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1.
J Vis Exp ; (182)2022 Apr 01.
Article de Anglais | MEDLINE | ID: mdl-35435911

RÉSUMÉ

Autologous arteriovenous fistula (AVF) is the primary and best option to obtain vascular access for hemodialysis treatment; other options are arteriovenous graft (AVG) and central venous catheterization (CVC). The implementation of radio-cephalic autologous arteriovenous fistula (RC-AVF) in the forearm was preferred among patients with superior vascular conditions. However, there is a high rate of early fistula failure. The chosen surgical method is understood to have an effect on the maturation of the fistula. New surgical procedures such as radial artery deviation and reimplantation (RADAR) have been significantly improved for juxta-anastomotic stenosis. Nevertheless, new problems such as stenosis of arteries and narrowing of surgical indication were also found. In this report, we presented a modified no-touch technique (MNTT) to create an RC-AVF, in which the venous and arterial wall avoid devascularization and the radial artery does not sever.


Sujet(s)
Fistule artérioveineuse , Anastomose chirurgicale artérioveineuse , Fistule artérioveineuse/étiologie , Fistule artérioveineuse/chirurgie , Anastomose chirurgicale artérioveineuse/effets indésirables , Anastomose chirurgicale artérioveineuse/méthodes , Sténose pathologique , Avant-bras/vascularisation , Avant-bras/chirurgie , Humains , Dialyse rénale/méthodes , Études rétrospectives , Résultat thérapeutique , Degré de perméabilité vasculaire
2.
Physiol Rep ; 10(8): e15256, 2022 04.
Article de Anglais | MEDLINE | ID: mdl-35439367

RÉSUMÉ

The study of vascular regulation often omits important information about the elastic properties of arteries under conditions of pulsatile flow. The purpose of this study was to examine the relationship between muscle sympathetic nerve activity (MSNA), vascular bed compliance, and peripheral blood flow responses in humans. We hypothesized that increases in MSNA would correlate with reductions in vascular compliance, and that changes in compliance would correspond with changes in peripheral blood flow during sympatho-excitation. MSNA (microneurography), blood pressure (Finopres), and brachial artery blood flow (Doppler ultrasound), were monitored in six healthy males at baseline and during the last 15 s of voluntary end-inspiratory, expiratory apneas and 5 min of static handgrip exercise (SHG; 20% maximum voluntary contraction) and 3 min of post-exercise circulatory occlusion (SHG + PECO; measured in the non-exercising arm). A lumped Windkessel model was employed to examine vascular bed compliance. During apnea, indices of MSNA were inversely related with vascular compliance, and reductions in compliance correlated with decreased brachial blood flow rate. During SHG, despite increased MSNA, compliance also increased, but was unrelated to increases in blood flow. Neither during SHG nor PECO did indices of MSNA correlate with forearm vascular compliance nor did vascular compliance correlate with brachial flow. However, during PECO, a linear combination of blood pressure and total MSNA was correlated with vascular compliance. These data indicate the elastic components of the forearm vasculature are regulated by adrenergic and myogenic mechanisms during sympatho-excitation, but in a reflex-dependent manner.


Sujet(s)
Avant-bras , Force de la main , Pression sanguine/physiologie , Avant-bras/vascularisation , Force de la main/physiologie , Rythme cardiaque/physiologie , Humains , Mâle , Muscles squelettiques/physiologie , Système nerveux sympathique/physiologie , Résistance vasculaire
3.
Anatol J Cardiol ; 26(1): 37-42, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-35191384

RÉSUMÉ

OBJECTIVE: Trans-palmar access is a novel, safe, and feasible technique for coronary artery angiography wherein its appropriate anesthetic methods is still concerned. In this study, we aimed to evaluate the pain severity, satisfaction, and possible complications with local ulnar nerve anesthesia through both distal and proximal forearm in patients undergoing trans-palmar coronary angiography. METHODS: This was a randomized clinical trial performed on 60 patients who were candidates for trans-palmar coronary angiography. The patients were randomized into 2 equal groups as proximal and distal approaches (those who received the same dose of subcutaneous lidocaine (2%) in the proximal and distal of forearm, respectively). Pain intensity at different times, duration of anesthesia, patient satisfaction, and occurrence of complications were evaluated. RESULTS: The mean age of the patients was 59.45±7.09 years, and, of them, 34 (61.8%) were men. Pain severity with the proximal anesthesia approach was significantly higher than that in the distal group at the time of puncture (5.39±0.73 vs. 2.30±0.60, p=0.001). Over time and immediately after the procedure and at discharge, the mean pain severity in the proximal group was significantly less than in the distal group (p<0.050). The proximal group also had a longer duration of anesthesia (67.14±11.58) than the distal group (53.52±8.06) (p=0.001). No differences were observed in terms of patient satisfaction and complications (p>0.050). CONCLUSION: Using the proximal ulnar nerve anesthesia approach was associated with a delayed onset and longer anesthesia than the distal method.


Sujet(s)
Avant-bras , Satisfaction personnelle , Sujet âgé , Anesthésie locale , Coronarographie , Avant-bras/vascularisation , Humains , Mâle , Adulte d'âge moyen , Mesure de la douleur , Satisfaction des patients
5.
J Physiol ; 600(6): 1373-1383, 2022 03.
Article de Anglais | MEDLINE | ID: mdl-34743333

RÉSUMÉ

High altitude-induced hypoxaemia is often associated with peripheral vascular dysfunction. However, the basic mechanism(s) underlying high-altitude vascular impairments remains unclear. This study tested the hypothesis that oxidative stress contributes to the impairments in endothelial function during early acclimatization to high altitude. Ten young healthy lowlanders were tested at sea level (344 m) and following 4-6 days at high altitude (4300 m). Vascular endothelial function was determined using the isolated perfused forearm technique with forearm blood flow (FBF) measured by strain-gauge venous occlusion plethysmography. FBF was quantified in response to acetylcholine (ACh), sodium nitroprusside (SNP) and a co-infusion of ACh with the antioxidant vitamin C (ACh+VitC). The total FBF response to ACh (area under the curve) was ∼30% lower at high altitude than at sea level (P = 0.048). There was no difference in the response to SNP at high altitude (P = 0.860). At sea level, the co-infusion of ACh+VitC had no influence on the FBF dose response (P = 0.268); however, at high altitude ACh+VitC resulted in an average increase in the FBF dose response by ∼20% (P = 0.019). At high altitude, the decreased FBF response to ACh, and the increase in FBF in response to ACh+VitC, were associated with the magnitude of arterial hypoxaemia (R2 = 0.60, P = 0.008 and R2 = 0.63, P = 0.006, respectively). Collectively, these data support the hypothesis that impairments in vascular endothelial function at high altitude are in part attributable to oxidative stress, a consequence of the magnitude of hypoxaemia. These data extend our basic understanding of vascular (mal)adaptation to high-altitude sojourns, with important implications for understanding the aetiology of high altitude-related vascular dysfunction. KEY POINTS: Vascular dysfunction has been demonstrated in lowlanders at high altitude (>4000 m). However, the extent of impairment and the delineation of contributing mechanisms have remained unclear. Using the gold-standard isolated perfused forearm model, we determined the extent of vasodilatory dysfunction and oxidative stress as a contributing mechanism in healthy lowlanders before and 4-6 days after rapid ascent to 4300 m. The total forearm blood flow response to acetylcholine at high altitude was decreased by ∼30%. Co-infusion of acetylcholine with the antioxidant vitamin C partially restored the total forearm blood flow by ∼20%. The magnitude of forearm blood flow reduction, as well as the impact of oxidative stress, was positively associated with the individual severity of hypoxaemia. These data extend our basic understanding of vascular (mal)adaptation to high-altitude sojourns, with important implications for understanding the aetiology of high altitude-related changes in endothelial-mediated vasodilatory function.


Sujet(s)
Antioxydants , Acide ascorbique , Acétylcholine/pharmacologie , Altitude , Antioxydants/pharmacologie , Acide ascorbique/pharmacologie , Endothélium vasculaire/physiologie , Avant-bras/vascularisation , Humains , Hypoxie , Nitroprussiate/pharmacologie , Débit sanguin régional , Vasodilatation , Vasodilatateurs/pharmacologie
6.
J Vasc Res ; 59(1): 24-33, 2022.
Article de Anglais | MEDLINE | ID: mdl-34784595

RÉSUMÉ

OBJECTIVE: The aim of this study was to investigate the effect of oral supplementation with L-arginine on serum biochemical profile, blood pressure, microcirculation, and vasoreactivity/endothelial function in young controls, and elderly women with and without type 2 diabetes mellitus (T2DM). METHODS: Healthy young (n = 25), healthy elderly (n = 25), and elderly women with type 2 diabetes mellitus (T2DME, n = 23, glycated Hb ≥6.4% and mean of 7.7 years for duration of the disease), aged 18-30 and older than 65 years, respectively, were included in the study. All patients underwent biochemical analysis (fasting glycemia and lipidogram), arterial blood pressure, nailfold videocapillaroscopy (capillary diameters, functional capillary density [FCD], peak red blood cell velocity [RBCVmax] after 1 min ischemia, time to reach peak RBCV [TRBCVmax]), and venous occlusion plethysmography (vasoreactivity), before and after 14 days of oral supplementation with L-arginine (5 g/day). RESULTS: L-Arginine did not change fasting glycemia and lipidogram, but it decreased systolic, diastolic, and mean arterial pressure in elderly women, increased RBCVmax in all groups, and did not decrease TRBCVmax in T2DME. Capillary diameters and FCD remained unchanged in all groups. L-Arginine improved vasoreactivity during reactive hyperemia and after sublingual nitroglycerin (0.4 mg) in all groups. CONCLUSION: L-Arginine supplementation (5g/day during 14 days) was able to improve vascular/microvascular health in the elderly women with or without T2DM.


Sujet(s)
Arginine/administration et posologie , Diabète de type 2/traitement médicamenteux , Compléments alimentaires , Avant-bras/vascularisation , Hémodynamique/effets des médicaments et des substances chimiques , Microcirculation/effets des médicaments et des substances chimiques , Ongles/vascularisation , Administration par voie orale , Adulte , Facteurs âges , Sujet âgé , Sujet âgé de 80 ans ou plus , Pression artérielle/effets des médicaments et des substances chimiques , Marqueurs biologiques/sang , Études cas-témoins , Diabète de type 2/sang , Diabète de type 2/physiopathologie , Femelle , Humains , Capillaroscopie , Pléthysmographie , Facteurs sexuels , Facteurs temps , Résultat thérapeutique , Vasodilatation/effets des médicaments et des substances chimiques , Jeune adulte
7.
J Stomatol Oral Maxillofac Surg ; 123(2): 215-217, 2022 Apr.
Article de Anglais | MEDLINE | ID: mdl-34688961

RÉSUMÉ

Nasal reconstruction for total rhinectomy is challenging, especially if locoregional flaps are unavailable. Herein, we report the case of a nasal reconstruction combining a forearm free flap as "vascular bridge" and a Delto-Acromial Artery Perforator (DAAP) flap in its free form. The forearm free flap was used to restore missing elements of the nasal lining while the distal part of the radial pedicle has served as a donor vessel for the DAAP free flap which restores the nasal covering. A chondrocostal graft was used as a nasal framework. The nasal aspect at 24 months postop support the patient's satisfaction. The main advantages of the DAAP Flap are the pliability, relative hairless nature, skin thinness and its geographical proximity with the nose avoiding major dyschromia. Moreover, the anatomy consistency makes it easier to harvest, the underlying muscles are respected, and it allows for tension free primary closure without shoulder movement limitation.


Sujet(s)
Lambeaux tissulaires libres , Lambeau perforant , Procédures de chirurgie reconstructive , Artères/chirurgie , Avant-bras/vascularisation , Avant-bras/chirurgie , Lambeaux tissulaires libres/transplantation , Humains , Lambeau perforant/vascularisation , Lambeau perforant/chirurgie , Procédures de chirurgie reconstructive/méthodes
8.
Vascular ; 30(2): 238-245, 2022 Apr.
Article de Anglais | MEDLINE | ID: mdl-33966507

RÉSUMÉ

INTRODUCTION: This retrospective study investigated the factors and the effects of different venous outflows on forearm arteriovenous graft patency. METHODS: The venous outflow sites included basilic, cephalic, median antecubital, and deep veins. Comparisons among multiple groups were analyzed. FINDINGS: A total of 179 patients with forearm loop arteriovenous grafts met the inclusion criteria. Of these, 72 were basilic, 48 were cephalic, 44 were median antecubital, and 15 were deep. The median observation period was 19 months. The survival rate was 84.9% at 24 months and 78.2% at 48 months. Primary, secondary, and assisted primary patency rates for all arteriovenous grafts were 48.9%, 72.4%, and 68.4% at 12 months; 13.8%, 33.9%, and 23.6% at 24 months; and 0.6%, 4.6%, and 2.3% at 48 months, respectively. Differences in primary patency were statistically significant compared with those of secondary and assisted primary patency (P < 0.05). Primary patency rates for cephalic, median antecubital, basilic, and deep were 47.9%, 48.6%, 47.7%, and 40.0% at 12 months and 12.5%, 13.9%, 22.7%, and 0% at 24 months, respectively. Secondary patency rates for cephalic, median antecubital, basilic, and deep were 75.0%, 69.4%, 75.0%, and 73.3% at 12 months and 39.6%, 30.6%, 38.6%, and 13.3% at 24 months, respectively. There was no significant difference in primary thrombosis among basilic, cephalic, median antecubital and deep. There were no significant differences observed in primary or secondary patency rates among all the groups. Stenoses in the venous anastomosis and outflow vein were frequently observed in all types of arteriovenous grafts. Central venous stenosis was most commonly seen in deep (26.67%). On average, 1.9 interventions per patient were performed on the graft to maintain function. CONCLUSION: Different venous outflow selections were not associated with long-term patency and the occurrence of thrombosis in hemodialysis forearm loop arteriovenous grafts.


Sujet(s)
Anastomose chirurgicale artérioveineuse , Avant-bras , Anastomose chirurgicale artérioveineuse/effets indésirables , Avant-bras/vascularisation , Occlusion du greffon vasculaire/imagerie diagnostique , Occlusion du greffon vasculaire/étiologie , Occlusion du greffon vasculaire/thérapie , Humains , Dialyse rénale/effets indésirables , Études rétrospectives , Facteurs temps , Résultat thérapeutique , Degré de perméabilité vasculaire
9.
J Vasc Surg ; 75(1): 248-254, 2022 01.
Article de Anglais | MEDLINE | ID: mdl-34314835

RÉSUMÉ

OBJECTIVE: To evaluate the outcomes of arteriovenous fistulae (AVF), created with VasQ external support device under standard clinical practice across three vascular access clinics. METHODS: This multinational, retrospective study evaluated prospectively collected clinical outcomes of both forearm and upper arm brachiocephalic AVF (BCAVF) created using the VasQ device. Fifty-one AVF patients were pooled from three different vascular access centers in Germany, Italy, and Spain. Postprocedure outcomes were assessed by flow measurement with ultrasound examination in all centers. Primary failure, usability, patency, and intervention rates during the study period were evaluated. RESULTS: Fifty-one VasQ devices were implanted during 37 forearm (36 radiocephalic and 1 ulnar-basilic AVF) and 14 BCAVF procedures. The study population comprised mostly males (73%) and Caucasians (82%), with a mean age of 62.5 years (range, 38-84 years) and mean body mass index of 29.2. One patient died owing to access-unrelated reasons, and one patient was lost to follow-up without AVF assessment after its creation. From the remaining 49, 3 patients had a follow-up of less than 4 weeks and were excluded from maturation, primary failure, and dialysis initiation analysis (because those factors could not be evaluated yet), leaving 46 patients in this evaluation. Maturation was achieved in 91% of patients. The primary failure rate was 9%. A primary patency rate of 77% was observed at 6, 12, and 18 months. The secondary patency rate was 91% at 6 months, and 85% at 12 months and 18 months. Both primary patency and secondary patency did not differ statistically when comparing forearm AVF with BCAVF (P > .25). Successful cannulation was achieved in 86% of patients (32/37) requiring dialysis with a median time from creation to cannulation of 46 days. Of those patients, the functional patency rate was 94%. Five patients underwent seven interventions to maintain or restore patency or functionality, with an overall rate of 0.248 interventions per patient-year. CONCLUSIONS: AVFs created with VasQ external support device demonstrated promising patency and functionality outcomes in multicentric real-world setting across the two most commonly used anatomic locations.


Sujet(s)
Anastomose chirurgicale artérioveineuse/instrumentation , Dialyse rénale/méthodes , Degré de perméabilité vasculaire , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Artère brachiale/chirurgie , Femelle , Études de suivi , Avant-bras/vascularisation , Humains , Défaillance rénale chronique/thérapie , Mâle , Adulte d'âge moyen , Études prospectives , Artère radiale/chirurgie , Dialyse rénale/instrumentation , Études rétrospectives , Résultat thérapeutique
10.
Am J Physiol Endocrinol Metab ; 322(2): E101-E108, 2022 02 01.
Article de Anglais | MEDLINE | ID: mdl-34894721

RÉSUMÉ

Arterial stiffness and endothelial dysfunction are both reported in children with type 1 diabetes (DM1) and may predict future cardiovascular events. In health, nitric oxide (NO) relaxes arteries and increases microvascular perfusion. The relationships between NO-dependent macro- and microvascular functional responses and arterial stiffness have not been studied in adolescents with DM1. Here, we assessed macro- and microvascular function in DM1 adolescents and age-matched controls at baseline and during an oral glucose challenge (OGTT). DM1 adolescents (n = 16) and controls (n = 14) were studied before and during an OGTT. At baseline, we measured: 1) large artery stiffness using both aortic augmentation index (AI) and carotid-femoral pulse wave velocity (cfPWV); 2) brachial flow-mediated dilation (FMD) and forearm endothelial function using postischemic flow velocity (PIFV); and 3) forearm muscle microvascular blood volume (MBV) using contrast-enhanced ultrasound. Following OGTT, AI, cfPWV, and MBV were reassessed at 60 min and MBV again at 120 min. Within individual and between-group, comparisons were made by paired and unpaired t tests or repeated measures ANOVA. Baseline FMD was lower (P = 0.02) in DM1. PWV at 0 and 60 min did not differ between groups. Baseline AI did not differ between groups but declined with OGTT only in controls (P = 0.02) and was lower than DM1 at 60 min (P < 0.03). Baseline MBV was comparable in DM1 and control groups, but declined in DM1 at 120 min (P = 0.01) and was lower than the control group (P < 0.03). There was an inverse correlation between plasma glucose and MBV at 120 min (r = -0.523, P < 0.01). No differences were noted between groups for V̇O2max (mL/min/kg), body fat (%), or body mass index (BMI). NO-dependent macro- and microvascular function, including FMD and AI, and microvascular perfusion, respectively, are impaired early in the course of DM1, precede increases of arterial stiffness, and may provide an early indicator of vascular risk.NEW & NOTEWORTHY This is the first study to show that type 1 diabetes impairs multiple nitric oxide-dependent vascular functions.


Sujet(s)
Artère brachiale/physiopathologie , Diabète de type 1/métabolisme , Diabète de type 1/physiopathologie , Endothélium vasculaire/physiopathologie , Monoxyde d'azote/métabolisme , Rigidité vasculaire , Adolescent , Vitesse du flux sanguin , Glycémie/analyse , Études cas-témoins , Femelle , Avant-bras/vascularisation , Hyperglycémie provoquée , Humains , Mâle , Muscles squelettiques/vascularisation , Analyse de l'onde de pouls , Vasodilatation
11.
PLoS One ; 16(12): e0261052, 2021.
Article de Anglais | MEDLINE | ID: mdl-34882760

RÉSUMÉ

Optical coherence tomography angiography (OCTA) performs non-invasive visualization and characterization of microvasculature in research and clinical applications mainly in ophthalmology and dermatology. A wide variety of instruments, imaging protocols, processing methods and metrics have been used to describe the microvasculature, such that comparing different study outcomes is currently not feasible. With the goal of contributing to standardization of OCTA data analysis, we report a user-friendly, open-source toolbox, OCTAVA (OCTA Vascular Analyzer), to automate the pre-processing, segmentation, and quantitative analysis of en face OCTA maximum intensity projection images in a standardized workflow. We present each analysis step, including optimization of filtering and choice of segmentation algorithm, and definition of metrics. We perform quantitative analysis of OCTA images from different commercial and non-commercial instruments and samples and show OCTAVA can accurately and reproducibly determine metrics for characterization of microvasculature. Wide adoption could enable studies and aggregation of data on a scale sufficient to develop reliable microvascular biomarkers for early detection, and to guide treatment, of microvascular disease.


Sujet(s)
Algorithmes , Avant-bras/imagerie diagnostique , Main/imagerie diagnostique , Traitement d'image par ordinateur/méthodes , Microvaisseaux/imagerie diagnostique , Tomographie par cohérence optique/méthodes , Adulte , Avant-bras/vascularisation , Main/vascularisation , Volontaires sains , Humains , Adulte d'âge moyen , Rapport signal-bruit
12.
Sci Rep ; 11(1): 22301, 2021 11 16.
Article de Anglais | MEDLINE | ID: mdl-34785678

RÉSUMÉ

An arteriovenous fistula, created by artificially connecting segments of a patient's vasculature, is the preferred way to gain access to the bloodstream for kidney dialysis. The increasing power and availability of supercomputing infrastructure means that it is becoming more realistic to use simulations to help identify the best type and location of a fistula for a specific patient. We describe a 3D fistula model that uses the lattice Boltzmann method to simultaneously resolve blood flow in patient-specific arteries and veins. The simulations conducted here, comprising vasculatures of the whole forearm, demonstrate qualified validation against clinical data. Ongoing research to further encompass complex biophysics on realistic time scales will permit the use of human-scale physiological models for basic and clinical medicine.


Sujet(s)
Fistule artérioveineuse/sang , Avant-bras/vascularisation , Hémodynamique , Humains
13.
PLoS One ; 16(10): e0259127, 2021.
Article de Anglais | MEDLINE | ID: mdl-34699565

RÉSUMÉ

INTRODUCTION: Port implantations at the forearm are associated with an increased risk of relevant vein thrombosis. Therefore, with this study we sought to identify the responsible risk factors to improve technical quality of the method. METHODS: This is a retrospective analysis of 313 patients with port implantation at the forearm in 2019. Then, exploratory statistics were conducted comprising Cox-Regression and Kaplan-Meier-Analyses. RESULTS: Mean age was 60 ± 14 years. 232 (74%) of the patients were female. No early infection was observed. 29 late infections and 57 cases of thrombosis occurred. In only 9% of the patients with thrombosis hospital admission was necessary for treatment. Median interval to the diagnosis of thrombosis was 23 days; inter-quartile-range: 16-75. Mean interval to elective port explantation was 227 ± 128 days. There was no effect of occurrence of thrombosis of the interventionalist, the assistance nor of several technical aspects. However, there was a significantly lower risk of thrombosis for primary implanted port system compared to replacement ports, Hazard-ratio: 0.34 [Confidence interval: 0.172, 0.674], p = 0.002. Age was a significant risk factor for late infections, Hazard-ratio: 3.35 [Confidence interval:1.84, 6.07], p < 0.0001. CONCLUSION: The main risk factor for adverse outcome after radiographically guided port implantation at the forearm is the type of the implanted port system. The reason for that might not be the material itself but the experience of a team with a certain port system. Age is a risk factor for late complications.


Sujet(s)
Cathétérisme veineux central/effets indésirables , Cathéters à demeure/effets indésirables , Avant-bras/vascularisation , Thrombose veineuse/étiologie , Sujet âgé , Cathétérisme veineux central/instrumentation , Femelle , Humains , Mâle , Adulte d'âge moyen , Appréciation des risques , Facteurs de risque
15.
Physiol Rep ; 9(17): e15018, 2021 09.
Article de Anglais | MEDLINE | ID: mdl-34435469

RÉSUMÉ

We hypothesized acute moderate and drastic reductions in uric acid concentration exert different effects on arterial function in healthy normotensive and hypertensive adults. Thirty-six adults (aged 58 [55;63] years) with or without primary hypertension participated in a three-way, randomized, double-blind, crossover study in which [placebo] and [febuxostat] and [febuxostat and rasburicase] were administered. Febuxostat and rasburicase reduce the uric acid concentration by xanthine oxidoreductase inhibition and uric acid degradation into allantoin, respectively. Endothelial function was assessed in response to acetylcholine, sodium nitroprusside, heating (with and without nitric oxide synthase inhibition) using a laser Doppler imager. Arterial stiffness was determined by applanation tonometry, together with blood pressure, renin-angiotensin system activity, oxidative stress, and inflammation. Uric acid concentration was 5.1 [4.1;5.9], 1.9 [1.2;2.2] and 0.2 [0.2;0.3] mg/dL with [placebo], [febuxostat] and [febuxostat-rasburicase] treatments, respectively (p < 0.0001). Febuxostat improved endothelial response to heat particularly when nitric oxide synthase was inhibited (p < 0.05) and reduced diastolic and mean arterial pressure (p = 0.008 and 0.02, respectively). The augmentation index decreased with febuxostat (ANOVA p < 0.04). Myeloperoxidase activity profoundly decreased with febuxostat combined with rasburicase (p < 0.0001). When uric acid dropped, plasmatic antioxidant capacity markedly decreased, while superoxide dismutase activity increased (p < 0.0001). Other inflammatory and oxidant markers did not differ. Acute moderate hypouricemia encompasses minor improvements in endothelial function, blood pressure, and arterial stiffness. Clinical Trial Registration: NCT03395977, https://clinicaltrials.gov/ct2/show/NCT03395977.


Sujet(s)
Endothélium vasculaire/métabolisme , Avant-bras/vascularisation , Avant-bras/physiologie , Stress oxydatif/physiologie , Acide urique/sang , Rigidité vasculaire/physiologie , Adulte , Sujet âgé , Pression sanguine/physiologie , Études croisées , Méthode en double aveugle , Endothélium vasculaire/effets des médicaments et des substances chimiques , Fébuxostat/pharmacologie , Femelle , Antigoutteux/pharmacologie , Humains , Fluxmétrie laser Doppler/méthodes , Mâle , Adulte d'âge moyen , Stress oxydatif/effets des médicaments et des substances chimiques
16.
PLoS One ; 16(8): e0255242, 2021.
Article de Anglais | MEDLINE | ID: mdl-34351946

RÉSUMÉ

Application of exposure to 50/60 Hz magnetic fields (MFs) has been conducted in the treatment of muscle pain and fatigue mainly in Japan. However, whether MFs could increase blood flow leading to muscle fatigue recovery has not been sufficiently tested. We investigated the acute effects of a 50 Hz sinusoidal MF at Bmax 180 mT on hemodynamics, electrocardiogram, and vascular endothelial function in healthy young men. Three types of regional exposures to a 50 Hz MF, i.e., forearm, upper arm, or neck exposure to MF were performed. Participants who received three types of real MF exposures had significantly increased ulnar arterial blood flow velocity compared to the sham exposures. Furthermore, after muscle loading exercise, MF exposure recovered hemoglobin oxygenation index values faster and higher than sham exposure from the loading condition. Moreover, participants who received real MF exposure in the neck region had significantly increased parasympathetic high-frequency activity relative to the sham exposure. The MF exposure in the upper arm region significantly increased the brachial artery flow-mediated dilation compared to the sham exposure. Computer simulations of induced in situ electric fields indicated that the order-of-magnitude estimates of the peak values were 100-500 mV/m, depending on the exposure conditions. This study provides the first evidence that a 50 Hz MF can activate parasympathetic activity and thereby lead to increase vasodilation and blood flow via a nitric oxide-dependent mechanism. Trial registration: UMIN Clinical Trial Registry (CTR) UMIN000038834. The authors confirm that all ongoing and related trials for this drug/intervention are registered.


Sujet(s)
Endothélium vasculaire/physiologie , Hémodynamique/physiologie , Champs magnétiques , Adulte , Vitesse du flux sanguin/physiologie , Pression sanguine/physiologie , Électricité , Électrocardiographie , Avant-bras/vascularisation , Rythme cardiaque/physiologie , Hémoglobines/métabolisme , Humains , Modèles théoriques , Oxygène/métabolisme , Projets pilotes , Débit sanguin régional , Taille de l'échantillon , Facteurs temps , Artère ulnaire/physiologie , Jeune adulte
17.
Skin Res Technol ; 27(6): 1152-1161, 2021 Nov.
Article de Anglais | MEDLINE | ID: mdl-34224600

RÉSUMÉ

BACKGROUND: Visual and molecular changes occurring upon aging are rather well characterized. Still, aging signs show great significant inter-individual variations, and little is known concerning the link between perceived age and cutaneous microcirculation. MATERIALS AND METHODS: To investigate this point, we recruited Caucasian women in their mid-50's to mid-70's and subsampled women looking older or younger than their age. We studied their facial skin color, as well as their microvascular reactivity to local heating assessed in the forearm skin. We also used skin biopsies from some of these women for gene expression or immunohistochemical analysis. RESULTS: Clinical and instrumental analysis of skin color revealed that subjects who look 5 years younger differ only by a higher glowing complexion. Our most striking result is that subjects looking 5 years younger than their age present a higher microcirculation reactivity in forearm skin. Transcriptome comparison of skin samples from women looking older or younger than their age revealed 123 annotated transcripts differentially expressed, among which MYL9 relates to microcirculation. MYL9 is downregulated in the group of women looking younger than their real age. Microscopy shows that the labeling of MYL9 and CD31 are altered and heterogeneous with age, as is the morphology of microvessels. CONCLUSION: Therefore, assessing generalized vascular reactivity in non-photo-exposed skin to focus on the intrinsic aging allows subtle discrimination of perceived age within elderly healthy subjects.


Sujet(s)
Avant-bras , Microcirculation , Vieillissement de la peau , Peau/vascularisation , Sujet âgé , Face , Femelle , Avant-bras/vascularisation , Humains
18.
Vascular ; 29(5): 784-789, 2021 Oct.
Article de Anglais | MEDLINE | ID: mdl-34142602

RÉSUMÉ

OBJECTIVES: In this study, the effects of anastomosis techniques on the results of patients with autogenous radial-cephalic proximal forearm fistula were investigated. METHODS: Patients who underwent radial-cephalic proximal forearm fistula surgery (arteriovenous fistula) between April 2015 and August 2017 at the Department of Cardiovascular Surgery of Ordu University were compared retrospectively in terms of the results of anastomosis techniques. The study included 131 patients who had arteriovenous fistulas created by side-to-side and end-to-side anastomosis technique. RESULTS: There was no significant difference in demographic data, comorbidities, radial artery, and cephalic vein diameters in patients undergoing radial-cephalic proximal forearm fistula surgery. However, it was observed that fistula maturation was earlier in the group with end-to-side anastomosis technique, and the one-year patency rates were higher in the group with side-to-side anastomosis technique. CONCLUSION: In Arteriovenous fistulas created in the proximal forearm region, the one-year patency rate of the side-to-side anastomosis technique was higher, while the maturation of the end-to-side technique observed earlier.


Sujet(s)
Anastomose chirurgicale artérioveineuse , Avant-bras/vascularisation , Artère radiale/chirurgie , Dialyse rénale , Degré de perméabilité vasculaire , Sujet âgé , Anastomose chirurgicale artérioveineuse/effets indésirables , Femelle , Occlusion du greffon vasculaire/étiologie , Occlusion du greffon vasculaire/physiopathologie , Humains , Mâle , Adulte d'âge moyen , Artère radiale/imagerie diagnostique , Artère radiale/physiopathologie , Études rétrospectives , Facteurs temps , Résultat thérapeutique
19.
Exp Physiol ; 106(8): 1689-1698, 2021 08.
Article de Anglais | MEDLINE | ID: mdl-34187092

RÉSUMÉ

NEW FINDINGS: What is the central question of this study? Sympathetically mediated vasoconstriction is preserved during hypoxaemia in humans, but our understanding of vascular control comes from predominantly male cohorts. We tested the hypothesis that young women attenuate sympathetically mediated vasoconstriction during steady-state hypoxaemia, whereas men do not? What is the main finding and its importance? Sympathetically mediated vasoconstriction is preserved or even enhanced during steady-state hypoxia in young men, and the peripheral vascular response to sympathetic activation during hypoxaemia is attenuated in young women. These data advance our understanding of sex-related differences in hypoxic vascular control. ABSTRACT: Activation of the sympathetic nervous system causes vasoconstriction and a reduction in peripheral blood flow. Sympathetically mediated vasoconstriction may be attenuated during systemic hypoxia to maintain oxygen delivery; however, in predominantly male participants sympathetically mediated vasoconstriction is preserved or even enhanced during hypoxaemia. Given the potential for sex-specific differences in hypoxic vascular control, prior results are limited in application. We tested the hypothesis that young women attenuate sympathetically mediated vasoconstriction during steady-state hypoxaemia, whereas men do not. Healthy young men (n = 13, 25 ± 4 years) and women (n = 11, 24 ± 4 years) completed two trials consisting of a 2-min cold pressor test (CPT, a well-established sympathoexcitatory stimulus) during baseline normoxia and steady-state hypoxaemia. Beat-to-beat blood pressure (finger photoplethysmography) and forearm blood flow (venous occlusion plethysmography) were measured continuously. Total and forearm vascular conductance (TVC and FVC, respectfully) were calculated. A change (Δ) in TVC and FVC from steady-state during the last 1 min of CPT was calculated and differences between normoxia and systemic hypoxia were assessed. In men, the reduction in TVC during CPT was greater during hypoxia compared to normoxia (ΔTVC, P = 0.02), whereas ΔTVC did not differ between conditions in women (P = 0.49). In men, ΔFVC did not differ between normoxia and hypoxia (P = 0.92). In women, the reduction in FVC during CPT was attenuated during hypoxia (ΔFVC, P < 0.01). We confirm sympathetically mediated vasoconstriction is preserved or enhanced during hypoxaemia in young men, whereas peripheral vascular responsiveness to sympathetic activation during hypoxaemia is attenuated in young women. The results advance our understanding of sex-related differences in hypoxic vascular control.


Sujet(s)
Hypoxie , Caractères sexuels , Pression sanguine , Femelle , Avant-bras/vascularisation , Humains , Mâle , Débit sanguin régional/physiologie , Système nerveux sympathique/physiologie , Vasoconstriction/physiologie
20.
Sci Rep ; 11(1): 13411, 2021 06 28.
Article de Anglais | MEDLINE | ID: mdl-34183707

RÉSUMÉ

Visualization and quantification of the skin microvasculature are important for studying the health of the human microcirculation. We correlated structural and pathophysiological changes of the dermal capillary-level microvasculature with age and blood pressure by using the reactive hyperemia optical coherence tomography angiography (RH-OCT-A) technique and evaluated both conventional OCT-A and the RH-OCT-A method as non-invasive imaging alternatives to histopathology. This observational pilot study acquired OCT-A and RH-OCT-A images of the dermal microvasculature of 13 young and 12 old healthy Caucasian female subjects. Two skin biopsies were collected per subject for histological analysis. The dermal microvasculature in OCT-A, RH-OCT-A, and histological images were automatically quantified and significant indications of vessel rarefaction in both old subjects and subjects with high blood pressure were observed by RH-OCT-A and histopathology. We showed that an increase in dermal microvasculature perfusion in response to reactive hyperemia was significantly lower in high blood pressure subjects compared to normal blood pressure subjects (117% vs. 229%). These results demonstrate that RH-OCT-A imaging holds functional information of the microvasculature with respect to physiological factors such as age and blood pressure that may help to monitor early disease progression and assess overall vascular health. Additionally, our results suggest that RH-OCT-A images may serve as a non-invasive alternative to histopathology for vascular analysis.


Sujet(s)
Vieillissement/physiologie , Angiographie/méthodes , Pression sanguine/physiologie , Hyperhémie/physiopathologie , Hypertension artérielle/physiopathologie , Microcirculation/physiologie , Microvaisseaux/physiologie , Peau/vascularisation , Tomographie par cohérence optique/méthodes , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Évolution de la maladie , Femelle , Avant-bras/vascularisation , Humains , Hyperhémie/imagerie diagnostique , Microvaisseaux/imagerie diagnostique , Microvaisseaux/ultrastructure , Projets pilotes , Jeune adulte
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