Biology subjects

McCabe, J.

Publications and source records attributed to McCabe, J..

3 recordsLinked to original sources

bioRxiv2025

Comparison of embolic effects between permanent and novel resorbable microspheres in a porcine renal artery embolization model for TAE

PurposeThis study evaluated porcine renal artery embolization using resorbable alginate microspheres versus permanent microspheres (Embozene), assessing vessel recanalization, local/systemic foreign body reactions, and potential complications. Materials and MethodsTwelve Yorkshire swine (3 female, 9 male) underwent unilateral kidney arterial embolization with either Embozene or resorbable microspheres. Angiography was performed to confirm embolization. Vessel recanalization for was determined through angiography. The effect of embolization was evaluated by assessment of serum chemistry markers and by renal histopathology at 1, 3, 7 and 28 days post-procedure. ResultsEmbolization procedures with both embolic agents were performed with 100% technical success. Hematology, coagulation factors and serum chemistry were largely unremarkable throughout the study period of 28 days. Alginate resorbable alginate microspheres facilitated compete recanalization and revascularisation within the initial 24hr observation window, while the permanent microsphere remained present at all evaluated time points. No inflammation was observed with resorbable microsphere whereas Embozene-induced inflammation was minimal to mild. Vascular histopathologic alteration with resorbable microspheres was limited and resolved by 24 hours, whereas Embozene caused sustained injury extending alteration to the internal elastic lamina, tunica media or adventitia. ConclusionAlginate resorbable microsphere demonstrated effective temporary embolization with a recanalization time of around 24 hours together with complete renal tissue recovery, no systemic impact, and minimal local reaction compared to Embozene. The findings suggest that embolization using resorbable microspheres is safe and may be suitable for use where temporary embolization of vessels is required.

bioengineering↗

bioRxiv2025

Resorbable alginate embolic microsphere for Musculoskeletal embolization applications

Resorbable embolic agents can be used for musculoskeletal (MSK) pain relief applications using a Transarterial Embolisation (TAE) technique. However, inconsistent particle size and shape, degradation rates, and unpredictable resorption and excretion of the breakdown products, limit their widespread clinical adoption. The present study reports self-degradable, rehydratable, freeze-dried, resorbable Ca2+-crosslinked alginate microspheres as a novel vascular embolic agent. The alginate lyase enzyme was incorporated into the alginate microspheres to achieve a controlled degradation rate under physiological conditions. Whilst the feasibility of alginate microspheres as embolic agents has been demonstrated, this is the first study where the controlled release is achieved in physiological conditions. To incorporate the alginate lyase enzyme in the alginate matrix, its activity was reversibly inhibited by preparing an alginate lyase-alginate-excipient mixture in a pH 3.6-3.9 buffered solution. An electrostatic encapsulator enabled the scalable preparation of microspheres of size 210 {+/-} 8 {micro}m at room temperature. The results showed that freeze-dried microspheres regained their shape and size within two minutes after reconstitution with saline, along with active alginate lyase. The reperfusion time of alginate microspheres was evaluated using digital subtraction angiography (DSA) and compared with imipenem and celestine (IMP-CS)in a porcine renal arterial embolisation model. It was observed that most of the blood vessels reperfused within 130-210 minutes, and complete vascular blush was recovered within 24 hours. Embolization with resorbable alginate microspheres induced recoverable ischemic necrosis in the targeted renal arteries. This unique feature of resorbable alginate microspheres in inducing ischemic necrosis, potentially in pain-propagating neovessels, makes it an ideal candidate embolic agent for treating MSK-associated pain using the TAE technique.

bioengineering↗

bioRxiv2024

Ancient Borrelia genomes document the evolutionary history of louse-borne relapsing fever

Several disease-causing bacteria have transitioned from tick-borne to louse-borne transmission, a process associated with increased virulence and genome reduction. However, the historical time frame and speed of such evolutionary transitions have not been documented with ancient genomes. Here, we discover four ancient cases of Borrelia recurrentis, the causative agent of louse-borne relapsing fever, in Britain between [~]600 and 2,300 years ago, and sequence whole genomes up to 29-fold coverage. We estimate a recent divergence from the closest tick-borne ancestor, likely within the last [~]8,000 years. We reconstruct a chronology of gene losses and acquisitions using the pan-genome of related species, and show that almost all of the reductive evolution observed in B. recurrentis had occurred by [~]2,000 years ago, and was thus a rapid process after divergence. Our observations provide a new understanding of the origins of B. recurrentis and document complex reductive evolution in a specialist vector-borne pathogen.

evolutionary biology↗