Objective: The aim of this article was to determine whether cathodal transcranial direct current stimulation (c-tDCS) to unaffected primary motor cortex (PMC) plus conventional occupational therapy (OT) improves functional motor recovery of the affected arm hand in patients after an acute ischemic stroke compared with sham transcranial direct current stimulation plus conventional OT. Design: In this prospective, randomized, double-blinded, sham-controlled trial of 16 severe, acute ischemic stroke patients with severe arm-hand weakness were randomly assigned to either experimental (c-tDCS plus OT; n = 8) or control (sham transcranial direct current stimulation plus OT; n = 8) groups. All patients received a standard 3-hr in-patient rehabilitation therapy, plus an additional ten 30-min sessions of tDCS. During each session, 1 mA of cathodal stimulation to the unaffected PMC is performed followed by the patient's scheduled OT. The primary outcome measure was change in Action Research Arm Test (ARAT) total and subscores on discharge. Result: Application of c-tDCS to unaffected PMC resulted in a clinically relevant 10-point improvement in the affected arm-hand function based on ARAT total score compared with a 2-point improvement in the control group. Conclusions: Application of 30-min of c-tDCS to the unaffected PMC showed a 10-point improvement in the ARAT score. This corresponds to a large effect size in improvement of affected arm-hand function in patients with severe, acute ischemic stroke. Although not statistically significant, this suggests that larger studies, enrolling at least 25 patients in each group, and with a longer follow-up are warranted. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.
from Rehabilitation via xlomafota13 on Inoreader http://ift.tt/2wa4slC
via IFTTT
Πέμπτη 24 Αυγούστου 2017
Curcumin limits weight gain, adipose tissue growth, and glucose intolerance following the cessation of exercise and caloric restriction in rats
Weight regain, adipose tissue growth, and insulin resistance can occur within days after the cessation of regular dieting and exercise. We investigated the effect of curcumin on preserving metabolic health and limiting adipose tissue growth following the cessation of daily exercise and caloric restriction (CR). Sprague-Dawley rats (6-7 wks old) underwent a 'training' protocol of 24 hr voluntary running wheel access and CR (15-20 g/day) for 3 wks ('All Trained') or were sedentary and fed ad libitum ('Sed'). After 3 wks, 'All Trained' were randomly divided into one group which was terminated immediately ('Trained'), and two detrained groups which had their wheels locked and were reintroduced to ad libitum feeding for 1 wk. The wheel locked groups received either a daily gavage of a placebo ('Detrained + Placebo') or curcumin (200 mg/kg) ('Detrained + Curcumin'). Cessation of daily CR and exercise caused an increase in body mass, as well as a 9- 14-fold increase in epididymal, perirenal, and inguinal fat mass, all of which were attenuated by curcumin (p<0.05). Insulin area under the curve (AUC) during an oral glucose tolerance test, HOMA-IR, and C-reactive protein (CRP) were all elevated in the Detrained + Placebo group versus the Trained group (all p<0.05). Curcumin reduced insulin AUC, HOMA-IR, and CRP versus the placebo group (all p<0.05). Our results indicate that curcumin has a protective effect against weight regain and impaired metabolic control following a successful period of weight loss through diet and exercise, perhaps via inhibition of glucocorticoid action and inflammation.
from Physiology via xlomafota13 on Inoreader http://ift.tt/2wtsgDy
via IFTTT
Acute hypoxia in a simulated high altitude airdrop scenario due to oxygen system failure
High Altitude High Opening (HAHO) is a military operational procedure in which parachute jumps are performed at high altitude requiring supplemental oxygen, putting personnel at risk of acute hypoxia in the event of oxygen equipment failure. This study was initiated by the Norwegian Army in order to evaluate potential outcomes during failure of oxygen supply, and to explore physiology during acute severe hypobaric hypoxia. A simulated HAHO without supplemental oxygen was carried out in a hypobaric chamber with decompression to 30 000 ft (9144 m) and then recompression to ground level with a descent rate of 1000 ft/min (305 m/min). Nine subjects were studied. Repeated arterial blood gas samples were drawn throughout the entire hypoxic exposure. Additionally, pulse oximetry, cerebral oximetry and hemodynamic variables were monitored. Desaturation evolved rapidly and the arterial oxygen tensions are amongst the lowest ever reported in volunteers during acute hypoxia. PaO2 decreased from baseline 18.4 (17.3 - 19.1) kPa, 138.0 (133.5 - 143.3) mmHg, to a minimum value of 3.3 (2.9 - 3.7) kPa, 24.8 (21.6 - 27.8) mmHg, after 180 (60 - 210) sec, [median (range)], N=9. Hyperventilation with ensuing hypocapnia was associated with both increased arterial oxygen saturation and cerebral oximetry values, and potentially improved tolerance to severe hypoxia. One subject had a sharp drop in heart rate and cardiac index and lost consciousness 4 min into the hypoxic exposure. A simulated high altitude airdrop scenario without supplemental oxygen results in extreme hypoxemia and may result in loss of consciousness in some individuals.
from Physiology via xlomafota13 on Inoreader http://ift.tt/2w9ibc7
via IFTTT
The Physiology of Oral Whistling: A Combined Radiographic and MRI Analysis
The fluid mechanics of whistling involve the instability of an air jet, resultant vortex rings, and the interaction of these rings with rigid boundaries (2,4). Experimental models support the hypothesis that the sound in human whistling is generated by a Helmholtz resonator, suggesting that the oral cavity acts as a resonant chamber bounded by two orifices, posteriorly by raising the tongue to the hard palate, and anteriorly by pursed lips 2,2,3). However, the detailed anatomical changes in the vocal tract and their relation to the frequencies generated have not been described in the literature. In this study, videofluoroscopic and simultaneous audio recordings were made of subjects whistling with the bilabial (i.e., "puckered lip") technique. One whistling subject was also recorded using magnetic resonance imaging. As predicted by theory, the frequency of sound generated decreased as the size of the resonant cavity increased; this relationship was preserved throughout various whistling tasks and was consistent across subjects. Changes in the size of the resonant cavity were primarily modulated by tongue position rather than jaw opening and closing. Additionally, when high-frequency notes were produced, lateral chambers formed in the buccal space. These results provide the first dynamic anatomical evidence concerning the acoustic production of human whistling.
from Physiology via xlomafota13 on Inoreader http://ift.tt/2wtimBX
via IFTTT
Ventilation and neurochemical changes during {micro}-opioid receptor activation or blockade of excitatory receptors in the hypoglossal motor nucleus of goats
Neuromodulator interdependence posits that changes in one or more neuromodulators are compensated by changes in other modulators to maintain stability in the respiratory control network. Herein, we studied compensatory neuromodulation in the hypoglossal motor nucleus (HMN) after chronic implantation of microtubules unilaterally (n=5) or bilaterally (n=5) into the HMN. After recovery, receptor agonists or antagonists in mock cerebrospinal fluid (mCSF) were dialyzed during the awake and NREM sleep state. During day studies, dialysis of the µ-opioid inhibitory receptor agonist DAMGO (100 µM) decreased pulmonary ventilation (VI), breathing frequency (f), and genioglossus (GG) muscle activity, but did not alter neuromodulators measured in the effluent mCSF. However, neither unilateral dialysis of a broad spectrum muscarinic receptor antagonist (atropine; 50 mM) nor unilateral or bilateral dialysis of a mixture of excitatory receptor antagonists altered VI or GG activity but did increase HMN serotonin (5-HT) levels. Finally, during night studies, DAMGO and excitatory antagonist decreased ventilatory variables during NREM sleep but not during wakefulness. These findings contrast to previous dialysis studies in the ventral respiratory column (VRC), where unilateral DAMGO or atropine dialysis had no effects on breathing and bilateral DAMGO or unilateral atropine increased VI and f and decreased GABA or increased 5-HT respectively. Thus, we conclude that the mechanisms of compensatory neuromodulation are less robust in the HMN than in the VRC under physiological conditions in adult goats, possibly due to site differences in the underlying mechanisms governing neuromodulator release and consequently neuronal activity, and/or responsiveness of receptors to compensatory neuromodulators.
from Physiology via xlomafota13 on Inoreader http://ift.tt/2w944DT
via IFTTT
Drowning in a river with an average depth of three feet: interpreting athletic performance gains
This is an invited editorial on the manuscript by Foss JL, Constantini K, Mickleborough TD, and Chapman RF. Short-term arrival strategies for endurance exercise performance at moderate altitude. J Appl Physiol (1985), 2017.
from Physiology via xlomafota13 on Inoreader http://ift.tt/2wsXWJd
via IFTTT
HIGH-ALTITUDE CHAMPIONS: BIRDS THAT LIVE AND MIGRATE AT ALTITUDE
High altitude is physiologically challenging for vertebrate life for many reasons, including hypoxia (low environmental oxygen); yet, many birds thrive at altitude. Compared to mammals, birds have additional enhancements to their oxygen transport cascade, the conceptual series of steps responsible for acquiring oxygen from the environment and transporting it to the mitochondria. These adaptations have allowed them to inhabit a number of high-altitude regions. Waterfowl are a taxon prolific at altitude. This mini-review explores the physiological responses of high-altitude waterfowl (geese and ducks), comparing the strategies of lifelong high-altitude residents to those of transient high-altitude performers, providing insight into how birds champion high-altitude life. In particular, this review highlights and contrasts the physiological hypoxia responses of bar-headed geese (Anser indicus), birds that migrate biannually through the Himalayas (4,500-6,500 m), and Andean geese (Chloephaga melanoptera), lifelong residents of the Andes (4,000-5,500m). These two species exhibit markedly different ventilatory and cardiovascular strategies for coping with hypoxia: bar-headed geese robustly increase convective oxygen transport elements (i.e. heart rate and total ventilation) whereas Andean geese rely predominantly on enhancements that are likely morphological in origin (i.e. increases in lung oxygen diffusion and cardiac stroke volume). The mini-review compares the short- and long-term cardiovascular and ventilatory trade-offs of these different physiological strategies and offers hypotheses surrounding their origins. It also draws parallels to high-altitude human physiology and research, and identifies a number of areas of further research. The field of high-altitude avian physiology offers a unique and broadly applicable insight into physiological enhancements in hypoxia.
from Physiology via xlomafota13 on Inoreader http://ift.tt/2w9yqG8
via IFTTT
Εγγραφή σε:
Αναρτήσεις (Atom)