LIVIVO - Search results -

Search results

Result 1 - 10 of total 112

Search options

Article ; Online: Characterization of scotopic and mesopic rod signaling pathways in dogs using the On–Off electroretinogram

Nate Pasmanter / Simon M. Petersen-Jones

BMC Veterinary Research, Vol 18, Iss 1, Pp 1-

2022 Volume 13

Abstract: Abstract Background The On–Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone ... ...

Abstract	Abstract Background The On–Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone photoreceptors and postreceptoral cells, including ON and OFF bipolar cells. Interspecies differences have been shown, with predominantly positive Off-response in humans and other primates and a negative Off-response in rodents and dogs. However, the rod signaling pathways that contribute to these differential responses have not been characterized. In this study, we designed a long flash protocol in the dog that varied in background luminance and stimulus strength allowing for some rod components to be present to better characterize how rod pathways vary from scotopic to mesopic conditions. Results With low background light the rod a-wave remains while the b-wave is significantly reduced resulting in a predominantly negative waveform in mesopic conditions. Through modeling and subtraction of the rod-driven response, we show that rod bipolar cells saturate with dimmer backgrounds than rod photoreceptors, resulting in rod hyperpolarization contributing to a large underlying negativity with mesopic backgrounds. Conclusions Reduction in rod bipolar cell responses in mesopic conditions prior to suppression of rod photoreceptor responses may reflect the changes in signaling pathway of rod-driven responses needed to extend the range of lighting conditions over which the retina functions.
Keywords	ERG ; Long flash ; On–off ; Dogs ; Rods ; Veterinary medicine ; SF600-1100
Subject code	571
Language	English
Publishing date	2022-12-01T00:00:00Z
Publisher	BMC
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Characterization of scotopic and mesopic rod signaling pathways in dogs using the On-Off electroretinogram.

Pasmanter, Nate / Petersen-Jones, Simon M

BMC veterinary research

2022 Volume 18, Issue 1, Page(s) 422

Abstract: Background: The On-Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone photoreceptors ...

Abstract	Background: The On-Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone photoreceptors and postreceptoral cells, including ON and OFF bipolar cells. Interspecies differences have been shown, with predominantly positive Off-response in humans and other primates and a negative Off-response in rodents and dogs. However, the rod signaling pathways that contribute to these differential responses have not been characterized. In this study, we designed a long flash protocol in the dog that varied in background luminance and stimulus strength allowing for some rod components to be present to better characterize how rod pathways vary from scotopic to mesopic conditions. Results: With low background light the rod a-wave remains while the b-wave is significantly reduced resulting in a predominantly negative waveform in mesopic conditions. Through modeling and subtraction of the rod-driven response, we show that rod bipolar cells saturate with dimmer backgrounds than rod photoreceptors, resulting in rod hyperpolarization contributing to a large underlying negativity with mesopic backgrounds. Conclusions: Reduction in rod bipolar cell responses in mesopic conditions prior to suppression of rod photoreceptor responses may reflect the changes in signaling pathway of rod-driven responses needed to extend the range of lighting conditions over which the retina functions.
MeSH term(s)	Humans ; Dogs ; Animals ; Signal Transduction ; Retina
Language	English
Publishing date	2022-12-03
Publishing country	England
Document type	Journal Article
ZDB-ID	2191675-5
ISSN	1746-6148 ; 1746-6148
ISSN (online)	1746-6148
ISSN	1746-6148
DOI	10.1186/s12917-022-03505-z
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

Article ; Online: The effects of feature extinction in dual-response feature-positive discriminations.

Bond, Sara R / Nerz, Jordan / Jones, Sophie / Pittman, Taryn / Jones, Nate / Leising, Kenneth J

Journal of experimental psychology. Animal learning and cognition

2023 Volume 49, Issue 4, Page(s) 273–288

Abstract: In a typical feature-positive discrimination, responding is reinforced (+) during the target stimulus (A) on trials with the feature stimulus (X), but not during target-alone trials (A-). When X and A are presented simultaneously, direct control by X is ... ...

Abstract	In a typical feature-positive discrimination, responding is reinforced (+) during the target stimulus (A) on trials with the feature stimulus (X), but not during target-alone trials (A-). When X and A are presented simultaneously, direct control by X is typically observed; however, when the stimuli are presented serially, X sets the occasion for responding to A. In the current dual-response procedures, one response (e.g., left lever press) was reinforced during feature-target trials (XA+) and a different response (e.g., right lever press) was reinforced during target-alone trials (A+). In Experiment 1, rats received either serial (X → A+) or simultaneous (X:A+) presentations of the feature-target compound along with target-alone trials (A+). Contrary to our predictions, the serial group failed to learn the discrimination and the simultaneous group demonstrated occasion setting. In Experiment 2, the salience of the feature was increased, which resulted in direct control by the feature in both groups. In Experiment 3, an additional serial group was included with a longer interval between the feature (X) and target (A). Despite the reduced temporal proximity of X to reinforcement, direct control was again observed in all groups. The current pattern of results in the simultaneous and serial groups is interpreted in relation to the enhanced salience of A relative to X, due to separate pairings of A-alone with reinforcement in the dual-response procedure. Consistent with previous findings, occasion setting was observed when A was most salient relative to X (Experiment 1, simultaneous group), but direct control was found when the salience of X was increased (Experiments 2-3). (PsycInfo Database Record (c) 2023 APA, all rights reserved).
MeSH term(s)	Animals ; Rats ; Learning ; Reinforcement, Psychology
Language	English
Publishing date	2023-10-26
Publishing country	United States
Document type	Journal Article
ISSN	2329-8464
ISSN (online)	2329-8464
DOI	10.1037/xan0000360
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Characterization of scotopic and mesopic rod signaling pathways in dogs using the On–Off electroretinogram

Pasmanter, Nate / Petersen-Jones, Simon M.

BMC Vet Res. 2022 Dec., v. 18, no. 1 p.422-422

2022

Abstract: BACKGROUND: The On–Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone photoreceptors ... ...

Abstract	BACKGROUND: The On–Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone photoreceptors and postreceptoral cells, including ON and OFF bipolar cells. Interspecies differences have been shown, with predominantly positive Off-response in humans and other primates and a negative Off-response in rodents and dogs. However, the rod signaling pathways that contribute to these differential responses have not been characterized. In this study, we designed a long flash protocol in the dog that varied in background luminance and stimulus strength allowing for some rod components to be present to better characterize how rod pathways vary from scotopic to mesopic conditions. RESULTS: With low background light the rod a-wave remains while the b-wave is significantly reduced resulting in a predominantly negative waveform in mesopic conditions. Through modeling and subtraction of the rod-driven response, we show that rod bipolar cells saturate with dimmer backgrounds than rod photoreceptors, resulting in rod hyperpolarization contributing to a large underlying negativity with mesopic backgrounds. CONCLUSIONS: Reduction in rod bipolar cell responses in mesopic conditions prior to suppression of rod photoreceptor responses may reflect the changes in signaling pathway of rod-driven responses needed to extend the range of lighting conditions over which the retina functions.
Keywords	dark adaptation ; dogs ; electroretinography ; photoreceptors ; retina
Language	English
Dates of publication	2022-12
Size	p. 422.
Publishing place	BioMed Central
Document type	Article ; Online
ZDB-ID	2191675-5
ISSN	1746-6148
ISSN	1746-6148
DOI	10.1186/s12917-022-03505-z
Database	NAL-Catalogue (AGRICOLA)

Order via subito

Article ; Online: Two-point Compression Ultrasound Technique Risks Missing Isolated Femoral Vein DVTs

Matthew Tabbut / Nate Ebersole / Lauren Icken / Robert Jones / Diane Gramer

Western Journal of Emergency Medicine, Vol 23, Iss

2022 Volume 4

Abstract: Background: Deep vein thrombosis (DVT) is a common vascular problem seen in the emergency department (ED) and is commonly identified using ultrasound performed by a vascular lab, the radiology department, or at the point of care. Previous studies have ... ...

Abstract	Background: Deep vein thrombosis (DVT) is a common vascular problem seen in the emergency department (ED) and is commonly identified using ultrasound performed by a vascular lab, the radiology department, or at the point of care. Previous studies have assessed the utility of a two-point vs sequential technique to identify the presence of a thrombus. One particular study reported a concerning rate of isolated femoral vein thrombi that would be missed by a two-point technique. Objectives: In this study we sought to determine whether the two-point technique misses isolated femoral vein thrombi. Methods: We conducted a retrospective review of patients who had a new diagnosis of DVT in the ED diagnosed with vascular lab, radiology, or point-of-care ultrasound to assess for the presence and rate of thrombi that would be missed using a two-point scanning technique. Results: We included in our study 356 patients with a diagnosis of new DVT. In our population, 21 (5.9%; 0.95 confidence interval: 3.7%, 8.9%) patients were identified with thrombi isolated to the femoral vein. Conclusion: The two-point technique for lower extremity vascular ultrasound is insufficient for ruling out proximal DVTs in ED patients.
Keywords	Medicine ; R ; Medical emergencies. Critical care. Intensive care. First aid ; RC86-88.9
Language	English
Publishing date	2022-07-01T00:00:00Z
Publisher	eScholarship Publishing, University of California
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Two-point Compression Ultrasound Technique Risks Missing Isolated Femoral Vein DVTs.

Tabbut, Matthew / Ebersole, Nate / Icken, Lauren / Jones, Robert / Gramer, Diane

The western journal of emergency medicine

2022 Volume 23, Issue 4, Page(s) 597–600

Abstract	Background: Deep vein thrombosis (DVT) is a common vascular problem seen in the emergency department (ED) and is commonly identified using ultrasound performed by a vascular lab, the radiology department, or at the point of care. Previous studies have assessed the utility of a two-point vs sequential technique to identify the presence of a thrombus. One particular study reported a concerning rate of isolated femoral vein thrombi that would be missed by a two-point technique. Objectives: In this study we sought to determine whether the two-point technique misses isolated femoral vein thrombi. Methods: We conducted a retrospective review of patients who had a new diagnosis of DVT in the ED diagnosed with vascular lab, radiology, or point-of-care ultrasound to assess for the presence and rate of thrombi that would be missed using a two-point scanning technique. Results: We included in our study 356 patients with a diagnosis of new DVT. In our population, 21 (5.9%; 0.95 confidence interval: 3.7%, 8.9%) patients were identified with thrombi isolated to the femoral vein. Conclusion: The two-point technique for lower extremity vascular ultrasound is insufficient for ruling out proximal DVTs in ED patients.
MeSH term(s)	Femoral Vein/diagnostic imaging ; Humans ; Lower Extremity/diagnostic imaging ; Point-of-Care Systems ; Ultrasonography/methods ; Venous Thrombosis/diagnostic imaging
Language	English
Publishing date	2022-06-03
Publishing country	United States
Document type	Journal Article
ZDB-ID	2375700-0
ISSN	1936-9018 ; 1936-9018
ISSN (online)	1936-9018
ISSN	1936-9018
DOI	10.5811/westjem.2022.2.53830
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article ; Online: ERG assessment of altered retinal function in canine models of retinitis pigmentosa and monitoring of response to translatable gene augmentation therapy.

Pasmanter, Nate / Occelli, Laurence M / Petersen-Jones, Simon M

Documenta ophthalmologica. Advances in ophthalmology

2021 Volume 143, Issue 2, Page(s) 171–184

Abstract: Purpose: To analyze ERG responses from two dog models of retinitis pigmentosa, one due to a PDE6A mutation and the other a CNGB1 mutation, both to assess the effect of these mutations on retinal function and the ability of gene augmentation therapy to ... ...

Abstract	Purpose: To analyze ERG responses from two dog models of retinitis pigmentosa, one due to a PDE6A mutation and the other a CNGB1 mutation, both to assess the effect of these mutations on retinal function and the ability of gene augmentation therapy to restore normal function. Methods: Scotopic and photopic ERGs from young affected and normal control dogs and affected dogs following AAV-mediated gene augmentation therapy were analyzed. Parameters reflecting rod and cone function were collected by modeling the descending slope of the a-wave to measure receptor response and sensitivity. Rod-driven responses were further assessed by Naka-Rushton fitting of the first limb of the scotopic b-wave luminance-response plot. Results: PDE6A Conclusions: Modeling of rod and cone a-waves and the luminance-response function of the scotopic b-wave characterized the loss of rod photoreceptor function in two dog models of retinitis pigmentosa and showed the effectiveness of gene augmentation therapy in restoring normal functional parameters.
MeSH term(s)	Animals ; Color Vision ; Dogs ; Electroretinography ; Retina ; Retinal Cone Photoreceptor Cells ; Retinitis Pigmentosa/genetics ; Retinitis Pigmentosa/therapy
Language	English
Publishing date	2021-04-05
Publishing country	Netherlands
Document type	Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
ZDB-ID	212594-8
ISSN	1573-2622 ; 0012-4486
ISSN (online)	1573-2622
ISSN	0012-4486
DOI	10.1007/s10633-021-09832-0
Database	MEDical Literature Analysis and Retrieval System OnLINE

Full text online

Accessible to users with ZB MED library card

In stock of ZB MED Cologne/Königswinter

Ul I Zs.100: Show issues

Location:
Je nach Verfügbarkeit (siehe Angabe bei Bestand)
bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
ab Jg. 2022: Lesesaal (EG)

Order via subito

Details ▾

Article ; Online: 3 A/B testing in healthcare

Simon Jones / Leora Horwitz / William King / Holly Krelle / Kyra Rosen / Sara Tsuruo / Nate Klapheke / Jay Stadelman

BMJ Open Quality, Vol 12, Iss Suppl

how you can apply tech industry methods to improve quality in your system

2023 Volume 4

Keywords	Medicine (General) ; R5-920
Language	English
Publishing date	2023-12-01T00:00:00Z
Publisher	BMJ Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Use of extended protocols with nonstandard stimuli to characterize rod and cone contributions to the canine electroretinogram.

Pasmanter, Nate / Occelli, Laurence M / Komáromy, András M / Petersen-Jones, Simon M

Documenta ophthalmologica. Advances in ophthalmology

2022 Volume 144, Issue 2, Page(s) 81–97

Abstract: Purpose: In this study, we assessed several extended electroretinographic protocols using nonstandard stimuli. Our aim was to separate and quantify the contributions of different populations of retinal cells to the overall response, both to assess ... ...

Abstract	Purpose: In this study, we assessed several extended electroretinographic protocols using nonstandard stimuli. Our aim was to separate and quantify the contributions of different populations of retinal cells to the overall response, both to assess normal function and characterize dogs with inherited retinal disease. Methods: We investigated three different protocols for measuring the full-field flash electroretinogram-(1) chromatic dark-adapted red and blue flashes, (2) increasing luminance blue-background, (3) flicker with fixed frequency and increasing luminance, and flicker with increasing frequency at a fixed luminance-to assess rod and cone contributions to electroretinograms recorded in phenotypically normal control dogs and dogs lacking rod function. Results: Temporal separation of the rod- and cone-driven responses is possible in the fully dark-adapted eye using dim red flashes. A- and b-wave amplitudes decrease at different rates with increasing background luminance in control dogs. Flicker responses elicited with extended flicker protocols are well fit with mathematical models in control dogs. Dogs lacking rod function demonstrated larger amplitude dark-adapted compared to light-adapted flicker responses. Conclusions: Using extended protocols of the full-field electroretinogram provides additional characterization of the health and function of different populations of cells in the normal retina and enables quantifiable comparison between phenotypically normal dogs and those with retinal disease.
MeSH term(s)	Animals ; Dark Adaptation ; Dogs ; Electroretinography/methods ; Photic Stimulation ; Retinal Cone Photoreceptor Cells/physiology ; Retinal Diseases
Language	English
Publishing date	2022-03-05
Publishing country	Netherlands
Document type	Journal Article ; Research Support, N.I.H., Extramural
ZDB-ID	212594-8
ISSN	1573-2622 ; 0012-4486
ISSN (online)	1573-2622
ISSN	0012-4486
DOI	10.1007/s10633-022-09866-y
Database	MEDical Literature Analysis and Retrieval System OnLINE

Full text online

Accessible to users with ZB MED library card

In stock of ZB MED Cologne/Königswinter

Ul I Zs.100: Show issues

Location:
Je nach Verfügbarkeit (siehe Angabe bei Bestand)
bis Jg. 2021: Bestellungen von Artikeln über das Online-Bestellformular
ab Jg. 2022: Lesesaal (EG)

Order via subito

Details ▾

Article ; Online: An unusual inherited electroretinogram feature with an exaggerated negative component in dogs.

Petersen-Jones, Simon M / Pasmanter, Nate / Occelli, Laurence M / Gervais, Kristen J / Mowat, Freya M / Querubin, Janice / Winkler, Paige A

Veterinary ophthalmology

2022 Volume 25, Issue 5, Page(s) 385–397

Abstract: Objectives: To assess an inherited abnormal negative response electroretinogram (NRE) that originated in a family of Papillon dogs.: Animals studied: Thirty-eight dogs (Papillons, or Papillon cross Beagles or Beagles).: Procedures: Dogs underwent ... ...

Abstract	Objectives: To assess an inherited abnormal negative response electroretinogram (NRE) that originated in a family of Papillon dogs. Animals studied: Thirty-eight dogs (Papillons, or Papillon cross Beagles or Beagles). Procedures: Dogs underwent routine ophthalmic examination and a detailed dark-adapted, light-adapted and On-Off electroretinographic study. Vision was assessed using a four-choice exit device. Spectral-domain optical coherence tomography (SD-OCT) was performed on a subset of dogs. Two affected males were outcrossed to investigate the mode of inheritance of the phenotype. Results: The affected dogs had an increased underlying negative component to the ERG. This was most pronounced in the light-adapted ERG, resulting in a reduced b-wave and an exaggerated photopic negative response (PhNR). Changes were more pronounced with stronger flashes. Similarly, the On-response of the On-Off ERG had a reduced b-wave and a large post-b-wave negative component. The dark-adapted ERG had a significant increase in the scotopic threshold response (STR) and a significant reduction in the b:a-wave ratio. Significant changes could be detected at 2 months of age but became more pronounced with age. Vision testing using a four-choice device showed affected dogs had reduced visual performance under the brightest light condition. There was no evidence of a degenerative process in the affected dogs up to 8.5 years of age. Test breeding results suggested the NRE phenotype had an autosomal dominant mode of inheritance. Conclusions: We describe an inherited ERG phenotype in Papillon dogs characterized by an underlying negative component affecting both dark- and light-adapted ERG responses.
MeSH term(s)	Animals ; Dog Diseases/genetics ; Dogs ; Electroretinography/methods ; Electroretinography/veterinary ; Male ; Retina/physiology ; Retinal Diseases/veterinary ; Tomography, Optical Coherence/veterinary
Language	English
Publishing date	2022-06-17
Publishing country	England
Document type	Journal Article
ZDB-ID	2011043-1
ISSN	1463-5224 ; 1463-5216
ISSN (online)	1463-5224
ISSN	1463-5216
DOI	10.1111/vop.12998
Database	MEDical Literature Analysis and Retrieval System OnLINE

Full text online

Accessible to users with ZB MED library card

Order via subito

Details ▾
- Full text online
- Order with fees

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

In stock of ZB MED Cologne/Königswinter

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

In stock of ZB MED Cologne/Königswinter

Order via subito

Full text online

More links

Kategorien

Order via subito