Changes In Blood Flow Velocity Research Articles

Comparative evaluation of the effectiveness of phlebotonic gels

Introduction. Varicose veins are a common disease with a chronic course and a high risk of complications and cosmetic defects. Venotonic drugs are widely used in conservative treatment of varicose veins.Aim. To study the comparative efficacy of venotonic drugs for local application in experimental conditions.Materials and Methods. Varicose veins were modeled in Wistar rats by partial stricture of the deep femoral vein. The studied drugs were applied in the course of 14 days from the operation. The assessed parameters were the change of local blood flow velocity in the skin in the dynamics and the degree of vascular permeability. The rate of local blood flow was assessed by Doppler ultrasound. Changes in vascular permeability were studied by the degree of extravasation of Evans blue dye in the Miles test. The results were processed using the methods of variation statistics.Results. The study showed that under the conditions of experimental chronic venous insufficiency, a course of application of all the analyzed drugs resulted in an increase in the rate of local blood flow in the skin and a decrease in the degree of vascular permeability. It was noted that application of the investigated gel based on escin, heparin and essential phospholipids to the skin of animals resulted in reliably (p < 0,05) lower indices of vascular permeability in comparison with the rats which received a course therapy with the heparin-containing gel; combined cosmetic agent as well as the gel based on troxerutin, heparin and dexpanthenol.Discussion. The results obtained testify that application of external dosage forms of combined venotonic drugs promotes the regression of chronic venous insufficiency manifestations. Maximum evident effect was registered while applying the studied drug, that can be related to its complex composition including essential phospholipids, heparin and aescin. It is known that aescin is a phlebotonic with a high degree of percutaneous absorption, the effect of which is significantly potentiated by the phospholipid component.Conclusions. The application of the combined product based on heparin, aescin and essential phospholipids provided an optimum rate of onset of pharmacological effect compared to the other analysed compositions.

Pilot study on the effect of grape seed proanthocyanidin extract on inferior vene cava blood flow in patients with chronic venous insufficiency using 4D flow MRI.

Four-dimensional (4D) flow magnetic resonance imaging (MRI) was used to objectively assess changes in blood flow velocity in patients with chronic venous insufficiency (CVI) who underwent stocking treatment alone and stocking combined with Grape seed proanthocyanidin extract (GSPE) treatment. Patients diagnosed with CVI were recruited from August 31, 2018 to December 31, 2020. A total of 23 participants were selected, with 10 and 13 patients in the stocking treatment and stocking + GSPE treatment groups, respectively. The blood flow velocity (Th-plane peak and average velocities) was calculated using 4D flow MRI. A paired t test was used to evaluate the differences in blood flow velocity before and after treatment. In the stocking treatment group, The Th-Plane peak velocity increased by 2.48 ± 5.05 cm/s after treatment (P = .16). In the stocking + GSPE treatment group, the Th-Plane peak velocity increased by 4.85 ± 5.57 cm/s after treatment (P < .001). The blood flow velocity on 4D flow MRI was significantly increased in participants who underwent GSPE, highlighting the potential of GSPE for CVI treatment.

The effect of relative cerebral hyperperfusion during cardiac surgery with cardiopulmonary bypass to delayed neurocognitive recovery.

Delayed neurocognitive recovery (dNCR) remains a common complication after surgery and the incidence of it is determined 30-80% after cardiac surgery with cardiac bypass (CPB) in eldery patients. Many researchers have identified that neuropsychological complications emerge from insufficient cerebral perfusion. Relative cerebral hyperperfusion also disrupts cerebral autoregulation and might play a significant role in dNCR development. The aim of this study is to determine hyperperfusion in the middle cerebral artery during CPB influence to dNCR development and brain biomarker glial fibrillary acidic protein (GFAP) impact in diagnosing dNCR. This prospective - case control study included patients undergoing elective coronary artery bypass grafting or/and valve surgery with CPB. For cognitive evaluation 101 patients completed Addenbrooke's cognitive examination - ACE-III. To determine mild cognitive dysfunction, cut - off 88 was chosen. Mean BFV was monitored with transcranial Doppler ultrasonography (TCD) and performed before surgery, after induction of anaesthesia, during CPB and after surgery. Preoperative BFV was converted to 100% and used as a baseline. The percentage change of cerebral blood flow velocity during CPB was calculated from baseline. Patients with decreased blood flow velocity were included for further investigation. To measure glial fibrillary acidic protein, blood samples were collected after anaesthesia induction, 24 and 48 h after the surgery. According to the ACE-III test results, patients with relative hyperperfusion were divided into two groups: with Delayed neurocognitive recovery and without dNCR (non-dNCR group). 101 patients were examined, 67 (69.1%) men and 29 (29.9%) women, age 67.9 (SD 9.2) Increased percentage of BFV was determined for 40 (39.60%) patients. There were no differences in sex, haematocrit, paCO2, aortic cross-clamping or CPB time between the two groups. Percentage change of BFV was 105.60% in the non-dNCR group and 132.29% in the dNCR group, p = .033. Patients who developed dNCR in the early post-surgical period were significantly older, p < .001 and had a lower baseline of BFV, p = .004. GFAP concentration significantly increased in the dNCR group 48hours after surgery, compared to the non-dNCR group, p = .01. Relative hyperperfusion during CPB may cause dNCR. Elderly patients are sensitive to blood flow velocity acceleration during CPB. GFAP concentration increased 48 h after surgery in dNCR group but did not have any connection with risk factors.

Toward a Better Understanding of Muscle Microvascular Perfusion During Exercise in Patients With Peripheral Artery Disease: The Effect of Lower-Limb Revascularization

Purpose: Leg muscle microvascular blood flow (perfusion) is impaired in response to maximal exercise in patients with peripheral artery disease (PAD); however, during submaximal exercise, microvascular perfusion is maintained due to a greater increase in microvascular blood volume compared with that seen in healthy adults. It is unclear whether this submaximal exercise response reflects a microvascular impairment, or whether it is a compensatory response for the limited conduit artery flow in PAD. Therefore, to clarify the role of conduit artery blood flow, we compared whole-limb blood flow and skeletal muscle microvascular perfusion responses with exercise in patients with PAD (n=9; 60±7 years) prior to, and following, lower-limb endovascular revascularization. Materials and Methods: Microvascular perfusion (microvascular volume × flow velocity) of the medial gastrocnemius muscle was measured before and immediately after a 5 minute bout of submaximal intermittent isometric plantar-flexion exercise using contrast-enhanced ultrasound imaging. Exercise contraction-by-contraction whole-leg blood flow and vascular conductance were measured using strain-gauge plethysmography. Results: With revascularization there was a significant increase in whole-leg blood flow and conductance during exercise (p<0.05). Exercise-induced muscle microvascular perfusion response did not change with revascularization (pre-revascularization: 3.19±2.32; post-revascularization: 3.89±1.67 aU.s−1; p=0.38). However, the parameters that determine microvascular perfusion changed, with a reduction in the microvascular volume response to exercise (pre-revascularization: 6.76±3.56; post-revascularization: 2.42±0.69 aU; p<0.01) and an increase in microvascular flow velocity (pre-revascularization: 0.25±0.13; post-revascularization: 0.59±0.25 s−1; p=0.02). Conclusion: These findings suggest that patients with PAD compensate for the conduit artery blood flow impairment with an increase in microvascular blood volume to maintain muscle perfusion during submaximal exercise. Clinical Impact The findings from this study support the notion that the impairment in conduit artery blood flow in patients with PAD leads to compensatory changes in microvascular blood volume and flow velocity to maintain muscle microvascular perfusion during submaximal leg exercise. Moreover, this study demonstrates that these microvascular changes are reversed and become normalized with successful lower-limb endovascular revascularization.

Cardiovascular System Modeling Using Windkessel Segmentation Model Based on Photoplethysmography Measurements of Fingers and Toes.

Background:Photoplethysmography (PPG) contains information about the health condition of the heart and blood vessels. Cardiovascular system modeling using PPG signal measurements can represent, analyze, and predict the cardiovascular system.Methods:This study aims to make a cardiovascular system model using a Windkessel model by dividing the blood vessels into seven segments. This process involves the PPG signal of the fingertips and toes for further analysis to obtain the condition of the elasticity of the blood vessels as the main parameter. The method is to find the Resistance, Inductance, and Capacitance (RLC) value of each segment of the body through the equivalent equation between the electronic unit and the cardiovascular unit. The modeling made is focused on PPG parameters in the form of stiffness index, the time delay (△t), and augmentation index.Results:The results of the model simulation using PSpice were then compared with the results of measuring the PPG signal to analyze changes in the behavior of the PPG signal taken from ten healthy people with an average age of 46 years, compared to ten cardiac patients with an average age of 48 years. It is found that decreasing 20% of capacitance value and the arterial stiffness parameter will close to cardiac patients' data. Compared with the measurement results, the correlation of the PPG signal in the simulation model is more than 0.9.Conclusions:The proposed model is expected to be used in the early detection of arterial stiffness. It can also be used to study the dynamics of the cardiovascular system, including changes in blood flow velocity and blood pressure.

Pharmacological characteristics of intranasal dosage forms containing Ginkgo biloba extracts

Background: This article reviews the pharmacological characteristics of developed dosage forms for intranasal administration. The influence of the type of dosage form on the efficacy of the drug is significant. Gel-like structures are interesting objects for research. Interest in understanding the nature and properties of such structures is due to the variety of effects observed when gels are used. The active ingredient in the studied forms is ginkgo biloba extract obtained by ultrasonic extraction followed by thickening. The object of comparison is standardized dried ginkgo biloba extract (EGB 76). The study of cerebrotropic activity of the developed gels was conducted on the model of bilateral occlusion of the common carotid arteries. The studied objects and the reference preparation were administered therapeutically after modeling cerebral ischemia once a day for 3 weeks. Aim of the study: To evaluate specific pharmacological activity of the developed dosage forms of ginkgo biloba. Materials and Methods: Studies were performed in an appropriate design by simulating cerebral ischaemia in rabbits using simultaneous bilateral occlusion of the common carotid arteries. Changes in cerebral blood flow velocity were performed by Doppler using an appropriate transducer and software package. The data obtained were statistically processed using an application software package. Results: Conducted investigations revealed that under conditions of experimental cerebral ischemia simulated by simultaneous occlusion of the common carotid arteries in large laboratory animals (rabbits), the use of the developed dosage forms promoted the reduction of the severity of neurological deficit, the restoration of cerebral hemodynamics and pro/antioxidant balance in the hippocampus. Conclusions: Developed nasal gels based on chitosan and sodium alginate are promising agents for chronic cerebrovascular accident with antioxidant mechanism of action and therapeutic potential similar to oral administration of standardized ginkgo biloba extract - EGB 761

Effect of high-intensity interval exercise on renal artery hemodynamics in healthy young adults.

High-intensity interval exercise is useful for sustained exercise; however, its effect on renal artery hemodynamics is unclear. This study aimed to evaluate changes in renal artery blood flow velocity due to high-intensity interval exercise. Ten healthy adults (age, 23.5±1.2 years) completed high-intensity interval exercise and moderate-intensity continuous exercise protocols on separate days. The high-intensity interval exercise protocol (total duration, 26 min) comprised eight sets of high-intensity exercise sessions at 85% maximum oxygen uptake for 1 min, with intervals of 40% maximum oxygen uptake for 2 min between sets. The moderate-intensity continuous exercise protocol comprised 40 min of exercise at 40% maximum oxygen uptake. Renal artery blood flow velocity and natural log-transformed high frequency spectral power (an index of cardiac parasympathetic nervous system activity) were measured before and after exercise. Additionally, exercise enjoyment was measured using a questionnaire. Renal artery blood flow velocity did not significantly differ between protocols or timepoints for either protocol. However, the natural log-transformed high frequency spectral power was significantly lower with high-intensity interval exercise than with moderate-intensity continuous exercise (P<0.001, F=25.97) during exercise and at 10 min after exercise, and it did not return to pre-exercise levels with high-intensity interval exercise. Moreover, there was no significant difference in exercise enjoyment between the two protocols. In healthy young adults, high-intensity interval exercise reduces parasympathetic activity; however, it does not produce any significant changes in renal artery hemodynamics after exercise.

Impact of Different Flushing Frequencies on Peripheral Intravenous Catheter Failure, Coagulation, and Tissue Injury—A Counterbalanced Preclinical Human Trial

Highlights Abstract Background: Peripheral intravenous venous catheters (PIVCs) are associated with a postinsertion failure incidence of 40%, yet the common maintenance and preventive strategy of saline flushing is poorly understood at a physiological level. Methods: We developed a human model of bilateral cephalic vein cannulation to study the impact of varied PIVC flushing frequency (high frequency, HF; low frequency, LF) over 5 hours on catheter failure (primary outcome), coagulation, platelet aggregation, and local tissue injury. Ultrasound was used in a subset to assess vascular diameter/catheter to vein, blood flow velocity, and thrombus formation. Results: Out of 34 catheters in 17 adult participants, 1/17 (6%) LF catheters failed, which was not significantly different from HF catheters (0/17). Platelet function, activated partial thromboplastin time, and tissue factor were also not different (P &amp;gt; 0.05). However, prothrombin time (PT) increased with HF versus LF after 5 hours (P &amp;lt; 0.05). Ultrasound demonstrated luminal thromboses in veins experiencing both HF (6/7) versus LF (5/7) conditions after 5 hours with nonsignificant changes in vascular diameter and blood flow velocity over time. Conclusions: Although no difference in PIVC failure was observed between HF and LF flushing conditions over 5 hours, greater flushing frequency increased PT time, suggesting delayed activation or consumption of extrinsic coagulation factors. This study also demonstrated feasibility in assessment of luminal thromboses, which were remarkably prevalent after PIVC placement, and changes in vascular diameter and blood flow. This manuscript illustrates that the development of a sensitive human model will be of great use for exploring the impact of interventions on reducing PIVC failure in the future.

The Influence of Sleep Duration on Cerebrovascular Reactivity

The impaired ability of the cerebrovasculature to dilate in response to a vasoactive stimulus (i.e., cerebrovascular reactivity, CVR) is associated with an increased risk of cognitive impairment. The association between sleep duration and dementia risk is “U‐shaped”, where adults who achieve seven hours of sleep have the lowest risk of cognitive impairment, compared to adults who achieve greater than or less than seven hours of sleep. In otherwise healthy adults, poor sleep quality and duration impairs peripheral vascular function, but its effect on CVR in generally healthy adults has remained largely been unexplored. The purpose of this study was to assess the relation between subjective sleep quality and CVR in healthy adults. Because the relation between sleep duration and cognitive impairment is an inverted U‐shape, we hypothesized that CVR would be lower in adults who slept longer than or shorter than the recommended 7‐8 hours of sleep. Data from thirty‐five individuals across the adult lifespan (21 males / 14 females, age: 44 ± 17 years; BMI: 26.8 ± 4.8 kg/m2; blood pressure, BP: 114 ± 12 / 71 ± 10 mmHg; heart rate, HR: 62 ± 8 bpm) were included in this analysis. CVR was assessed by measuring the change in middle cerebral artery blood flow velocity (MCAv) at baseline and following a 3‐minute hypercapnic stimulus (+9 mmHg increase in the end‐tidal partial pressure of CO2) using transcranial Doppler ultrasound. MCAv was normalized to beat‐to‐beat BP (MCACVC), and CVR was calculated as the percentage change in MCACVC and normalized to the absolute change in end‐tidal CO2.Sleep duration was negatively predictive of lower CVR (R2=0.17, β1± SE = ‐0.45 ± 0.18 %/mmHg/hour, P=0.014). A correlation matrix was performed to determine if any variables other than sleep duration (e.g., age, sex, etc) might also impact CVR. Age (P=0.53), BMI (P=0.93), systolic BP (P=0.22), diastolic BP (P=0.84), HR (P=0.071), and mean arterial pressure (P=0.57) were not associated with CVR. Only sex was significantly associated with CVR (R= ‐0.36, P=0.036), where men had augmented CVR compared to women (2.20 ± 0.73 %/mmHg vs. 1.59 ± 0.93 %/mmHg, P=0.036). Importantly, sex (β1± SE= ‐0.18 ± 0.27 %/mmHg, P=0.51) did not influence the relation between CVR (β1± SE= ‐0.41 ± 0.16 %/mmHg/hour, P=0.013) and sleep duration (model adjusted for sex: R2= 0.17, P=0.042). In conclusion, longer sleep duration was independently associated with lower CVR in healthy adults. Future studies should include more individuals with shorter sleep duration to test the possibility of an inverted U‐shaped association with CVR.

Evaluation of Hemodynamic Changes in Retrobulbar Blood Vessels Using Color Doppler Imaging in Diabetic Patients.

Background—Diabetic retinopathy is a common complication of long-standing hyperglycemia. Microangiopathy-induced retinal changes are well-visualized on ophthalmoscopic examination. However, certain hemodynamic alterations have also been documented in the diabetic population, which have not been completely understood. Aim—To study the hemodynamic changes in retrobulbar circulation in diabetic patients with and without retinopathy, and to compare these changes with non-diabetic controls. Materials and Methods—This hospital-based prospective study included 50 diabetic and 50 non-diabetic patients. The diabetic groups consisted of 25 patients without retinopathy and 25 patients with retinopathy, and were labeled as Groups I and II, respectively. All subjects underwent orbital color Doppler ultrasonography using a linear high-frequency probe. The color Doppler parameters (peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI)) were measured and recorded using the spectral waveform of the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA). Comparison of obtained values was carried out using appropriate tests of significance. Results—The resistive indices of the ophthalmic, central retinal, and short posterior ciliary arteries were significantly higher in diabetic patients compared to controls (p < 0.001). The difference was also significant between Group I and Group II. Comparison of PSV and EDV of CRA and SPCAs among three groups using one-way ANOVA revealed a significant difference, with the highest blood flow velocities in the control group and the lowest in diabetics with retinopathy. The ophthalmic artery showed no significant change in blood flow velocity. Analysis using the Pearson correlation coefficient provided a positive correlation between the RI values of OA, CRA, and SPCA and the presence of diabetic retinopathy (OA = r 0.417, p < 0.001; CRA = r 0.466, p < 0.001; SPCA = r 0.438; p < 0.001). Conclusions—The resistive index of OA, CRA, and SPCA is a reliable indicator to assess diabetic-associated hemodynamic changes. The use of orbital color Doppler ultrasonography in diabetic patients can help in the identification of patients who are at risk of developing retinopathy.

Comparative Assessment of Retinal Blood Flow Velocity Changes Following Brimonidine and Brinzolamide Administration Using Retinal Function Imaging.

PurposeImpaired ocular blood flow has been associated with the etiopathogenesis of glaucoma. Topical brimonidine lowers intraocular pressure, a major glaucoma risk factor. However, brimonidine's influence on retinal blood flow remains to be fully elucidated. Our aim was to compare the effect of topical brimonidine and brinzolamide administration on retinal blood flow velocity in second and third order vessels in healthy adults using the retinal function imager.MethodsIn 10 healthy probands between 23 and 32 years of age, one eye was randomly selected to receive 2 treatment rounds with 3 single doses of brimonidine 2 mg/mL and brinzolamide 10 mg/mL at 12-hour intervals each. The fellow eyes served as intra-individual controls. Immediately before the first drop and 2 hours after the last drop of each treatment round, all subjects were examined, including Goldmann tonometry, Pascal tonometry, assessment of retinal blood flow velocity using the retinal function imager, as well as blood pressure and pulse measurements.ResultsIntraocular pressure decreased significantly in treated eyes while remaining stable in control eyes, indicating reliable application of brimonidine and brinzolamide drops. In contrast, retinal blood flow velocities did not demonstrate any significant differences between groups after both treatment rounds.ConclusionsNeither brimonidine nor brinzolamide appear to alter retinal blood flow velocity in a clinically relevant manner. The slight velocity changes detected in our study are likely physiologic fluctuations. Our findings do not support the rationale of a detrimental effect of topical brimonidine on ocular blood flow and hence brimonidine may be further administered for lowering intraocular pressure with the appropriate caution. However, our study is strongly limited by the small sample size and, thus, further research with larger cohorts of healthy volunteers and patients with glaucoma is needed to confirm the results.Translational RelevanceThe study provides information about the effect of the topically administered antiglaucoma medications brimonidine and brinzolamide on the ocular blood flow and its regulation. The findings indicate that beside the lowering of IOP there is no evidence for an additional effect on the development of glaucoma.

Long-term changes of choroidal blood flow velocity in Vogt-Koyanagi-Harada disease.

To evaluate changes in choroidal blood flow in patients with Vogt-Koyanagi-Harada (VKH) disease after initiation of corticosteroid treatment. Fourteen patients (10 men and 4 women) with acute VKH disease followed for 2years were retrospectively reviewed; only right eyes were included in the analysis. Mean blur rate (MBR) in the macula was measured by laser speckle flowgraphy (LSFG) and central choroidal thickness (CCT) was measured by optical coherence tomography (OCT), both prior to treatment and over 2years after initiation of corticosteroid treatment. Of 14 patients included in this study, 13 received initial treatment consisting of intravenous corticosteroid pulse therapy and one patient was treated using bilateral sub-Tenon injections of triamcinolone acetonide. Mean percentage change in MBR was significantly increased after initiation of treatment compared to pretreatment values (P < 0.001). Mean CCTs were significantly decreased after initiation of treatment, compared to pretreatment thicknesses (P < 0.001). There was no significant change in either MBR change or CCT at 1month after initiation of treatment through 2years of follow-up. The mean MBR percentage change was significantly higher in eyes with sunset glow fundus (SGF) compared to eyes without SGF at 1year. With initiation of corticosteroid treatment in VKH disease patients, choroidal blood flow improved and was maintained for 2years. However, the presence of SGF should be taken into consideration when interpreting MBR results in VKH disease patients.

Preventive and Therapeutic Effects of Low-Intensity Ultrasound Stimulation on Migraine in Rats.

This study sought to systematically evaluate the prophylactic and therapeutic effects of low-intensity transcranial ultrasound stimulation on migraine in rats. We used video recordings to assess the head scratching behavior and laser speckle contrast imaging to record the changes in cerebral blood flow velocity of freely moving rats in a healthy group, migraine group, migraine group with ultrasound prevention, and migraine group with ultrasound therapy. Results demonstrated that (1) head scratching during migraine attacks in rats was accompanied by an decrease in cerebral blood flow; (2) both ultrasound prevention and therapy significantly reduced the number of head scratches but did not reduce the cerebral blood flow velocity; and (3) the number of head scratches in the ultrasound stimulation groups was not affected by the auditory effect. These results reveal that low-intensity ultrasound has the potential to be used clinically in the prevention and therapeutic treatment of migraine.

Principal component analysis to identify the major contributors to task-activated neurovascular responses.

Consensus on the optimal metrics for neurovascular coupling (NVC) is lacking. The aim of this study was to use principal component analysis (PCA) to determine the most significant contributors to NVC responses in healthy adults (HC), Alzheimer's disease (AD), and mild cognitive impairment (MCI). PCA was applied to three datasets: 1) 69 HC, 2) 30 older HC, 34 AD, and 22 MCI, 3) 1&2 combined. Data were extracted on peak percentage change in cerebral blood flow velocity (CBFv), variance ratio (VR), cross-correlation function peak (CCF), and blood pressure, for five cognitive tasks. An equamax rotation was applied and factors were significant where the eignevalue was ≥1. Rotated factor loadings ≥0.4 determined significant NVC variables. PCA identified 12 significant factors accounting for 78% of variance (all datasets). Contributing variables loaded differently on the factors across the datasets. In datasets 1&2, peak percentage change in CBFv contributed to factors explaining the most variance (45-58%), whereas cognitive test scores, fluency and memory domains contributed the least (15-37%). In the combined dataset, CBFv, CCF and fluency domain contributed the majority (33-43%), whereas VR and attention the least (6-24%). Peak percentage change in CBFv and the visuospatial task consistently accounted for a large proportion of the variance, suggesting these are robust NVC markers for future studies.

Effects of 16 Weeks of Taekwondo Training on the Cerebral Blood Flow Velocity, Circulating Neurotransmitters, and Subjective Well-Being of Obese Postmenopausal Women.

We investigated the effects of Taekwondo training on the body composition, serum lipid profiles, plasma neurotransmitter levels, cerebral blood flow velocities, and subjective well-being of 24 obese postmenopausal women. The women were randomly assigned into the experimental (n = 12) and control (n = 12) groups. The experimental group underwent Taekwondo training five times per week for 16 weeks, while the control group did not. All participants underwent evaluation for the following parameters before and after the intervention: body composition; serum lipid profiles; plasma serotonin and dopamine levels; cerebral blood flow velocities; positive and negative affect schedule (PANAS) scores; satisfaction with life scale (SWLS) scores. After the intervention, it was observed that the weight, body mass index, body fat percentage, total cholesterol, low-density lipoprotein cholesterol, and PANAS-NA (negative affect in the PANAS questionnaire) scores were significantly decreased (p < 0.05)—while the plasma serotonin levels were significantly increased (p < 0.05)—in the experimental group. Conversely, there were no significant changes in the cerebral blood flow velocities (p > 0.05). Taekwondo training can be effective in not only reducing obesity, but also in increasing the circulating neurotransmitters and enhancing the subjective well-being of obese postmenopausal women.

Vertically Polarized Laser Speckle Contrast Imaging to Monitor Blood Flow in Pulp

This research aimed to study a polarized laser speckle contrast imaging (LSCI) system to assess the pulp blood flow, where the ability of vertically polarized LSCI (vp-LSCI) and the non-polarized LSCI (np-LSCI) systems has been compared through space contrast algorithm and time contrast algorithm. The results showed that the vp-LSCI system could detect a wider contrast dynamic range in the pulp flow, approximately 1.5–2 times than that of the np-LSCI system. The time contrast algorithm detected small velocity changes of 0.03–0.07 mm/s, and its detectability index was 5–10 times than the space contrast algorithm. The vp-LSCI system combined with time contrast algorithm greatly improves the ability of laser speckle to detect pulp blood flow and can detect a wider range of blood flow velocity and smaller changes of blood flow. It indicated that our system may be a promising tool for clinical assessment of pulp blood flow.

Ten days of high dietary sodium does not impair cerebral blood flow regulation in healthy adults.

High dietary sodium impairs cerebral blood flow regulation in rodents and is associated with increased stroke risk in humans. However, the effects of multiple days of high dietary sodium on cerebral blood flow regulation in humans is unknown. Therefore, the purpose of this study was to determine whether ten days of high dietary sodium impairs cerebral blood flow regulation. Ten participants (3F/7M; age: 30±10years; blood pressure (BP): 113±8/62±9mmHg) participated in this randomized, cross-over design study. Participants were placed on 10-day diets that included either low- (1000mg/d), medium- (2300mg/d) or high- (7000mg/d) sodium separated by ≥four weeks. Urinary sodium excretion, beat-to-beat BP (finger photoplethysmography), middle cerebral artery velocity (transcranial Doppler), and end-tidal carbon dioxide (capnography) was measured. Dynamic cerebral autoregulation during a ten-minute baseline was calculated and cerebrovascular reactivity assessed by determining the percent change in middle cerebral artery blood flow velocity to hypercapnia (8% CO2, 21% oxygen, balance nitrogen) and hypocapnia (via mild hyperventilation). Urinary sodium excretion increased in a stepwise manner (ANOVA P=0.001) from the low, to medium, to high condition. There were no differences in dynamic cerebral autoregulation between conditions. While there was a trend for a difference during cerebrovascular reactivity to hypercapnia (ANOVA P=0.06), this trend was abolished when calculating cerebrovascular conductance (ANOVA: P=0.28). There were no differences in cerebrovascular reactivity (ANOVA P=0.57) or conductance (ANOVA: P=0.73) during hypocapnia. These data suggest that ten days of a high sodium diet does not impair cerebral blood flow regulation in healthy adults.

Cerebral lateralisation of first and second languages in bilinguals assessed using functional transcranial Doppler ultrasound

Background: Lateralised language processing is a well-established finding in monolinguals. In bilinguals, studies using fMRI have typically found substantial regional overlap between the two languages, though results may be influenced by factors such as proficiency, age of acquisition and exposure to the second language. Few studies have focused specifically on individual differences in brain lateralisation, and those that have suggested reduced lateralisation may characterise representation of the second language (L2) in some bilingual individuals. Methods: In Study 1, we used functional transcranial Doppler sonography (FTCD) to measure cerebral lateralisation in both languages in high proficiency bilinguals who varied in age of acquisition (AoA) of L2. They had German (N = 14) or French (N = 10) as their first language (L1) and English as their second language. FTCD was used to measure task-dependent blood flow velocity changes in the left and right middle cerebral arteries during phonological word generation cued by single letters. Language history measures and handedness were assessed through self-report. Study 2 followed a similar format with 25 Japanese (L1) /English (L2) bilinguals, with proficiency in their second language ranging from basic to advanced, using phonological and semantic word generation tasks with overt speech production. Results: In Study 1, participants were significantly left lateralised for both L1 and L2, with a high correlation (r = .70) in the size of laterality indices for L1 and L2. In Study 2, again there was good agreement between LIs for the two languages (r = .77 for both word generation tasks). There was no evidence in either study of an effect of age of acquisition, though the sample sizes were too small to detect any but large effects. Conclusion: In proficient bilinguals, there is strong concordance for cerebral lateralisation of first and second language as assessed by a verbal fluency task.

Computed Tomography Images under Optimized Iterative Reconstruction Algorithm for Blood Flow Field Characteristics in Cerebral Aneurysm before and after Stent Implantation

In order to study the analysis of blood flow field characteristics of cerebral aneurysm patients before and after stent implantation based on CT images of ART-TV-PI, this paper firstly improved the ART-TV algorithm of algebraic reconstruction technology and obtained the ART-TV-PI algorithm, which was compared with the ART algorithm and ART-TV algorithm. Afterwards, the CT images based on the above three algorithms were used to analyze the changes of average blood flow velocity, average wall pressure, average wall deformation, and average shear force of 48 cases of cerebral aneurysm patients before and after stent implantation. The results showed that the mean square error and radiation dose of the ART-TV-PI algorithm (0.00012 and 1.65 mSv) were significantly lower than those of the ART algorithm (0.0031 and 3.09 mSv) and ART-TV algorithm (0.00082 and 2.52 mSv), and the signal-to-noise ratio (23.94) was significantly higher than those of the ART algorithm (11.32) and ART-TV algorithm (16.89), with statistically significant differences ( P &lt; 0.05 ). The differences of mean blood flow velocity, mean wall pressure, mean wall deformation, and mean shear force before and after stent implantation among the three algorithms were not statistically significant ( P &gt; 0.05 ), and the average index of the ART-TV-PI algorithm was the highest. Under the ART-TV-PI algorithm, the mean blood flow velocity (0.044 m/s), the mean wall pressure (71.7 Pa), the mean wall deformation (0.057 mm), and the mean shear force (889 Pa) after stent implantation were significantly lower than those before stent implantation (0.165 m/s, 160.8 Pa, 0.721 mm, and 2690 Pa), with average decreases of 73.3%, 55.4%, 92.1%, and 64.3%, respectively, and the differences were statistically significant ( P &lt; 0.05 ). In conclusion, the images reconstructed by the ART-TV-PI algorithm have good image quality, which provides great convenience for surgical examination of cerebral aneurysm stent implantation and is worthy of clinical application.

Cerebral lateralisation of first and second languages in bilinguals assessed using functional transcranial Doppler ultrasound

Background: Lateralised language processing is a well-established finding in monolinguals. In bilinguals, studies using fMRI have typically found substantial regional overlap between the two languages, though results may be influenced by factors such as proficiency, age of acquisition and exposure to the second language. Few studies have focused specifically on individual differences in brain lateralisation, and those that have suggested reduced lateralisation may characterise representation of the second language (L2) in some bilingual individuals.Methods: In Study 1, we used functional transcranial Doppler sonography (FTCD) to measure cerebral lateralisation in both languages in high proficiency bilinguals who varied in age of acquisition (AoA) of L2. They had German (N = 14) or French (N = 10) as their first language (L1) and English as their second language. FTCD was used to measure task-dependent blood flow velocity changes in the left and right middle cerebral arteries during phonological word generation cued by single letters. Language history measures and handedness were assessed through self-report. Study 2 followed a similar format with 25 Japanese (L1) /English (L2) bilinguals, with proficiency in their second language ranging from basic to advanced, using phonological and semantic word generation tasks with overt speech production.Results: In Study 1, participants were significantly left lateralised for both L1 and L2, with a high correlation (r = .70) in the size of laterality indices for L1 and L2. In Study 2, again there was good agreement between LIs for the two languages (r = .77 for both word generation tasks). There was no evidence in either study of an effect of age of acquisition, though the sample sizes were too small to detect any but large effects. Conclusion: In proficient bilinguals, there is strong concordance for cerebral lateralisation of first and second language as assessed by a verbal fluency task.