The Smithsonian imaged the following SEM showing blood vessel remains
in Meteorite Leoville:
http://www.wretch.cc/album/show.php?i=lin440315&b=29&f=1782807415&p=58
Image source: http://mineralsciences.si.edu/facilities/sem.htm

Mr. Tom Phillips also imaged blood vessel remains in the same
meteorite as marked in the following micrographs:
http://www.wretch.cc/album/show.php?i=lin440315&b=29&f=1782807416&p=59

http://www.wretch.cc/album/show.php?i=lin440315&b=29&f=1782807414&p=60

Image source: Second and third photos in Leoville micrographs at
http://www.meteorite.com/meteorite-gallery/meteorites-alpha_frame.htm