Blood Flow Levels Research Articles

Relationship Between Blood Flow and Performance Recovery: A Randomized, Placebo-Controlled Study.

To investigate the effect of different limb blood-flow levels on cycling-performance recovery, blood lactate concentration, and heart rate. Thirty-three high-intensity intermittent-trained athletes completed two 30-s Wingate anaerobic test sessions, 3 × 30-s (WAnT 1-3) and 1 × 30-s (WAnT 4), on a cycling ergometer. WAnT 1-3 and WAnT 4 were separated by a randomly assigned 24-min recovery intervention selected from among blood-flow restriction, passive rest, placebo stimulation, or neuromuscular electrical-stimulation-induced blood flow. Calf arterial inflow was measured by venous occlusion plethysmography at regular intervals throughout the recovery period. Performance was measured in terms of peak and mean power output during WAnT 1 and WAnT 4. After the recovery interventions, a large (r = .68 [90% CL .42; .83]) and very large (r = .72 (90% CL .49; .86]) positive correlation were observed between the change in calf arterial inflow and the change in mean and peak power output, respectively. Calf arterial inflow was significantly higher during the neuromuscular-electrical-stimulation recovery intervention than with the blood-flow-restriction, passive-rest, and placebo-stimulation interventions (P < .001). This corresponds to the only intervention that allowed performance recovery (P > .05). No recovery effect was linked to heart rate or blood lactate concentration levels. For the first time, these data support the existence of a positive correlation between an increase in blood flow and performance recovery between bouts of high-intensity exercise. As a practical consideration, this effect can be obtained by using neuromuscular electrical stimulation-induced blood flow since this passive, simple strategy could be easily applied during short-term recovery.

Effects of Platelet-Rich Plasma (PRP) on a Model of Renal Ischemia-Reperfusion in Rats.

Renal ischemia-reperfusion injury is a major cause of acute renal failure, causing renal cell death, a permanent decrease of renal blood flow, organ dysfunction and chronic kidney disease. Platelet-rich plasma (PRP) is an autologous product rich in growth factors, and therefore able to promote tissue regeneration and angiogenesis. This product has proven its efficacy in multiple studies, but has not yet been tested on kidney tissue. The aim of this work is to evaluate whether the application of PRP to rat kidneys undergoing ischemia-reperfusion reduces mid-term kidney damage. A total of 30 monorrenal Sprague-Dawley male rats underwent renal ischemia-reperfusion for 45 minutes. During ischemia, PRP (PRP Group, n = 15) or saline solution (SALINE Group, n = 15) was administered by subcapsular renal injection. Control kidneys were the contralateral organs removed immediately before the start of ischemia in the remaining kidneys. Survival, body weight, renal blood flow on Doppler ultrasound, kidney weight, kidney volume, blood biochemistry and histopathology were determined for all subjects and kidneys, as applicable. Correlations between these variables were searched for. The PRP Group showed significantly worse kidney blood flow (p = 0.045) and more histopathological damage (p<0.0001). Correlations were found between body weight, kidney volume, kidney weight, renal blood flow, histology, and serum levels of creatinine and urea. Our study provides the first evidence that treatment with PRP results in the deterioration of the kidney’s response to ischemia-reperfusion injury.

17. Intraoperative neurophysiologic monitoring of cerebral aneurysm surgery and endovascular procedures

Intraoperative neurophysiologic monitoring (IONM) can be used to assess the functional state of the brain during surgical and endovascular treatment of cerebrovascular disorders, including cerebral aneurysms. This is possible because evoked potentials and EEG are altered in a very predictive manner with different levels of regional cerebral blood flow (rCBF). A variety of studies have shown the following conclusions: 1. Major EEG changes occur with rCBF of

Is Brachial Artery Blood Flow Measured by Sonography During Early Postoperative Periods Predictive of Arteriovenous Fistula Failure in Hemodialysis Patients?

The aim of our study was to determine a brachial artery blood flow level measured by sonography during early postoperative periods that is predictive of arteriovenous fistula failure in hemodialysis patients. Doppler sonography was used to estimate the blood flow in the brachial artery of 103 patients at 1 and 14 days after arteriovenous fistula creation. The performance of brachial artery blood flow during early postoperative periods for predicting fistula failure was evaluated, and optimal cutoff values were determined. During a 6-month follow-up, 85 fistulas were classified as mature, and 18 were classified as failures. The reproducibility of blood flow measurements in the brachial artery was good (intraclass correlation coefficient, 0.912). The blood flow in the failure group was significantly lower than that in the mature group at both 1 and 14 days after fistula creation (P < .05). During the first 2 postoperative weeks, the blood flow increased by 40.7% in the failure group versus 78.3% in the mature group. The areas under the receiver operating characteristic curves of brachial artery blood flow for predicting failure were 0.77 (95% confidence interval, 0.66-0.87; optimal cutoff value, 310 mL/min)at 1 day and 0.91 (95% confidence interval, 0.83-0.99; 413 mL/min) at 14 days after fistula creation. Brachial artery blood flow measured by sonography during early postoperative periods may be predictive of forearm fistula failure. Blood flow of less than 310 mL/min at 1 day and 413 mL/min at 14 days after fistula creation may indicate a risk of failure to mature.

Functional and anatomical evidence of cerebral tissue hypoxia in young sickle cell anemia mice

Cerebral ischemia is a significant source of morbidity in children with sickle cell anemia; however, the mechanism of injury is poorly understood. Increased cerebral blood flow and low hemoglobin levels in children with sickle cell anemia are associated with increased stroke risk, suggesting that anemia-induced tissue hypoxia may be an important factor contributing to subsequent morbidity. To better understand the pathophysiology of brain injury, brain physiology and morphology were characterized in a transgenic mouse model, the Townes sickle cell model. Relative to age-matched controls, sickle cell anemia mice demonstrated: (1) decreased brain tissue pO2 and increased expression of hypoxia signaling protein in the perivascular regions of the cerebral cortex; (2) elevated basal cerebral blood flow , consistent with adaptation to anemia-induced tissue hypoxia; (3) significant reduction in cerebrovascular blood flow reactivity to a hypercapnic challenge; (4) increased diameter of the carotid artery; and (5) significant volume changes in white and gray matter regions in the brain, as assessed by ex vivo magnetic resonance imaging. Collectively, these findings support the hypothesis that brain tissue hypoxia contributes to adaptive physiological and anatomic changes in Townes sickle cell mice. These findings may help define the pathophysiology for stroke in children with sickle cell anemia.

Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted.

Novel translational model of resolving inflammation triggered by UV-killed E. coli.

Whilst numerous studies investigating the aetiology of inflammatory diseases have been performed in rodents, the applicability of these data to human pathophysiology is frequently debated. Regardless of the strengths and weaknesses of rodent models in biomedical research, there is a need to develop models of experimental inflammation in humans. Here, we describe a self‐resolving acute inflammatory response triggered by the intradermal injection of UV‐killed Escherichia coli into the forearm of healthy volunteers. Cells and exudates were harvested from onset to resolution by applying negative pressure over the inflamed site. Onset was characterized by high blood flow, neutrophilia and peak levels of pro‐inflammatory cytokines, whilst resolution showed a decline in blood blow, reduction in neutrophils, increase in monocytes/macrophages and waning of classic pro‐inflammatory cytokine levels. An anti‐inflammatory effect, defined as suppression of onset phase events, was demonstrated by administering naproxen, a conventional non‐steroidal anti‐inflammatory drug. In summary, this model of resolving acute inflammation is minimally invasive, highly tractable and allows simultaneous investigation of the vascular response, cellular trafficking and chemical mediator profile of onset and resolution phases of acute inflammation in humans. It can serve as a translational platform to provide mechanistic insights and to test the clinical efficacy of novel anti‐inflammatory and pro‐resolving drugs, and also as a tool in patients to explore inherent defects in resolution pathways.

The Driving Mechanism for Unidirectional Blood Flow in the Tubular Embryonic Heart.

The embryonic heart of vertebrate embryos, including humans, has a tubular thick-wall structure when it first starts to beat. The tubular embryonic heart (TEH) does not have valves, and yet, it produces an effective unidirectional blood flow. The actual pumping mechanism of the TEH is still controversial with pros and cons for either peristaltic pumping (PP) or impedance pumping (IP). On the other hand, observation of movies of the contractile TEH of the quail revealed a propagating wave from the venous end towards the arterial end that occludes the lumen behind the leading edge. This pattern of contraction represents a complex PP with a duty cycle, and was defined here as biological pumping (BP). In this work we developed a heart-like model that represents the main features of the chick TEH and allows for numerical analysis of all the three pumping mechanisms (i.e., IP, PP, and BP) as well as a comprehensive sensitivity evaluation of the structural, operating, and mechanical parameters. The physical model also included components representing the whole circulatory system of the TEH. The simulations results revealed that the BP mechanism yielded the level and time-dependent pattern of blood flow and blood pressure, as well as contractility that were observed in experiments.

Нейропротекторное действие фенибута и нейроглутама при экспериментальной ишемии головного мозга на фоне измененной иммунореактивности

Изучена церебропротекторная активность фенильных производных гамма-аминомасляной (фенибута) и L-глутаминовой кислоты (нейроглутама) при моделировании ишемии головного мозга (ИГМ) на фоне интактного и измененного иммунитета животных. Исследуемые вещества вводились внутрибрюшинно соответственно в дозах 25 и 26 мг/кг в течение 7 дней после завершения моделирования ИГМ методом поэтапной перевязки общих сонных артерий. Установлено, что супрессия иммунной системы (ИС), вызванная 13-дневным пероральным введением циклоспорина ежедневно в дозе 5 мг/кг, ухудшает течение ИГМ, что проявляется увеличением летальности, более выраженным неврологическим дефицитом, более высоким содержанием в сыворотке крови маркеров повреждения нервной ткани нейронспецифической енолазы (NSE) и основного белка миелина (MBP), снижением мышечной силы, нарушением координации движений, угнетением двигательной и ориентировочно-исследовательской активности по сравнению с животными с ишемией мозга и интактным иммунитетом. ИГМ в условиях стимуляции ИС, вызванной 7-кратным внутрибрюшинным введением липополисахарида (пирогенал, Россия) через день в дозе 10 мкг/кг, вызывала меньшую летальность крыс, а у выживших животных наблюдался меньший неврологический дефицит и более низкие уровни NSE и MBP в сыворотке крови в среднем на 35 % (p ≤ 0,05), более высокие показатели координации движений, мышечной силы и локомоторной активности в среднем на 90 % (p ≤ 0,05). Состояние иммунной системы оказывало значительное влияние на нейропротекторное действие исследуемых веществ при ИГМ. Нейроглутам был эффективен как при интактном иммунитете животных, так и на фоне измененной иммунореактивности. Однако при иммуносупрессии он оказывал максимальный терапевтический эффект при ИГМ, достоверно повышая уровень мозгового кровотока на 56 %, снижая концентрацию NSE и MBP на 57 и 76 % соответственно через 7 дней лечения по сравнению с контрольной группой крыс. Терапевтический потенциал фенибута в большей степени был выражен на фоне активированного иммунитета животных, а при иммуносупрессии его эффективность была низкой.

Impaired renal oxygenation in obese Zucker rats following orthopedic trauma

Wepreviously found increased acute kidney injury (AKI) following orthopedictrauma in obese (OZ) as compared to lean Zucker rats (LZ), in agreement with results reported in lean and obese trauma patients. Impaired renal oxygenation due to elevated oxygen consumption (VO2) and/or decreased oxygen delivery(DO2) has been shown to be an important mechanism of AKI in in many critical illnesses, but few studies have investigated the mechanisms of AKI following orthopedic trauma, particularly in obesity. We hypothesized that the increased AKI in OZ following orthopedic trauma is associated with impaired renal oxygenation. Soft tissue injury, fibula fracture, and bone component injection were performed in both hind limbs in male LZ and OZ (~12wk old) to induce orthopedictrauma. A day later, food intake, circulating aldosterone, renal blood flow (RBF), GFR, and renal medullary glycogen levels were measured. Renal DO2 and VO2 were calculated from renal arterial and venous blood gases. Sodium (Na+) reabsorption was calculated based on GFR, plasma and urine [Na+], and urine output. Following trauma, RBF, GFR, Na+ filtration, renal DO2, and medullary glycogen levels were decreased in OZ but not in LZ. Food intake was markedly decreased in both LZ and OZ, which was associated with significantly increased Na+ reabsorption and aldosterone levels. However, compared to LZ, OZ exhibited lower Na+ uptake but higher aldosterone levels, renal VO2, and oxygen extraction ratio (VO2/DO2). These results suggest that trauma‐induced AKI in OZ is associated with impairments in renal oxygenation and the efficient oxygen utilization.Support or Funding InformationGrants: AHA‐12SDG12050525, National Institutes of HealthP20GM104357, HL‐51971, HL‐89581, and T32 HL‐105324.DoD Disclaimer: The opinions orassertions contained herin are the private views of the author and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.

IN-PATIENT OUTCOMES OF PHARMACOINVASIVE REPERFUSION STRATEGY FOR ST ELEVATION MYOCARDIAL INFARCTION

Aim. To evaluate efficacy of pharmacoinvasive strategy (PCS) of treatment in ST elevation myocardial infarction (STEMI) in Rostovskaya Region, during the nearest (in-patient) period. Material and methods. The analysis performed, of 587 STEMI patients, who were referred to Regional Vascular Center “ROKB” of Rostov-na-Donu city from hospitals of the city and neighborhoods since January 2010 till June 2015, with the aim to undergo percutaneous coronary intervention (PCI) after thrombolytic therapy (TT) as PCS reperfusion strategy. Timeline mediana from pain onset to the start of TT was 140 minutes (interquartile range: 80,5-205 min). In 36,5% cases, TT was done at prehospital stage. Timeline mediana between TT and PCI was 34 hours. The results were evaluated in the nearest (in-hospital) period by the parameters as success of TT by ST dynamics on ECG, the level of blood flow restore in infarction-related artery (IRA) by TIMI score on coronary arteriography after TT in finishing of PCI, the rate of bleedings by TIMI and combinatory parameter of major adverse cardiovasular events (death, recurrent MI, stroke, need for another revascularization of target vessel). Results. ТТ regarded as successful in 52,5% of patients. By the results of coronary arteriography, blood flow TIMI-2/3 after TT was reached in 378 from 586 (64,5%) of patients. Stenting of coronary arteries was done in 548 among 586 (93,5%) of patients; in 25 (4,3%) of patients after TT there were no hemodynamically significant stenoses, in 13 (2,2%) patients stenting of IRA was technically impossible. Application of PCS in STEMI treatment made it to achieve TIMI-2/3 blood flow in IRA in 98,5% (577 among 586) patients. Rate of major bleedings was 1,9%. Stent thrombosis and recurrent infarctions did not happen, in-hospital mortality was 3,6%, rate of major adverse cardiovascular events — 3,7%. Conclusion. PCS makes it to increase time parameters of reperfusion and to increase its efficacy comparing to thrombolysis in those hospitals where it is impossible to perform primary PCI to improve long-term results of PCS it is important to reduce the time “pain-needle”, and to perform coronary angiography in maximum short time after thrombolysis. Regardless that the PCS matches with the region specifics, it is important to optimize healthcare with the aim to perform primary PCI for the highest possible number of patients.

The relationship between total mass and blood supply of parathyroid glands and their secretion of parathyroid hormone in hemodialysis patients with secondary hyperparathyroidism.

Characteristics of parathyroid glands usually determined by ultrasonography such as its total weight or volume might be a good indicator for the induction or suppression of parathyroid hormone (PTH) secretion from these glands. In the present study, we investigated the relationship between the volume and blood supply grade of the parathyroid glands, and its PTH secretion. Study subjects included 52 consecutive patients with the secondary hyperparathyroidism undergoing maintenance hemodialysis therapy referred to dialysis wards of the Imam Khomeini and Amiralam University Hospitals in Tehran. Serum intact PTH (i-PTH) was measured by an ELISA assay. The parathyroid glands characteristics were identified by ultrasonography that was performed simultaneously with blood collection. Parathyroid blood flows were evaluated by power-Doppler color imaging. There was no significant correlation between the total mass of the glands and serum concentration of i-PTH. No significant correlations were also observed between both total central and peripheral parathyroid glands blood flow and serum i-PTH level. Dialysis duration and serum alkaline phosphatase were significantly correlated in a positive manner with i-PTH level. Furthermore, serum level of i-PTH was not correlated with the total signals of glands blood flow in a multivariable linear regression analysis. Serum secreted i-PTH level might not be predictable by a total mass of parathyroid glands as well as their blood supply.

Plateau Waves of Intracranial Pressure and Partial Pressure of Cerebral Oxygen.

This study investigates 55 intracranial pressure (ICP) plateau waves recorded in 20 patients after severe traumatic brain injury (TBI) with a focus on a moving correlation coefficient between mean arterial pressure (ABP) and ICP, called PRx, which serves as a marker of cerebrovascular reactivity, and a moving correlation coefficient between ABP and cerebral partial pressure of oxygen (pbtO2), called ORx, which serves as a marker for cerebral oxygen reactivity. ICP and ICPamplitude increased significantly during the plateau waves, whereas CPP and pbtO2 decreased significantly. ABP, ABP amplitude, and heart rate remained unchanged. In 73 % of plateau waves PRx increased during the wave. ORx showed an increase during and a decrease after the plateau waves, which was not statistically significant. Our data show profound cerebral vasoparalysis on top of the wave and, to a lesser extent, impairment of cerebral oxygen reactivity. The different behavior of the indices may be due to the different latencies of the cerebral blood flow and oxygen level control mechanisms. While cerebrovascular reactivity is a rapidly reacting mechanism, cerebral oxygen reactivity is slower.

Interneurons contribute to the hemodynamic/metabolic response to epileptiform discharges.

Interpretation of hemodynamic responses in epilepsy is hampered by an incomplete understanding of the underlying neurovascular coupling, especially the contributions of excitation and inhibition. We made simultaneous multimodal recordings of local field potentials (LFPs), firing of individual neurons, blood flow, and oxygen level in the somatosensory cortex of anesthetized rats. Epileptiform discharges induced by bicuculline injections were used to trigger large local events. LFP and blood flow were robustly coupled, as were LFP and tissue oxygen. In a parametric linear model, LFP and the baseline activities of cerebral blood flow and tissue partial oxygen tension contributed significantly to blood flow and oxygen responses. In an analysis of recordings from 402 neurons, blood flow/tissue oxygen correlated with the discharge of putative interneurons but not of principal cells. Our results show that interneuron activity is important in the vascular and metabolic responses during epileptiform discharges.

Vasodilation Mechanism of Cerebral Microvessels Induced by Neural Activation under High Baseline Cerebral Blood Flow Level Results from Hypercapnia in Awake Mice.

We investigated the effects of the baseline CBF level at resting state on neurovascular coupling. Diameters of arterioles, capillaries, and venulas in awake mouse brain were measured by a two-photon microscope. Vasodilation in each of the cerebral vessels was caused by three experimental conditions: (1) sensory stimulation, (2) 5% CO2 inhalation (hypercapnia), (3) simultaneous exposure to sensory stimulation and 5% CO2 inhalation. CBF and CBV were also measured by a microscope and a CCD camera. Increases in CBF and CBV were observed under all experimental conditions. After the increases in CBF and CBV due to hypercapnia, additional increases in CBF and CBV occurred during sensory stimulation. Diameter changes in arterioles were significantly larger than those in capillaries and venulas under both sensory stimulation and 5% CO2 inhalation. Additional vasodilation from sensory stimulation was observed under hypercapnia. The diameter change in each vessel type during sensory stimulation was maintained under simultaneous exposure to sensory stimulation and hypercapnia. The diameter change of cerebral vessels during neural activation is reproducible regardless of whether baseline CBF has increased or not. Our finding directly demonstrates the concept of uncoupling between energy consumption and energy supply during cortical activation.

Dual-wavelength laser speckle imaging for monitoring brain metabolic and hemodynamic response to closed head traumatic brain injury in mice.

Abstract. The measurement of dynamic changes in brain hemodynamic and metabolism events following head trauma could be valuable for injury prognosis and for planning of optimal medical treatment. Specifically, variations in blood flow and oxygenation levels serve as important biomarkers of numerous pathophysiological processes. We employed the dual-wavelength laser speckle imaging (DW-LSI) technique for simultaneous monitoring of changes in brain hemodynamics and cerebral blood flow (CBF) at early stages of head trauma in a mouse model of intact head injury (n=10). For induction of head injury, we used a weight-drop device involving a metal mass (∼50 g ) striking the mouse’s head in a regulated manner from a height of ∼90 cm. In comparison to baseline measurements, noticeable dynamic variations were revealed immediately and up to 1 h postinjury, which indicate the severity of brain damage and highlight the ability of the DW-LSI arrangement to track brain pathophysiology induced by injury. To validate the monitoring of CBF by DW-LSI, measurements with laser Doppler flowmetry (LDF) were also performed (n=5), which confirmed reduction in CBF following injury. A secondary focus of the study was to investigate the effectiveness of hypertonic saline as a neuroprotective agent, inhibiting the development of complications after brain injury in a subgroup of injured mice (n=5), further demonstrating the ability of DW-LSI to monitor the effects upon brain dynamics of drug treatment. Overall, our findings further support the use of DW-LSI as a noninvasive, cost-effective tool to assess changes in hemodynamics under a variety of pathological conditions, suggesting its potential contribution to the biomedical field. To the best of our knowledge, this work is the first to make use of the DW-LSI modality in a small animal model to (1) investigate brain function during the critical first hour of closed head injury trauma, (2) correlate between injury parameters of LDF measurements, and (3) monitor brain hemodynamic and metabolic response to neuroprotective drug treatment.

Increasing venoarterial extracorporeal membrane oxygenation flow negatively affects left ventricular performance in a porcine model of cardiogenic shock.

BackgroundThe aim of this study was to assess the relationship between extracorporeal blood flow (EBF) and left ventricular (LV) performance during venoarterial extracorporeal membrane oxygenation (VA ECMO) therapy.MethodsFive swine (body weight 45 kg) underwent VA ECMO implantation under general anesthesia and artificial ventilation. Subsequently, acute cardiogenic shock with signs of tissue hypoxia was induced. Hemodynamic and cardiac performance parameters were then measured at different levels of EBF (ranging from 1 to 5 L/min) using arterial and venous catheters, a pulmonary artery catheter and a pressure–volume loop catheter introduced into the left ventricle.ResultsMyocardial hypoxia resulted in a decline in mean (±SEM) cardiac output to 2.8 ± 0.3 L/min and systolic blood pressure (SBP) to 60 ± 7 mmHg. With an increase in EBF from 1 to 5 L/min, SBP increased to 97 ± 8 mmHg (P < 0.001); however, increasing EBF from 1 to 5 L/min significantly negatively influences several cardiac performance parameters: cardiac output decreased form 2.8 ± 0.3 L/min to 1.86 ± 0.53 L/min (P < 0.001), LV end-systolic volume increased from 64 ± 11 mL to 83 ± 14 mL (P < 0.001), LV stroke volume decreased from 48 ± 9 mL to 40 ± 8 mL (P = 0.045), LV ejection fraction decreased from 43 ± 3 % to 32 ± 3 % (P < 0.001) and stroke work increased from 2096 ± 342 mmHg mL to 3031 ± 404 mmHg mL (P < 0.001). LV end-diastolic pressure and volume were not significantly affected.ConclusionsThe results of the present study indicate that higher levels of VA ECMO blood flow in cardiogenic shock may negatively affect LV function. Therefore, it appears that to mitigate negative effects on LV function, optimal VA ECMO blood flow should be set as low as possible to allow adequate tissue perfusion.

Kidney Function and Cerebral Blood Flow: The Rotterdam Study.

CKD is linked with various brain disorders. Whereas brain integrity is dependent on cerebral perfusion, the association between kidney function and cerebral blood flow has yet to be determined. This study was performed in the framework of the population-based Rotterdam Study and included 2645 participants with mean age of 56.6 years (45% men). We used eGFR and albumin-to-creatinine ratio to assess kidney function and performed phase-contrast magnetic resonance imaging of basilar and carotid arteries to measure cerebral blood flow. Participants had an average (SD) eGFR of 86.3 (13.4) ml/min per 1.73 m(2) and a median (interquartile range) albumin-to-creatinine ratio of 3.4 (2.2-6.1) mg/g. In age- and sex-adjusted models, a higher albumin-to-creatinine ratio was associated with lower cerebral blood flow level (difference in cerebral blood flow [milliliters per minute per 100 ml] per doubling of the albumin-to-creatinine ratio, -0.31; 95% confidence interval, -0.58 to -0.03). The association was not present after adjustment for cardiovascular risk factors (P=0.10). Each 1 SD lower eGFR was associated with 0.42 ml/min per 100 ml lower cerebral blood flow (95% confidence interval, 0.01 to 0.83) adjusted for cardiovascular risk factors. Thus, in this population-based study, we observed that lower eGFR is independently associated with lower cerebral blood flow.

Effect of intra-aortic balloon pump on coronary blood flow during different balloon cycles support: A computer study.

Intra-aortic balloon pump (IABP) has been used in clinical treatment as a mechanical circulatory support device for patients with heart failure. A computer model is used to study the effect on coronary blood flow (CBF) with different balloon cycles under both normal and pathological conditions. The model of cardiovascular and IABP is developed by using MATLAB SIMULINK. The effect on coronary blood flow has been studied under both normal and pathological conditions using different balloon cycles (balloon off; 1:4; 1:2; 1:1). A pathological heart is implemented by reducing the left ventricular contractility. The result of this study shows that the rate of balloon cycles is related to the level of coronary blood flow.

Effect of extracorporeal shockwave therapy (ESWT) on pulpal blood flow after orthodontic treatment: a randomized clinical trial

The effect of non-invasive extracorporeal shockwaves on pulpal blood flow in orthodontic patients who have undergone active treatment was investigated. Seventy-two adult patients were enrolled in the clinical trial and allocated by block randomization to a treatment or a placebo group at a 1:1 ratio. The patients were required to be otherwise healthy. Blinding was performed for the subjects and the outcome assessor. The region of interest was the mandibular incisors and canines, which were vital, unrestored, and had experienced no trauma. The active treatment group received a single shockwave treatment with 1000 impulses at 0.19-0.23 mJ/mm(2) while the placebo group was treated with a deactivated shockwave applicator but acoustic sham. Pulpal blood flow was evaluated four times over a period of 6 months starting from the day of bracket removal, using a laser Doppler device. Thirty patients were evaluated in each group. Orthodontic patients who have undergone active treatment tend to have high levels of pulpal blood flow which decrease over a period of 6 months. Pulpal blood flow did not differ significantly over 6 months between the placebo and treatment group. Shockwave treatment was associated with no significant effect in respect of tooth type, age, sex, or mean blood pressure, and had no unintended pernicious effects. Extracorporeal shockwaves had no statistically significant effect on pulpal blood flow. Multiple applications of ESWT in a pathological setup may be needed in future studies to demonstrate significant differences. The absence of any adverse effects justifies further principal investigations of the use of shockwave treatment in the oral cavity.