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This is a multi-part message in MIME format. ------=_NextPart_000_0042_01C1B2BE.A9B7A600 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I just queried George privately on this same thing. Bennett & Elliott, "Physiology and Medicine of Diving", 4th ed., pp = 367-368, describes an experiment. Three groups of five men were run = through a chamber dive, on a known bends-free schedule, 100 fsw for 60 = min. Their red blood cell counts were then monitored over the next = several days. The data showed a significant die-off of red blood cells = over the first couple of days, with red blood cell counts only returning = to normal several days later. This may or may not be related. I'd bet it is. ----- Original Message -----=20 From: swanncruz@oc*.ne*.au*=20 To: George Irvine ; techdiver@aquanaut.com ; quest@gu*.co*=20 Sent: Monday, February 11, 2002 12:03 AM Subject: Red Blood Cell Rigidity "High partial pressures of nitrogen cause the red cells to become = rigid and get hung up in capillaries or damage them. The response of the body to = this and the immune response tend to close off the area . Anyone ( but a = dive instructor) can see what that means for decompression." Hi George & List, As always, thanks for the info. With respect to red cell rigidity with a high pp of N2, my knowledge = of physiology has dulled somewhat over the years, but red cells do = distort (squash) as they move through smaller capillaries, which would = make the prospect of increased rigidity of the RBC quite alarming. That = is, small capillaries are smaller than RBC. Hence, it could be that we = see RBCs unable to pass and associated capillary rupture. Do you think there is a threshold partial pressure where the effect of = RBC rigidity becomes marked, or is there a linear change? I would think there would be an age variable here as well. If so, did this (theoretical) threshold partial pressure of N2 = (causing BBC rigidity) influence the GUE recomended mixes? I realize you are keeping the narcotic values at around or less than = 30m. What I am getting at is a "threshold physiologically damaging pp of = N2", as well as a narcotic level. We seem to be able to quantify a narcotic value (=3Dlevel). This is fascinating stuff, and would keep some PhD students going for = years. Regards, Jeff the Darwinian. I'm going to send this quick, B4 I confuse myself any = further............. ------=_NextPart_000_0042_01C1B2BE.A9B7A600 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 5.50.4522.1800" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><FONT face=3DArial size=3D2>I just queried George privately on this = same=20 thing.</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Bennett & Elliott, "Physiology and = Medicine of=20 Diving", 4th ed., pp 367-368, describes an experiment. Three = groups=20 of five men were run through a chamber dive, on a known bends-free = schedule, 100=20 fsw for 60 min. Their red blood cell counts were then monitored = over the=20 next several days. The data showed a significant die-off of red = blood=20 cells over the first couple of days, with red blood cell counts only = returning=20 to normal several days later.</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>This may or may not be related. = I'd bet it=20 is.</FONT></DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A title=3Dswanncruz@oc*.ne*.au*=20 href=3D"mailto:swanncruz@oc*.ne*.au*">swanncruz@octa4.net.au</A> = </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A = title=3Dkirvine@sa*.ne*=20 href=3D"mailto:kirvine@sa*.ne*">George Irvine</A> ; <A=20 title=3Dtechdiver@aquanaut.com=20 href=3D"mailto:techdiver@aquanaut.com">techdiver@aquanaut.com</A> ; <A = title=3Dquest@gu*.co* href=3D"mailto:quest@gu*.co*">quest@gue.com</A> = </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, February 11, 2002 = 12:03=20 AM</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Red Blood Cell = Rigidity</DIV> <DIV><BR></DIV> <DIV><FONT face=3DArial size=3D2>"High partial pressures of nitrogen = cause the red=20 cells to become rigid and<BR>get hung up in capillaries or damage = them. The=20 response of the body to this<BR>and the immune response tend to close = off the=20 area . Anyone ( but a dive<BR>instructor) can see what that means for=20 decompression."</FONT></DIV> <DIV><FONT face=3DArial size=3D2>Hi George & List,<BR>As always, = thanks for=20 the info.</FONT></DIV> <DIV><FONT face=3DArial size=3D2>With respect to red cell rigidity = with a high pp=20 of N2, my knowledge of physiology has dulled somewhat over the years, = but red=20 cells do distort (squash) as they move through smaller capillaries, = which=20 would make the prospect of increased rigidity of the RBC quite=20 alarming.</FONT><FONT face=3DArial size=3D2> That is, small = capillaries are=20 smaller than RBC. Hence, it could be that we see RBCs unable to pass = and=20 associated capillary rupture.</FONT></DIV> <DIV><FONT face=3DArial size=3D2>Do you think there is a threshold = partial=20 pressure where the effect of RBC rigidity becomes marked, or is there = a linear=20 change?</FONT></DIV> <DIV><FONT face=3DArial size=3D2>I would think there would be an age = variable here=20 as well.</FONT></DIV> <DIV><FONT face=3DArial size=3D2>If so, did this (theoretical) = threshold partial=20 pressure of N2 (causing BBC rigidity) influence the GUE recomended=20 mixes?</FONT></DIV> <DIV><FONT face=3DArial size=3D2>I realize you are keeping the = narcotic values at=20 around or less than 30m.</FONT></DIV> <DIV><FONT face=3DArial size=3D2>What I am getting at is a "threshold=20 physiologically damaging pp of N2", as well as a narcotic = level.</FONT></DIV> <DIV><FONT face=3DArial size=3D2>We seem to be able to quantify a = narcotic value=20 (=3Dlevel).</FONT></DIV> <DIV><FONT size=3D2><FONT face=3DArial>This is fascinating stuff, and = would keep=20 some PhD students going for years.</FONT></FONT></DIV> <DIV><FONT size=3D2><FONT face=3DArial>Regards,</FONT></FONT></DIV> <DIV><FONT size=3D2><FONT face=3DArial>Jeff the = Darwinian.</FONT></FONT></DIV> <DIV><FONT size=3D2><FONT face=3DArial></FONT></FONT> </DIV> <DIV><FONT size=3D2><FONT face=3DArial>I'm going to send this quick, = B4 I confuse=20 myself any=20 further.............<BR></DIV></BLOCKQUOTE></FONT></FONT></BOD Y></HTML> ------=_NextPart_000_0042_01C1B2BE.A9B7A600-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. 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