Re: [Histonet] Re: histonet gas bubbles

From:Wayne Kreider

Acoustic detection is our primary method.  With traditional ultrasound 
methods at 3-5 MHz, we can detect individual bubbles on the order of 3 
microns.  Our interest in histology is to develop an independent method 
to correlate identifiable bubbles and associated biological damage with 
the acoustic data.  We hadn't thought much about acoustic microscopy at 
higher frequencies because of limitations on penetration depth relative 
to the size of our treatment area.  Also, assessing in detail the state 
of treated tissue is a relatively new direction for us.  However, 
acoustic microscopy just might provide a nice compromise with 
information on the bubbles in addition to some of the more traditional 
histological detail.  I'll have to explore this further.

We'll see where this leads.  We may get some help next week to look at a 
frozen sample with light microscopy.  I think the favored approach by 
our local help here is to use cryogen cooled isopentane to freeze a 
relatively large chunk of tissue (order of 2 mm per side).  I'm not 
sure, but they may also require use of a cryoprotectant for their 
processing.   Whatever we see will be questionable, but it will be a new 
data point for us.  As you descibed, there are likely better ways to try 
to catch and view an intact bubble.  This stuff is all related to my 
dissertation work, so at some point in the next year or two I'll be 
making a push to obtain this information in some rigorous way. When I do 
make some significant progress on it, I'll drop a note to keep you up to 
date.  I definitely appreciate your input. Wayne

Philip Oshel wrote:

> Wayne,
> This triggered another thought:
> How big are your bubbles? I forget the details of resolution, etc., 
> but there is acoustic microscopy. The density differences between 
> tissue and bubbles would make them good targets for AM. And if the 
> bubbles are within the resolution (I doubt this, but...), ultrasound.
> Depending on the strength and frequency of the sonication used to 
> produce the bubbles.
> Seems like it should be possible to both produce and detect or image 
> the bubbles by the same general method -- acoustics.
> Phil
>> Linda,
>> Thanks for the input.  I did get a chance to look at this paper 
>> briefly.  Using these types of markers might be useful if we could 
>> see them with a high enough resolution.  However, given my 
>> understanding of the method, we would have trouble directly 
>> differentiating a bubble from dissolved gases, as is our primary 
>> goal.  I'm not just sure where we're headed with this in the future, 
>> but I'll let you know if we have some success.
>> Wayne
>> wrote:
>>> Hello Wayne,
>>> I recently read an article that may give you some direction. It 
>>> explains
>>> how some gases can be detected by use of trapping agents.  This 
>>> article on
>>> nitric oxide( half-life of only a few seconds) summarizes recent 
>>> methods
>>> for visualizing NO in living tissues. Nitric Oxide 9 (2003) 217-228. 
>>> Nitric
>>> oxide imaging in living neuronal tissues using fluorscent probes. 
>>> Author
>>> Oliver von Bohen und Halbach. If you solve this I would be 
>>> interested in
>>> your method. Good luck!
>>> Linda(Lin)Bauer
>>> Department of Genetics, Cell Biology, and Anatomy
>>> 985455 Nebraska Medical Center
>>> Omaha, NE 68198-5455
>>> Phone: (402) 559-2863
>>> Fax:   (402) 559-4001
>>> Email:
>> -- 
>> /**********************/
>> /Wayne Kreider/
>> /University of Washington/
>> /Applied Physics Lab / CIMU/
>> /106 Old Fisheries/
>> /206-543-1324/
>> _______________________________________________
>> Histonet mailing list



/Wayne Kreider/

/University of Washington/

/Applied Physics Lab / CIMU/

/106 Old Fisheries/


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