scholarly journals Post-Exposure Anti-Ricin Treatment Protects Swine against Lethal Systemic and Pulmonary Exposures

Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 354
Author(s):  
Reut Falach ◽  
Anita Sapoznikov ◽  
Yentl Evgy ◽  
Moshe Aftalion ◽  
Arik Makovitzki ◽  
...  

Ricin, a plant-derived toxin originating from the seeds of Ricinus communis (castor bean plant), is one of the most lethal toxins known. To date, there is no approved post-exposure therapy for ricin exposures. This work demonstrates for the first time the therapeutic efficacy of equine-derived anti-ricin F(ab’)2 antibodies against lethal pulmonary and systemic ricin exposures in swine. While administration of the antitoxin at 18 h post-exposure protected more than 80% of both intratracheally and intramuscularly ricin-intoxicated swine, treatment at 24 h post-exposure protected 58% of the intramuscular-exposed swine, as opposed to 26% of the intratracheally exposed animals. Quantitation of the anti-ricin neutralizing units in the anti-toxin preparations confirmed that the disparate protection conferred to swine subjected to the two routes of exposure stems from variance between the two models. Furthermore, dose response experiments showed that approximately 3 times lesser amounts of antibody are needed for high-level protection of the intramuscularly compared to the intratracheally intoxicated swine. This study, which demonstrates the high-level post-exposure efficacy of anti-ricin antitoxin at clinically relevant time-points in a large animal model, can serve as the basis for the formulation of post-exposure countermeasures against ricin poisoning in humans.

2000 ◽  
Vol 98 (5) ◽  
pp. 561-567 ◽  
Author(s):  
Simon A. WEMYSS-HOLDEN ◽  
Gavin S. M. ROBERTSON ◽  
Ashley R. DENNISON ◽  
Paula S. VANDERZON ◽  
Pauline de la M. HALL ◽  
...  

The majority of liver tumours are inoperable and an alternative treatment to surgical resection is urgently needed. Electrolysis has been investigated in a rat model and the procedure is safe, with accurate and predictable effects. The necrosis produced has also been shown to cause destruction of tumour deposits in the rat liver. A similar evaluation in a large animal model was necessary before clinical trials could commence. Using platinum electrodes connected to a d.c. generator, areas of hepatic necrosis were created in the pig liver. Animals were killed at various time points after treatment to assess the extent of healing. Treatment was uneventful and all animals made a full recovery. No animal died from the treatment or had to be killed prematurely. After 2 days of treatment, healing was minimal but at successive time points there was progressive evidence of healing, such that after 4 months, the original electrolytic lesion was greatly reduced in size and the large area of necrosis seen at the early time points was largely replaced by a fibrous scar with only small islands of necrotic tissue. In a large animal model, electrolysis is a safe method for creating areas of hepatic necrosis. The lesions heal with time and are associated with minimal morbidity. The results support a trial of electrolysis in patients with unresectable liver tumours.


2020 ◽  
pp. neurintsurg-2020-016589
Author(s):  
Robert M King ◽  
Jildaz Caroff ◽  
Erin T Langan ◽  
Anita Leporati ◽  
Aurora Rodriguez-Rodriguez ◽  
...  

ObjectiveTo investigate in situ decellularization of a large animal model of saccular aneurysm as a strategy for achieving aneurysmal growth and lasting inflammation.Methods18 New Zealand White rabbits were randomized 2:1 to receive endoluminal sodium dodecyl sulfate infusion (SDS, 1% solution, 45 min) following elastase or elastase-only treatment (control). All aneurysms were measured by digital subtraction angiography every 2 weeks. Every 2 weeks, three of the rabbits (two elastase + SDS, one control) underwent MRI, followed by contrast injection with myeloperoxidase (MPO)-sensing contrast agent. MRI was repeated 3 hours after contrast injection and the enhancement ratio (ER) was calculated. Following MRI, aneurysms were explanted and subjected to immunohistopathology.ResultsDuring follow-up MRI, the average ER for SDS-treated animals was 1.63±0.20, compared with 1.01±0.06 for controls (p<0.001). The width of SDS-treated aneurysms increased significantly in comparison with the elastase aneurysms (47% vs 20%, p<0.001). Image analysis of thin sections showed infiltration of MPO-positive cells in decellularized aneurysms and surroundings through the 12-week observation period while control tissue had 5–6 times fewer cells present 2 weeks after aneurysm creation. Immunohistochemistry demonstrated the presence of MPO-positive cells surrounding decellularized lesions at early time points. MPO-positive cells were found in the adventitia and in the thrombi adherent to the aneurysm wall at later time points.ConclusionsIn situ decellularization of a large animal model of saccular aneurysms reproduces features of unstable aneurysms, such as chronic inflammation (up to 12 weeks) and active aneurysm wall remodeling, leading to continued growth over 8 weeks.


Analgesia ◽  
1995 ◽  
Vol 1 (4) ◽  
pp. 598-602 ◽  
Author(s):  
L.D. Napier ◽  
Z. Mateo ◽  
D.A. Yoshishige ◽  
B.A. Barron ◽  
J.L. Caffrey

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Premila D. Leiphrakpam ◽  
Hannah R. Weber ◽  
Andrea McCain ◽  
Roser Romaguera Matas ◽  
Ernesto Martinez Duarte ◽  
...  

Abstract Background Acute respiratory distress syndrome (ARDS) is multifactorial and can result from sepsis, trauma, or pneumonia, amongst other primary pathologies. It is one of the major causes of death in critically ill patients with a reported mortality rate up to 45%. The present study focuses on the development of a large animal model of smoke inhalation-induced ARDS in an effort to provide the scientific community with a reliable, reproducible large animal model of isolated toxic inhalation injury-induced ARDS. Methods Animals (n = 21) were exposed to smoke under general anesthesia for 1 to 2 h (median smoke exposure = 0.5 to 1 L of oak wood smoke) after the ultrasound-guided placement of carotid, pulmonary, and femoral artery catheters. Peripheral oxygen saturation (SpO2), vital signs, and ventilator parameters were monitored throughout the procedure. Chest x-ray, carotid, femoral and pulmonary artery blood samples were collected before, during, and after smoke exposure. Animals were euthanized and lung tissue collected for analysis 48 h after smoke inhalation. Results Animals developed ARDS 48 h after smoke inhalation as reflected by a decrease in SpO2 by approximately 31%, PaO2/FiO2 ratio by approximately 208 (50%), and development of bilateral, diffuse infiltrates on chest x-ray. Study animals also demonstrated a significant increase in IL-6 level, lung tissue injury score and wet/dry ratio, as well as changes in other arterial blood gas (ABG) parameters. Conclusions This study reports, for the first time, a novel large animal model of isolated smoke inhalation-induced ARDS without confounding variables such as cutaneous burn injury. Use of this unique model may be of benefit in studying the pathophysiology of inhalation injury or for development of novel therapeutics.


2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
J Josiassen ◽  
OKL Helgestad ◽  
NLJ Udesen ◽  
A Banke ◽  
PH Frederiksen ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation Unrestricted research grant from Abiomed Background No strong evidence exists regarding the treatment of cardiogenic shock (CS) caused by acute right ventricular (RV) failure which has mainly consisted of vasoactive drugs. There is expert agreement that treatment with the recently developed Impella RP is feasible, but no previous studies have compared vasoactive treatment strategies with the Impella RP in terms of cardiac unloading and end-organ perfusion. Hypothesis Treatment with the Impella RP device will be associated with lower RV myocardial workload (pressure-volume area) compared to vasoactive treatment strategies and can furthermore be achieved without compromising organ perfusion. Methods CS was induced by a stepwise injection of polyvinyl alcohol microspheres into the right coronary artery in twenty adult female Danish landrace pigs weighing 75-80 kg. After induction of CS, the pigs were allocated to one of the two interventions for 180 minutes: 1) vasoactive therapy comprised a continuous infusion of norepinephrine (0.1 µg/kg/min) for the first 30 minutes, supplemented by an infusion of milrinone (0.4 µg/kg/min) for the remaining 150 minutes or 2) immediate insertion of and treatment with the Impella RP.  The results are presented as median [Q1;Q3]. Results Treatment with the Impella RP was associated with a lower RV workload compared to the vasoactive group, while no difference was observed with regards to left ventricular workload among intervention groups, Figure 1. Renal venous oxygen saturation increased to a similar degree following both interventions compared to the state of CS. A trend towards a higher cerebral venous oxygen saturation was observed with norepinephrine compared to Impella RP (Impella RP 51 [47;61] % vs Norepinephrine 62 [57;71] % ; p = 0.07), which became significantly higher with the addition of milrinone (Impella RP 45 [32;63] % vs Norepinephrine +Milrinone 73 [66;81] %; p = 0.002). Conclusion In this large animal model of profound CS caused by predominantly RV failure the Impella RP unloaded the failing RV. The vasoactive treatment, however, caused a higher cerebral venous oxygen saturation, while both interventions increased renal venous oxygen saturation to a similar degree. Abstract Figure 1


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