Search results for "Response"
showing 10 items of 4136 documents
Brimonidine versus dapiprazole: Influence on pupil size at various illumination levels.
2005
To evaluate the influence of dapiprazole versus brimonidine on pupil size at various illumination levels.Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.In randomized prospective study, 19 healthy volunteers received 2 ophthalmic solutions, dapiprazole and brimonidine, 1 in each eye, for intraindividual comparison. Before and after application, pupil diameter was measured using an infrared binocular pupillometer at 3 illumination levels (0.03, 0.82, and 6.4 lux).Only slight pupil dilation was observed under scotopic conditions after application of both agents. After 20 minutes, the median reduction in pupil width was 1.4 mm for brimonidine and 0.9 mm for dapiprazo…
The pupillary response to mental overload
1977
The hypothesis that the pupil constricts below base level in situations of mental overload was tested. Subjects had to perform in a four-alternative forced-choice task at 75%, 100%, and 125% the speed of their maximum processing capacity. No indication of a pupillary constriction in the overload situation was found. The pupil dilated under all three conditions. The pupil diameter of male subjects significantly decreased after the sharp increase at the beginning of the experimental phases, while the female subjects’ pupil diameter remained at the same level after the initial increase. The amount of dilation depended on information load for male subjects only. Results were taken as further in…
Effect of Phenylephrine on the Accommodative System
2016
Accommodation is controlled by the action of the ciliary muscle and mediated primarily by parasympathetic input through postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia. During accommodation the pupil constricts to increase the depth of focus of the eye and improve retinal image quality. Researchers have traditionally faced the challenge of measuring the accommodative properties of the eye through a small pupil and thus have relied on pharmacological agents to dilate the pupil. Achieving pupil dilation (mydriasis) without affecting the accommodative ability of the eye (cycloplegia) could be useful in many clinical and research contexts. Phenylephr…
Clinical Features and Natural History of AMD
2009
Over recent years, OCT has become an essential part of the examination in routine follow up for AMD to guide clinical practice and analyze the response to treatment. OCT examinations can clearly demonstrate the efficacy of treatment by showing regression or persistence of leakage. Moreover, alterations of the outer retinal layers can also be analyzed.
Rapid Assessment of COVID-19 Screening Program for Travelers in Iran: A Qualitative Study
2022
AbstractObjective:Coronavirus disease 2019 (COVID-19) screening stations set up by Iranian Red Crescent Society have been available for 17 d with the aim of identifying and treating people with coronavirus, reducing road trips, and sensitizing people to the problem. This study aims to investigate the challenges of the procedure.Methods:A qualitative study was used to find the challenges of the COVID-19 screening centers. Volunteers, branch managers, and headquarter managers of the Iranian Red Crescent Society participated in this study applying snowball sampling. Data were collected by means of in-depth semi-structured telephone interviews in April 2020 after completion of the fever screeni…
The Female Sex Confers Different Prognosis in Heart Failure: Same Mortality but More Readmissions
2021
Introduction: Heart failure (HF) is a major cause of morbimortality both in men and women. Differences between sex in etiopathogenesis, response to treatment, and quality of care have been found in patients with HF. Females are usually under-represented in clinical trials and there is no solid evidence demonstrating the influence of sex in the prognostic of chronic HF. The primary objective of this study was to analyse the differences in mortality and probability of hospital readmission between males and females with HF. The secondary objective was to compare mortality and probability of hospital readmission by ejection fraction (reduced vs. preserved).Methods: Patients with decompensated H…
Heart rate variability as predictor of mortality in sepsis: A systematic review.
2018
Background Autonomic dysregulation is one of the recognized pathophysiological mechanisms in sepsis, generating the hypothesis that heart rate variability (HRV) can be used to predict mortality in sepsis. Methods This was a systematic review of studies evaluating HRV as a predictor of death in patients with sepsis. The search was performed by independent researchers in PubMed, LILACS and Cochrane, including papers in English, Portuguese or Spanish, indexed until August 20th, 2017 with at least 10 patients. Study quality was assessed by Newcastle-Ottawa Scale. To analyze the results, we divided the articles between those who measured HRV for short-term recordings ( 1 hour), and those who did…
Somatosensory Illusions Elicited by Sham Electromagnetic Field Exposure: Experimental Evidence for a Predictive Processing Account of Somatic Symptom…
2020
OBJECTIVE According to the predictive processing theory of somatic symptom generation, body sensations are determined by somatosensory input and central nervous predictions about this input. We examined how expectations shape predictions and consequently bodily perceptions in a task eliciting illusory sensations as laboratory analogue of medically unexplained symptoms. METHODS Using the framework of signal detection theory, the influence of sham Wi-Fi on response bias (c) and somatosensory sensitivity (d') for tactile stimuli was examined using the somatic signal detection task (SSDT). A healthy student sample (n = 83) completed the SSDT twice (sham Wi-Fi on/off) in a randomized order after…
Augmenting–reducing paradox lost? A test of Davis et al.'s (1983) hypothesis
2002
Abstract The aim of the experiment was to test Davis et al.'s [Davis, C., Cowles, M., & Kohn, P. (1983). Strength of the nervous system and augmenting–reducing: paradox lost. Personality and Individual Differences, 4, 491–498.] hypothesis, that Petrie-style reducers become evoked potential (EP) augmenters at high intensities. Central, autonomic, and subjective responses to auditory stimuli of five intensities from 65 to 105 dB(A) were recorded in subjects classified as augmenters/reducers according to the Vando reducer–augmenter scale (RAS). Forty-five white noise stimuli of each intensity were presented. EEG, ECG, EDA, subjective and behavioral data were recorded. It was hypothezised that …
The Inhibitory Effects of Prednisone, 16-Methylen-Prednisolone, and Acth on Con-A Induced Lymphokines (Interferon-Y) as Measured by the Chemiluminesc…
1988
When lymphocytes are stimulated with mitogens or antigens they are enhanced via a cascade of lymphokines to produce interferon-y (IFN-y). IFN-y augments the H2O2 secretion of human monocytes which indirectly can be measured by chemiluminescence. We tested prednisone, 16-methylen-prednisolone and ACTH for their effect to inhibit the Con-A induced stimulation of the chemiluminescence-activity. All three hormones inhibited significantly the stimulation: prednisone up to 52.5% (concentration = 150 micrograms/ml, p = 0.000005), 16-methylen-prednisolone up to 22.5% (concentration = 2.5 micrograms/ml, p = 0.006) and ACTH up to 33% (concentration = 10 micrograms/ml, p = 0.0036).