scholarly journals Optimal Methods of Documenting Analgesic Efficacy in Neonatal Piglets Undergoing Castration

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1450 ◽  
Author(s):  
Meredith Sheil ◽  
Adam Polkinghorne
Keyword(s):  
Analgesic Efficacy ◽  
Vocal Response ◽  
Sensory Threshold ◽  
Optimal Methods ◽  
Neonatal Piglets ◽  
Threshold Response ◽  
Literature Base ◽  
High Degree ◽  
Response Testing ◽  
Proof Of Efficacy

Analgesic products for piglet castration are critically needed. This requires extensive animal experimentation such as to meet regulatory-required proof of efficacy. At present, there are no validated methods of assessing pain in neonatal piglets. This poses challenges for investigators to optimize trial design and to meet ethical obligations to minimize the number of animals needed. Pain in neonatal piglets may be subtle, transient, and/or variably expressed and, in the absence of validated methods, investigators must rely on using a range of biochemical, physiological and behavioural variables, many of which appear to have very low (or unknown) sensitivity or specificity for documenting pain, or pain-relieving effects. A previous systematic review of this subject was hampered by the high degree of variability in the literature base both in terms of methods used to assess pain and pain mitigation, as well as in outcomes reported. In this setting we provide a narrative review to assist in determining the optimal methods currently available to detect piglet pain during castration and methods to mitigate castration-induced pain. In overview, the optimal outcome variables identified are nociceptive motor and vocal response scores during castration and quantitative sensory-threshold response testing and pain-associated behaviour scores following castration.

scholarly journals Optimal Methods of Documenting Analgesic Efficacy in Neonatal Piglets Undergoing Castration

2020 ◽  
Author(s):  
Meredith Sheil ◽  
Adam Polkinghorne
Keyword(s):  
Analgesic Efficacy ◽  
Vocal Response ◽  
Sensory Threshold ◽  
Optimal Methods ◽  
Neonatal Piglets ◽  
Threshold Response ◽  
Literature Base ◽  
High Degree ◽  
Response Testing ◽  
Proof Of Efficacy

Analgesic products for piglet castration are critically needed. This requires extensive animal experimentation such as to meet regulatory-required proof of efficacy. At present, there are no validated methods of assessing pain in neonatal piglets. This poses challenges for investigators to optimize trial design and to meet ethical obligations to minimize the number of animals needed. Pain in neonatal piglets may be subtle, transient and / or variably expressed and, in the absence of validated methods, investigators must rely on using a range of biochemical, physiological and behavioural variables, many of which appear to have very low (or unknown) sensitivity or specificity for documenting pain, or pain-relieving effects. A previous systematic review of this subject was hampered by the high degree of variability in the literature base both in terms of methods used to assess pain and pain mitigation, as well as in outcomes reported. In this setting we provide a narrative review, to assist in determining the optimal methods currently available to detect piglet pain during castration and methods to mitigate castration-induced pain. In overview, the optimal outcome variables identified are nociceptive motor and vocal response scores during castration, and quantitative sensory-threshold response testing and pain-associated behaviour scores following castration.

scholarly journals Optimal methods of documenting analgesic efficacy in neonatal piglets undergoing castration

2020 ◽  
Author(s):  
Meredith Sheil ◽  
Adam Polkinghorne
Keyword(s):  
Analgesic Efficacy ◽  
Vocal Response ◽  
Sensory Threshold ◽  
Optimal Methods ◽  
Neonatal Piglets ◽  
Threshold Response ◽  
Literature Base ◽  
High Degree ◽  
Response Testing ◽  
Proof Of Efficacy

Analgesic products for piglet castration are critically needed. This requires extensive animal experimentation such as to meet regulatory-required proof of efficacy. At present, there are no validated methods of assessing pain in neonatal piglets. This poses challenges for investigators to optimize trial design and to meet ethical obligations to minimize the number of animals needed. Pain in neonatal piglets may be subtle, transient and / or variably expressed and, in the absence of validated methods, investigators must rely on using a range of biochemical, physiological and behavioural variables, many of which appear to have very low (or unknown) sensitivity or specificity for documenting pain, or pain-relieving effects. A previous systematic review of this subject was hampered by the high degree of variability in the literature base both in terms of methods used to assess pain and pain mitigation, as well as in outcomes reported. In this setting we provide a narrative review, to assist in determining the optimal methods currently available to detect piglet pain during castration and methods to mitigate castration-induced pain. In overview, the optimal outcome variables identified are nociceptive motor and vocal response scores during castration, and quantitative sensory-threshold response testing and pain-associated behaviour scores following castration.

scholarly journals Constraints on vocal production learning in budgerigars (Melopsittacus undulates)

2021 ◽  
Vol 49 (1) ◽  
pp. 150-158
Author(s):  
Michael S. Osmanski ◽  
Yoshimasa Seki ◽  
Robert J. Dooling
Keyword(s):  
Visual Cues ◽  
Auditory Stimuli ◽  
Vocal Response ◽  
Contact Call ◽  
Vocal Production ◽  
Sensory Stimuli ◽  
Vocal Responses ◽  
Specific Contact ◽  
Contact Calls ◽  
High Degree

AbstractBudgerigars (Melopsittacus undulatus) are small Australian parrots with a well-documented, learned vocal repertoire and a high degree of vocal production learning. These birds live in large, social flocks and they vocally interact with each other in a dynamic, reciprocal manner. We assume that budgerigars must process and integrate a wide variety of sensory stimuli when selecting appropriate vocal responses to conspecifics during vocal interactions, but the relative contributions of these different stimuli to that process are next to impossible to tease apart in a natural context. Here we show that budgerigars, under operant control, can learn to respond to specific stimuli with a specific vocal response. Budgerigars were trained to produce contact calls to a combination of auditory and visual cues. Birds learned to produce specific contact calls to stimuli that differed either in location (visual or auditory) or quality (visual). Interestingly, the birds could not learn to associate different vocal responses with different auditory stimuli coming from the same location. Surprisingly, this was so even when the auditory stimuli and the responses were the same (i.e., the bird’s own contact call). These results show that even in a highly controlled operant context, acoustic cues alone were not sufficient to support vocal production learning in budgerigars. From a different perspective, these results highlight the significant role that social interaction likely plays in vocal production learning so elegantly shown by Irene Pepperberg’s work in parrots.

Sensory Thresholds of Normal Human Feet

2000 ◽  
Vol 21 (6) ◽  
pp. 501-504 ◽  
Author(s):  
Clifford Jeng ◽  
James Michelson ◽  
Mark Mizel
Keyword(s):  
Diabetic Patients ◽  
Sensory Threshold ◽  
Hereditary Neuropathy ◽  
Sensory Thresholds ◽  
Threshold Response ◽  
Positive Threshold ◽  
History Of ◽  
Protective Sensation ◽  
The Right ◽  
Foot Sensation

Hypotheses/Purpose: Although several studies in the literature have evaluated the abnormal sensory thresholds of diabetic feet to Semmes-Weinstein monofilament testing, there is very limited data on the sensory thresholds of individuals without diabetes or peripheral neuropathy. The purpose of this study was to assess the dorsal and plantar sensation of the feet from 40 healthy, college-aged volunteers using Semmes-Weinstein monofilaments. Conclusions/Significance: Semmes-Weinstein testing is a useful tool in predicting which diabetic patients may be at risk for ulceration of the feet. Several studies have determined 5.07 to be the threshold for protective sensation. Based on the normal values derived in this study, the inability to feel a Semmes-Weinstein monofilament of 5.07 (as in diabetic neuropathy) represents a sensory threshold that is more than 50 times greater than normal. This means that roughly 98% of the sensory ability has been lost. Methods: 20 male and 20 female volunteers between the ages of 18 to 22 years old were selected. None had a history of any significant injury or previous surgery to the foot or ankle. There were no known medical conditions associated with decreased foot sensation, (e.g.- diabetes, syphilis, leprosy, myelomeningocele, syringomyelia, or hereditary neuropathy). Volunteers were also questioned regarding participation in athletic activities. The subjects were blindfolded with the leg resting comfortably on a chair as 14 plantar and 5 dorsal locations were tested on each foot. The right foot was always tested first. Each site on the foot had the Semmes-Weinstein monofilaments applied to it first, in an order of increasing stiffness, then repeated in decreasing order, using all twenty monofilaments in the set. A positive threshold response was recorded when the subject could feel the filament and could accurately locate where on the foot the stimulus had been applied. The left foot was then tested in an identical fashion. Results: The mean sensitivity for all sites was 3.63 (0.0075 SEM). There were significant differences between sites, between using increasing or decreasing monofilament stiffness, between subjects, and in some instances, between right foot and left foot values. When testing was performed from the higher to lower monofilament stiffness, subjects were found to have significantly better sensitivity, which indicates the importance of a consistent testing protocol (either all up or all down). Sensation in the lesser toes and the arch were the most sensitive followed by the hallux and the plantar metatarsal heads. The least sensitive site was the heel, with 1/6th the sensitivity of the most sensitive toes.

scholarly journals Efficacy of Intra-Operative Topical Wound Anaesthesia to Mitigate Piglet Castration Pain—A Large, Multi-Centred Field Trial

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2763
Author(s):  
Meredith Sheil ◽  
Giulia Maria De Benedictis ◽  
Annalisa Scollo ◽  
Suzanne Metcalfe ◽  
Giles Innocent ◽  
...  
Keyword(s):  
Field Trial ◽  
Animal Ethics ◽  
Skin Incision ◽  
Commercial Production ◽  
Vocal Response ◽  
Neonatal Piglets ◽  
Vocal Responses ◽  
Post Operative Pain ◽  
On Farm ◽  
Production Conditions

Piglet castration results in acute pain and stress to the animal. There is a critical need for effective on-farm methods of pain mitigation. Local anaesthesia using Tri-Solfen® (Animal Ethics Pty Ltd., Melbourne, Australia), a topical local anaesthetic and antiseptic formulation instilled to the wound during surgery, is a newly evolving on-farm method to mitigate castration pain. To investigate the efficacy of Tri-Solfen®, instilled to the wound during the procedure, to alleviate subsequent castration-related pain in neonatal piglets, we performed a large, negatively controlled, randomised field trial in two commercial pig farms in Europe. Piglets (173) were enrolled and randomised to undergo castration with or without Tri-Solfen®, instilled to the wound immediately following skin incision. A 30 s wait period was then observed prior to completing castration. Efficacy was investigated by measuring pain-induced motor and vocal responses during the subsequent procedure and post-operative pain-related behaviour in treated versus untreated piglets. There was a significant reduction in nociceptive motor and vocal response during castration and in the post-operative pain-related behaviour response in Tri-Solfen®-treated compared to untreated piglets, in the first 30 min following castration. Although not addressing pain of skin incision, Tri-Solfen® is effective to mitigate subsequent acute castration-related pain in piglets under commercial production conditions.

Effects on breathing of carotid body denervation in neonatal piglets

1999 ◽  
Vol 87 (6) ◽  
pp. 2128-2135 ◽  
Author(s):  
T. F. Lowry ◽  
H. V. Forster ◽  
L. G. Pan ◽  
A. Serra ◽  
J. Wenninger ◽  
...  
Keyword(s):  
Carotid Body ◽  
Major Effect ◽  
Descending Aorta ◽  
Postnatal Maturation ◽  
Neonatal Piglets ◽  
Surgical Access ◽  
Age Dependent ◽  
High Degree ◽  
Hypoxic Gas Mixture ◽  
Irregular Breathing

The purpose of these studies was to test the hypothesis that carotid chemoreceptor activity is necessary for postnatal maturation of the ventilatory control system. By using a lateral surgical access, 17 piglets were carotid body denervated (CBD) and 14 were sham denervated at 3–25 days of age. After surgery, there was no irregular breathing in any group. There was no significant hypoventilation when CBD was performed at less than 5 days of age ( n = 5) and only a mild (arterial[Formula: see text] 5 Torr; P < 0.05) to moderate, transient (arterial [Formula: see text] 8 Torr; P < 0.5) hypoventilation in piglets denervated at 10–15 ( n = 6) and 20–25 ( n = 6) days of age, respectively. Three weeks after surgery, both breathing of a hypoxic gas mixture and jugular venous NaCN injections elicited a hyperpnea in the CBD piglets that was attenuated compared with that in sham CBD piglets. In the CBD piglets, there was no response to injections of NaCN in the carotid arteries, but there was a response to NaCN injected into the proximal descending aorta, suggesting the residual peripheral chemosensitivity was of aortic origin. Carotid chemoreceptor-intact piglets had carotid and aortic NaCN chemosensitivity by 2 days of age. The carotid response persisted for the 40 days of the study, but the aortic reflex persisted only until ∼8 days of age. We conclude that 1) the major effect of CBD per se in neonatal piglets is age-dependent hypoventilation and 2) there is a high degree of plasticity in peripheral chemosensitivity in neonates that may contribute to minimizing the changes in breathing after CBD.

Tissue section lifting for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 86-87
Author(s):  
Adrian F. van Dellen
Keyword(s):  
Infectious Disease ◽  
Electron Microscopy ◽  
Tissue Culture ◽  
Organ System ◽  
Surrounding Tissue ◽  
Paraffin Sections ◽  
Surface Areas ◽  
Specific Determination ◽  
High Degree ◽  
Accuracy And Repeatability

The morphologic pathologist may require information on the ultrastructure of a non-specific lesion seen under the light microscope before he can make a specific determination. Such lesions, when caused by infectious disease agents, may be sparsely distributed in any organ system. Tissue culture systems, too, may only have widely dispersed foci suitable for ultrastructural study. In these situations, when only a few, small foci in large tissue areas are useful for electron microscopy, it is advantageous to employ a methodology which rapidly selects a single tissue focus that is expected to yield beneficial ultrastructural data from amongst the surrounding tissue. This is in essence what "LIFTING" accomplishes. We have developed LIFTING to a high degree of accuracy and repeatability utilizing the Microlift (Fig 1), and have successfully applied it to tissue culture monolayers, histologic paraffin sections, and tissue blocks with large surface areas that had been initially fixed for either light or electron microscopy.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

New Aspects in the Design of Electron Optical Magnification Systems

1972 ◽  
Vol 30 ◽  
pp. 606-607
Author(s):  
Willem H.J. Andersen
Keyword(s):  
Electron Microscope ◽  
Imaging System ◽  
Chromatic Aberration ◽  
Research Tool ◽  
Energy Losses ◽  
Objective Lens ◽  
Theoretical Limit ◽  
Optical Magnification ◽  
Chromatic Aberrations ◽  
High Degree

Electron microscope design, and particularly the design of the imaging system, has reached a high degree of perfection. Present objective lenses perform up to their theoretical limit, while the whole imaging system, consisting of three or four lenses, provides very wide ranges of magnification and diffraction camera length with virtually no distortion of the image. Evolution of the electron microscope in to a routine research tool in which objects of steadily increasing thickness are investigated, has made it necessary for the designer to pay special attention to the chromatic aberrations of the magnification system (as distinct from the chromatic aberration of the objective lens). These chromatic aberrations cause edge un-sharpness of the image due to electrons which have suffered energy losses in the object.There exist two kinds of chromatic aberration of the magnification system; the chromatic change of magnification, characterized by the coefficient Cm, and the chromatic change of rotation given by Cp.

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