Velocity Index Research Articles

Intermittent hypoxia training improves cerebral blood flow without cognitive impairment.

Brief exposure to intermittent hypoxia has been shown to potentially induce protective effects in the body. Animal studies suggest that intermittent hypoxia could increase cerebral blood flow and confer resistance to subsequent hypoxic-ischemic injury, yet clinical investigations are limited. This study aimed to evaluate the impact of a moderate short-term intermittent hypoxia protocol on cerebral blood flow and cognitive performance. Subjects who met the inclusion criteria were recruited to this study and randomized into the intermittent hypoxia group or the control group, which receives intermittent hypoxia training and sham-intermittent hypoxia training, respectively. Cerebral hemodynamics, cognitive performance, cerebral perfusion pressure, and oxygen saturation were assessed before and after the intervention. A total of 100 healthy participants were included in this study. Compared to the control group, the intermittent hypoxia group exhibited higher peak systolic blood flow velocity (108.64 ± 22.53 vs. 100.21 ± 19.06, p = 0.049) and cerebrovascular conduction index (0.74 ± 0.17 vs. 0.66 ± 0.21, p = 0.027), and lower cerebrovascular resistance index (1.41 ± 0.29 vs. 1.54 ± 0.36, p = 0.044) following intermittent hypoxia training. Additionally, within-group comparisons revealed that intermittent hypoxia training led to increased cerebral blood flow velocity, elevated cerebrovascular conductance index, and decreased cerebrovascular resistance index (p < 0.05). Other indicators including cognitive function, cerebral perfusion pressure, and oxygen saturation did not exhibit significant differences between groups. These findings revealed that intermittent hypoxia may represent a safe and effective strategy for improving cerebral blood flow.

Electroacupuncture at acupoints of liver meridian for diminished ovarian reserve of liver depression: a randomized controlled trial

To observe the therapeutic effect of electroacupuncture at acupoints of liver meridian in patients with diminished ovarian reserve (DOR) of liver depression. A total of 62 patients with DOR of liver depression were randomly divided into an electroacupuncture group (31 cases, 1 case discontinued) and a western medication group (31 cases, 1 case was eliminated). Electroacupuncture was applied at bilateral Taichong (LR 3), Ligou (LR 5), Ququan (LR 8), Jimai (LR 12) in the electroacupuncture group, with continuous wave, in frequency of 2 Hz and current of 0.5-1.0 mA, 30 min each time, once every other day, 3 times a week. Femoston was taken orally in the western medication group, oral estradiol tablets were taken for the first 14 days, followed by oral estradiol/progesterone complex tablets for the rest 14 days, 1 tablet a day. Both groups were treated for 3 consecutive menstrual cycles. Before and after treatment, the scores of TCM syndrome, self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were observed, serum levels of follicle stimulating hormone (FSH) and anti-Müllerian hormone (AMH) were detected, and antral follicle count (AFC), peak systolic velocity (PSV) and resistance index (RI) of ovarian artery were measured by color Doppler ultrasound in the two groups, and the clinical efficacy was evaluated after treatment. After treatment, the scores of primary symptom and secondary symptom, as well as the total scores of TCM syndrome were decreased compared with those before treatment (P<0.01), the scores of SAS and SDS, as well as the serum FSH levels and RI of ovarian artery were decreased compared with those before treatment (P<0.01), while the serum AMH levels, AFC and PSV of ovarian artery were increased compared with those before treatment (P<0.05, P<0.01) in the two groups. After treatment, in the electroacupuncture group, the primary symptom score of TCM syndrome was higher than that in the western medication group (P<0.01), the secondary symptom score of TCM syndrome and the scores of SAS and SDS were lower than those in the western medication group (P<0.05, P<0.01). The total effective rate was 70.0% (21/30) in the electroacupuncture group and 73.3% (22/30) in the western medication group respectively, there was no significant difference in the total effective rate between the two groups (P>0.05). Electroacupuncture at acupoints of liver meridian can effectively improve the clinical symptoms, anxiety and depression, regulate the serum sex hormone levels, increase AFC and improve ovarian blood supply in DOR patients of liver depression.

The impact of prediabetes on preclinical atherosclerosis in general apparently healthy population: A cross-sectional study

Background The hypothesis that not only diagnosed diabetes (DM), but also milder dysglycemia may affect the development of atherosclerosis still requires further study. In our population-based study, we aimed to evaluate the impact of prediabetic state on preclinical atherosclerosis and whether it may affect the cardiovascular risk (CVR) in the general population. Methods The analysis was a part of the Bialystok PLUS cohort study and represented a random sample of Bialystok (Poland) residents aged 20–79 years at the time of sampling (July 2017-January 2023). The cross-sectional analysis included 1431 participants of a population-based study (mean age 46.82 years). Comprehensive biochemical assessments were performed. An Oral Glucose Tolerance Test (OGTT) was performed on fasting patients who did not report having a DM. Results The population with prediabetes, based on HbA1c and OGTT, accounted for more than half of the study participants (n = 797, 55.7%). Atherosclerotic plaques in the carotid arteries were significantly more common in individuals with prediabetes considering all CVR categories. Prediabetes was associated with the occurrence of more advanced preclinical atherosclerosis, especially in the low to moderate CVR category. Serum glucose concentration after 1h and HbA1c proved to be statistically significant indicators of the presence of atherosclerotic plaques in ultrasound (respectively, AUC = 0.73 and 0.72). In multivariate logistic regression, prediabetes was independently associated with significantly increased risk of preclinical atherosclerosis (OR = 1.56, 95% CI 1.09–2.24), along with CVR categories, pulse wave velocity and central blood pressure augmentation index. Conclusions Prediabetes is associated with the occurrence and progression of the preclinical atherosclerosis. Importantly, many of those patients are in the low to moderate cardiovascular risk category, hence may have a severely underestimated risk. Inclusion of prediabetes into CVR assessment may improve risk stratification. An early identification of dysglycemic population is necessary to effectively implement the cardiovascular and metabolic prevention measures.

Clinical efficacy of intracavernous injection of platelet lysate for erectile dysfunction

BackgroundAmong the emerging treatments for erectile dysfunction (ED), platelet-rich plasma (PRP), known for its ability to enhance tissue repair and regeneration, stands out as a promising therapeutic approach. In this innovative study, we aimed to assess the efficacy of intracavernous injections of platelet lysate (PL), a derivative of PRP, in improving erectile function among ED patients.MethodsWe enrolled twenty-six patients, aged between 35 and 70 years (mean age 51.6 ± 11.3 years), who had been experiencing ED for over six months and had an International Index of Erectile Function-5 (IIEF-5) score of 21 or less. Participants received autologous PL injections intracavernously every two weeks for a total of five administrations. We assessed Erection Hardness Score (EHS) and International Index of Erectile Function-5 (IIEF-5) bi-weekly for 16 weeks and conducted penile Doppler ultrasounds pre- and post-treatment to record peak systolic velocity (PSV) and resistance index (RI).ResultsBefore treatment, the mean EHS was 2.15 ± 0.88 and IIEF-5 was 10.92 ± 5.28. Remarkable improvements were observed post-treatment, with the EHS significantly increasing to 3.15 ± 0.83 (p < 0.05) and IIEF-5 to 17.23 ± 5.26 (p < 0.05). Penile Doppler ultrasound exhibited an increase in both PSV and RI post-treatment, with the rise in RI being statistically significant.ConclusionsOur findings indicate that intracavernous injections of PL substantially enhance erectile function, as evidenced by improvements in EHS, IIEF-5, and the RI of penile Doppler ultrasound, without hemorrhagic events or other adverse reactions apart from temporary pain at the injection site during the 16-week follow-up period. These encouraging results suggest that PL injections are a safe and effective treatment modality for patients with moderate ED, potentially providing a less invasive and more physiologically friendly alternative to current ED management strategies.Trial registrationThe study received approval from the Institutional Review Board of National Taiwan University Hospital (IRB Number 202008061RIPC, date of registration 08/28/2020).

Central Pulse Wave Velocity and Augmentation Index Are Repeatable and Reproducible Measures of Arterial Function.

Arterial function (specifically arterial stiffness) is an important cardiovascular risk factor. Pulse wave velocity (PWV) and augmentation index (Al ) are established indicators of arterial function. The present study aimed to evaluate the repeatability and reproducibility of PWV and Al in healthy individuals. Forty healthy participants (age 33 ± 11 years, 17 females) underwent resting supine PWV and Al assessments. Measurements were made in triplicate and repeated 1 week apart. Al was measured by brachial occlusion and PWV was measured from the carotid artery to the femoral artery via the tonometer-oscillometric method. Repeatability and reproducibility were assessed using the intraclass correlation coefficient (ICC). Interoperator reproducibility was performed on 10 participants. The average values for week-to-week visits for PWV and Al were 6.20 ± 0.91 versus 6.13 ± 0.91 ms-1 and 14.0 ± 11.8 versus 16.3 ± 12.2% respectively. For same-day measurements, both PWV and Al showed excellent repeatability (PWV: ICC = 0.96, 95% CI: 0.92-0.98, p < 0.01; Al : ICC = 0.90, 95% CI: 0.84-0.94, p < 0.01) and interoperator reproducibility (PWV: ICC = 0.98, 95% CI: 0.93-1.00, p < 0.01; Al : ICC = 0.93, 95% CI: 0.69-0.98, p < 0.01). Measurements were repeated 1 week apart and showed good reproducibility (PWV: ICC = 0.77, 95% CI: 0.61-0.87, p ≤ 0.01; Al : ICC = 0.73, 95% CI: 0.73-0.86, p < 0.01). PWV and Al demonstrate excellent repeatability and good reproducibility. Considering these variables are noninvasive and easy-to-measure, arterial function assessment may have a role in routine clinical practice to facilitate risk stratification in cardiovascular diseases.

Association between body shape index and arterial stiffness: results of the EVasCu study and a meta-analysis.

The aim of this study was to analyse the association between body shape index (ABSI) and arterial stiffness in healthy subjects using data from the EVasCu study. In addition, a meta-analysis was performed to compare the association between ABSI and central, peripheral and systemic arterial stiffness in the general population. The EVasCu study included 390 healthy subjects. ABSI was calculated from waist circumference, body mass index and height, and arterial stiffness was assessed with aortic pulse wave velocity (a-PWv) and cardio-ankle vascular index (CAVI). A meta-analysis of previous studies, including data from the EVasCu study, was performed to obtain pooled estimates of correlation coefficients (r) and their respective 95% confidence intervals (95% CIs) for the association between ABSI and central, peripheral and systemic arterial stiffness. In addition, pooled OR estimates and their 95% CIs were calculated. In the EVasCu study, the correlation coefficient estimate was 0.458 (p < 0.01) for the association of a-PWv and ABSI and 0.408 (p < 0.01) for the association of CAVI and ABSI. In the meta-analysis, the pooled correlation coefficient estimate was 0.22 (95% CIs: 0.16, 0.28) for central arterial stiffness and ABSI, 0.21 (95% CIs: 0.14, 0.28) for peripheral arterial stiffness and ABSI, and 0.28 (95% CI: 0.21, 0.3) for systemic arterial stiffness and ABSI. When pooled ORs were calculated, the pooled OR estimate was 2.12 (95% CIs: 1.68, 2.56) for central arterial stiffness and ABSI, 2.21 (95% CIs: 1.81, 2.60) for peripheral arterial stiffness and ABSI, and 2.99 (95% CIs: 2.14, 3.85) for systemic arterial stiffness and ABSI. Based on both the results obtained in the EVasCu study and the meta-analysis, there is a positive association between ABSI and arterial stiffness, both in healthy subjects and in participants with comorbidities. For each unit of cm/kg/m²/m increase in ABSI, the risk of arterial stiffness increased by 112% for central arterial stiffness, 121% for peripheral arterial stiffness, and 199% for systemic arterial stiffness. However, further research is needed in this field of knowledge.

Continuation of beta-blockers at discharge is associated with improved outcome in patients with HFpEF and concomitant moderate aortic stenosis

Abstract Background In patients with severe aortic stenosis or decompensated heart failure with preserved ejection fraction (HFpEF), beta-blockers are usually discontinued despite the absence of unequivocal evidence. The data on the effect of beta-blockers in patients with moderate aortic stenosis (MAS) are scarce. Aim To investigate the relationship between beta-blocker use and outcome in patients with MAS, who were hospitalized for decompensated HFpEF. Methods The current study includes 61 patients admitted for decompensated HFpEF with concomitant MAS. The mean age of the population was 82.7±7.59 years old and 41% were females. The diagnosis MAS was established on criteria including aortic valve area between 1-1.5 cm², mean gradient - 20-39 mmHg, and max velocity between 3-3.9 m/s. For those with borderline measurements, the Doppler Velocity Index (DVI) was calculated (DVI &amp;lt; 0.25 indicates severe aortic stenosis). All echocardiographic data were assessed by an experienced echocardiographer. Patients with previous aortic valve replacement and a severe mixed of multivalvular disease were excluded. Result The median follow-up was 52 months (interquartile range 34-63 months). During this period 38 patients (62.3%) died from any cause while 42 (68.9%) individuals experienced a composite endpoint, of all-cause death or hospitalization due to worsening HFpEF. In survivors, we observed higher prescription of beta-blockers at hospital discharge (66% vs. 34%, p&amp;lt;0,05) and better diastolic function than in patients with endpoints. In multivariate Cox regression analysis the use of beta-blockers (HR = 0,27; 95% CI 0,13-0,57; p&amp;lt;0.01) and better diastolic function, defined as higher septal e` (HR=0,76; 95% CI 0,61-0,94; p=0.01) were identified as independent predictors for both - survival and composite endpoint (Figure 1). Advanced age was recognized as an associated factor for outcomes. Conclusion In the present study, continuation of beta-blockers at discharge was independently associated with better survival in patients with decompensated HFpEF and concomitant MAS. It remains to be addressed in future studies, whether or not beta-blockers should be started in these patients or if there is any prognostic interaction between beta-blockers and aortic valve intervention for MAS.Figure 1.Kaplan-Meier survival curve

Shear-Wave Elastography Improves Diagnostic Accuracy in Chronic Kidney Disease Compared to Conventional Ultrasound.

Non-invasive tests are increasingly demanded for diagnosing and prognostication of chronic kidney disease (CKD). Shear-wave elastography (SWE), an emerging technique for measuring tissue stiffness, shows promise for distinguishing between individuals with different stages of renal fibrosis. This study aimed to compare the diagnostic accuracy of two-dimensional SWE (2D-SWE) and conventional ultrasound for detecting CKD, employing renal biopsy as the gold standard. From May 2020 to October 2023, this prospective study included 30 healthy volunteers and 169 patients with CKD who had undergone 2D-SWE and conventional ultrasound of both kidneys. Cortical and medullary stiffness, cortical pixel intensity, renal length, parenchymal and cortical thickness, interlobar artery peak systolic velocity, end-diastolic velocity (EDV), and resistive index were measured. The diagnostic accuracy of 2D-SWE and conventional ultrasound was compared using the receiver operating characteristic curve (ROC) and Delong test. For diagnosing CKD, the area under the ROC (AUC) of cortical stiffness (0.96 [95% CI, 0.93, 0.99]) was significantly higher than that of all conventional ultrasound parameters, including EDV (0.78 [95% CI, 0.71, 0.86]) and cortical thickness (0.74 [95% CI, 0.67, 0.80]). The sensitivity of cortical stiffness (91%) was significantly higher than that of EDV (68%) and cortical thickness (53%). No significant difference was found in the specificity of cortical stiffness (96%) compared to that of EDV (79%) and cortical thickness (100%). Two-dimensional SWE showed higher diagnostic accuracy than that of conventional ultrasound for detecting CKD.

Influence of Chemical Weathering and Microcracks on Permeability Variations in Crystalline Rocks

Rock permeability, an important factor in subsurface fluid migration, can be influenced by microcracks and chemical weathering due to water–rock interactions. Understanding the relationship between permeability, chemical weathering, and microcracks is crucial for assessing fluid flow in rocks. This study focuses on the hydrogeological characteristics of granite and gneiss, potential host rocks for high-level radioactive waste disposal in South Korea. Samples were analyzed for permeability, porosity, P-wave velocity, and chemical weathering indices. Regression analysis revealed a weak correlation between permeability and both porosity and rock density, while an inverse correlation was observed between permeability and chemical weathering indices. Interestingly, some samples showed low permeability (10−21 to 10−22 m2) despite high weathering, while others showed high permeability (10−18 to 10−19 m2) despite low weathering. SEM-EDS analysis indicated the presence of microcracks within the rocks or the filling of these cracks with secondary minerals. The findings suggest that chemical weathering generally increases pore size and porosity, but actual permeability can vary depending on the presence and connectivity of microcracks and the extent to which they are filled with secondary minerals. Therefore, both chemical weathering and microcrack connectivity must be considered when evaluating the hydrogeological characteristics of crystalline rocks.

The Relationships Among Atherogenic Index of Plasma and Carotid-Femoral Pulse Wave Velocity in Adults.

The relationships between the atherogenic index of plasma (AIP) and carotid-femoral pulse wave velocity (cfPWV) in adults were investigated. A total of 1398 subjects were included according to the inclusion criteria. Demographic data, medical history, and biochemical indicators were collected. The cfPWV was measured using the Complior Analyse device. AIP was calculated using the following formula: AIP=log (triglycerides/high-density lipoprotein cholesterol). Correlation analysis, multiple linear regression, and logistic regression were performed to explore the relationships between AIP and cfPWV. Compared to the cfPWV normal group, the cfPWV elevated group had a higher level of AIP (p<0.05). In all subjects, mild-to-moderate correlations were found between AIP and cfPWV (p<0.05). Stepwise multiple linear regression analysis revealed that AIP was an independent factor associated with cfPWV (β=0.156, p<0.05). Logistic regression analysis indicated that the prevalence of cfPWV ≥ 10 m/s increased with the rise of AIP (OR=18.291, p<0.05). The ROC curve analysis showed that the area under the curve for AIP was 0.697. The critical point for AIP was determined as 0.00 by the Youden index (sensitivity of 76.2% and specificity of 54.3%). Stepwise multiple linear regression analysis showed that in the young and middle-aged group with normal cfPWV, AIP was an independent factor associated with cfPWV (p<0.05). In adults, AIP is an independent factor associated with an increased cfPWV. When AIP>0.00, it has a certain predictive value in the screening of atherosclerosis.

Cerebral Vasomotor Reactivity to Carbon Dioxide Using the Rebreathe Technique: Assessment of Within-day and Between-day Repeatability.

The cerebral vasodilator response to increased arterial carbon dioxide (CO2) concentration, termed cerebral vasomotor reactivity (CVMR), is used to assess cerebral vascular function. We sought to assess the within-day and between-day repeatability of CVMR to rebreathing-induced hypercapnia. Twelve healthy adults performed a within-day short interval protocol (17±2 minutes between trials), ten performed a within-day long interval protocol (145±16 minutes between trials), and seventeen performed a between-day protocol (5±2 days between visits). Repeatability of the slope of the percent change in middle cerebral artery mean blood velocity (%MCAvmean) and cerebral vascular conductance index (%CVCi), to the change in partial pressure of end-tidal CO2 (PETCO2) between the two trials/days was assessed. Within-day short interval %MCAvmean slope demonstrated fair to excellent repeatability (intraclass correlation, ICC=0.92 [95% confidence interval 0.72-0.98]; p<0.001) while %CVCi slope showed more variability (ICC=0.84 [0.47-0.95]; p=0.002]). Within-day long interval, %MCAvmean (ICC=0.95 [0.80-0.99]) and %CVCi (ICC=0.94 [0.71-0.99]) slopes showed good to excellent and fair to excellent repeatability respectively (p<0.001 for both). For between-day trials, better repeatability was observed for %CVCi (ICC=0.85 [0.57-0.95]; p<0.001) compared to %MCAvmean (ICC=0.76 [0.33-0.91]; p=0.004) slope. These findings indicate repeatable within- and between-day CVMR responses to rebreathe induced hypercapnia. However, a longer interval may be better for within-day repeat trials, particularly for CVCi measures.

Correlation Between Thrombin Generation and Hepatic Fibrosis in Chronic Liver Diseases.

Hepatic stellate cells (HSC) are recruited to the siteof injury in the liver tissue repair mechanism, and the changes HSC undergo reflect paracrine stimulation by all cell types (sinusoidal endothelial cells, Kupffer cells, hepatocytes, platelets, and leukocytes). This study aimed to analyse a possible correlation between the degree of liver fibrosis and thrombin generation in patients with chronic liver diseases. Background Coagulation disorders in patients with chronic liver disease continue to challenge clinicians. A more accurate assessment of the coagulation cascade is provided by investigating thrombin production in individuals with chronic liver disease with varying degrees of fibrosis. Methods This prospective observational pilot study was done on hospitalized patients with chronic liver diseases.Thrombin generation from their platelet-poor plasma was studied and the degree of liver fibrosis assessed by transient elastography versus that of control subjects. Results The peak thrombin is significantly higher in those with severe liver stiffness (F3) than in those with more advanced fibrosis/liver cirrhosis (F4). Also, the total concentration of thrombin formed in the time interval (area under the curve (AUC)) and velocity index (VI) is higher in those with F3 than those with F4. Conclusion Thrombin generation decreases with the progression of liverfibrosis.

A modular, low-field magnetic resonance design with pre-polarization for characterizing flows

We have recently demonstrated a magnetic resonance method using variable τ spin echoes to simultaneously determine both the average velocity and flow behavior index in a variety of pipe flows. In this work, we present a new, modular, low-field design built specifically for use with our methodology. The design is based on low-cost ceramic magnets. It consists of a sensor built using a pitched magnet arrangement in combination with several modular pre-polarizing units to facilitate a controlled pre-polarization length for measurements on flows that require a significant amount of time in a magnetic field to become polarized (e.g., aqueous solutions). Here, measurements made with this design are shown for a range of flow rates that span the laminar regime and into the turbulent regime.

Effects of single- and bilateral limb immersion on systemic and cerebral hemodynamic responses to the cold pressor test.

The cold pressor test (CPT) involves cold water immersion of either the upper or lower limb(s) and elicits increases in sympathetic nervous activity (SNA), heart rate (HR), and mean arterial pressure (MAP) via stimulation of pain and cutaneous thermoreceptors. Greater pain perception during the CPT is associated with greater increases in SNA and more robust physiological responses. Due to potential differential sensitivity to both painful and thermal stimuli between upper and lower limbs, as well as potential effects of total exposure area, it is unclear whether the choice of limb(s) in CPT protocol design differentially affects systemic and cerebral hemodynamic responses. Our objective was to assess systemic and cerebral hemodynamic and ventilatory responses to different CPT protocols of the hand (CPTH), foot (CPTF), or bilateral feet (CPTBF). We hypothesized CPTBF would elicit greatest physiological responses due to increased exposure area to the cold stimulus. Twenty-eight (14 M, 14 F) healthy young adults [23.4 (SD: 2.4) yr] participated in three 3-min CPT protocols during a single visit. Blood pressure, HR, middle cerebral artery blood velocity (MCAv) and cerebrovascular conductance index, and end-tidal carbon dioxide ([Formula: see text]) were averaged over the final 30 s of each minute of the CPT for each protocol, and perceived pain was recorded at the end of each minute of the CPT. We found significant effects of the time-CPT protocol interaction on systolic blood pressure (P = 0.02), diastolic blood pressure (P < 0.01), MAP (P < 0.01), and HR (P < 0.001). There were no differences between CPT protocols on either MCAv (P = 0.4) or cerebrovascular conductance index (P = 0.1). HR responses peaked in the first minute of the CPT, and changes from baseline were greater in CPTBF [Δ14(16) beats/min] compared with CPTH [Δ5(13) beats/min; P = 0.01] and CPTF [Δ4.04(13.3) beats/min; P = 0.02]. MAP responses peaked in minute 2 of the CPT, and changes from baseline were greater in CPTH [Δ12(8) mmHg) and CPTBF (Δ13(9) mmHg] compared with CPTF [Δ8(7) mmHg; P < 0.01]. Perceived pain was significantly greater in the CPTBF [CPT1 7(2.3), CPT2 6.5(2.3), CPT3 6(3)] condition compared with CPTH [CPT1 6(1.3), CPT2 6(2.3), CPT3 6(2.3)] and CPTF [CPT1 6(3.0), CPT2 6(2.0), CPT3 5.5(3.0)] protocols at all three stages of the CPT (P ≤ 0.01). Our findings suggest choice of limb(s) in CPT protocols may lead to differences in systemic hemodynamic responses, with pain perception potentially influencing these responses. Based on our results, we suggest that choice of limb should be considered in future design of CPT studies, with hand CPT providing the best balance between participant tolerability and robust physiological responses.NEW & NOTEWORTHY Choice of limb(s) in cold pressor test (CPT) studies appears to influence systemic hemodynamics. Hand and bilateral feet induce more robust responses than single-foot CPT, potentially due to increased exposure area and pain perception. Despite no significant cerebrovascular effects, a sustained hyperventilatory response was noted in bilateral feet CPT. Hand CPTs may provide a balance between robust physiological responses and tolerability. These findings underscore the need for careful limb selection in future CPT studies.

Relationship Between Renin, Aldosterone, Aldosterone-to-Renin Ratio and Arterial Stiffness and Left Ventricular Mass Index in Young Adults.

Primary aldosteronism, characterized by renin-independent aldosterone production, is associated with adverse cardiovascular remodeling and outcomes. Elevated cardiovascular risk is observed even in subclinical forms of primary aldosteronism according to studies conducted primarily in middle-aged and elderly populations. This study aimed to assess whether early changes in primary aldosteronism biomarkers during young adulthood are associated with arterial stiffness and left ventricular mass index (LVMI) before the onset of overt disease. The Raine Study is a longitudinal, population-based cohort study in Western Australia that enrolled women during pregnancy. We analyzed the data from the offspring of these women at 17 (2006-2009) and 27 (2016-2018) years of age. Participants with elevated high-sensitivity C-reactive protein (>10 mg/L) and female participants who were on oral contraception were excluded. Pulse wave velocity and aortic augmentation index were measured by SphygmoCor Pulse Wave System at both ages, and aortic distensibility and LVMI were measured by cardiac magnetic resonance imaging at 27 years. Multivariable linear regression was used to examine the relationship between plasma renin, aldosterone, or aldosterone-to-renin ratio and arterial stiffness and LVMI. Mediation analysis was used to test the role of systolic blood pressure. This study included 859 participants at 17 (38.0% female) and 758 participants at 27 (33.2% female) years of age. Females had lower renin concentration at both 17 (20.7 mU/L versus 25.7 mU/L; P<0.001) and 27 (12.0 mU/L versus 15.4 mU/L; P<0.001) years of age; hence, the aldosterone-to-renin ratio was significantly higher at both 17 (18.2 versus 13.5; P<0.001) and 27 (21.0 versus 15.6; P<0.001) years of age in females compared with males. At 27 years of age, a significant association was detected between aldosterone and LVMI in males (β=0.009 [95% CI, 0.001-0.017]; P=0.027) and between aldosterone-to-renin ratio and LVMI in females (β=0.098 [95% CI, 0.001-0.196]; P=0.050) independently of systolic blood pressure and other confounders. No association was found between primary aldosteronism biomarkers and measures of arterial stiffness (pulse wave velocity, aortic augmentation index, and aortic distensibility) at either age. Aldosterone concentration and aldosterone-to-renin ratio were positively associated with the LVMI in young males and females, respectively, independently of systolic blood pressure. Long-term follow-up is required to determine whether the relationship persists over time, and clinical trials are needed to assess the cardiovascular benefits of early interventions to block aldosterone.

Immediate effect of hip exercises-inducing motor unit recruitment on static and dynamic postural balance in patients with piriformis muscle syndrome

IntroductionA single session of exercises-inducing motor unit recruitment has been reported to immediately improve static and dynamic postural balance in different populations. It remains unclear whether such an effect occurs in patients with piriformis muscle syndrome (PMS). Thus, this study aimed to explore the immediate effect of hip exercises-inducing motor unit recruitment on postural balance in these patients. MethodsIn this pre-post-repeated measure study design, twelve patients with PMS were enrolled. These patients participated in a single session of hip exercises-inducing motor unit recruitment, consisting of two exercises, bilateral bridging to target hip extensors and side lying clams to target hip abductors and external rotators. Static (stabilometric platform) and dynamic (timed up and go test (TUGT) and Functional reach test (FRT)) postural balance, and pain were evaluated before and immediately after the intervention protocol. ResultsPatients with PMS had significant (p<0.001) lower centre of pressure velocity and symmetry index values during the unipedal posture (eyes closed) in post- compared to pre- session. However, no significant effects of hip exercises-inducing motor unit recruitment were found on static bipedal and dynamic postural balance or pain in these patients. ConclusionA single session of hip exercises-inducing motor unit recruitment immediately improved static postural balance (unipedal posture with eyes closed) in patients with PMS. Given that this protocol is simple and easy to implement, it is recommended that patients with PMS consider incorporating these exercises into their daily physical activity.

Intrarater Reliability and Agreement of Blood Pressure, Arterial Stiffness, and Heart Rate Variability Assessments in Patients With Parkinson's Disease.

To assess the intrarater reliability and agreement of blood pressure (BP), arterial stiffness, and heart rate variability (HRV) assessments in patients with Parkinson`s disease (PD). Twenty patients with PD visited the laboratory three times, during which brachial and central BP (auscultatory and applanation tonometry, respectively), arterial stiffness (carotid-femoral pulse wave velocity and augmentation index), and HRV assessments were performed at rest. Brachial and central systolic BP presented greater values on visit 1 when compared to visits 2 and 3 (122±13 vs. 116±16 vs. 120±15, p=0.029). There were no significant differences (p>0.05) among the experimental visits for other parameters. Brachial and central BP showed an intraclass correlation coefficient (ICC) above 0.842 and a standard error of measurement (SEM) lower than 5.0%. Bland-Altman plots indicated low agreement between visits 1 and 2 and good agreement between visits 2 and 3. Arterial stiffness indices exhibited ICC values between 0.781 and 0.886, and SEM ranged from 7.3% to 25.2%. Bland-Altman plots indicated moderate to good agreement among visits for arterial stiffness parameters. HRV indices presented ICC values ranging from 0.558 to 0.854 and SEM values ranging from 5.1% to 76.0%. Bland-Altman plots indicated moderate agreement among visits for HRV parameters. In PD patients, brachial and central BP present low intrarater reliability and agreement between visits 1 and 2 and good intrarater reliability and agreement between visits 2 and 3. In general, arterial stiffness and HRV assessments present acceptable intrarater reliability and agreement among visits, except for cardiac sympathovagal balance.

Enhanced thrombin and plasmin generation profiles in alpha-2-antiplasmin–deficient patients: Data from the Rare Bleeding disorders in the Netherlands study

Backgroundα2-Antiplasmin (A2AP) deficiency is a rare and often unidentified disorder characterized by increased fibrinolysis and subsequent bleeding. Global hemostasis assays may increase insight into the altered coagulation and fibrinolysis in these patients. ObjectivesTo explore thrombin and plasmin generation profiles in A2AP-deficient patients, corresponding A2AP activity levels and associated bleeding phenotypes. MethodsThe Nijmegen hemostasis assay was used to assess thrombin and plasmin generation in 23 A2AP-deficient patients (median age, 50 years; 70% women) from the cross-sectional Rare Bleeding disorders in the Netherlands study. Analyzed parameters included thrombin peak height, thrombin potential, fibrin lysis time, plasmin peak height, plasmin velocity index, and plasmin potential. These parameters were expressed as percentages of a reference obtained from 37 healthy controls (median age, 46 years; 57% women). The Nijmegen hemostasis assay data were correlated with A2AP activity levels and International Society on Thrombosis and Hemostasis Bleeding Assessment Tool scores using Pearson correlation coefficients. ResultsPatients’ A2AP activity levels ranged from 23% to 83% (reference range, 89%-122%). Plasmin generation increased, as evidenced by significantly shorter fibrin lysis times (73%; P < .001) and higher plasmin peak heights (203%; P < .001), plasmin velocity indices (302%; P < .001) and plasmin potentials (154%; P < .001) in A2AP-deficient patients than those in healthy controls. Moreover, significantly higher thrombin potentials (146%; P < .001) and thrombin peak heights (132%; P < .001) were observed. Enhanced plasmin generation parameters showed statistically significant correlations with lower A2AP activity levels and higher International Society on Thrombosis and Hemostasis Bleeding Assessment Tool scores. ConclusionA2AP-deficient patients exhibited augmented plasmin generation profiles that correlated with A2AP activity level and bleeding phenotype. Interestingly, increased thrombin generation profiles were also found in these patients.

A new evaluation method for sand control performance of slotted screen

Evaluation method of slotted screen performance is a critical concern for sand control. Despite its significance, comprehensive investigations into quantitative study of sand retaining during the complex flow process need further in-depth study, particularly in numerical simulation research model of the slotted screen. This paper adopts the two-way coupling calculation method of computational fluid dynamics (CFD) and discrete element method (DEM) for the particle movement and fluid flow at the slotted screen and establishes a numerical model of the sand particle migration process through the slotted screen. The sand particle deposition and plugging dynamics on the surface of the sand retaining medium and the micro sand plugging mechanism and blockage pattern are studied. The fractal dimension of formation sand is introduced to characterize different distribution of formation sand. The effects of fluid viscosity, width of the slotted screen, sand production concentration, fluid velocity and particle size distribution on sand production, sand passing rate and particle size distribution of formation sand passing through the slot and plugging behavior are studied. The sand plugging process of slotted screen can be divided into three stages: the beginning of blockage, the intensification of blockage, and the balance of blockage. Under simulated conditions, the initial sand plugging rate is 87%, and as the blockage intensifies, the sand plugging rate gradually increases to 96.5%. Based on the analysis of numerical simulation results, the index of total seepage resistance damage amplitude and velocity, general sand retention ratio and passed-sand size were defined to construct the integrated evaluation method of slotted screen media, which involves the performance of sand retention, anti-plugging and flow ability. A brand new set of ideas on quantifying the integrated evaluation method were introduced to calculate the individual and integrated performance indicators of the slotted screen based on simulated data. The quantitative evaluation of the sand control performance of the slotted screen provides guidance and reference for the parameter design of the slotted screen in the target oil region and the accuracy optimization of the sand control medium.

Acromegaly: The Relationship between Hemodynamic Profiles Assessed via Impedance Cardiography and Left Ventricular Systolic Function Assessed via Echocardiography.

Background/Objectives: Acromegaly-induced prolonged exposure to growth hormone and insulin-like growth factor 1 may have significant cardiovascular effects. The purpose of this study was to assess the relationship between hemodynamic parameters measured via impedance cardiography (ICG) and parameters of systolic left ventricular function measured via echocardiography in patients with acromegaly. Methods: The observational cohort study included 33 patients with newly diagnosed acromegaly, with a mean age of 47 years and without significant comorbidities. Correlation analysis (Spearman's rank correlation coefficient R) was performed on parameters obtained by ICG and left ventricular systolic function parameters obtained by echocardiography. ICG assessment included indices of (1) cardiac function as a pump: stroke volume index (SI), cardiac index (CI), Heather index (HI), velocity index (VI), and acceleration index (ACI); (2) afterload: systemic vascular resistance index (SVRI) and total arterial compliance index (TACI); and (3) thoracic fluid content (TFC). Echocardiographic examinations evaluated left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS). Results: A lower LVEF was associated with a lower SI (R = 0.38; p = 0.03) and a higher SVRI (R = -0.35; p = 0.046), whereas lower GLS was associated with lower SI (R = 0.43; p = 0.02), CI (R = 0.62; p < 0.001), VI (R = 0.59; p < 0.001), ACI (R = 0.38; p = 0.048), HI (R = 0.59; p < 0.001), and TACI (R = 0.50; p = 0.006) and a higher SVRI (R = -0.59; p < 0.001). No significant correlation was observed between either LVEF or GLS and TFC. Conclusions: In patients with acromegaly, poorer echocardiographic parameters of left ventricular systolic function are associated with impaired function of the heart as a pump and higher afterload as assessed via ICG.