomy, especially 1 month after operation. Conclusion: The bioinformatics characteristics of uterus changed obviously before and after myomectomy. Ultrasonography is useful to evaluate these changed.

Effects of indomethacin on PMA-induced pulmonary endothelial enzyme dysfunction in vivo

1992 ◽  
Vol 262 (2) ◽  
pp. L153-L162 ◽  
Author(s):  
X. Chen ◽  
S. E. Orfanos ◽  
J. D. Catravas
Keyword(s):  
Blood Flow ◽  
Left Lung ◽  
Substrate Utilization ◽  
Endothelial Damage ◽  
Metabolic Dysfunction ◽  
Before And After ◽  
Entire Lung ◽  
Metabolically Healthy ◽  
Microvascular Recruitment

We investigated the effects of phorbol myristate acetate (PMA) on metabolic pulmonary endothelial ectoenzyme dysfunction. Anesthetized rabbits were placed on total heart bypass, and the single-pass transpulmonary metabolism of [3H]benzoyl-Phe-Ala-Pro (BPAP) by endothelial-bound angiotensin-converting enzyme (ACE) and [14C]adenosine 5'-monophosphate (AMP) by 5'-nucleotidase (NCT) was calculated before and after PMA (10 micrograms/kg iv), a dose that does not produce histologically evident endothelial damage. Under conditions of partial microvascular recruitment (blood flow = 400 ml/min through the entire lung), PMA, but not the vehicle, significantly reduced substrate utilization of both BPAP and adenosine 5'-monophosphate (AMP) and increased the apparent Michaelis constant (Km) values of ACE for BPAP, indicative of metabolic dysfunction. These changes were completely prevented by pretreatment with indomethacin. Under conditions of near full microvascular recruitment (blood flow = 640 ml/min through the left lung only), PMA similarly reduced substrate utilization and increased the apparent Km of ACE for BPAP. In this case, however, indomethacin failed to prevent the observed PMA-induced metabolic dysfunction. We conclude that PMA alters endothelial ectoenzyme substrate metabolism independently from changes in pulmonary blood flow; indomethacin appears to antagonize the effects of PMA under conditions of partial microvascular recruitment only, perhaps by diverting flow to previously unperfused, unexposed to PMA, and hence metabolically healthy vessels.

Sodium channels are required during in vivo sodium chloride hyperosmolarity to stimulate increase in intestinal endothelial nitric oxide production

2005 ◽  
Vol 288 (1) ◽  
pp. H89-H95 ◽  
Author(s):  
Brett G. Zani ◽  
H. Glenn Bohlen
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Intestinal Blood Flow ◽  
No Production ◽  
Sodium Ions ◽  
Major Mechanism ◽  
Before And After ◽  
Endothelial Nitric Oxide

NaCl hyperosmolarity increases intestinal blood flow during food absorption due in large part to increased NO production. We hypothesized that in vivo, sodium ions enter endothelial cells during NaCl hyperosmolarity as the first step to stimulate an increase in intestinal endothelial NO production. Perivascular NO concentration ([NO]) and blood flow were determined in the in vivo rat intestinal microvasculature at rest and under hyperosmotic conditions, 330 and 380 mosM, respectively, before and after application of bumetanide (Na+-K+-2Cl− cotransporter inhibitor) or amiloride (Na+/H+ exchange channel inhibitor). Suppressing amiloride-sensitive Na+/H+ exchange channels diminished hypertonicity-linked increases in vascular [NO], whereas blockade of Na+-K+-2Cl− channels greatly suppressed increases in vascular [NO] and intestinal blood flow. In additional experiments we examined the effect of sodium ion entry into endothelial cells. We proposed that the Na+/Ca2+ exchanger extrudes Na+ in exchange for Ca2+, thereby leading to the calcium-dependent activation of endothelial nitric oxide synthase (eNOS). We blocked the activity of the Na+/Ca2+ exchanger during 360 mosM NaCl hyperosmolarity with KB-R7943; complete blockade of increased vascular [NO] and intestinal blood flow to hyperosmolarity occurred. These results indicate that during NaCl hyperosmolarity, sodium ions enter endothelial cells predominantly through Na+-K+-2Cl− channels. The Na+/Ca2+ exchanger then extrudes Na+ and increases endothelial Ca2+. The increase in endothelial Ca2+ causes an increase in eNOS activity, and the resultant increase in NO increases intestinal arteriolar diameter and blood flow during NaCl hyperosmolarity. This appears to be the major mechanism by which intestinal nutrient absorption is coupled to increased blood flow.

scholarly journals Cerebral Blood Flow and Brain Oxygenation in Rats Breathing Oxygen under Pressure

2005 ◽  
Vol 25 (10) ◽  
pp. 1288-1300 ◽  
Author(s):  
Ivan T Demchenko ◽  
Yuriy I Luchakov ◽  
Alexander N Moskvin ◽  
Diana R Gutsaeva ◽  
Barry W Allen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Platinum Electrodes ◽  
Brain Oxygenation ◽  
Before And After ◽  
Scatter Plots ◽  
Opposing Effects ◽  
Breathing Room

Hyperbaric oxygen (HBO2) increases oxygen tension (PO2) in blood but reduces blood flow by means of O2-induced vasoconstriction. Here we report the first quantitative evaluation of these opposing effects on tissue PO2 in brain, using anesthetized rats exposed to HBO2 at 2 to 6 atmospheres absolute (ATA). We assessed the contribution of regional cerebral blood flow (rCBF) to brain PO2 as inspired PO2 (PiO2) exceeds 1 ATA. We measured rCBF and local PO2 simultaneously in striatum using collocated platinum electrodes. Cerebral blood flow was computed from H2 clearance curves in vivo and PO2 from electrodes calibrated in vitro, before and after insertion. Arterial PCO2 was controlled, and body temperature, blood pressure, and EEG were monitored. Scatter plots of rCBF versus pO2 were nonlinear ( R2 = 0.75) for rats breathing room air but nearly linear ( R2 = 0.88–0.91) for O2 at 2 to 6 ATA. The contribution of rCBF to brain PO2 was estimated at constant inspired PO2, by increasing rCBF with acetazolamide (AZA) or decreasing it with N-nitro-l-arginine methyl ester (l-NAME). At basal rCBF (78 mL/100 g min), local PO2 increased 7- to 33-fold at 2 to 6 ATA, compared with room air. A doubling of rCBF increased striatal PO2 not quite two-fold in rats breathing room air but 13- to 64-fold in those breathing HBO2 at 2 to 6 ATA. These findings support our hypothesis that HBO2 increases PO2 in brain in direct proportion to rCBF.

scholarly journals The potential of high-frequency ultrasound Dopplerography in the assessment of microcirculatory disorders in post-COVID-19 patients with a cardiovascular profile

2022 ◽  
Vol 20 (4) ◽  
pp. 101-105
Author(s):  
Yu. S. Andozhskaya
Keyword(s):  
Blood Flow ◽  
High Frequency ◽  
Spectral Characteristics ◽  
Preventive Therapy ◽  
High Frequency Ultrasound ◽  
Group I ◽  
Before And After ◽  
Microcirculatory Disorders ◽  
Cardiovascular Profile ◽  
Frequency Ultrasound

Introduction. Patients with cardiovascular diseases have endothelial dysfunction and a higher risk of severe course of COVID-19, and thrombotic complications. Associated endotheliitis caused by virus penetration and cytokines storm leads to the release of tissue factor, the formation of excess thrombin and fibrin and thrombosis. The aim. To identify the potential of high-frequency ultrasound Dopplerography (HFUDG) for the assessment of microcirculatory disorders in post-COVID-19 patients with cardiovascular profile and to assess the microcirculatory bed condition before and after treatment with sulodexide. Materials and methods. 49 patients recovered from moderate-severe COVID-19 one month ago, aged 20–80, were examined. 24 patients, received prophylaxis with POACs for 1 month, formed group I, group II – 25 patients without prophylaxis. The nail bed of the upper limb 1st finger was examined using HFUDG and a 25 MHz sensor. Shape and spectrum of curves taken from dopplerograms were analyzed. The control examination was performed 4 weeks after therapy. Results. In patients after COVID19, depletion of spectral characteristics was revealed in comparison with dopplerograms of healthy individuals. The predominantly red part of the spectrum corresponding to the fastest particles was recorded. Slow-moving particles corresponding to the lighter part of the spectrum were nearly non-existent. In patients administrated POAC prophylaxis, amplitude indices were higher. Significant increase in D-dimer, antithrombin III, and soluble fibrin monomer complexes (SFMC) was also detected. The remaining parameters of the coagulogram were within the norm before and after treatment. After a course of sulodexide therapy, the spectral characteristics and coagulogram parameters returned to normal. Conclusion. HFUDG allows to detect stasis of capillary blood flow, the appearance of shunt blood flow corresponding to microtrombosis. Microcirculation indicators in post-COVID-19 patients improved after a course of preventive therapy with sulodexide.

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