scholarly journals Pulses of melanopsin-directed contrast produce highly reproducible pupilresponses that are insensitive to a change in background radiance

2018 ◽  
Author(s):  
Harrison McAdams ◽  
Aleksandra Sasha Igdalova ◽  
Manuel Spitschan ◽  
David H. Brainard ◽  
Geoffrey K. Aguirre
Keyword(s):  
Blue Light ◽  
Human Subjects ◽  
Clinical Pathology ◽  
Primary Interest ◽  
High Reproducibility ◽  
Pupil Response ◽  
Silent Substitution ◽  
Temporal Shape ◽  
Pupil Constriction ◽  
Average Pupil

AbstractPurposeTo measure the pupil response to pulses of melanopsin-directed contrast, and compare this response to those evoked by cone-directed contrast and spectrally-narrowband stimuli.Methods3-second unipolar pulses were used to elicit pupil responses in human subjects across 3 sessions. Thirty subjects were studied in Session 1, and most returned for Sessions 2 and 3. The stimuli of primary interest were “silent substitution” cone‐ and melanopsin-directed modulations. Red and blue narrowband pulses delivered using the post-illumination pupil response (PIPR) paradigm were also studied. Sessions 1 and 2 were identical, while Session 3 involved modulations around higher radiance backgrounds. The pupil responses were fit by a model whose parameters described response amplitude and temporal shape.ResultsGroup average pupil responses for all stimuli overlapped extensively across Sessions 1 and 2, indicating high reproducibility. Model fits indicate that the response to melanopsin-directed contrast is prolonged relative to that elicited by cone-directed contrast. The group average cone‐ and melanopsin-directed pupil responses from Session 3 were highly similar to those from Sessions 1 and 2, suggesting that these responses are insensitive to background radiance over the range studied. The increase in radiance enhanced persistent pupil constriction to blue light.ConclusionsThe group average pupil response to stimuli designed through silent substitution provides a reliable probe of the function of a melanopsin-mediated system in humans. As disruption of the melanopsin system may relate to clinical pathology, the reproducibility of response suggests that silent substitution pupillometry can test if melanopsin signals differ between clinical groups.

Prior Light Exposure Enhances the Pupil Response to Subsequent Short Wavelength (Blue) Light

2011 ◽  
Vol 02 (05) ◽  
Author(s):  
Michael Stormly Hansen ◽  
Birgit Sander ◽  
Aki Kawasaki ◽  
Adam Elias Brøndsted ◽  
Claus Nissen
Keyword(s):  
Blue Light ◽  
Short Wavelength ◽  
Light Exposure ◽  
Pupil Response

Animal Models of Exercise and Obesity

2013 ◽  
Vol 31 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Christine E. Kasper
Keyword(s):  
Animal Models ◽  
Human Subjects ◽  
Clinical Pathology ◽  
Nursing Research ◽  
Exercise Science ◽  
System Adaptation ◽  
Genetic Mechanisms ◽  
Extensive Body ◽  
Response To Exercise ◽  
Experimental Use

Animal models have been invaluable in the conduct of nursing research for the past 40 years. This review will focus on specific animal models that can be used in nursing research to study the physiologic phenomena of exercise and obesity when the use of human subjects is either scientifically premature or inappropriate because of the need for sampling tissue or the conduct of longitudinal studies of aging. There exists an extensive body of literature reporting the experimental use of various animal models, in both exercise science and the study of the mechanisms of obesity. Many of these studies are focused on the molecular and genetic mechanisms of organ system adaptation and plasticity in response to exercise, obesity, or both. However, this review will narrowly focus on the models useful to nursing research in the study of exercise in the clinical context of increasing performance and mobility, atrophy and bedrest, fatigue, and aging. Animal models of obesity focus on those that best approximate clinical pathology.

scholarly journals Dataset of red light induced pupil constriction superimposed on post-illumination pupil response

Data in Brief ◽  
2016 ◽  
Vol 8 ◽  
pp. 1300-1302
Author(s):  
Shaobo Lei ◽  
Herbert C. Goltz ◽  
Jaime C. Sklar ◽  
Agnes M.F. Wong
Keyword(s):  
Red Light ◽  
Pupil Response ◽  
Pupil Constriction

Effects of blue light on inflammation and skin barrier recovery following acute perturbation. Pilot study results in healthy human subjects

2017 ◽  
Vol 34 (3) ◽  
pp. 184-193 ◽  
Author(s):  
Denise Falcone ◽  
Natallia E. Uzunbajakava ◽  
Frank van Abeelen ◽  
Gerrit Oversluizen ◽  
Malou Peppelman ◽  
...  
Keyword(s):  
Pilot Study ◽  
Blue Light ◽  
Human Subjects ◽  
Skin Barrier ◽  
Healthy Human ◽  
Study Results ◽  
Healthy Human Subjects

scholarly journals Electrochromic selective filtering of chronodisruptive visible wavelengths

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241900
Author(s):  
Maria Angeles Bonmati-Carrion ◽  
Javier Padilla ◽  
Raquel Arguelles-Prieto ◽  
Anna M. Österholm ◽  
John R. Reynolds ◽  
...  
Keyword(s):  
Blue Light ◽  
Ganglion Cells ◽  
Light Exposure ◽  
Control Sample ◽  
Color Naming ◽  
Internal Clock ◽  
Light Sources ◽  
Melatonin Suppression ◽  
Pupil Constriction ◽  
Visible Wavelengths

We present evidence of pupil response modification, as well as differential theoretical melatonin suppression through selective and dynamic electrochromic filtering of visible light in the 400–500 nm range to minimize chronodisruptive nocturnal blue light exposure. A lower activation of intrinsically photosensitive retinal ganglion cells (ipRGCs), the first step for light to reach a human’s internal clock, is related to melatonin secretion therefore avoiding detrimental effects of excessive blue light exposure. Pupillary Light Reflex and Color Naming were experimentally assessed under light filtered by two different coloration states (transmissive and absorptive) of these novel dynamic filters, plus an uncoated test device, in 16 volunteers. Also, different commercial light sources at illuminances ranging from 1 to 1000 lux were differentially filtered and compared in terms of theoretical melatonin suppression. Representative parameters of the pupil responses reflected lower pupil constriction when the electrochromic filters (ECFs) were switched on (absorptive state, blue light is absorbed by the filter) compared to uncoated filters (control sample), but failed to do so under transmissive state (blue light passes through the filter) indicating less activation of ipRGCs under absorptive state (although no significant differences between states was found). Out of eight colors tested, just one showed significant differences in naming between both filter states. Thus, the ECF would have some protecting effect on ipRGC activation with very limited changes in color perception. While there are some limitations of the theoretical model used, the absorptive state yielded significantly lower theoretical melatonin suppression in all those light sources containing blue wavelengths across the illuminance range tested. This would open the way for further research on biological applications of electrochromic devices.

Post-illumination pupil response after blue light: Reliability of optimized melanopsin-based phototransduction assessment

2015 ◽  
Vol 139 ◽  
pp. 73-80 ◽  
Author(s):  
Wisse P. van der Meijden ◽  
Bart H.W. te Lindert ◽  
Denise Bijlenga ◽  
Joris E. Coppens ◽  
Germán Gómez-Herrero ◽  
...  
Keyword(s):  
Blue Light ◽  
Pupil Response

scholarly journals Individual Differences in the Post-Illumination Pupil Response to Blue Light: Assessment without Mydriatics

Biology ◽  
2016 ◽  
Vol 5 (3) ◽  
pp. 34 ◽  
Author(s):  
Jessica Bruijel ◽  
Wisse van der Meijden ◽  
Denise Bijlenga ◽  
Farangis Dorani ◽  
Joris Coppens ◽  
...  
Keyword(s):  
Individual Differences ◽  
Blue Light ◽  
Pupil Response

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Elevated level of circulatory sTLT1 induces inflammation through SYK/MEK/ERK signalling in coronary artery disease

2019 ◽  
Vol 133 (22) ◽  
pp. 2283-2299
Author(s):  
Apabrita Ayan Das ◽  
Devasmita Chakravarty ◽  
Debmalya Bhunia ◽  
Surajit Ghosh ◽  
Prakash C. Mandal ◽  
...  
Keyword(s):  
Risk Factors ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Chronic Inflammation ◽  
Ex Vivo ◽  
Human Subjects ◽  
Critical Role ◽  
Atherosclerotic Cardiovascular Disease ◽  
Tnf Α ◽  
Artery Disease

Abstract The role of inflammation in all phases of atherosclerotic process is well established and soluble TREM-like transcript 1 (sTLT1) is reported to be associated with chronic inflammation. Yet, no information is available about the involvement of sTLT1 in atherosclerotic cardiovascular disease. Present study was undertaken to determine the pathophysiological significance of sTLT1 in atherosclerosis by employing an observational study on human subjects (n=117) followed by experiments in human macrophages and atherosclerotic apolipoprotein E (apoE)−/− mice. Plasma level of sTLT1 was found to be significantly (P<0.05) higher in clinical (2342 ± 184 pg/ml) and subclinical cases (1773 ± 118 pg/ml) than healthy controls (461 ± 57 pg/ml). Moreover, statistical analyses further indicated that sTLT1 was not only associated with common risk factors for Coronary Artery Disease (CAD) in both clinical and subclinical groups but also strongly correlated with disease severity. Ex vivo studies on macrophages showed that sTLT1 interacts with Fcɣ receptor I (FcɣRI) to activate spleen tyrosine kinase (SYK)-mediated downstream MAP kinase signalling cascade to activate nuclear factor-κ B (NF-kB). Activation of NF-kB induces secretion of tumour necrosis factor-α (TNF-α) from macrophage cells that plays pivotal role in governing the persistence of chronic inflammation. Atherosclerotic apoE−/− mice also showed high levels of sTLT1 and TNF-α in nearly occluded aortic stage indicating the contribution of sTLT1 in inflammation. Our results clearly demonstrate that sTLT1 is clinically related to the risk factors of CAD. We also showed that binding of sTLT1 with macrophage membrane receptor, FcɣR1 initiates inflammatory signals in macrophages suggesting its critical role in thrombus development and atherosclerosis.

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