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BACKGROUND: Sympathetic-mediated vasoconstriction from the superior cervical ganglion (SCG) is a significant contributor to cerebral vasospasm. Inhibition of the SCG has been shown to improve cerebral blood flow and reverse cerebral vasospasm in swine models. We evaluated the efficacy of a novel minimally invasive endovascular approach to target and pharmacologically inhibit the SCG, using a Micro-Infusion Device for transmural drug delivery. METHODS: Eight SCGs in four Yorkshire swine were surgically identified. After confirming appropriate sympathetic-mediated intracranial vasoconstriction response with SCG stimulation, an endovascular Micro-Infusion Device was used for transmural targeting of the SCG and delivery of 1.5-2 mL of 1% lidocaine-contrast mixture to the perivascular space. Digital subtraction angiography was obtained at: (1) baseline; (2) with SCG stimulation; and (3) after lidocaine delivery to the SCG using the Micro-Infusion Device with concurrent SCG stimulation. Vessel diameters were measured and compared. RESULTS: Endovascular transmural delivery of lidocaine to the SCG and carotid perivascular tissue using the Micro-Infusion Device successfully inhibited sympathetic-mediated vasoconstriction response. Measured vessel diameters after lidocaine delivery were comparable to baseline despite SCG stimulation. CONCLUSION: A novel endovascular technique of transmural delivery of lidocaine to the SCG and carotid artery perivascular tissues successfully inhibits the sympathetic input to the cerebral vasculature and modulates sympathetic-mediated cerebral vasospasm. These results suggest promising steps towards translation to potential clinical use for patients suffering from cerebral vasospasm.

It is important to understand the dynamics of red blood cells (RBCs) in blood flow. This requires the formulation of coarse-grained RBC models that reproduce the hydrodynamic properties of blood accurately. One of the models that successfully reproduces the rheology and morphology of blood has been proposed by Fedosov et al. [Comput. Methods Appl. Mech. Eng. 199, 1937–1948 (2010)]. The proposed RBC model contains several parameters whose values are determined by either various experiments or physical requirements. In this study, we developed a new method of determining parameter values precisely from the fluctuations of the RBC membrane. Specifically, we studied the relationship between the spectra of the fluctuations and model parameters. Characteristic peaks were observed in the spectra, whose peak frequencies were dependent on the parameter values. In addition, we investigated the spectra of the radius of gyration. We identified the peaks originating from the spring potential and the volume-conserving potential appearing in the spectra. These results lead to the precise experimental determination of the parameters used in the RBC model. [ABSTRACT FROM AUTHOR]

Endothelial cells of mammalian blood vessels have multiple levels of heterogeneity along the vascular tree and among different organs. Further heterogeneity results from blood flow turbulence and variations in shear stress. In the aorta, vascular endothelial protein tyrosine phosphatase (VE-PTP), which dephosphorylates tyrosine kinase receptor Tie2 in the plasma membrane, undergoes downstream polarization and endocytosis in endothelial cells exposed to laminar flow and high shear stress. VE-PTP sequestration promotes Tie2 phosphorylation at tyrosine992 and endothelial barrier tightening. The present study characterized the heterogeneity of VE-PTP polarization, Tie2-pY992 and total Tie2, and claudin-5 in anatomically defined regions of endothelial cells in the mouse descending thoracic aorta, where laminar flow is variable and IgG extravasation is patchy. We discovered that VE-PTP and Tie2-pY992 had mosaic patterns, unlike the uniform distribution of total Tie2. Claudin-5 at tight junctions also had a mosaic pattern, whereas VE-cadherin at adherens junctions bordered all endothelial cells. Importantly, the amounts of Tie2-pY992 and claudin-5 in aortic endothelial cells correlated with downstream polarization of VE-PTP. VE-PTP and Tie2-pY992 also had mosaic patterns in the vena cava, but claudin-5 was nearly absent and extravasated IgG was ubiquitous. Correlation of Tie2-pY992 and claudin-5 with VE-PTP polarization supports their collective interaction in the regulation of endothelial barrier function in the aorta, yet differences between the aorta and vena cava indicate additional flow-related determinants of permeability. Together, the results highlight new levels of endothelial cell functional mosaicism in the aorta and vena cava, where blood flow dynamics are well known to be heterogeneous.

In the present study, a Caputo–Fabrizio (C–F) time-fractional derivative is introduced to the governing equations to present the flow of blood and the transport of magnetic nanoparticles (MNPs) through an inclined porous artery with mild stenosis. The rheology of blood is defined by the non-Newtonian visco-elastic Jeffrey fluid. The transport of MNPs is used as a drug delivery application for cardiovascular disorder therapy. The momentum and transport equations are solved analytically by using the Laplace transform and the finite Hankel transform along with their inverses, and the solutions are presented in the form of Laplace convolutions. To display the solutions graphically, the Laplace convolutions are solved using the numerical integration technique. The study presents the impacts of different governing parameters on blood and MNP velocities, volumetric flow rate, flow resistance, and skin friction. The study demonstrates that blood and MNP velocities boost with an increase in the fractional order parameter, Darcy number, and Jeffrey fluid parameter. The volumetric flow rate decreases and flow resistance increases with enhancement in stenosis height. The non-symmetric shape of stenosis and the rheology of blood decrease skin friction, whereas enhancement in MNP concentration increases skin friction. A comparison of the present result with the previous work shows excellent agreement. The present study will be beneficial for the field of medical science to further study atherosclerosis therapy and other similar disorders. [ABSTRACT FROM AUTHOR]

Clinical Scenario: Stress fractures are one of the most common injuries in athletes. Unfortunately, they are hard to diagnose, require multiple radiology exams and follow-up which leads to more exposure to radiation and an increase in cost. Stress fractures that are mismanaged can lead to serious complications and poorer outcomes for the athlete. During the rehabilitation process, it would be beneficial to be able to monitor the healing of fractures to know when it is safe to gradually allow a patient to a return to sport because the return to activity is not usually objective and based on pain level. Clinical Question: Can infrared thermography (IRT) be a useful tool to measure the pathophysiological state of the fracture healing? The aim of this critically appraised topic is to analyze the current evidence of IRT for measuring the temperature change in fractures to provide recommendations for medical practitioners. Summary of Key Findings: For this critically appraised topic, we examined 3 articles that compared medical imaging and IRT over multiple time points during the follow-up. The 3 articles concluded that a 1 °C asymmetry in temperature followed by a return to normal (less than 0.3 °C) temperature during the healing process of fractures can be monitored using IRT. Clinical Bottom Line: Once the patient has been diagnosed with a fracture, IRT can safely be used to monitor the evolution of a fracture. When the thermogram progresses from a hot thermogram to a cold thermogram, the healing is considered good enough to return to sport. Strength of Recommendation: Grade 2 evidence exists to support IRT being used by clinicians to monitor fracture healing. Due to the limited research and novelty of the technology, the current recommendations are for following the treatment of the fracture once the initial diagnosis is made. [ABSTRACT FROM AUTHOR]

Eccentric exercise has gained attention as a novel exercise modality that increases muscle performance at a lower metabolic demand. However, vascular responses to eccentric cycling (ECC) are unknown, thus gaining knowledge regarding endothelial shear stress (ESS) during ECC may be crucial for its application in patients. The purpose of this study was to explore ECC-induced blood flow patterns and ESS across three different intensities in ECC. Eighteen young, apparently healthy subjects were recruited for two laboratory visits. Maximum oxygen consumption, power output, and blood lactate (BLa) threshold were measured to determine workload intensities. Blood flow patterns in the brachial artery were measured via ultrasound imaging and Doppler on an eccentric ergometer during a 5 min workload steady exercise test at low (BLa of 0–2 mmol/L), moderate (BLa 2–4 mmol/L), and high intensity (BLa levels > 4 mmol/L). There was a significant increase in the antegrade ESS in an intensity-dependent manner (baseline: 44.2 ± 8.97; low: 55.6 ± 15.2; moderate: 56.0 ± 10.5; high: 70.7 ± 14.9, all dynes/cm2, all p values < 0.0002) with the exception between low and moderate and Re (AU) showed turbulent flow at all intensities. Regarding retrograde flow, ESS also increased in an intensity-dependent manner (baseline 9.72 ± 4.38; low: 12.5 ± 3.93; moderate: 15.8 ± 5.45; high: 15.7 ± 6.55, all dynes/cm2, all p values < 0.015) with the exception between high and moderate and Re (AU) showed laminar flow in all intensities. ECC produced exercise-induced blood flow patterns that are intensity-dependent. This suggests that ECC could be beneficial as a modulator of endothelial homeostasis. [ABSTRACT FROM AUTHOR]

Background: Radiation-induced skin injury is a significant adverse reaction to radiotherapy. However, there is a lack of effective prevention and treatment methods for this complication. Ferulic acid (FA) has been identified as an effective anti-radiation agent. Conventional administrations of FA limit the reaching of it on skin. We aimed to develop a novel FA hydrogel to facilitate the use of FA in radiation-induced skin injury. Methods: We cross-linked carbomer 940, a commonly used adjuvant, with FA at concentrations of 5%, 10%, and 15%. Sweep source optical coherence tomography system, a novel skin structure evaluation method, was applied to investigate the influence of FA on radiation-induced skin injury. Calcein-AM/PI staining, CCK8 assay, hemolysis test and scratch test were performed to investigate the biocompatibility of FA hydrogel. The reducibility of DPPH and ABTS radicals by FA hydrogel was also performed. HE staining, Masson staining, laser Doppler blood flow monitor, and OCT imaging system are used to evaluate the degree of skin tissue damage. Potential differentially expressed genes were screened via transcriptome analysis. Results: Good biocompatibility and in vitro antioxidant ability of the FA hydrogels were observed. 10% FA hydrogel presented a better mechanical stability than 5% and 15% FA hydrogel. All three concentrations of FA remarkably promoted the recovery of radiation-induced skin injury by reducing inflammation, oxidative conidiation, skin blood flow, and accelerating skin tissue reconstruction, collagen deposition. FA hydrogel greatly inhibiting the levels of NLRP3, caspase-1, IL-18, pro-IL-1β and IL-1β in vivo and vitro levels through restraining the activation of NLRP3 inflammasome. Transcriptome analysis indicated that FA might regulate wound healing via targeting immune response, inflammatory response, cell migration, angiogenesis, hypoxia response, and cell matrix adhesion. Conclusions: These findings suggest that the novel FA hydrogel is a promising therapeutic method for the prevention and treatment of radiation-induced skin injury patients. [ABSTRACT FROM AUTHOR]

A comparative application of major dynamic light scattering (DLS)‐based image methodologies applied to transcranial cerebral blood flow imaging is presented. In particular, the study delves into assessing capability of Laser Doppler Flowmetry (LDF), Laser Speckle Contrast Imaging (LSCI), and Diffuse Correlation Spectroscopy (DCS) in enhancing the spatial and temporal resolution of transcranial blood flow imaging. An integral part of the study is focused on the modulation of blood flow through the administration of the vasodilator drug, Sodium Nitroprusside (SNP). This pharmacological intervention facilitated a direct observation of cerebral vasculature's responsiveness to external stimuli, illuminating the physiological adaptations within the brain's microvascular architecture. Advanced LSCI processing techniques are incorporated, notably entropy and principal component analysis (PCA). Entropy is providing a quantifiable measure of the randomness and complexity within the speckle patterns of transcranial blood flow images, revealing remarkably similar outcomes with DSC approach in terms of blood flow dynamics and its quantitative evaluation. The application of PCA approach is provided a more nuanced understanding of blood flow dynamics, facilitating the identification of subtle changes induced by drug administration. This method proved instrumental in enhancing the visualization and detection of nuanced blood flow dynamics, thereby allowing for a more detailed examination of cerebral circulation alterations induced by SNP administration. The study seeks to offer a wider‐ranging insight into comprehending the translating further the concept of DLS into transcrainial blood flow vizualization and explore its practical applications, considering hardware, advanced quantitative image processing, and data acquisition. [ABSTRACT FROM AUTHOR]

Background Purpose Methods Results Conclusion Ultra‐high dose rate irradiation (≥40 Gy/s, FLASH) has been shown to reduce normal tissue toxicity, while maintaining tumor control compared to conventional dose‐rate radiotherapy. The radiolytic oxygen (O2) depletion (ROD) resulting from FLASH has been proposed to explain the normal tissue protection effect; however, in vivo experiments have not confirmed that FLASH induced global tissue hypoxia. Nonetheless, the experiments reported are based on volume‐averaged measurement, which have inherent limitations in detecting microscopic phenomena, including the potential preservation of stem cells niches due to local FLASH‐induced O2 depletion. Computational modeling offers a complementary approach to understand the ROD caused by FLASH at the microscopic level.We developed a comprehensive model to describe the spatial and temporal dynamics of O2 consumption and transport in response to irradiation in vivo. The change of oxygen enhancement ratio (OER) was used to quantify and investigate the FLASH effect as a function of physiological and radiation parameters at microscopic scale.We considered time‐dependent O2 supply and consumption in a 3D cylindrical geometry, incorporating blood flow linking the O2 concentration ([O2]) in the capillary to that within the tissue through the Hill equation, radial and axial diffusion of O2, metabolic and zero‐order radiolytic O2 consumption, and a pulsed radiation structure. Time‐evolved distributions of [O2] were obtained by numerically solving perfusion‐diffusion equations. The model enables the computation of dynamic O2 distribution and the relative change of OER (δROD) under various physiological and radiation conditions in vivo.Initial [O2] level and the subsequent changes during irradiation determined δROD distribution, which strongly depends on physiological parameters, i.e., intercapillary spacing, ultimately determining the tissue area with enhanced radioresistance. We observed that the δROD/FLASH effect is affected by and sensitive to the interplay effect among physiological and radiation parameters. It renders that the FLASH effect can be tissue environment dependent. The saturation of FLASH normal tissue protection upon dose and dose rate was shown. Beyond ∼60 Gy/s, no significant decrease in radiosensitivity within tissue region was observed. In turn, for a given dose rate, the change of radiosensitivity became saturated after a certain dose level. Pulse structures with the same dose and instantaneous dose rate but with different delivery times were shown to have distinguishable δROD thus tissue sparing, suggesting the average dose rate could be a metric assessing the FLASH effect and demonstrating the capability of our model to support experimental findings.On a macroscopic scale, the modeling results align with the experimental findings in terms of dose and dose rate thresholds, and it also indicates that pulse structure can vary the FLASH effect. At the microscopic level, this model enables us to examine the spatially resolved FLASH effect based on physiological and irradiation parameters. Our model thus provides a complementary approach to experimental methods for understanding the underlying mechanism of FLASH radiotherapy. Our results show that physiological conditions can potentially determine the FLASH efficacy in tissue protection. The FLASH effect may be observed under optimal combination of physiological parameters, not limited to radiation conditions alone. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Methods Results Conclusions This study aimed to examine the spatiotemporal coherence of capillary lumen fluctuations in relation to spatial variations in the pericyte lining in the cortex of anesthetized mice.Two‐photon microscopic angiography data (previously published) were reanalyzed, and spatial variations in capillary diameter fluctuations at rest and in capillary lining with vascular mural cells were measured along capillary centerlines.Relatively large diameters of the capillaries (5.5 μm) coincided with a dense pericyte lining, while small capillaries (4.3 μm) had a sparse pericyte lining. Temporal variations had a frequency of about 0.1 Hz with an amplitude of 0.5 μm, which were negatively correlated with pericyte lining density. Spatial frequency analysis further revealed a common pattern of spatial variations in capillary diameter and pericyte lining, but temporal variations differed. The temporal variations in capillary lumens were locally distinct from those in neighboring locations, suggesting intrinsic fluctuations independent of the pericyte lining.Capillary lumens in the brain exhibit slow microfluctuations that are independent of pericyte lining. These microfluctuations could affect the distribution of flowing blood cells and may be important for homogenizing their distribution in capillary networks. [ABSTRACT FROM AUTHOR]

The investigation of blood flow into curved arteries is fascinating and essential to prevent the advancement of vascular disease. Motivated by electro-kinetic manipulation, gold nanoparticles, and their size applications, a mathematical model is developed to explain blood flow, entropy generation, and electro-kinetic energy conversion (EKEC) efficiency in curved arterial flow. To make this study more realistic, a patient-specific overlapped stenosis condition and non-Newtonian (power-law fluid) blood flow model have been considered. The effects of a magnetic field, external heating, and chemical reactions are also included. The Stone's strongly implicit scheme has been considered to solve the system of non-linear partial differential equations (PDE's) in the" MATLAB" software. In this numerical investigation, an error tolerance of 10 − 6 has been considered for every iteration step under Stone's scheme. The significance of various physical parameters, such as nanoparticle volume fraction (m), their size (dp), magnetic field intensity (M), inverse Debye length ( κ ¯ ), flow behavior index (Sc), heat source (H), and chemical reaction parameter (ξ) on the blood flow velocity, temperature, concentration, EKEC efficiency, and entropy generation have been explained graphically. This study also developed stream function contours to describe flow trapping patterns. The findings of this study conclude that the blood flow EKEC efficiency reduces with the presence of nanoparticles and stenosis in the artery. In addition, both flow velocity and entropy enhance by adopting large-size nanoparticles instead of small diametric nanoparticles. Clinical researchers and biologists may use the results of this computational study to forecast endothelial cell damage and plaque deposition in curved arteries with WSS profiles, by which the severity of these conditions can be reduced. [ABSTRACT FROM AUTHOR]

Key points We tested the hypothesis that in human hypertension, an increased tonicity/sensitivity of the peripheral chemoreflex causes a sympathetically mediated restraint of nutritive blood flow to the exercising muscles. Fourteen patients with treated hypertension (age 69 ± 11 years, 136 ± 12/80 ± 11 mmHg; mean ± SD) were studied under conditions of intravenous 0.9% saline (control) and low‐dose dopamine (2 µg kg−1 min−1) to inhibit the peripheral chemoreflex, at baseline, during isocapnic hypoxic rebreathing and during rhythmic handgrip exercise (3 min, 50% maximum voluntary contraction). At baseline, dopamine did not change mean blood pressure (95 ± 10 vs. 98 ± 10 mmHg, P = 0.155) but increased brachial artery blood flow (59 ± 20 vs. 48 ± 16 ml min−1, P = 0.030) and vascular conductance (0.565 ± 0.246 vs. 0.483 ± 0.160 ml min−1 mmHg−1; P = 0.039). Dopamine attenuated the increase in mean blood pressure (∆3 ± 4 vs. ∆8 ± 6 mmHg, P = 0.007) to isocapnic hypoxic rebreathing and reduced peripheral chemoreflex sensitivity by 28 ± 37% (P = 0.044). Rhythmic handgrip exercise induced increases in brachial artery blood flow and vascular conductance (both P < 0.05 vs. rest after 45 s) that were greater with dopamine than saline (e.g. Δ76 ± 54 vs. Δ60 ± 43 ml min−1 and Δ0.730 ± 0.440 vs. Δ0.570 ± 0.424 ml min−1 mmHg−1, respectively, at 60 s; main effect of condition both P < 0.0001). Our results indicate that the peripheral chemoreflex is tonically active at rest and restrains the blood flow and vascular conductance increases to exercise in treated human hypertension. It was hypothesised that in human hypertension, an increased tonicity/sensitivity of the peripheral chemoreflex causes a sympathetically mediated restraint of nutritive blood flow to the exercising muscles. Treated patients with hypertension (n = 14) were studied under conditions of intravenous 0.9% saline (control) and low‐dose dopamine (2 µg kg−1 min−1) to inhibit the peripheral chemoreflex. Low‐dose dopamine reduced resting ventilation and peripheral chemoreflex sensitivity, and while mean blood pressure was unchanged, brachial artery blood flow and vascular conductance were increased. Low‐dose dopamine augmented the brachial artery blood flow and vascular conductance responses to rhythmic handgrip. These findings indicate that the peripheral chemoreflex is tonically active at rest and restrains the blood flow, and vascular conductance increases to exercise in treated human hypertension. [ABSTRACT FROM AUTHOR]

In the brain, a microvascular sensory web coordinates oxygen delivery to regions of neuronal activity. This involves a dense network of capillaries that send conductive signals upstream to feeding arterioles to promote vasodilation and blood flow. Although this process is critical to the metabolic supply of healthy brain tissue, it may also be a point of vulnerability in disease. Deterioration of capillary networks is a feature of many neurological disorders and injuries and how this web is engaged during vascular damage remains unknown. We performed in vivo two-photon microscopy on young adult mural cell reporter mice and induced focal capillary injuries using precise two-photon laser irradiation of single capillaries. We found that ~59% of the injuries resulted in regression of the capillary segment 7 to 14 d following injury, and the remaining repaired to reestablish blood flow within 7 d. Injuries that resulted in capillary regression induced sustained vasoconstriction in the upstream arteriole-capillary transition (ACT) zone at least 21 days postinjury in both awake and anesthetized mice. The degree of vasomotor dynamics was chronically attenuated in the ACT zone consequently reducing blood flow in the ACT zone and in secondary, uninjured downstream capillaries. These findings demonstrate how focal capillary injury and regression can impair the microvascular sensory web and contribute to cerebral hypoperfusion. [ABSTRACT FROM AUTHOR]

Pachychoroid spectrum disease (PSD) involves various chorioretinal pathologies associated with increased choroidal blood flow. Theoretically, PSD could worsen after cataract surgery since the choroidal thickness tends to increase after surgery. Therefore, we evaluated the prevalence of asymptomatic PSD in patients who underwent cataract surgery and compared the clinical characteristics according to the presence of PSD. The subretinal fluid (SRF) development risk was evaluated using the Cox proportional hazard model. Of 924 eyes, 184 (19.9%) showed asymptomatic PSD. Patients with asymptomatic PSD were older, predominantly male, hyperopic, and showed thicker choroid (P < 0.001, 0.001, < 0.001, and < 0.001). Seven (3.8%) of 184 eyes with asymptomatic PSD developed SRF. The Cox proportional hazard model showed that the flat, irregular pigment epithelial detect (FI-PED; HR 37.337, 95% CI 3.880–359.9300, P = 0.002) was the sole indicator for the SRF development after adjustment of age, sex, and axial length. The SRF-developed PSD group experienced a profound and prolonged increase in the choroidal thickness (P = 0.001, 0.002, and 0.002 at 1, 3, and 12 months). Meticulous preoperative evaluation for FI-PED and postoperative monitoring for choroidal thickness would predict SRF development after cataract surgery in eyes with asymptomatic PSD. [ABSTRACT FROM AUTHOR]

Introduction Material and Methods Results Conclusions Imaging fibroid vascularity may predict fibroid growth and aid to determine most appropriate therapy. Microvascular (MV) flow imaging is relatively new and is able to detect slow flow in small vessels. Data on feasibility, reproducibility, and reliability of MV‐flow imaging in fibroids is lacking. The purpose of our study was to determine the reproducibility of MV‐flow imaging and to explore this technique for clinical practice for assessing blood flow in fibroids.Thirty patients with one or multiple fibroids (diameter 1.5–12.0 cm) were prospectively included. Transvaginal ultrasound scanning was performed in B‐mode, 2D MV‐Flow™, 2D and 3D power Doppler mode (HERA W10, Samsung) by two experienced gynecologists at a tertiary care clinic from February to December 2021. The primary outcome was intra‐ and interobserver agreement of the vascular index (VI) and color score (CS). The following parameters: ‘2D MV‐flow VI’, ‘3DPD VI’, ‘2D MV‐flow CS’ and ‘2DPD CS’ were measured offline in the center, pseudocapsule, and entire fibroid. Secondary offline outcomes for exploring 2D MV‐flow for clinical practice, included (1) ability to discern vascular structures, (2) assessing the degree of vascularity via CS and calculating a VI, and (3) determining penetration depth of the ultrasound signal in both power Doppler and MV‐flow imaging.All scans of the 30 included patients were of sufficient quality to analyze. Inter‐ and intra‐observer correlations of all studied parameters were good to excellent, both for 2D MV‐flow and 2D power Doppler (intercorrelation coefficient 0.992–0.996). Using 2D MV‐flow different vascular structures were visible in detail, in contrary to using 2D and 3D power Doppler. In significantly more fibroids central flow could be visualized using 2D MV‐flow (63%) than with 2D power Doppler (13%, p = 0.001). Finally, penetration of the ultrasound signal was deeper using 2D MV‐flow (3.92 cm) than with 2D power Doppler (2.95 cm, p = 0.001).Using 2D MV‐flow imaging for determining vascularity is highly reproducible. It has potential added value for clinical practice as it depicts detailed vascular structures and the degree of vascularity, especially in the center of the fibroid. [ABSTRACT FROM AUTHOR]

Objective: We aimed to probe the diagnostic value of transvaginal color Doppler ultrasound (TV-CDU) parameters in cesarean scar pregnancy (CSP) and CSP sub-types, and the relevant factors affecting patients' surgical effects. Methods: Seventy-five CSP patients (all requested termination of pregnancy) were selected as the observation group, and 75 normal pregnant women with a history of cesarean section were selected as the control group. All the study subjects underwent TV-CDU and their cesarean scar muscle (CSM) thickness, minimum sagittal muscle thickness and resistance index (RI) of blood flow in the anterior wall of the lower uterine segment were calculated. The diagnostic value of CSM, minimum sagittal muscle thickness, and RI for CSP and CSP sub-types was analyzed. The patients in the observation group were grouped into the effective group and the ineffective group according to whether the surgical treatment was effective or not, and the independent factors affecting CSP efficacy were analyzed. Results: The observation group had lower CSM, minimum sagittal muscle thickness and RI than the control group. CSM, RI, and minimum sagittal thickness in patients with type II CSP were lower than those in patients with type I, and these indicators in patients with type III were lower than those in patients with type II. The area under the curve (AUC) of CSM, RI and minimum sagittal muscle thickness in combination for CSP diagnosis and the AUC for CSP sub-types were higher than those of each indicator alone. Gestational sac size and CSM were independent factors affecting CSP treatment. Conclusion: Changes in TV-CDU parameters facilitates CSP diagnosis after cesarean section. CSM, minimum sagittal muscle thickness changes, and RI in combination possesses high value for CSP diagnosis and CSP sub-types. Gestational sac size and CSM are independent factors affecting CSP treatment. [ABSTRACT FROM AUTHOR]

Transarterial chemoembolization (TACE) is an image-guided minimally invasive treatment for liver cancer which involves delivery of chemotherapy and embolic material into tumor-supplying arteries to block blood flow to a liver tumor and to deliver chemotherapy directly to the tumor. However, the released drug diffuses only less than a millimeter away from the beads. To enhance the efficacy of TACE, the development of microbubbles electrostatically bound to the surface of drug-eluting beads loaded with different amounts of doxorubicin (0–37.5 mg of Dox/mL of beads) is reported. Up to 400 microbubbles were bound to Dox-loaded beads (70–150 microns). This facilitated ultrasound imaging of the beads and increased the release rate of Dox upon exposure to high intensity focused ultrasound (HIFU). Furthermore, ultrasound exposure (1 MPa peak negative pressure) increased the distance at which Dox could be detected from beads embedded in a tissue-mimicking phantom, compared with a no ultrasound control. [ABSTRACT FROM AUTHOR]

Objective Methods Results Interpretation Neuromuscular evaluation increasingly employs muscle ultrasonography to determine muscle thickness, mean grayscale echointensity, and visual semiquantitative echotexture attenuation. However, these measures provide low sensitivity for detection of mild muscle abnormality. Exercise‐induced intramuscular blood flow is a physiologic phenomenon, which may be impaired in mildly affected muscles, particularly in dystrophinopathies, and may indicate functional muscle ischemia. We aimed to determine if muscle blood flow is reduced in patients with neuromuscular disorders and preserved muscle strength, and if it correlates with echointensity and digital echotexture measurements.Peak exercise‐induced blood flow, echointensity, and echotexture were quantified in the elbow flexor muscles of 15 adult patients with Becker muscular dystrophy (BMD) and 13 patients with other muscular dystrophies (OMD). These were compared to 17 patients with Charcot–Marie–Tooth type 1 (CMT1) neuropathy and 21 healthy adults from a previous study.Muscle blood flow was reduced in all patient groups compared to controls, most prominently in BMD patients (p < 0.0001). Echointensity was similarly increased in all patient groups (p < 0.05), while echotexture was reduced only in muscular dystrophy patients (p ≤ 0.002). In BMD, blood flow correlated with echotexture (Pearson r = 0.6098, p = 0.0158) and strength (Spearman r = 0.5471; p = 0.0370). In patients with normal muscle strength, reduced muscle blood flow was evident in all patient groups (p < 0.001), echotexture was reduced in BMD and OMD (p < 0.01), and echointensity was increased in CMT (p < 0.05).Muscle blood flow is a sensitive measure to detect abnormality, even in muscles with normal strength. Increased echointensity may indicate a neurogenic disorder when strength is preserved, while low echotexture suggests a dystrophic disease. [ABSTRACT FROM AUTHOR]

Heat transfer in the human eyeball, a complex organ, is significantly influenced by various pathophysiological and external parameters. Particularly, heat transfer critically affects fluid behavior within the eye and ocular drug delivery processes. Overcoming the challenges of experimental analysis, this study introduces a comprehensive three‐dimensional mathematical and computational model to simulate the heat transfer in a realistic geometry. Our work includes an extensive sensitivity analysis to address uncertainties and delineate the impact of different variables on heat distribution in ocular tissues. To manage the model's complexity, we employed a very fast model reduction technique with certified sharp error bounds, ensuring computational efficiency without compromising accuracy. Our results demonstrate remarkable consistency with experimental observations and align closely with existing numerical findings in the literature. Crucially, our findings underscore the significant role of blood flow and environmental conditions, particularly in the eye's internal tissues. Clinically, this model offers a promising tool for examining the temperature‐related effects of various therapeutic interventions on the eye. Such insights are invaluable for optimizing treatment strategies in ophthalmology. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Trial Registration Patients with hypoplastic left heart syndrome undergo the comprehensive stage 2 procedure as the second stage in the hybrid approach toward Fontan circulation. The complexity of comprehensive stage 2 procedure is considered a potential limitation, and limited information is available on its anesthetic management. This study aims to address this gap.A single‐center retrospective cohort study analyzed 148 HLHS patients who underwent comprehensive stage 2 procedure, divided into Group A (stable condition, n = 116) and Group B (requiring preoperative intravenous inotropic therapy, n = 32). Demographic data, intraoperative hemodynamics, anesthetic management, and postoperative outcomes were collected.Etomidate (40%) was the most common induction agent, followed by esketamine (24%), midazolam (16%), and propofol (13%). Inhaled induction was rarely necessary (2%), occurring only in Group A patients. No statistical differences were found between groups for induction drug choice. Post‐cardiopulmonary bypass management included moderate hypoventilation, inhaled nitric oxide (100%), and hemodynamic support with milrinone (97%) and norepinephrine (77%). Group B patients more frequently required additional levosimendan (20%) and epinephrine (18%). Extracorporeal membrane oxygenation was necessary in 8 patients (5%) with no between‐group differences. Switching from fentanyl to remifentanil reduced postoperative ventilation time overall. However, Group B experienced significantly longer ventilation (6.3 vs. 3.5 h) and ICU stay (22 vs. 14 days). In‐hospital mortality was 5% overall (Group A: 4%, Group B: 9%). Long‐term survival analysis revealed a significant advantage for Group A.The use of short‐acting opioids and adjusted ventilation modes enables optimal pulmonary blood flow and rapid transition to spontaneous breathing. Differentiated hemodynamic support with milrinone, norepinephrine, supplemented by levosimendan and epinephrine in high‐risk patients, can mitigate the effects on the preoperatively volume‐loaded right ventricle. However, differences in long‐term survival probability were observed between groups.Local ethics committee, Medical Faculty, Justus‐Liebig‐University‐Giessen (Trial Code Number: 216/14). [ABSTRACT FROM AUTHOR]

Aim Methods Results Conclusions This study assessed the effects of hand‐bathing on sympathetic nervous activity exacerbated by psychological stress. Participants immersed one hand in warm water for 2 min while exposed to noise, and changes in blood flow and skin temperature of the non‐immersed hand were observed.Twenty‐nine healthy university students aged 20 years or older were randomly assigned to either the hand‐bathing group (n = 14) or the control group (n = 15). After a brief rest in a quiet environment, participants were exposed to noise for 6 min. Those in the hand‐bathing group submerged their left hand in a 40°C thermostatic bath for 2 min, starting 2 min into the noise exposure. The tympanic temperature, blood flow, and skin temperature of the non‐immersed hand were continuously measured, along with blood pressure and subjective evaluations before and after the noise exposure.Both groups experienced a decrease in fingertip skin temperature at the start of the noise exposure, persisting longer in the control group. Conversely, the hand‐bathing group showed increased fingertip skin temperature after 150 s, significantly higher after the noise exposure than the control group (p = .04). Participants in the hand‐bathing group reported significantly increased overall body warmth, thermal comfort, and relaxation during hand‐bathing (p = .007, p = .01, p < .001).The 2‐min hand‐bathing intervention reversed the pronounced vasoconstrictive response induced by noise exposure and elicited heightened sensations of overall body warmth, thermal comfort, and relaxation. Hand‐bathing may mitigate heightened sympathetic nervous activity associated with psychological stress induced by noise exposure. [ABSTRACT FROM AUTHOR]

The Windkessel (WK) model is a simplified mathematical model used to represent the systemic arterial circulation. While the WK model is useful for studying blood flow dynamics, it suffers from inaccuracies or uncertainties that should be considered when using it to make physiological predictions. This paper aims to develop an efficient and easy‐to‐implement uncertainty quantification method based on a local gradient‐based formulation to quantify the uncertainty of the pressure waveform resulting from aleatory uncertainties of the WK parameters and flow waveform. The proposed methodology, tested against Monte Carlo simulations, demonstrates good agreement in estimating blood pressure uncertainties due to uncertain Windkessel parameters, but less agreement considering uncertain blood‐flow waveforms. To illustrate our methodology's applicability, we assessed the aortic pressure uncertainty generated by Windkessel parameters‐sets from an available in silico database representing healthy adults. The results from the proposed formulation align qualitatively with those in the database and in vivo data. Furthermore, we investigated how changes in the uncertainty of the Windkessel parameters affect the uncertainty of systolic, diastolic, and pulse pressures. We found that peripheral resistance uncertainty produces the most significant change in the systolic and diastolic blood pressure uncertainties. On the other hand, compliance uncertainty considerably modifies the pulse pressure standard deviation. The presented expansion‐based method is a tool for efficiently propagating the Windkessel parameters' uncertainty to the pressure waveform. The Windkessel model's clinical use depends on the reliability of the pressure in the presence of input uncertainties, which can be efficiently investigated with the proposed methodology. For instance, in wearable technology that uses sensor data and the Windkessel model to estimate systolic and diastolic blood pressures, it is important to check the confidence level in these calculations to ensure that the pressures accurately reflect the patient's cardiovascular condition. [ABSTRACT FROM AUTHOR]

Exploring electrokinetics phenomena in the context of diverse currents and nanoparticle blends introduces the possibility of novel biomedical approaches. This research is aimed at exploring the streaming patterns of electro-magnetized blood infused with titanium dioxide nanoparticles and single-walled carbon nanotubes (SWCNTs) in a squeezed arterial channel under the influence of electroosmosis. The model is deliberated through the imposition of an intense external magnetic field that is aligned perpendicular to the channel, resulting in effects such as Hall and ion-slip currents and Joule warming. The distribution of electric potential within the electric double layer (EDL) is predicted by solving the Poisson–Boltzmann equation. The Runge–Kutta–Fehlberg (RKF45) shooting scheme via bvp4c solver in Mathematica is hired to execute the proposed blood flow model computation. By presenting informative graphs and tables, a study is carried out to comprehend and elucidate the physical effects of crucial factors on flow dynamical features and physical quantities. A statistical analysis is carried out to identify the intricate association of model parameters with physical flow characteristics, enriching the study’s novelty. Some key outcomes are that the blood temperature attenuates with swilling values of Hall and ion slip parameters. The skin friction on the artery’s upper wall is lessened when the electroosmosis parameter gets increase. Expanding volume fraction of nanoparticles results in an elevation of the Nusselt number on the upper wall. In squeezed artery, the streamlines in the blood flow are notably aligned. The study’s findings could contribute to improving drug delivery strategies, diagnostics, medical imaging, patient care, treatment outcomes, design of biomedical devices, such as stents and catheters, and understanding of blood flow behavior in intricate arterial configurations. [ABSTRACT FROM AUTHOR]

Aims Methods Results Conclusion Intubated patients with methicillin‐resistant Staphylococcus aureus pneumonia, fail optimized treatment with intravenous (IV) vancomycin (serum trough 15–20 μg/mL) in 38–79% of cases. Airway blood flow is diminished compared to alveoli and we hypothesized that vancomycin concentrations achieved in airway secretions are suboptimal and nonbactericidal. Targeted therapy by inhalation may overcome this deficit.Airway pharmacokinetics of optimized IV and inhaled vancomycin in infected clinically stable prolonged mechanically ventilated patients were measured. First, IV vancomycin was given until optimized concentrations were achieved (15–20 μg/mL), and, at the same time point, sputum vancomycin concentrations were measured. Then, sputum concentrations were re‐assessed after 4 treatments of inhaled vancomycin (120 mg/2 mL) via a previously characterized nebulizing system that deposited 18 ± 2 mg in the lungs. Vancomycin post‐distribution phase serum peak and trough concentrations were also obtained. Serum albumin was measured to assess binding to vancomycin.Mean serum trough concentration was 18.4 ± 6.5 μg/mL. Sputum concentrations were affected by serum albumin. Only patients with severe hypoalbuminaemia had penetration of drug leading to therapeutic (15.7–17 μg/mL) sputum concentrations. Following inhaled vancomycin, sputum concentrations increased significantly to 199 ± 37.0 μg/mL (P = .002) exceeding minimum inhibitory concentration by 2 orders of magnitude.Despite optimized serum concentrations, patients with albumin near normal had suboptimal concentrations of vancomycin in their sputum. Inhaled therapy may be clinically important for successful treatment of ventilator‐associated methicillin‐resistant Staphylococcus aureus infection. Further studies of inhaled therapy are needed to define their role as adjunctive therapy in ventilator‐associated pneumonia and as single therapy in tracheobronchitis. [ABSTRACT FROM AUTHOR]

ABSTRACT The brain microvasculature, which delivers oxygen and nutrients and forms a critical barrier protecting the central nervous system via capillaries, is deleteriously affected by both Alzheimer's disease (AD) and type 2 diabetes (T2D). T2D patients have an increased risk of developing AD, suggesting potentially related microvascular pathological mechanisms. Pericytes are an ideal cell type to study for functional links between AD and T2D. These specialized capillary‐enwrapping cells regulate capillary density, lumen diameter, and blood flow. Pericytes also maintain endothelial tight junctions to ensure blood–brain barrier integrity, modulation of immune cell extravasation, and clearance of toxins. Changes in these phenomena have been observed in both AD and T2D, implicating “pericyte pathology” as a common feature of AD and T2D. This review examines the mechanisms of AD and T2D from the perspective of the brain microvasculature, highlighting how pericyte pathology contributes to both diseases. Our review identifies voids in understanding how AD and T2D negatively impact the brain microvasculature and suggests future studies to examine the intersections of these diseases. [ABSTRACT FROM AUTHOR]

Highlights Doppler ultrasound may be used to assess leg blood flow (Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$), but the reliability of this method remains unexplored in patients with chronic obstructive pulmonary disease (COPD), where between‐subject variability may be larger than healthy due to peripheral vascular changes. This study aimed to investigate the reliability of Doppler ultrasound in quantifying Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ during single‐leg knee‐extensor exercise (KEE) in COPD patients compared with those obtained from healthy matched controls. In this case–control study, 16 participants with COPD were matched based on sex and age with 16 healthy controls. All participants underwent measurement of Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ using Doppler ultrasound in a KEE set‐up at various intensities on two separate visits. Confounding factors on Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ were controlled for, and the ultrasound scans were consistently performed by the same sonographer. During exercise, smallest real difference (SRD) ranged from 367 mL to 583 mL in COPD and 438 mL to 667 mL in the control group. The coefficient of variation (CV) ranged from 7.9% to 14.3% in COPD and 9.4% to 10.4% in the control group. The intraclass correlation coefficient ranged from 0.75 to 0.92 in COPD and 0.67 to 0.84 in the control group. CV was lower in the control group during exercise at 0 W, but apart from that, reliability was not different between groups during exercise. Doppler ultrasound showed nearly equal reliability when evaluating Q̇leg${{\dot{Q}}_{{\mathrm{leg}}}}$ in COPD patients and healthy individuals with a CV below 15% during exercise for both groups. What is the central question of this study? What is the between‐day reliability of Doppler ultrasound when quantifying leg blood flow during single‐leg knee‐extensor exercise in COPD patients compared to healthy matched controls? What is the main finding and its importance? This study demonstrates a coefficient of variation ranging from 7.9 to 14.3% during single‐leg knee‐extensor exercise for between‐day reliability when applying Doppler ultrasound to assess leg blood flow in patients with COPD. Furthermore, it offers insights into the peripheral circulatory constraints in COPD, as evidenced by diminished leg blood flow. This study is the first of its kind to evaluate the reliability of Doppler ultrasound in the assessment of the peripheral circulation during exercise in COPD. What is the central question of this study?What is the between‐day reliability of Doppler ultrasound when quantifying leg blood flow during single‐leg knee‐extensor exercise in COPD patients compared to healthy matched controls?What is the main finding and its importance?This study demonstrates a coefficient of variation ranging from 7.9 to 14.3% during single‐leg knee‐extensor exercise for between‐day reliability when applying Doppler ultrasound to assess leg blood flow in patients with COPD. Furthermore, it offers insights into the peripheral circulatory constraints in COPD, as evidenced by diminished leg blood flow. This study is the first of its kind to evaluate the reliability of Doppler ultrasound in the assessment of the peripheral circulation during exercise in COPD. [ABSTRACT FROM AUTHOR]

Aim: The purpose of the present study was to evaluate the diagnostic performance of serum miR-4534 combined with Transvaginal Color Doppler Ultrasound (TVCDS) in cervical cancer patients. Methods: Blood samples from 126 patients with cervical cancer and 83 patients with benign uterine lesions were retrospectively analyzed. Quantitative real time polymerase chain reaction (qRT-PCR) was applied to examine the relative abundances of serum miR-4534 in cervical cancer based on a case–control study. Chi-square test was adopted to analyze the association between serum miR-4534 and other clinicopathological factors. The blood flow of cervix was examined using TVCDS, and the blood flow resistance index (RI) of cervix was summarized. Receiver operating characteristic (ROC) curves were plotted to explore the diagnostic capacity of serum miR-4534 combined with blood flow RI. Logistic regression was employed to analyze the risk factors of cervical cancer. Results: Serum miR-4534 was distinctly increased in the study group compared with the control group (P < 0.05), while blood flow RI was dramatically decreased (P < 0.05). Moreover, increased miR-4534 was closely associated with lymph node metastasis (P = 0.010), FIGO stage (P = 0.007) and HR-HPV (P = 0.025). ROC curves demonstrated that the area under curve (AUC) of serum miR-4534 combined with the blood flow RI was 0.854, with the sensitivity and specificity of 88.9% and 73.5%, respectively, which displayed a better diagnostic capacity than serum miR-4534 and blood flow RI alone. Logistic regression analysis demonstrated that serum miR-4534 (OR = 8.805, 95% CI = 4.124–18.798; P < 0.001) was a risk factor related to the initiation and formation of cervical cancer, as well as blood flow RI (OR = 0.112; 95% CI = 0.054–0.235; P < 0.001). Conclusion: Serum miR-4534 was highly expressed in cervical cancer, and associated with the development and metastasis of cervical cancer patients. MiR-4534 combined with TVCDS exhibited a considerable biomarker to detect cervical cancer patients. [ABSTRACT FROM AUTHOR]

Clinical and experimental studies have been shown,that after the combined craniocerebral injury, physiological mechanisms are damaged We maintain perfusion pressure. Partially or completely disruptedShares Autoregulating the brain blood flow. In these conditions after the craniocerebral injury, the brain is not able to respond to the systemic violator Wear homeostasis. As a result, various secondary damage ariseIn the brain tissue is predominantly corridor character thatWe are curved in 80-90% of the dead patients. Is currently among the systemsviolations of homeostasis, most often as secondary damaging factors of the headthe brain. The following: hypotension, hypoxemia, sodium exchange and osmotoostomy, hypocapnia and hyperDrip, hyperthermia, extra-causal inflammatory complications, etc. [1,2,3,4,10,11]. [ABSTRACT FROM AUTHOR]

Neurovascular coupling (NVC), which mediates rapid increases in cerebral blood flow in response to neuronal activation, is commonly used to map brain activation or dysfunction. Here we tested the reemerging hypothesis that CO2 generated by neuronal metabolism contributes to NVC. We combined functional ultrasound and two-photon imaging in the mouse barrel cortex to specifically examine the onsets of local changes in vessel diameter, blood flow dynamics, vascular/perivascular/intracellular pH, and intracellular calcium signals along the vascular arbor in response to a short and strong CO2 challenge (10 s, 20%) and whisker stimulation. We report that the brief hypercapnia reversibly acidifies all cells of the arteriole wall and the periarteriolar space 3–4 s prior to the arteriole dilation. During this prolonged lag period, NVC triggered by whisker stimulation is not affected by the acidification of the entire neurovascular unit. As it also persists under condition of continuous inflow of CO2, we conclude that CO2 is not involved in NVC. A remerging hypothesis suggests that CO2 generated by neuronal metabolism contributes to neurovascular coupling (NVC). Here, the authors show that NVC is unaffected by the acidification of the entire arteriolar column during cerebrovascular reactivity to CO2, demonstrating that CO2 is not a mediator of NVC. [ABSTRACT FROM AUTHOR]

Elastomeric interphases (liners) protect the residual limb and distribute mass bearing to the prosthetic socket. However, discomfort due to excessive sweat and heat in the residual limb is the most relevant factor that negatively affects the quality of life in transfemoral prosthetics users. Additionally, a warm and humid environment and the non-uniform mass distribution can compromise blood flow in the residual limb; these factors favor the development of skin lesions, the dropout rate of prosthetic use, and subsequent amputations. Previous mathematical models that predict skin temperature distribution based on Pennes' model and explain the Fourier and non-Fourier thermic response are available. However, these models require knowledge of difficult parameters to obtain in conditions that lead to amputation. Therefore, the current study aims to propose an experimentally based method to design a personalized liner with areas of different diffusivity rates by using perforations according to thermal needs, preserving the mechanical properties of the liner. After thermal and mechanical characterization, we elaborated a personalized plane liner according to the thermal expression of the anterior thigh using infrared analysis. We tested the liner to probe its ability to dissipate heat. [ABSTRACT FROM AUTHOR]

Surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) are options in severe aortic valve stenosis (AVS). Cardiovascular (CV) and cerebrovascular (CBV) control markers, derived from variability of heart period, systolic arterial pressure, mean cerebral blood velocity and mean arterial pressure, were acquired in 19 AVS patients (age: 76.8 ± 3.1 yrs, eight males) scheduled for SAVR and in 19 AVS patients (age: 79.9 + 6.5 yrs, 11 males) scheduled for TAVI before (PRE) and after intervention (POST, <7 days). Left ventricular function was preserved in both groups. Patients were studied at supine resting (REST) and during active standing (STAND). We found that: (i) both SAVR and TAVI groups featured a weak pre‐procedure CV control; (ii) TAVI ensured better CV control; (iii) cerebral autoregulation was working in PRE in both SAVR and TAVI groups; (iv) SAVR and TAVI had no impact on the CBV control; (v) regardless of group, CV and CBV control markers were not influenced by STAND in POST. Even though the post‐procedure preservation of both CV and CBV controls in TAVI group might lead to privilege this procedure in patients at higher risk, the missing response to STAND suggests that this advantage could be insignificant. [ABSTRACT FROM AUTHOR]

Using a 50‐compartment Python‐coded mathematical lung model, we compared mixed venous blood flow (Q) distributions and arterial oxygen tension/inspired oxygen fraction (PaO2/FiO2) relationships in lungs modeled with log normal distributions (LND) of inspired (VI) versus expired (VA) alveolar gas volumes. In lungs with normal V/Q heterogeneity, Q versus VA/Q and Q versus VI/Q distributions were similar with either approach, and PaO2/FiO2 sequences remained indistinguishable. In V/Q heterogeneous lungs at high FiO2, VILND generated low Q versus VA/Q shoulders and some negative VA units, while VALND preserved Q versus VA/Q log normality by blood flow diversion from low VI/Q units. We managed VILND‐induced negative VA units either by shunt conversion (VI decreased to 0) or VI redistribution simulating collateral ventilation (VI increased till VA = 0). Comparing oxygen transfer: VALND > VILND (redistribution) > VILND (shunt). In V/Q heterogeneous lungs VALND and VILND (redistribution) regained near optimal oxygen transfer on 100% oxygen, while impairment persisted with VILND (shunt). Unlike VALND, VILND (redistribution) produced Q versus VA/Q distributions in V/Q heterogeneity compatible with multiple inert gas (MIGET) reports. VILND (redistribution) is a physiologically–based MIGET–compatible alternative to West's original VALND lung modeling approach. [ABSTRACT FROM AUTHOR]

Articular cartilage receives nutrients and oxygen from the synovial fluid to maintain homeostasis. However, compared to tissues with abundant blood flow, articular cartilage is exposed to a hypoxic environment (i.e., physioxia) and has an enhanced hypoxic stress response. Hypoxia-inducible factors (HIFs) play a pivotal role in this physioxic environment. In normoxic conditions, HIFs are downregulated, whereas in physioxic conditions, they are upregulated. The HIF-α family comprises three members: HIF-1α, HIF-2α, and HIF-3α. Each member has a distinct function in articular cartilage. In osteoarthritis, which is primarily caused by degeneration of articular cartilage, HIF-1α is upregulated in chondrocytes and is believed to protect articular cartilage by acting anabolically on it. Conversely, in contrast to HIF-1α, HIF-2α exerts a catabolic influence on articular cartilage. It may therefore be possible to develop a new treatment for OA by controlling the expression of HIF-1α and HIF-2α with drugs or by altering the oxygen environment in the joints. [ABSTRACT FROM AUTHOR]

Systemic vasodilating agents like nitroglycerin (NG) or iloprost (Ilo) show beneficial effects on intestinal microcirculation during sepsis, which could be attenuated by activation of the sympathetic nervous system or systemic side effects of vasodilating agents. This exploratory study aimed to investigate the effects of topically administered vasodilators and the parasympathetic drug carbachol on colonic microcirculatory oxygenation (µHbO2), blood flow (µFlow) and mitochondrial respiration. A total of 120 male Wistar rats were randomly assigned to twelve groups and underwent either colon ascendens stent peritonitis (CASP) or sham surgery. After 24 h, animals received the following therapeutic regimes: (1) balanced full electrolyte solution, (2) carbachol, (3) NG, (4) Ilo, (5) NG + carbachol, and (6) Ilo + carbachol. Mitochondrial respiration was measured in colon homogenates by respirometry. In sham animals, NG (−13.1%*) and Ilo (−10.5%*) led to a decrease in µHbO2. Additional application of carbachol abolished this effect (NG + carbachol: −4.0%, non-significant; Ilo + carbachol: −1.4%, non-significant). In sepsis, carbachol reduced µHbO2 when applied alone (−10.5%*) or in combination with NG (−17.6%*). Thus, the direction and degree of this effect depend on the initial pathophysiologic condition. [ABSTRACT FROM AUTHOR]

The endothelium is a cell monolayer that lines vessels and separates tissues from blood flow. Endothelial cells (ECs) have a multitude of functions, including regulating blood flow and systemic perfusion through changes in vessel diameter. When an injury occurs, the endothelium is affected by altering its functions and structure, which leads to endothelial dysfunction, a characteristic of many vascular diseases. Understanding the role that the endothelium plays in pulmonary vascular and cardiopulmonary diseases, and exploring new therapeutic strategies is of utmost importance to advance clinically. Currently, there are several treatments able to improve patients' quality of life, however, none are effective nor curative. This review examines the critical role of the endothelium in the pulmonary vasculature, investigating the alterations that occur in ECs and their consequences for blood vessels and potential molecular targets to regulate its alterations. Additionally, we delve into promising non-pharmacological therapeutic strategies, such as exercise and diet. The significance of the endothelium in cardiopulmonary disorders is increasingly being recognized, making ECs a relevant target for novel therapies aimed at preserving their functional and structural integrity. [ABSTRACT FROM AUTHOR]

Background: Free muscle flaps can develop significant postoperative edema and wound exudation, thereby increasing interstitial pressure and potentially compromising microcirculation. While concerns exist regarding negative pressure wound therapy (NPWT) to compress free flaps and hinder monitoring, recent studies have indicated a reduction in edema and an increase in blood flow. Objective: To compare microcirculation in free latissimus dorsi muscle (LDM) flaps dressed with and without NPWT. Methods: This retrospective cohort study analyzed prospectively collected data of patients who received free LDM flap reconstruction. Patients were separated into two groups according to management with or without NPWT. Microcirculation was evaluated continuously for up to 72 h utilizing laser doppler flowmetry and tissue spectrometry. Results: In total, n = 61 patients (26 females, 35 males) with an average age of 56.90 (17.4) years were included. NPWT was applied in 12 patients, while a regular cotton dressing was used in 49 patients. Overall, no significant differences in the number of minor and major complications were observed between groups. Both groups showed an increase in microvascular flow over the investigated time period. The flow showed higher absolute values in the NPWT group, reaching statistical significance at 12 h post-anastomosis, p = 0.038. There was a tendency for lower rHb values in the NPWT group, without reaching statistical significance. Conclusions: The presented study confirms the increase in microvascular flow after NPWT application. Whilst ensuring continuous free flap monitoring utilizing laser doppler flowmetry and spectrometry, the data further support the safety of NPWT application without risking vascular compromise due to external compression. [ABSTRACT FROM AUTHOR]

Pericytes are versatile cells integral to the blood vessel walls of the microcirculation, where they exhibit specific stem cell traits. They are essential in modulating blood flow, ensuring vascular permeability, and maintaining homeostasis and are involved in the tissue repair process. The human endometrium is a unique and complex tissue that serves as a natural scar-free healing model with its cyclical repair and regeneration process every month. The regulation of pericytes has gained increasing attention due to their involvement in various physiological and pathological processes. However, endometrial pericytes are less well studied compared to the pericytes in other organs. This review aims to provide a comprehensive overview of endometrial pericytes, with a focus on elucidating their physiological function and potential implications in uterine disorders. [ABSTRACT FROM AUTHOR]

Background: A skin ulcer is an open sore caused by poor blood supply. Adequate blood flow is necessary for wound healing. But if we have any circulation problems, minor injuries won’t heal properly. Over time, an injury can turn into an ulcer. If an ulcer becomes infected, it should be treated quickly Objective: To study the outcome of healing between dermatotraction versus vacuum assisted dressing in diabetic wounds. Materials and Methods: This randomized interventional study was conducted on inpatient basis at S.S.Institute of Medical Sciences, Davangere, Katnataka India.Institutional ethical committee clearance was taken prior to the start of study. Results: Average size of the wound to which dermatotraction was applied was length 9.4cms and width of 4.76cms, whereas vacuum dressing was done to the wound of average size length 12.2cms and width 7.1cms. It was difficult in our study to apply dermatotraction for wounds with bigger size than for vacuum dressing. The most common primary procedure performed was debridement of the infected wound which was done in about 60% in the people in dermatotraction group and 82.5% in people undergoing vacuum assisted dressing. Average duration for complete closure of the wound was studied and compared between the two groups, which took dermatotraction an average of 22.725 days and vacuum dressing 26.550 days indicating complete closure is faster in cases of dermatotraction. Conclusions: Dermatotraction in one of the effective ways of closure of infected wounds. One of the major advantages of dermatotraction is anaesthesia. In our study all the study population undergoing dermatotraction were given local anaesthesia which is readily available, easily, quick and safe and can be repeated safely if needed. Dermatotraction is a simple and easy technique which can be done in a minor OT procedure room unlike vacuum dressing where it requires another procedure for closure of wound like grafting or flap in major operation theater. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy combined with vascular occlusion test (NIRS-VOT) is a reactive hyperemia technique for in vivo evaluation of skeletal muscle microvascular reactivity. Previous studies using NIRS-VOT have been shown to be able to detect impairments in microvascular function in high-risk cardiovascular disease populations, such as older individuals. It has been demonstrated that older individuals have slower reactive hyperemia compared with young individuals. Importantly, older individuals also show less desaturation during ischemia compared with young individuals. Based on these findings, it has been suggested that the slower reactive hyperemia observed in older individuals is explained by the lower desaturation during blood flow occlusion (reduced ischemic stimulus). This retrospective analysis compared reactive hyperemia in 36 young and 47 older tissue desaturation-matched individuals that underwent 5-min blood flow occlusion. Overall, we showed that older individuals have impaired reactive hyperemia compared with young when matching for the degree of desaturation and blood flow occlusion time. These findings provide evidence that lower tissue desaturation during ischemia is not a major determinant of impaired reactive hyperemia in older individuals. NEW & NOTEWORTHY: Previous findings have suggested that aging-related impairment in skeletal muscle reactive hyperemia is majorly influenced by a lower degree of tissue desaturation during ischemia in older individuals compared with young individuals. In a retrospective analysis including 83 tissue desaturation-matched individuals, we show that the degree of tissue desaturation is not a major determinant of aging-related impairments in reactive hyperemia. [ABSTRACT FROM AUTHOR]

Purpose: This study is to evaluate the correlation between retrobulbar perfusion deficits and glaucomatous visual field defects. Methods: Eighty-four patients with glaucoma and 17 normal subjects serving as controls were selected. Color Doppler imaging (CDI) was used to measure the changes in blood flow parameters in the retrobulbar ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs). Visual field testing was performed using a Humphrey perimeter, categorizing the visual field deficits into four stages according to the Advanced Glaucoma Intervention Study (AGIS) scoring method. Subsequently, the correlation of retrobulbar hemodynamic parameter alterations among glaucomatous patients with varying visual field defects was examined. Results: The higher the visual field stage, the lower the peak systolic velocity (PSV) of the OA, CRA, and SPCAs in glaucomatous patients. The CRA had the highest sensitivity to changes in its PSV. The PSV of the temporal SPCA (TSPCA-PSV) was lower in advanced glaucoma than in early-stage glaucoma. The PSVs of the OA, CRA, and TSPCA, as well as the resistance index of the CRA (CRA-RI), were positively correlated with the visual field index and the mean deviation. Except for that of OA, the PSV of the retrobulbar vessels was negatively correlated with the pattern standard deviation (PSD). The OA-PSV and end-diastolic velocity (EDV) of the CRA and TSPCA were lower in patients with superior visual field defects than in those with inferior visual field defects. Conclusions: Greater severity of visual field defects corresponded to poorer retrobulbar blood flow in glaucomatous patients. Patients suffered significant perfusion impairments in the CRA at the early stage, accompanied by SPCA perfusion disorder at the advanced stage. The presence of a bow-shaped defect in the superior or inferior region of the visual field in moderate-stage glaucoma was closely correlated with retrobulbar vascular EDV. Trial registration: ChiCTR2200059048 (2022–04-23). [ABSTRACT FROM AUTHOR]

Purpose: A finite element computational methodology on a curved boundary using an efficient subparametric point transformation is presented. The proposed collocation method uses one-side curved and two-side straight triangular elements to derive exact subparametric shape functions. Design/methodology/approach: Our proposed method builds upon the domain discretization into linear, quadratic and cubic-order elements using subparametric spaces and such a discretization greatly reduces the computational complexity. A unique subparametric transformation for each triangle is derived from the unique parabolic arcs via a one-of-a-kind relationship between the nodal points. Findings: The novel transformation derived in this paper is shown to increase the accuracy of the finite element approximation of the boundary value problem (BVP). Our overall strategy is shown to perform well for the BVP considered in this work. The accuracy of the finite element approximate solution increases with higher-order parabolic arcs. Originality/value: The proposed collocation method uses one-side curved and two-side straight triangular elements to derive exact subparametric shape functions. [ABSTRACT FROM AUTHOR]

Background: Chronic spontaneous urticaria (CSU) is a common, debilitating skin disorder characterized by recurring episodes of raised, itchy and sometimes painful wheals lasting longer than 6 weeks. CSU is mediated by mast cells which are absent from peripheral blood. However, lineage−CD34hiCD117int/hiFcεRI+ cells in blood have previously been shown to represent a mast cell precursor. Methods: We enumerated FcεRI−, FcεRI+ and FcεRIhi lineage−CD34+CD117+ cells using flow cytometry in blood of patients with CSU (n = 55), including 12 patients receiving omalizumab and 43 not receiving omalizumab (n = 43). Twenty‐two control samples were studied. Disease control and patient response to omalizumab was evaluated using the urticaria control test. We performed single‐cell RNA sequencing (scRNA‐Seq) on lineage−CD34hiCD117hi blood cells from a subset of patients with CSU (n = 8) and healthy controls (n = 4). Results: CSU patients had more lineage−CD34+CD117+FcεRI+ blood cells than controls. Lineage−CD34+CD117+FcεRI+ cells were significantly higher in patients with CSU who had an objective clinical response to omalizumab when compared to patients who had poor disease control 90 days after initiation of omalizumab. scRNA‐Seq revealed that lineage−CD34+CD117+FcεRI+ cells contained both lymphoid and myeloid progenitor lineages, with omalizumab responsive patients having proportionally more myeloid progenitors. The myeloid progenitor lineage contained small numbers of true mast cell precursors along with more immature FcεRI− and FcεRI+ myeloid progenitors. Conclusion: Increased blood CD34+CD117+FcεRI+ cells may reflect enhanced bone marrow egress in the setting of CSU. High expression of these cells strongly predicts better clinical responses to the anti‐IgE therapy, omalizumab. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association between pretreatment blood flow velocity in the choroid and optic nerve head (ONH) and retinal oxygen metabolism in the acute uveitic phase and the development of 'sunset glow fundus' in Vogt‐Koyanagi‐Harada (VKH) disease. Methods: Retrospective analysis of 41 patients (82 eyes). Laser speckle flowgraphy and retinal oximetry measurements were performed at the presentation. The main outcome measure was the development of 'sunset glow fundus'. Results: Twenty patients (40 eyes) presented in the phase preceding anterior segment inflammation (early presentation), and 21 patients (42 eyes) presented with anterior segment inflammation (late presentation). In ONH, mean blur rate (MBR)‐vessel, representing blood flow velocity in retinal vessels, was significantly lower in the late presentation group, while choroidal MBR was not significantly different. The late presentation group had significantly lower oxygen saturation in retinal venules, a higher arteriovenous oxygen saturation difference and a smaller calibre of retinal arterioles compared with the early presentation group. Eyes that subsequently developed 'sunset glow fundus' had significantly lower ONH MBR‐vessels, lower oxygen saturation in retinal venules, a higher arteriovenous oxygen saturation difference and a smaller calibre of retinal arterioles compared with eyes without 'sunset glow fundus'. ONH MBR‐vessel had a significant negative correlation with arteriovenous oxygen saturation difference and a significant positive correlation with calibre of retinal arterioles. Conclusions: In the acute uveitic phase of VKH disease, the development of 'sunset glow fundus' is associated with pretreatment reduced retinal blood flow velocity, calibre of retinal arterioles and oxygen saturation in retinal venules, as well as an increased arteriovenous oxygen saturation difference. [ABSTRACT FROM AUTHOR]

Purpose: To assess intra‐ (repeatability) and inter‐observer (reproducibility) variability of laser speckle flowgraphy (LSFG) for retinal blood flow (RBF) measurement in 20 eyes of wild type (C57BL/6J) mice and effect of intravitreal Aflibercept on RBF in optic nerve head (ONH) region of 10 eyes of Ins2 (Akita) diabetic mice. Methods: 'Mean blur rate (MBR)' was measured for all quadrants of tissue area (MT), vessel (MV) and total area (MA) of ONH region. Changes in MT were analysed at each timepoint. Repeatability was evaluated by measuring MBR variability without changing mouse head position, and reproducibility after resetting mouse head position by another operator. Coefficient of repeatability (CR) through Bland–Altman plot method coefficient of variation (COV) and Intraclass correlation coefficient (ICC) was calculated. Intravitreal Aflibercept (1 μg) was administered to Akita eyes and intraocular pressure (IOP) was measured using a tonometer at baseline, day 7, 14, 21 and 28 post‐injection. Hurvich and Tsai's criterion was used. Results: Coefficient of repeatability values of repeatability and reproducibility for all quadrants were within limits of agreement. Reliability was excellent (ICC 0.98–0.99) and reproducibility was moderate to excellent (ICC 0.64–0.96). There was a non‐significant IOP increase in all Akita eyes at Day 28 (p > 0.05), and significant increase in MT in all quadrants at Day 21 and superior, inferior and temporal quadrants at Day 28 (p < 0.05). Conclusion: Laser speckle flowgraphy demonstrates excellent repeatability and moderate to excellent reproducibility in measuring RBF. Intravitreal Aflibercept injection results in a significant increase in MT up to 28 days post‐injection without significant increase in IOP. [ABSTRACT FROM AUTHOR]