Hello gkwalt :
Microparticles
Micro particles are micron sized vesicles [about one tenth the diameter of a red blood cell] inthe blood. They are normally in low concentration in the plasma but levels increase with injury, particularly vascular disease. They are formed from cell membranes from calcium ions,flipase, flopase and scramblase an apparent admixture of an active literary imagination.
These vesicles are present, among others, in vascular diseases, arteriosclerotic disease,sickle cell children, and obstructive sleep apnea. Since I have the latter [and use a CPAPdevice], I guess I have these particles also, to some degree.
Bubbles and DCS
In my work published since 1971, I have argued that the bubbles in the vascular system are not theones causing DCS. These bubbles arise primarily from muscle and fat tissue and DCS [bends] bubbles are primarily extravascular. The relationship between DCS and Doppler bubbles is not strong for this reason [vascular and extravascular bubbles]. This concept has not been popular since I first stated it in 1975. Simply put, peoplelove Dopplers and vascular bubbles.
Powell,M. R. 1971. Decompression from pressure:monitoring by ultrasound. Union CarbideCorporation Technical Memo, Tarrytown, New York
MRPowell. Leg pain and gas bubbles in therat following decompression from pressure: monitoring by ultrasound: Aerospace Med., 43, 168-172 (1972).
MRPowell. Gas phase separation followingdecompression in asymptomatic rats: visual and ultrasound monitoring: Aerospace Med., 43, 1240-1244 (1972).
Bends and Severe DCS
Researchers tellme that they are not really interested anymore in bends DCS since this is simple and straightforward. Thus I will assume that Dr Thom is discussing severe, neurologic DCS. Historically, every few years, something newis found and is trumpeted as the new cause of DCS. In the 70s, this was red cell aggregation andthen platelet aggregation. In the 80s,we had various biochemical intermediates. None produced the results in humans that were observed in animals.
Animal experiments virtually always have death as the endpoint. Any diver knows that death is not the endpoint in tables it is joint pain. Joint pain DCS and animal death are notrelated. I first published this in 1971 [above]with other experiments in 1974.
MRPowell. Doppler ultrasound monitoring ofvenous gas bubbles in pigs following decompression from helium, neon, andair. Aerospace Med., 45, 505-508 (1974).
The experimentsmentioned in the Thom paper also have death as the endpoint. Who knows what would find with so many bubbles that pulmonary gas embolism results and death ensues.
I found that big biochemical changes were associated with a gross gas load and very severe DCS.
GFDoebbler, MR Powell, RW Hamilton, Jr. Biochemical indicators of decompression sickness. In: Proceedings: International Symposium on Blood-Bubble Interactions. In Decompression Sickness, Toronto, August(1974).
MRPowell, GF Doebbler, RW Hamilton, Jr. Serum enzyme level changes in pigsfollowing decompression trauma. Aerospace Med., 45, 519-524 (1974).
DCS bubblesare fun to study but that is not where the real question is. What is needed to know is why some individuals produce a gas phase in the first place. I retired before I could ever begin to tackle that question.
Dr Deco :doctor:
