Hibernating Bears Provide Clue to Preventing Serious Clots in Humans

Good news! What brown bears hibernate for six months!

"... researchers found that when bears enter their sleepy winter state, they tamp down on the production of heat-shock protein 47 (HSP47), which typically sits on the surface of platelets and helps them bind to collagen. This phenomenon isn’t unique to bears—humans and pigs also temper HSP47 production in times of immobility, the team discovered. ..."

From the perspective abstract:

"Deep vein thrombosis (DVT) is a common feature of short-term immobilization, which occurs, for example, for patients with acute paralysis. However, in chronic immobilization—e.g., owing to spinal cord injury (SCI)—the incidence of DVT equals that in the general population. The mechanisms that protect against DVT during chronic immobilization in SCI patients are unknown. ....  report an analysis of the thromboinflammatory machinery in hibernating brown bears (Ursus arctos), which rarely suffer from DVT despite 6 months of immobilization during hibernation. They found that platelets from hibernating bears exhibit an antithrombotic signature characterized by decreased expression of heat shock protein 47 (HSP47) and overall reduced biomarkers of thromboinflammation compared with those of active brown bears. Further, this signature is conserved across different animal species, including mice, pigs, and humans, suggesting that this could be a therapeutic target to reduce DVT in immobilized patients."

From the abstract:

"Venous thromboembolism (VTE) comprising deep venous thrombosis and pulmonary embolism is a major cause of morbidity and mortality. Short-term immobility-related conditions are a major risk factor for the development of VTE. Paradoxically, long-term immobilized free-ranging hibernating brown bears and paralyzed spinal cord injury (SCI) patients are protected from VTE. We aimed to identify mechanisms of immobility-associated VTE protection in a cross-species approach. Mass spectrometry–based proteomics revealed an antithrombotic signature in platelets of hibernating brown bears with heat shock protein 47 (HSP47) as the most substantially reduced protein. HSP47 down-regulation or ablation attenuated immune cell activation and neutrophil extracellular trap formation, contributing to thromboprotection in bears, SCI patients, and mice. This cross-species conserved platelet signature may give rise to antithrombotic therapeutics and prognostic markers beyond immobility-associated VTE."

Hibernating Bears Provide Clue to Preventing Serious Clots in Humans | The Scientist Magazine® Low levels of the clotting factor HSP47 protect the sleeping giants from blood clots, and the same may be possible for humans and other mammals.

Sleep like a bear (perspective, no public access) Reduced expression of a platelet protein protects against thrombosis during chronic immobilization

Immobility-associated thromboprotection is conserved across mammalian species from bear to human (no public access)

Outdoor research

Vortex ultrasound tool breaks down blood clots in the brain

Good news! This new treatment option may make a huge positive difference in the outcomes of stroke events, between ending up in a permanent vegetative state or much better!

"... The device ... eliminated clots faster than existing techniques, and could restore blood flow through a completely blocked in vitro model of CVST in just 8 min. ...
In a technique known as sonothrombolysis, ultrasound is used to cavitate microbubbles surrounding a clot, causing it to break down. Compared with conventional anticoagulant or thrombolytic drugs that dissolve the blood clot, sonothrombolysis has potential to remarkably reduce the required treatment time. Previous strategies, however, have not been clinically effective when treating large, completely occluded veins or arteries. ...
The researchers created a vortex ultrasound transducer using a 2 x 2 array of small-aperture, low-frequency (1.8 MHz) piezoelectric transducers. Assembling the array with a quarter-wavelength (0.21 mm) shift between the forward-viewing surfaces of neighbouring transducers induces the physical phase delay required to generate a helical wavefront. ..."

From the abstract:

"This research aims to demonstrate a novel vortex ultrasound enabled endovascular thrombolysis method designed for treating cerebral venous sinus thrombosis (CVST). This is a topic of significant importance since current treatment modalities for CVST still fail in as many as 20-40% of the cases and the incidence of  CVST  has  increased  since  the  outbreak  of  the  COVID-19  pandemic.  Compared  with  conventional  anticoagulant or thrombolytic drugs, sonothrombolysis has the potential to remarkably shorten the required treatment  time  owing  to  the  direct  clot  targeting  with  acoustic  waves.  However,  previously  reported  strategies for sonothrombolysis have not demonstrated clinically meaningful outcomes (e.g., recanalization within 30 minutes) in treating large, completely occluded veins or arteries. In this paper, we demonstrated a  new  vortex  ultrasound  technique  for  endovascular  sonothrombolysis  utilizing  wave-matter interaction-induced shear stress to enhance the lytic rate substantially. Our in vitro experiment showed that the lytic rate was increased by at least 64.3 % compared with the nonvortex endovascular ultrasound treatment. A 23.1 g, 7.5 cm long, completely occluded invitro 3D model of acute CVST was fully recanalized within 8 minutes  with  a  record-high  lytic  rate  of  237.5  mg/min  for  acute  bovine  clot  in  vitro.  Furthermore,  we  confirmed that the vortex ultrasound causes no vessel wall damage over ex vivo bovine veins. This vortex ultrasound thrombolysis technique potentially presents a new life-saving tool for severe CVST cases that cannot be efficaciously treated using existing therapies."

Vortex ultrasound tool breaks down blood clots in the brain – Physics World

A model of high-speed endovascular Sonothrombolysis with vortex ultrasound-induced shear stress to treat cerebral venous sinus thrombosis (open access)

Thrombolysis Before Thrombectomy for Acute Ischemic Stroke

Recommendable! This non-inferiority comparison does not convince me! I would say that a combination therapy is superior instead of relying on thrombectomy alone. As the expert pointed out chemical thrombolysis can be applied immediately as paramedics make contact with the patient.