Search results for "Blood Flow"
showing 10 items of 568 documents
Limb Ischemic Conditioning Induces Oxidative Stress Followed by a Correlated Increase of HIF-1α in Healthy Volunteers.
2019
Background Local and remote ischemic preconditioning has been used as a protective intervention against ischemia/reperfusion (I/R) damage in several preclinical and clinical studies. However, its physiological mechanisms are not completely known. I/R increases the production of reactive oxygen species, which also serve as messengers for a variety of functions. Hypoxia-inducible factor 1 alpha (HIF-1α) is probably the most important transcription factor mediator of hypoxic signaling. Objective We hypothesized that limb ischemic conditioning (LIC) induces a local oxidative/nitrosative stress and a correlated increase of HIF-1α plasma levels. Methods An observational, prospective, and single-c…
Frequent blood flow restricted training not to failure and to failure induces similar gains in myonuclei and muscle mass
2021
The purpose of the present study was to compare the effects of short-term high-frequency failure vs non-failure blood flow–restricted resistance exercise (BFRRE) on changes in satellite cells (SCs), myonuclei, muscle size, and strength. Seventeen untrained men performed four sets of BFRRE to failure (Failure) with one leg and not to failure (Non-failure; 30-15-15-15 repetitions) with the other leg using knee-extensions at 20% of one repetition maximum (1RM). Fourteen sessions were distributed over two 5-day blocks, separated by a 10-day rest period. Muscle samples obtained before, at mid-training, and 10-day post-intervention (Post10) were analyzed for muscle fiber area (MFA), myonuclei, an…
Multiple periscope and chimney grafts to treat ruptured thoracoabdominal and pararenal aortic aneurysms
2011
Purpose: To report midterm outcomes after urgent endovascular repair of ruptured pararenal or thoracoabdominal aortic aneurysms using multiple periscope and chimney grafts to preserve renovisceral branch perfusion and facilitate aneurysm exclusion. Methods: Nine consecutive men (mean age 72614 years, range 40–88) presenting with ruptured thoracoabdominal (n56), pararenal (n52), or infrarenal (n51) aortic aneurysm underwent urgent endovascular repair with at least 1 periscope graft delivered via a transfemoral access; chimney grafts were installed from an axillary access. In all, 17 periscope and 7 chimney grafts were used to reperfuse 11 renal and 13 visceral arteries in the 9 patients. The…
Blood Flow Restriction Alters Motor Unit Behavior During Resistance Exercise.
2019
AbstractWe aimed to determine whether blood flow restriction (BFR) alters the characteristics of individual motor units during low-intensity (LI) exercise. Eight men (26.0±3.8 yrs) performed 5 sets of 15 knee extensions at 20% of one-repetition maximum (with and without BFR). Maximal isometric voluntary contractions (MVC) were performed before and after exercise to quantify force decrement. Submaximal isometric voluntary contractions were additionally performed for 18 s, matching trapezoidal target-force trajectories at 40% pre-MVC. EMG activity was recorded from the vastus lateralis muscle. Then, signals were decomposed to extract motor unit recruitment threshold, firing rates and action p…
Free amino acid pool and muscle protein balance after resistance exercise.
2003
The aim of this study was to assess the effects of a resistance exercise session (RES) on free amino acid concentrations and protein synthesis and breakdown of the vastus lateralis (VL) muscle during recovery in male subjects.Both the exercise group (EG) and the control group (CG) consisted of six healthy physically active men. On the experiment day in fasting conditions, a stable isotopic tracer of L-[ring-2H(5)] phenylalanine was infused and EG started a heavy 50-min hypertrophic RES for lower extremities after 55 min of infusion. At the same time, CG was at rest. During recovery of 195 min after RES, several blood samples were drawn from the femoral artery (FA) and the femoral vein (FV) …
Insulin resistance and glomerular hemodynamics in essential hypertension
2002
Insulin resistance and glomerular hemodynamics in essential hypertension. Background Arterial hypertension is an important cause of end-stage renal failure. Insulin has been shown to modify glomerular hemodynamics in hypertensive subjects. The aim of this work, therefore, was to observe the relationships between renal hemodynamics and insulin resistance in arterial hypertension. Methods Sixty-two non-diabetic hypertensive patients and 25 healthy normal subjects were studied. Renal plasma flow and the glomerular filtration fraction were determined by renoscintigraphy and the insulin sensitivity by an oral glucose test. Results Renal plasma flow in hypertensive subjects was lower than expecte…
Acute Neuromuscular Adaptations in Response to Low-Intensity Blood-Flow Restricted Exercise and High-Intensity Resistance Exercise: Are There Any Dif…
2018
Fatela, P, Reis, JF, Mendonca, GV, Freitas, T, Valamatos, MJ, Avela, J, and Mil-Homens, P. Acute neuromuscular adaptations in response to low-intensity blood flow restricted exercise and high-intensity resistance exercise: are there any differences? J Strength Cond Res 32(4): 902-910, 2018-Numerous studies have reported similar neuromuscular adaptations between low-intensity (LI) blood-flow restricted exercise (BFRE) and high-intensity (HI) resistance training. Unfortunately, none of these experimental designs individualized blood flow restriction (BFR) levels to each participant. Thus, their findings are difficult to interpret. We aimed at comparing the acute effects of LI BFR (80% of abso…
Regression of structural vascular changes in hypertensives after captopril treatment.
1992
In order to investigate whether hypertension-related structural vascular changes may be influenced by antihypertensive treatment, 10 patients were studied suffering from essential arterial hypertension, five males and five females, aged between 34 and 61 years (mean age: 46.9 +/- 8.13 years). All patients received a placebo for 1 week and then captopril, 75 mg b.i.d. for 3 months. After placebo and captopril treatments, the following parameters were evaluated: SBP, DBP, mean blood pressure (MBP), by the formula 1/3 (SBP + 2 x DBP) and basal and minimal vascular resistances, respectively obtained by the ratios MBP/rest flow and MBP/peak flow. Blood flows have been obtained by strain gauge pl…
Blood flow velocity waveforms of the fetal middle cerebral artery in a normal population: reference values from 18 weeks to 42 weeks of gestation
2002
The aim of this prospective cross-sectional study was to establish new Doppler reference curves for peak blood flow velocities (Vmax, Vmean, Vmin) and impedance indices (PI, RI) of the middle cerebral artery at 18-42 weeks of gestation by an automatic wave form analysis integrated into the ultrasound device. In 962 low-risk pregnancies, blood flow velocities were derived from the middle cerebral artery with pulsed color Doppler ultrasonography. Reference curves were constructed for the individual parameters based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square principle for maximum blood flow velocities, as well as on a pol…
Does ovarian blood flow distinguish between ovulatory and anovulatory patients with polycystic ovary syndrome?
2003
The purpose of this study was to determine whether parameters of ovarian blood flow distinguish between women with polycystic ovary syndrome (PCOS) who ovulate and those who are anovulatory.This was a prospectively enrolled trial, carried out as a cross-sectional comparison of 12 ovulatory patients with PCOS and 20 matched subjects with classic PCOS and 10 healthy control subjects. Hormonal parameters and ovarian blood flow by color flow Doppler imaging were obtained in the early follicular phase.Characteristic elevations in luteinizing hormone (LH) and androgens were found in both groups with PCOS compared with control groups. Women with anovulatory PCOS had high insulin levels and lower Q…