Urethral catheterization is a technique frequently used in the pediatric emergency department. Intravesicular knotting of the catheter is a rare but potentially preventable complication that can involve significant morbidity. However, because of the relative rarity of this complication there remains a persistent lack of awareness in the pediatric clinical community. The risk of intravesicular c...

A case is presented of an ileosigmoid knot in a 70 year old man. A strangulated loop of ileum was wrapped around the neck of a sigmoid volvulus. Following small bowel resection and sigmoid colectomy with colostomy, the patient made an uneventful recovery.

During coronary angiography knotting of a coronary catheter is a recognised complication. It commonly results through excessive manipulation of a catheter in an attempt to engage the right coronary artery. Although simple manoeuvres of the catheter can often result in resolution of a kink, tighter knots may not be amenable to such measures. There is, however, little published material regarding...

A fifty seven years old female patient came to operating room for coronary artery bypass grafting (CABG) surgery. After induction, invasive monitoring lines were placed. Pulmonary artery catheter (PAC) floated after three attempts and it was wedged at 60cm. Intra operative course was smooth and patient transferred to cardiac intensive care unit (CICU). First chest X-ray revealed PAC knotting in...

Here, we propose a planning method for knotting/unknotting of deformable linear objects. First, we propose a topological description of the state of a linear object. Second, transitions between these states are defined by introducing four basic operations. Then, possible sequences of crossing state transitions, i.e. possible manipulation processes, can be generated once the initial and the obje...

Urethral catheterization is a common procedure with a relatively low complication rate. Knotting of an indwelling urethral catheter is a very rare complication, and there are only a few case reports on knotted catheters, most of them concerning children. We report an especially rare case where a urethral catheter formed a knot around a double-J ureteral stent after a kidney transplantation. We ...

While analyzing all available protein structures for the presence of knots and slipknots, we detected a strict conservation of complex knotting patterns within and between several protein families despite their large sequence divergence. Because protein folding pathways leading to knotted native protein structures are slower and less efficient than those leading to unknotted proteins with simil...

This work explores the impact of knots, knot depth and motif of the threading terminus in protein folding properties (kinetics, thermodynamics and mechanism) via extensive Monte Carlo simulations of lattice models. A knotted backbone has no effect on protein thermodynamic stability but it may affect key aspects of folding kinetics. In this regard, we found clear evidence for a functional advant...