Search results for "processes"
showing 10 items of 3831 documents
Activation of Astrocytes in the Persistence of Post-hypoxic Respiratory Augmentation
2021
Acute hypoxia increases ventilation. After cessation of hypoxia loading, ventilation decreases but remains above the pre-exposure baseline level for a time. However, the mechanism of this post-hypoxic persistent respiratory augmentation (PHRA), which is a short-term potentiation of breathing, has not been elucidated. We aimed to test the hypothesis that astrocytes are involved in PHRA. To this end, we investigated hypoxic ventilatory responses by whole-body plethysmography in unanesthetized adult mice. The animals breathed room air, hypoxic gas mixture (7% O2, 93% N2) for 2min, and again room air for 10min before and after i.p. administration of low (100mg/kg) and high (300mg/kg) doses of a…
Comparison of Standard Cardiopulmonary Resuscitation Versus the Combination of Active Compression-Decompression Cardiopulmonary Resuscitation and an …
2003
Background— Active compression-decompression (ACD) CPR combined with an inspiratory impedance threshold device (ITD) improves vital organ blood flow during cardiac arrest. This study compared survival rates with ACD+ITD CPR versus standard manual CPR (S-CPR). Methods and Results— A prospective, controlled trial was performed in Mainz, Germany, in which a 2-tiered emergency response included early defibrillation. Patients with out-of-hospital arrest of presumed cardiac pathogenesis were sequentially randomized to ACD+ITD CPR or S-CPR by the advanced life support team after intubation. Rescuers learned which method of CPR to use at the start of each work shift. The primary end point was 1-ho…
Implementation of computed tomography angiography (CTA) and computed tomography perfusion (CTP) in Polish guidelines for determination of cerebral ci…
2021
Background: Brain death/death by neurologic criteria (BD/DNC) guidelines are routinely analyzed, compared and updated in the majority of countries and are later implemented as national criteria. At the same time, extensive works have been conducted in order to unify clinical procedures and to validate and implement new technologies into a panel of ancillary tests. Recently evaluated computed tomography angiography and computed tomography perfusion (CTA/CTP) seem to be superior to traditionally used digital subtraction angiography (DSA), transcranial Doppler (TCD) and cerebral perfusion scintigraphy for diagnosis of cerebral circulatory arrest (CCA). In this narrative review, we would like t…
Directional Control Mechanisms in Multidirectional Step Initiating Tasks.
2020
Typical anticipatory postural adjustments (APAs) in forward gait or step initiation tasks to prepare for possible disturbances caused by prime voluntary movements and to accelerate the body forward have been previously reported. However, it is not clear how wide the variations in step directions are differentiated and controlled in non-forward step initiation tasks during the APA phase. The main goal of this study is to explain the directional control mechanisms by investigating the APA of step initiation tasks in forward, diagonal, lateral, and posterior directions. The center of pressure (COP) trajectories and related muscle (soleus, tibialis anterior, and gluteus medius of both lower lim…
DHEA, DHEAS and PCOS.
2014
Approximately 20-30% of PCOS women demonstrate excess adrenal precursor androgen (APA) production, primarily using DHEAS as a marker of APA in general and more specifically DHEA, synthesis. The role of APA excess in determining or causing PCOS is unclear, although observations in patients with inherited APA excess (e.g., patients with 21-hydroxylase deficient congenital classic or non-classic adrenal hyperplasia) demonstrate that APA excess can result in a PCOS-like phenotype. Inherited defects of the enzymes responsible for steroid biosynthesis, or defects in cortisol metabolism, account for only a very small fraction of women suffering from hyperandrogenism or APA excess. Rather, women wi…
Postoperative Lens Position Preoperatively Determined by Scheimpflug Photography
1999
The position of the artificial lens has an important influence on refractive power calculation. We compared the position of the crystalline lens with that of the artificial lens after cataract surgery by means of Scheimpflug photography. A difference in position of approximately 0.8 mm in the anterior direction could be determined.
The Effects of Stochastic Galvanic Vestibular Stimulation on Body Sway and Muscle Activity
2020
Objective: This study aimed to investigate whether galvanic vestibular stimulation with stochastic noise (nGVS) modulates the body sway and muscle activity of the lower limbs, depending on visual and somatosensory information from the foot using rubber-foam.Methods: Seventeen healthy young adults participated in the study. Each subject maintained an upright standing position on a force plate with/without rubber-foam, with their eyes open/closed, to measure the position of their foot center of pressure. Thirty minutes after baseline measurements under four possible conditions (eyes open/closed with/without rubber-foam) performed without nGVS (intensity: 1 mA, duration: 40 s), the stimulation…
Risk Factors Regarding Portal Vein Thrombosis in Chronic Liver Disease
2020
Abstract The portal vein thrombosis (PVT) is one of the most frequent vascular diseases of the liver, with a high rate of morbidity and mortality. The most common causes of the PVT are hepatic cirrhosis, hepatobiliary neoplasms, inflammatory and infectious abdominal diseases, and myeloproliferative syndromes.(1,2) The natural progress of the PVT has as a result portal hypertension which leads to splenomegaly and the formation of portosystemic collateral vessels, as well as gastroesophageal, duodenal and jejunal varices. Ultrasonography, especially Doppler ultrasound, is the most widely used imaging method to asses, supervise and diagnose PVT in patients with hepatopathies. The purpose of ac…
Mapping symbols to sounds: electrophysiological correlates of the impaired reading process in dyslexia
2012
Dyslexic and control first-grade school children were compared in a Symbol-to-Sound matching test based on a non-linguistic audiovisual training which is known to have a remediating effect on dyslexia. Visual symbol patterns had to be matched with predicted sound patterns. Sounds incongruent with the corresponding visual symbol (thus not matching the prediction) elicited the N2b and P3a event-related potential (ERP) components relative to congruent sounds in control children. Their ERPs resembled the ERP effects previously reported for healthy adults with this paradigm. In dyslexic children, N2b onset latency was delayed and its amplitude significantly reduced over left hemisphere whereas P…
Interference of Illusory Contour Perception by a Distractor
2021
The visual system is capable of recognizing objects when object information is widely separated in space, as revealed by the Kanizsa-type illusory contours (ICs). Attentional involvement in perception of ICs is an important topic, and the present study examined whether and how the processing of ICs is interfered with by a distractor. Discrimination between thin and short deformations of an illusory circle was investigated in the absence or presence of a central dynamic patch, with difficulty of discrimination varied in three levels (easy, medium, and hard). Reaction time (RT) was significantly shorter in the absence compared to the presence of the distractor in the easy and medium condition…