arterial-pouch-microsurgical-bifurcation-aneurysm-model-in-the-rabbit

Arterial Pouch Microsurgical Bifurcation Aneurysm Model in the Rabbit

Endovascular treatment for intracranial aneurysms gained importance over the past decades, consequently there is an increased need of testing endovascular ...

creation-two-saccular-elastase-digested-aneurysms-with-different

Creation of Two Saccular Elastase-Digested Aneurysms with Different Hemodynamics in One Rabbit

Preclinical animal models with hemodynamic, morphologic, and histologic characteristics close to human intracranial aneurysms play a key role in the ...

University of Bern

To determine the potency ratio between S-ketamine and racemic ketamine as inductive agents for achieving tracheal intubation in dogs.

S-ketamine versus racemic ketamine in dogs: their relative potency as induction agents.

Acute pain and peripheral sensitization development after cautery disbudding was investigated in 33 calves administered preventive multimodal analgesia. The animals were assigned randomly to three groups: 1) Group SH (Control), undergoing sham disbudding at 1 and 4weeks of age; 2) Group ED (Early Disbudding), undergoing disbudding at 1week of age and sham disbudding at 4weeks of age; 3) Group LD (Late Disbudding), undergoing sham disbudding at 1week of age and disbudding at 4weeks of age. Physiological parameters (heart rate, respiratory rate, rectal temperature, invasive blood pressure, cortisol, β-endorphin, interleukin-1β, interleukin-6, tumor necrosis factor-α and haptoglobin plasmatic concentration), local variables (tactile sensitivity score, pressure pain thresholds and horn temperature), behavior and pain scores [multidimensional pain scale and visual analogue scale (VAS)] were assessed at baseline and at several pre-determined time points until 24h after disbudding. Tactile sensitivity score significantly and equally increased in both groups ED and LD and pressure pain thresholds significantly decreased in group LD until 24h after disbudding compared to group SH. Pain and VAS scores significantly and equally increased in both groups ED and LD until 24h after disbudding compared to group SH. No significant differences in physiological parameters, behavior and horn temperature were detected among groups. The present study suggests that acute pain and peripheral sensitization develop and do not differ in calves disbudded at 1week and 4weeks of age. Moreover, the use of physiological and behavioral parameters as sole indicators of acute pain might lead to improper conclusions and should be reassessed.

Acute pain and peripheral sensitization following cautery disbudding in 1- and 4-week-old calves.

To describe and assess the ultrasound-guided transversus abdominis plane (TAP) block feasibility in calf cadavers, to compare two injection volumes and to evaluate possible undesired solution spreads.

Ultrasound-guided lateral and subcostal transversus abdominis plane block in calves: a cadaveric study.

Calf disbudding is a welfare-relevant invasive husbandry procedure. While it is widely recognized that disbudding elicits acute pain, its chronic consequences are currently unknown.

Can disbudding of calves (one versus four weeks of age) induce chronic pain?

Disbudding of calves is a standard husbandry procedure to reduce the risk of injuries to other cattle and to workers. Whereas acute pain resulting from disbudding has been studied extensively, little is known about chronic pain as a potential long-term consequence. The goal of the present study was to investigate possible morphological changes in the cornual nerve as a function of disbudding. Samples were collected from 17 randomly selected bulls and from 21 calves from a prospective clinical study. Among the calves, 13 were disbudded and 8 were sham-disbudded. Out of the disbudded calves, 4 showed signs of chronic pain. In all the animals, the infraorbital nerve was used as a methodological check. Morphological analysis included measuring minimal diameters of the axons present in both the cornual and infraorbital nerves. Sympathetic fibers were identified as based on the presence of Tyroxine hydroxylase (TH). TH-negative fibers were considered afferents. Trigeminal ganglia from the calves were immunostained for glial fibrillary acidic protein (GFAP) and Activating transcription factor 3 (ATF3). R. cornualis and N. infraorbitalis differed in terms of axon diameters and proportion of TH-positive fibers. Weak evidence (p > .091) of a difference in axon diameters between control and disbudded calves was found in R. cornualis, but the proportion of TH-positive fibers was alike in both groups. Average glial envelope and the percentages of ATF3-positive neurons revealed no difference between calves with and without signs of pain. Thus, available evidence is insufficient to support neuropathic changes as a result of disbudding in calves.

Assessment of potential neuropathic changes in cattle after cautery disbudding.

The inflammatory pathway in cerebrospinal fluid (CSF) leads to delayed cerebral vasospasm (DCVS) and delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH). The role of IL-1α has never been evaluated in a rabbit SAH model. The aim of our study is to analyze systemic and CSF changes of IL-1α, and to evaluate potential associations with the onset of DCVS in a rabbit closed cranium SAH model. Methods 17 New Zealand white rabbits were randomized into two groups, SAH ( = 12) and sham ( = 5). In the first group, SAH was induced by extracranial-intracranial shunting from the subclavian artery into the cerebral cistern of magna under intracranial pressure (ICP) monitoring. The sham group served as a control. The CSF and blood samples for IL-1α measurement were taken at day zero before SAH induction and at day three.

Systemic and CSF Interleukin-1α Expression in a Rabbit Closed Cranium Subarachnoid Hemorrhage Model: An Exploratory Study.

Temporary parent vessel occlusion performed to establish a high-flow interpositional bypass carries the risk of infarcts. The authors investigated the feasibility of a novel technique to establish a high-flow bypass without temporary parent vessel occlusion in order to lower the risk of ischemic complications.

An endovascular assisted, nonocclusive cerebral bypass: a technical feasibility study in a rabbit model.

High central venous pressure (CVP) acutely decreases venous return. How this affects hepatic oxygen transport in sepsis remains unclear. The aim of this study was to evaluate the effects of repeated increases in CVP via standard nursing procedures (NPs) on hepato-splanchnic and renal oxygen transport in a prolonged porcine sepsis model. Twenty anesthetized and mechanically ventilated pigs with regional hemodynamics monitored were randomized to fecal peritonitis or controls ( = 10 pigs/group). Resuscitation was started after 8 h of observation and continued for 3 days. NPs were performed at baseline and 8 h, 32 h, 56 h, and 72 h after resuscitation started. NPs increased CVP by 4-7 mmHg in both groups. In controls, this was associated with less decrease in hepatic arterial (Q; 62 ± 70 mL/min) than portal venous flow (Q; 364 ± 151 mL/min). Portal venous oxygen content and hepatic O delivery (Do) and consumption (V̇o) decreased by 11 ± 6 mL/dL and 0.9 ± 0.3 and 0.4 ± 0.3 mL·min·kg, respectively. In septic animals, hepatic Do decreased more in response to increasing CVP (1.5 ± 0.9 mL·min·kg), which was attributable to a larger fall in both Q (88 ± 66 ml/min) and portal O content (14 ± 10 mL/dL, all  < 0.05). This resulted in numerically lower hepatic V̇o since O extraction did not increase significantly. In control conditions, a smaller decrease in Q compared with Q helped to limit the reduction in hepatic V̇o in response to acute CVP increase. In sepsis, the contribution of Q to maintain hepatic Do was reduced, which jeopardized hepatic V̇o further. Renal arterial flow was similarly affected by CVP increase as Q. Sepsis impairs intrinsic mechanisms to attenuate effects of increasing back pressure on hepatic oxygen transport.

Defense mechanisms to increasing back pressure for hepatic oxygen transport and venous return in porcine fecal peritonitis.

Early brain injury (EBI), delayed cerebral vasospasm (DCVS), and delayed cerebral ischemia (DCI) are common complications of subarachnoid hemorrhage (SAH). Inflammatory processes in the cerebrospinal fluid (CSF) are one of the causes for such complications. Our aim to study the effects of an IL-6 receptor antagonist (Tocilizumab) examines the occurrence of DCVS, neuronal cell death, and microclot formation in an acute SAH rabbit model. Twenty-nine New Zealand white rabbits were randomized into one of three groups as the SAH, SAH + Tocilizumab, and sham groups. In SAH groups, hemorrhage was induced by extracranial-intracranial arterial blood shunting from the subclavian artery into the cisterna magna under intracranial pressure (ICP) monitoring. In the second group, Tocilizumab was given once intravenously 1 h after SAH induction. Digital subtraction angiography was performed, and CSF and blood were sampled before and after (day 3) SAH induction. IL-6 plasma and CSF levels were measured. TUNEL, FJB, NeuN, and caspase-3 immunostaining were used to assess cell apoptosis, neurodegeneration, and neuronal cell death, respectively. Microclot formation was detected by fibrinogen immunostaining. Between baseline and follow-up, there was a significant reduction of angiographic DCVS (p < 0.0001) in the Tocilizumab compared with the SAH group. Tocilizumab treatment resulted in decreased neuronal cell death in the hippocampus (p = 0.006), basal cortex (p = 0.001), and decreased microclot formation (p = 0.02). Tocilizumab reduced DCVS, neuronal cell death, and microclot formation in a rabbit SAH model, and could be a potential treatment to prevent DCVS and DCI in SAH patients.

Tocilizumab Reduces Vasospasms, Neuronal Cell Death, and Microclot Formation in a Rabbit Model of Subarachnoid Hemorrhage.

 Donation after circulatory death (DCD) could substantially improve donor heart availability. However, warm ischemia prior to procurement is of particular concern for cardiac graft quality. We describe a rat model of DCD with  ischemia in order to characterize the physiologic changes during the withdrawal period before graft procurement, to determine effects of cardioplegic graft storage, and to evaluate the post-ischemic cardiac recovery in comparison with an established  ischemia model.  Following general anesthesia in male, Wistar rats (404 ± 24 g,  = 25), withdrawal of life-sustaining therapy was simulated by diaphragm transection. Hearts underwent no ischemia or 27 min  ischemia and were explanted. , hearts were subjected to a cardioplegic flush and 15 min cold storage or not, and 60 min reperfusion. Cardiac recovery was determined and compared to published results of an entirely  ischemia model ( = 18).  In donors, hearts were subjected to hypoxia and hemodynamic changes, as well as increased levels of circulating catecholamines and free fatty acids prior to circulatory arrest. Post-ischemic contractile recovery was significantly lower in the  ischemia model compared to the  model, and the addition of cardioplegic storage improved developed pressure-heart rate product, but not cardiac output.  The  model provides insight into conditions to which the heart is exposed before procurement. Compared to an entirely  ischemia model, hearts of the  model demonstrated a lower post-ischemic functional recovery, potentially due to systemic changes prior to ischemia, which are partially abrogated by cardioplegic graft storage.

Comparison of Experimental Rat Models in Donation After Circulatory Death (DCD):  vs.  Ischemia.

Aneurysm wall degeneration is linked to growth and rupture. To address the effect of aspirin (ASA) on aneurysm formation under various wall conditions, this issue was analyzed in a novel rabbit bifurcation model.

ArticleTotal : 2	Year
Publication title Cited by 11	2020
Publication title Cited by 2	2021

Article	Year
S-ketamine versus racemic ketamine in dogs: their relative potency as induction agents. Veterinary anaesthesia and analgesia\| PubMed ID: 25041216	2015
Acute pain and peripheral sensitization following cautery disbudding in 1- and 4-week-old calves. Physiology & behavior\| PubMed ID: 29221809	2018
Ultrasound-guided lateral and subcostal transversus abdominis plane block in calves: a cadaveric study. Veterinary anaesthesia and analgesia\| PubMed ID: 29625919	2018
Can disbudding of calves (one versus four weeks of age) induce chronic pain? Physiology & behavior\| PubMed ID: 30414886	2019
Assessment of potential neuropathic changes in cattle after cautery disbudding. Research in veterinary science\| PubMed ID: 31419617	2019
Systemic and CSF Interleukin-1α Expression in a Rabbit Closed Cranium Subarachnoid Hemorrhage Model: An Exploratory Study. Brain sciences\| PubMed ID: 31554320	2019
An endovascular assisted, nonocclusive cerebral bypass: a technical feasibility study in a rabbit model. Journal of neurosurgery\| PubMed ID: 32502997	2020
Defense mechanisms to increasing back pressure for hepatic oxygen transport and venous return in porcine fecal peritonitis. American journal of physiology. Gastrointestinal and liver physiology\| PubMed ID: 32658622	2020
Tocilizumab Reduces Vasospasms, Neuronal Cell Death, and Microclot Formation in a Rabbit Model of Subarachnoid Hemorrhage. Translational stroke research\| PubMed ID: 33409731	2021
Comparison of Experimental Rat Models in Donation After Circulatory Death (DCD): vs. Ischemia. Frontiers in cardiovascular medicine\| PubMed ID: 33521061	2020
Aspirin treatment prevents inflammation in experimental bifurcation aneurysms in New Zealand White rabbits. Journal of neurointerventional surgery\| PubMed ID: 33785639	2021

Daniela Casoni

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